Volume 3-2016-Agricultural, Food, And Feed Process Engineering

Draft: May 2016

A.T.Belonio D.A.H. Belonio 2016

AG R I C U LT U R A L

ENGINEERING

REVIEWER

VOLUME

Agricultural, Food and Feed Process Engineering

Agricultural, Food and Feed Process Engineering AGRICULTURAL ENGINEERING REVIEWER VOLUME 3

by

Alexis T. Belonio, MS, PAE, ASEAN Engineer Daniel Alexis H. Belonio, PAE

Copyright  2016 No part of this book is allowed to be photocopied or reproduced in any form without any written permission from the author.

Revised Edition

Acknowledgment/Prayer: We are very much thankful to you God the Father for inspiring us to prepare this review material to help those who graduated the agricultural engineering degree to pass the Professional Agricultural Engineering Licensure Examination. May you grant them the desires of their hearts to pass the exam and be used by You in the future years to come! All glory and honor belongs to You! In Jesus name, Amen!

PREFACE This book, Agricultural Engineering Comprehensive Board Exam Reviewer Volume 3, was prepared primarily for the agricultural engineering graduates who are preparing for the professional agricultural engineering licensure examination. With this material, they can be refreshed and updated on the new principles and developments in agricultural engineering. Also, they can develop their analytical ability in analyzing the problems related to current practices in agricultural engineering. The contents of the book are series of questions and problems that compel the students to review the fundamentals, theories, and concepts in agricultural engineering. The questions and problems are grouped into subtopics. Most questions are practical in nature but tricky to test whether students have thorough understanding of the principles in each of the different subject matters in agricultural and food process engineering. The answer for each question and problem is provided at the end of every topic. This book is the third of the six volumes of the Reviewer. It focuses on the different topics on agricultural, food, and feed process engineering. It also includes specific topics on refrigeration, cold storage, heat transfer, and thermal insulation. This book is still in draft form and is produced in limited copies. Additional items will be included in the future to make this material more comprehensive. Comments and suggestions are welcome for the improvement of this book. May this book become useful to the aspiring Agricultural Engineers as they prepare for the Agricultural Engineering Board Examination. God bless!

ALEXIS T. BELONIO DANIEL ALEXIS H. BELONIO

Table of Contents No. of Pages General Information Basic Engineering Properties of Agricultural and Food Products Moisture Content Cleaning, Grading, and Sorting Size Reduction and Sieving Mixing and Blending Air Moving Device Material Handling Crop Drying

Crop Storage Rice Milling Corn Milling Coconut Flour Processing Sugar Processing Food Process Engineering

Feed Milling Refrigeration and Cold Storage Heat Transfer and Thermal Insulation

General Information 1. A study that deals with the principles and practices of processing agricultural products suitable for food and feeds. a. Agricultural processing b. Food processing c. Feed processing d. All of the above 2. A study that deals with the application and practices in converting agricultural products into different kinds and forms of food. a. Agricultural processing b. Food processing c. Feed processing d. All of the above 3. A study that deals with the application and practices in converting agricultural products into different kinds and forms of food suitable for animal consumption. a. Agricultural processing b. Food processing c. Feed processing d. All of the above 4. These are crops that are produced and harvested with normally low moisture content of about 20 to 30% and do not easily deteriorate or spoil. a. Perishable crops b. Durable crops c. Flexible crops d. None of the above

5. These are crops that have high moisture content of 30% and more such as fruits and vegetables including dairy, meat, poultry, and fish and easily deteriorate or spoil. a. Perishable crops b. Durable crops c. Flexible crops d. None of the above 6. Processing operation which does not significantly change the physical characteristics of the product such as drying and dehydration of fruits and vegetables. a. Primary processing b. Secondary processing c. Tertiary processing d. None of the above 7. Processing operation which changes the physical properties of the product such as processing banana into catsup. a. Primary processing b. Secondary processing c. Tertiary processing d. None of the above 8. Which country do not belong to the ASEAN Free Trade Agreement? a. China b. Japan c. Korea d. All of the above e. None of the above

Basic Engineering

1. The study that deals with fluids at rest such as those fluids like coconut oil, milk, etc. a. Hydrodynamic b. Hydrostatic c. Hydro pneumatic d. None of the above 2. The study that deals with the various factors affecting the relationship between the rate of flow of fluid and the various pressure tending it to cause or inhibit its flow. a. Hydrodynamic b. Hydrostatic c. Hydro pneumatic d. None of the above 3. a. b. c. d.

Fluids include ___. solid, gas, and liquid gas and liquid liquid all of the above

4. Which of the following resources are considered fluid? a. Biogas b. Producer gas c. Bioethanol d. Coconut oil e. Sugar cane juice f. All of the above g. None of the above 5. Which of the following resources are not fluid? a. Biomass b. Grains and Cereals c. Fruits and vegetables d. All of the above

6. Newton’s law of motion states that: a. Everybody continues in a state of rest or of uniform motion in a straight line unless compelled by force to change that state. b. The rate of change of momentum is proportional to the force applied and took place in the direction of the force application. c. To every action there is always an equal and opposite reaction. d. All of the above 7. Mass flow rate states that: a. The rate of flow of fluid is constant at any point in the system and there is no accumulation or depletion of fluid within the system. b. The rate of flow of fluid is not constant at any point in the system and there is accumulation or depletion of fluid within the system. c. The rate of flow of fluid increases at any point of the system and there is accumulation and no depletion within the system. d. None of the above 8. What is the mass flow rate of coconut oil in a 2-in. pipe if the velocity of the fluid is measured at 0.02 m/s? The specific weight of oil is 1500 kg/m3. a. 3.54 kg/sec b. 3.13 kg/sec c. 2.35 kg/sec d. None of the above

Basic Engineering 9. Which of the following factors affect the flow of fluid in pipes? a. Characteristics of fluid b. Size of pipe c. Shape of pipe d. Condition inside the surface of the pipe e. Fluid velocity f. All of the above g. None of the above 10. When fluids flow in parallel elements, it is classified as ___. a. turbulent flow b. laminar flow c. mixture of laminar and turbulent flow d. None of the above 11. When fluids flow in elemental swirl or eddies, it is classified as ___. a. turbulent flow b. laminar flow c. mixture of laminar and turbulent flow d. None of the above 12. This refers to the internal resistance of fluid to shear. a. Viscosity b. Coefficient of friction of fluid to fluid c. All of the above d. None of the above 13. Reynolds number is a function of the ___. a. inside diameter of the pipe b. velocity of fluid inside the pipe c. specific weight of the fluid d. fluid viscosity e. All of the above f. None of the above

14. Reynolds number equation. a. Re = DVδ/μ b. Re = DV/μ c. Re = DV/δμ d. None of the above 15. This refers to the characteristics of fluid that is linearly related to shear force. a. Newtonian fluid b. Non-Newtonian fluid c. All of the above d. None of the above 16. This refers to the characteristics of fluid not linear with the shear force. a. Newtonian fluid b. Non-Newtonian fluid c. All of the above d. None of the above 17. An example of Newtonian fluid. a. Coconut oil b. Butter c. Slurries d. None of the above 18. An example of Non-Newtonian fluid. a. Purees b. Jathropha oil c. Coconut water d. None of the above 19. The characteristic of agricultural products that determines the angle by which it will move freely by gravity with respect to the material in which it is held, such as hopper bottom of a storage bin structure. a. Angle of repose b. Angle of friction c. Angle of slide d. None of the above

Basic Engineering 20. The angle formed by agricultural product itself with respect to the horizontal axis which varies with the moisture content and the amount of foreign matter. a. Angle of repose b. Angle of friction c. Angle of slide d. None of the above 21. The unit of pressure. a. Psi b. Inches of water c. Inches of mercury d. All of the above e. None of the above 22. High pressure is usually expressed in ___. a. psi b. inches of water c. inches of mercury d. All of the above e. None of the above 23. Low pressure is usually expressed in ___. a. psi b. inches of water c. inches of mercury d. All of the above e. None of the above 24. Very low pressure is usually expressed in ___. a. psi b. inches of water c. inches of mercury d. All of the above e. None of the above

25. The plenum chamber of a flatbed dryer registers 2 inches of water. How much is the equivalent pressure of the chamber in psig? a. 0.072 psig b. 1.201 psig c. 1.537 psig d. None of the above 26. The pressure taken perpendicular from the direction of fluid where sample application of which is taking the velocity of flow of fluid in pipes using pitot- tube manometer. a. Static pressure b. Dynamic pressure c. Isothermic pressure d. None of the above 27. The pressure taken from the direction of fluid which is also the pressure resulting from force due to change in velocity of the fluid. a. Static pressure b. Dynamic pressure c. Isothermic pressure d. None of the above 28. A simple device used to measure pressure by taking the difference in the height of fluid inside a tube. a. Pyschrometer b. Hydrometer c. Manometer d. None of the above 29. An open tube pointing to the direction of flow of the fluid that is usually used with manometer to measure static and dynamic pressures. a. Pitot-Tube b. Orifice c. Weir d. None of the above

Basic Engineering 30. Which of the following instruments can measure the flow of fluid? a. Pitot tube b. Venturi meter c. Hot wire anemometer d. All of the above e. None of the above 31. Which of the following fluids is considered as highly incompressible? a. Flue gases b. Biogas c. Vegetable oil d. All of the above 32. Which of the following fluids is considered as compressible? a. Producer gas b. Vegetable oil c. Molasses d. None of the above 33. The mass flow rate equation: a. Q = AVδ b. Q = AV c. Q = Aδ d. None of the above 34. The available energy due to the elevation above a reference plane. a. Pressure Energy b. Kinetic Energy c. Potential Energy d. None of the above 35. The available energy due to the internal pressure. a. Pressure Energy b. Kinetic Energy c. Potential Energy d. None of the above

36. The energy available from moving fluids. a. Pressure Energy b. Kinetic Energy c. Potential Energy d. None of the above 37. In fluid mechanics, the total hydraulic energy is the sum of ___ energy plus the work supplied by the pump or blower less friction (conduit and fittings) in the system. a. potential and kinetic b. pressure and kinetic c. potential, kinetic, and pressure d. None of the above 38. Which of the following statements is true? a. The velocity of fluid flowing in a pipe is highest at the center and decreases towards its surfaces. b. The velocity gradient for streamlined flow in a long circular conduit is parabolic in shape. c. The velocity gradient for turbulent flow flattens and the relationship between the maximum and the average velocity changes. d. All of the above e. None of the above

39. The process which results in the diffusion of substances from the region of high concentration to the region of low concentration. a. Energy transfer b. Mass transfer c. Heat transfer d. None of the above

Basic Engineering 40. The amount of heat transfer from within the product. a. Thermal diffusivity b. Thermal conductivity c. Thermal expansion d. None of the above

Basic Engineering Conversion of Units Inches of water

Psi x 27.648

Inches of water

In. mercury x 13.6

psi

In. of water x 0.0361

psi

In. mercury x 0.491

Inches mercury

Psi x 2.036

Inches of mercury

In. of water x 0.0736

Static Pressure P = WH where: P - intensity of pressure, kg/m2 W - unit weight of liquid, 1000 kg/m3 H - depth of water, m Velocity of Flow V = [2 g H] 1/2 where: V - velocity of flow, m/s g - gravitational acceleration, m/s2 H - height of water, m

Flow from Vertical Pipe (50- to 200-mm Pipe Diameter with H = 0.075 to 0.1m ) 0.87 D2 H 1/2 Q = -------------------287 where: Q - pipe discharge, lps D - pipe diameter, mm H - vertical rise of water jet, m Flow from Horizontal Pipe Q = 3.6 A X/ y ½ where: Q - discharge, gpm A - cross sectional area of water at the end of the pipe, in2 X - coordinate of the point on the surface measured parallel to the pipe, in y - vertical coordinate, in

Continuity Equation Q =A V where: Q - discharge, m3/sec A - cross sectional area of pipe, m2 V - average velocity of water, m/s Friction Loss in Pipe Hf = [f L V2 ] / [2 g D] where: Hf - pressure loss in pipe, m f - friction factor L - length of pipe, m V - average velocity of water in pipe, m/s g - gravitational acceleration, 9.8 m/s2 D - pipe diameter, m Flow from Vertical Pipe (50- to 200-mm Pipe Diameter with H = 0.3 to 0.6m ) 0.97 D2 H 1/2 Q = -------------------287 where: Q - pipe discharge, lps D - pipe diameter, mm H - vertical rise of water jet, m

Basic Engineering Problem 1 What is the rate of flow of coconut oil in a 2- in. pipe if the velocity of the fluid is measured at 0.02 m/s? The specific weight of oil is 1500 kg/m3. Given: Inside diameter of pipe Fluid velocity Specific weight of fluid

- 2 in. - 0.02 m/s - 1500 kg/m3

Required: Mass flow rate Solution: Q = AVd = 3.14 (2 in.)2/4 x 0.025 m/in. x 0.02 m/s x 1500 kg/m3 = 2.35 kg/sec

Basic Engineering Problem 2 A coconut oil is to be pumped into a 6meter-high tank from the pump at 100 kg per minute rate. The container where the oil is contained is located 1 m below the pump. The estimated dynamic head loss in the system is 0.2 m of water. What is the horsepower required to pump the oil? Assume a 0.93 kg/l specific weight of oil. Also ,compute the brake horsepower and motor horsepower, if the efficiencies for pump, transmission, and motor are 60%, 80%, and 90%, respectively. Given: Q Hsd Hss Hd Y

-

100 kg/min 6m 1m 0.2 m 0.93 kg/l

Required: Fluid Horsepower Solution: FHP = Q H Y / 33,000 ft-lb/min Q = 100 kg/min = 220 lb/min H = (6 m + 1 m + 0.2 m) x 3.28 ft/m = 23.6 ft FHP = 220 lb/min x 23.616 ft / 33,000 ftlb/min-hp = 0.158 hp BHP = FHP / Ep = 0.158 hp / 0.6 = 0.263 hp MHP = BHP / (Em x Et) = 0.263 hp / (0.9 x 0.8) = 0.36 hp Therefore, use ½-hp pump.

Basic Engineering Problem 3 A rotary pump is used in pumping vegetable oil to a tank at a rate of 1 gpm. The pump is driven directly by an electric motor with an input power of 1.5 hp running at 1700-rpm speed. The total head loss of the system is 10 m. If the motor drives the pump at 2200 rpm, what is the rate of flow of the pump? What is the change in the total head delivered by the pump? What would be the increase in the input power of the pump? Given: Q1 - 1 gpm HP1 - 1.5 hp N1 - 1700 rpm H1 - 10 m N2 - 2200 rpm Required:

Q2, HP2, and H2

Solution: N1/N2 = Q1/Q2 Q2 = N2Q1/N1 = 2200 rpm ( 1gpm)/1700 rpm = 1.294 gpm N12/N22 = H1/H2 H2 = H1 (N22) / N12 = 10 m (2200 rpm)2 / (1700 rpm)2 = 16.75 m N13/N23 = HP1/HP2 HP2 = HP1 (N23) / N13 = 1.5 hp (2200 rpm)3 / (1700 rpm)3 = 3.25 hp

Properties of Agricultural Products 1. a. b. c. d.

The unhulled grain of Oryza sativa. Palay Paddy Rough rice All of the above

2. The fibrous layer of paddy when hull is removed and is commonly known as the silver skin of brown rice. a. Lemma and Palea b. Pericarp c. Bran layer d. None of the above 3. An angle with tangent equals the coefficient of friction between surfaces of the stored materials. a. Angle of contact b. Angle of friction c. Angle of repose d. All for the above 4. The coefficient of friction of rice to steel material is 0.41. What would be the minimum angle of the hopper required for the system? a. 22 deg. b. 30 deg. c. 50 deg. d. None of the above 5. The drying temperature of copra is ___. a. less than 50C b. between 50° to 95C c. above 95C d. None of the above 6. The density of pig and poultry feeds is approximately ___. a. 250 kg/m3 b. 450 kg/m3 c. 650 kg/m3 d. None of the above

7. The slender type paddy has ___ length to width ratio. a. less than 2.0 b. between 2 to 3 c. more than 3.0 d. None of the above 8. The free space between the husk of rough rice and the brown rice kernel greatly affects milling in the sense that ___. a. the larger the free space the greater is the amount of broken grains b. the smaller the free space the lesser its abrasive effect to the rubber-roll huller c. the larger the free space, the lesser the breakage and losses d. All of the above 9. The uneven expansion and contraction of the inner and the outer layers of the grains that cause fissuring is a factor of ___. a. mechanical stress b. thermal stress c. physical stress d. All of the above e. None of the above 10. The specific gravity of rice. a. 1.11 to 1.12 b. 1.19 to 1.30 c. 1.22 to 1.26 d. None of the above 11. The specific gravity of corn. a. 1.11 to 1.12 b. 1.19 to 1.30 c. 1.22 to 1.26 d. None of the above

Properties of Agricultural Products 12. The specific gravity of sorghum a. 1.11 to 1.12 b. 1.19 to 1.30 c. 1.22 to 1.26 d. None of the above 13. The bulk density of rough rice. a. 25 lbs/ft3 b. 36 lbs/ft3 c. 45 lbs/ft3 d. None of the above 14. The bulk density of shelled corn. a. 25 lbs/ft3 b. 36 lbs/ft3 c. 45 lbs/ft3 d. None of the above 15. The physical properties of important agricultural processing. a. Surface area b. Porosity c. Bulk density d. Angle of repose e. Angle of friction f. All of the above 16. The angle of repose of rough rice. a. 27 degrees b. 33 degree c. 36 degrees d. None of the above 17. The angle of repose of shelled corn. a. 27 degrees b. 33 degree c. 36 degrees d. None of the above 18. The angle of repose of sorghum. a. 27 degrees b. 33 degree c. 36 degrees d. None of the above

19. The angle of friction of rough rice in steel. a. 0.41 b. 0.37 c. 0.36 d. None of the above 20. The angle of friction of shelled corn in steel. a. 0.41 b. 0.37 c. 0.36 d. None of the above 21. The angle of friction of soybean in steel. a. 0.41 b. 0.37 c. 0.36 d. None of the above 22. Which of the following thermal properties are important in agricultural processing? a. Thermal conductivity b. Specific heat c. Coefficient of thermal expansion d. Heat of vaporization e. Thermal diffusivity f. All of the above 23. The thermal conductivity of paddy grain ___ linearly with temperature, bulk density, and moisture content. a. increases b. decreases c. do not increase or decrease d. None of the above

Properties of Agricultural Products 24. The amount of heat required to raise the temperature of the product one degree higher when heat is added. a. Heat of vaporization b. Specific heat c. Thermal diffusivity d. None of the above

30. The equivalent loss in the dry matter of a product due to respiration during storage. a. Moisture loss b. Dry matter loss c. Respiration loss d. None of the above

25. The amount of heat required to remove a certain amount of moisture from the product. a. Heat of vaporization b. Specific heat c. Thermal diffusivity d. None of the above

31. The pressure drop in the product during drying is a function of ___. a. airflow b. amount of foreign matter present c. moisture content d. depth of drying e. All of the above

26. Hygroscopic properties important in agricultural processing. a. Equilibrium moisture content b. Mass transfer coefficient c. Dry matter loss d. Tempering period e. All of the above

32. The terminal velocity of rough rice. a. 1.3 to 5.2 m/s b. 6.0 to 7.1 m/s c. 7.5 to 9.0 m/s d. None of the above

27. The property of a product that holds moisture when subjected to a prolong condition of known temperature and relative humidity. a. Dry matter loss b. Mass transfer coefficient c. Equilibrium moisture content d. None of the above 29. The mass transfer among agricultural products is a function of ___. a. air temperature b. air relative humidity c. airflow rate d. thickness e. All of the above

Properties of Agricultural Products Paddy Porosity Pm = 69.05 - 0.885 M Pl = 65.55 - 0.475 M where: Pm – porosity for medium paddy, % Pl – porosity for long paddy, %t M – moisture content wet basis, % Specific Heat of Paddy C = 0.22008 + 0.01301 M where: C – specific heat, BTU/lb-F M – moisture content, % wet basis Width of Paddy (Short Grain) 11.21%M21.89% W = 0.3358 + 0.00089 M where: W - width of paddy, cm M – moisture content of paddy, % Coefficient of Thermal Expansion of Milled Rice (For Temperature Below 53C) Ck = 0.0002403 perC where: Ck – coefficient of thermal expansion at storage moisture over a temperature of 30-70C Latent Heat of Vaporization of Paddy HV = 2.32 [1094-1.026 x (T+17.78)] x [1 + 2.4962 Exp (-21.73M)] where: HV – latent heat of vaporization, KJ/kg T – air temperature, C M – moisture content, decimal dry basis

Mass Transfer Coefficient of Paddy Kg = 0.008489-0.000225T +0.000236 RH – 0.00042 Q where: Kg – mass transfer coefficient, moisture decimal drybasi-cm2/h-m2-kg T – temperature of drying air, C RH – relative humidity, % Q – airflow rate of drying air, m3/min

Thermal Conductivity of Paddy Grains K = 0.0500135 + 0.000767 M where: K – thermal conductivity, BTU/hr-ft-F M – moisture content, % wet basis

Length of Paddy (Short Grain) 11.21%M21.89% L = 0.7318 + 0.00122 M where: L - length of paddy, cm M – moisture content of paddy, % Thickness of Paddy (Short Grain) 10.40%M22.59% T = 0.2187 + 0.000089 M where: T - thickness of paddy, cm M – moisture content of paddy, % Coefficient of Thermal Expansion of Milled Rice (For Temp. Equal and Above 53C) Ck = 0.0003364 perC where: Ck – coefficient of thermal expansion at storage moisture over a temperature of 30-70C Equilibrium Moisture Content Md = E – F ln [ -R ( T + C) ln RH ] where: Md – moisture content, decimal dry basis E – constant, 0.0183212 to 0.480920 F – constant, 0.026383 to 0.066826 R – universal gas constant, 1.987 T – temperature, C C – constant, 12.354 to 120.098 RH – relative humidity, decimal

Properties of Agricultural Products Problem 1 What is the porosity of a medium-sized paddy having 21% moisture content wet basis? If the paddy is to be dried to 14% wet basis, what is the percentage increase in the porosity of the sample? Given: MC wb 1 - 21% MCwb 2 - 14% Required: Porosity and percentage increase if sample is dried to 14% Solution: At 21% MC, PM = 69.05 - 0.885 MC = 69.05 – 0.885 (0.21) = 68.86% At 14% MC, PM = 69.05 – 0.885 MC = 69.05 – 0.885 (0.14) = 68.92% % Increased = (68.92% - 68.86%) x 100 / 68.86% = 0.1% Problem 2 A receiving pit for rough rice is to be designed for a rice mill. If concrete material is to be used, what is the minimum angle of inclination of the pit to make it selfemptying? Consider a 0.52 coefficient of friction for rough rice to smooth concrete. If steel will be used instead of concrete with 0.46 coefficient of friction, what will be the inclination needed for the pit? Given: Material - rough rice Coef. of friction to concrete - 0.52 Coef. of friction to steel - 0.46 Required: Minimum angle of friction to concrete and steel materials Solution: Angle of friction for concrete = tan -1 0.52 for concrete = 27.47 degrees Angle of friction for steel = tan -1 0.46 for steel = 24.70 degrees

Properties of Agricultural Products Problem 3 Ten tons of shelled corn is to be stored in a cylindrical silo. Loading is from the bottom to the top of the cylindrical container, without considering the additional volume of the cone due to the effect of the angle of repose of the sample. If the silo requires a ratio of 2D = H, what would be the dimension of the silo? Assume a 45 lb/ft3 bulk density for shelled corn. Given: Sample - shelled corn Weight of sample - 10 tons Ratio - 2D = H Density of sample - 45 lb/ft3 Required: Dimension of silo Solution: Volume of paddy = Weight/Density = [10 tons x 1000 kg/ton]/[45 lb/ft3 x kg/2.2lb x (3.28 ft/m)3 ] = 13.85 m3

D2 /4 x H = 13.85 m3 D2/4 x 2 D = 13.85 m3 D3 = (8/) 13.85 m3 D = 2.07 m H = 4.14 m

Properties of Agricultural Products Problem 4 What is the amount of heat needed to raise the temperature of a 1.5-tons medium-sized paddy from 27°C to 45°C? The moisture content of paddy is 14% wet basis.

Given: Sample Weight of sample Initial temperature of sample Final temperature of sample Moisture content

- paddy - 1.5 tons - 27°C (106.2°F) - 45°C (138.6°F) - 14% wet basis

Required: Heat energy required to raise the temperature of the sample Solution: C = 0.22008 + 0.1301 M = 0.22008 + 0.1301 (0.14) = 0.22190 BTU/lb-F Qs = 1.5 tons x 0.2219 BTU/lb-°F x (138.6°F – 106.2°F) = 23,725.548 BTU

Properties of Agricultural Products

Problem 5 What is the latent heat of vaporization of paddy at 28% moisture content wet basis and at 40°C temperature. If 200-kg moisture will be removed from the bulk of paddy, what is the amount of heat required to remove it? Given: Moisture content - 28% wet basis Temperature - 40°C Moisture to be removed - 200 kg

Required: Latent heat of vaporization Amount of heat required to remove the moisture Solution: HV = 2.32 [1094-1.026(T+17.78)][1+2.4962 – 21.73 M] = 2.32 [1094 – 1.026 (40°C + 17.78][1+2.496 – 21.73 (0.28)] = 2,409.731 kJ/kg of water Heat to be removed = HV x Moisture to be removed = 2,409.731 kJ/kg x 200 kg = 481,946.2 kJ

Properties of Agricultural Products Problem 6 Five hundred tons of paddy, at 16% wet basis, is to be stored in a silo for 6 months. If the storage temperature in the warehouse will be maintained at 95°F, what would be the expected weight of the paddy after the storage period? Neglect losses due to insect and pests. Given: Product Weight of product Storage time Moisture content Storage temperature

- paddy - 500 tons - 6 months - 16% - 95°F

Required: Weight of paddy after storage Solution: DML = 1- exp [(A x TC) exp [D (T-60)] exp (E (W-0.14))] = 1-exp [(-0.000914 x 4.32 0.6540) exp [0.03756 (95-60)] Exp [33.61 (0.16 – 0.14)]] = 1 – exp [-(0.00237)(3.715)(1.958)] = 1 – 0.983 = 0.01 Therefore, the weight of paddy after 6 months is 491.45 tons.

Properties of Agricultural Products Problem 7 If the coefficient of friction of rice to steel material is 0.41, what is the minimum angle of hopper required for the system? Given: Coefficient of friction Required:

- 0.41

Angle of friction of the hopper

Solution: tan θ = 0.41 θ = tan -1 0.41 = 22.3°

Problem 8 A grain dryer was used to reduce the moisture content of four tons of paddy rice from 25% to 15% wet basis. What is the amount of moisture removed? Given: MC initial - 25% MC final - 14% Initial weight - 4 tons Required:

Weight of moisture removed

Solution: Wt. of Moisture removed = Wi - Wf Wt. final = Wi (1 – MCi) / (1 – MCf) = 4 tons (1- 0. 25) / (1 -0.14) = 4(0.75) / (0.86) = 3.53 tons Wt. of moisture removed = 4 tons – 3.53 tons = 0.47 ton

Moisture Content 1. The amount of moisture in the grain expressed as a percentage of the total weight of the samples. a. Moisture content dry basis b. Moisture content wet basis c. Moisture content d. All of the above

6. The method of measuring the moisture content of the product by direct extraction of water. a. Primary method b. Secondary method c. Tertiary method d. None of the above

2. The amount of moisture in the grain expressed as a percentage of the weight of dry matter. a. Moisture content dry basis b. Moisture content wet basis c. Moisture content d. None of the above

7. If a product has 12% moisture content expressed in wet basis, the equivalent percentage moisture content in dry basis is ___. a. 13.6% b. 16.3% c. 13.4% d. None of the above

3. A moisture meter that determines the moisture content of the product based on the ability of the current to pass through the material. a. Capacitance-type moisture meter b. Resistance-type meter c. Infrared moisture meter d. All of the above 4. The moisture found on the surface of the material. a. Unbound water b. Bound water c. Free moisture d. All of the above 5. When the amount of water in a product is determined based on its dry matter content, the moisture content is expressed in ___. a. wet basis b. dry basis c. semi wet basis d. None of the above

8. A product has 25% moisture content expressed in dry basis. What is the percentage moisture content of the product in wet basis? a. 20% b. 22% c. 26% d. None of the above 9. An expression of moisture content commonly used in commercial scale. a. Moisture content wet basis b. Moisture content dry basis c. Moisture content d. All of the above 10. A plot or a graph representing the equilibrium moisture content of grains at different relative humidity but with constant temperature. a. Isothermal graph b. Sorption isotherms c. Isothermal humidity d. None of the above

Moisture Content 11. An important index to determine whether the paddy is ready for harvesting, storage or milling. a. Color b. Moisture content c. Hardness d. None of the above

16. The appliance usually used in calibrating resistance- and capacitortype moisture meters. a. Oven b. Distillation c. Infrared d. All of the above

12. The moisture inside the tissue of a material that can only be removed by heating or reducing the vapor pressure within the material. a. Chemically bound moisture b. Bound moisture c. Free moisture d. All of the above

17. The device used by the industry in determining moisture content of grains. a. Oven b. Electrical resistance and capacitancetype meter c. Infrared moisture meter d. All of the above

13. The difficult-to-remove moisture from the product that requires other method than heating in order to remove it. a. Chemically-bound moisture b. Bound moisture c. Free moisture d. All of the above 14. Which of the following is considered primary method in determining moisture content? a. Oven method b. Distillation method c. Infrared method d. All of the above e. None of the above 15. Which of the following is considered secondary method in determining moisture content? a. Electrical resistance method b. Electrical capacitance method c. Chemical method d. Hygrometric method e. All of the above f. None of the above

18. If 20 kg of water is to be removed from 110-kg paddy, what is the percentage moisture content of the paddy in wet basis? a. 14.5% b. 16.9% c. 18.18% d. None of the above 19. What is the percentage moisture content of the paddy in Item 18 above when expressed in dry basis? a. 16.4% b. 19.9% c. 22.2% d. None of the above 20. Determine the amount of moisture that can be removed from 9 tons of paddy with 24% initial moisture content dried to 14%. a. 1.05 tons b. 1.26 tons c. 1.57 tons d. None of the above

Moisture Content

Moisture Content (Wet Basis) MCw = (Ws – Wdm)100 / Ws where: MCw - moisture content wet basis, % MCd - moisture content dry basis, % Ws - weight of sample, g Wdm - weight of dry mater, g

Moisture Content (Dry Basis) MCd = (Ws – Wdm) 100 / Wdm where: MCw - moisture content wet basis, % MCd - moisture content dry basis, % Ws - weight of sample, g Wdm - weight of dry mater, g

Wet Basis to Dry Basis MCd = MCw 100 / (100 – MCw) where: MCd - moisture content dry basis, % MCw - moisture content wet basis, %

Dry Basis to Wet Basis MCw = MCd 100 / (100 + MCd) where: MCd - moisture content dry basis, % MCw - moisture content wet basis, %

Moisture Loss Wi ( 1 – MCi ) = Wf ( 1- MCf ) ML = Wi - Wf where: Wi - initial weight of sample, kg Wf - final weight of sample, kg Mci - initial moisture content, % wb MCf - final moisture content, % wb ML - moisture loss, kg

Moisture Content Problem 1 What is the amount of moisture to be removed from a material with 14.5% moisture content and 76 kg dry matter weight? Given: MCi Wdm

- 14.5% - 76 kg

Required: Amount of moisture to be removed Solution: MC = Wmr x 100 / (Ww + Wdm) Wmr = 0.145 (Wm + 76 kg) Wmr = 0.145 Wmr + 11.02 kg 0.855 Wmr = 11.02 kg Wmr = 11.02 kg / 0.855 = 12.89 kg

Problem 2 What is the percentage moisture content of paddy in Problem 1 above when expressed in dry basis? Given: MCw

- 14.5%

Required:

MCd

Solution: MCd = (MCw x 100 )/ (100 - MCw) = (14.5 x 100) / (100-14.5) = 16.95%

Moisture Content

Problem 3 What is the equilibrium moisture content of paddy stored in bags at 27°C storage temperature with 90% humidity. If the moisture content of paddy stored is 14% wet basis, is there a danger for the grains to deteriorate when the condition prevails for a longer period? Given: Storage temperature - 27°C Storage humidity - 90% Moisture content of sample - 14% Required: Equilibrium moisture content Solution: Md = E – F ln [-R (T+C) ln RH) = 0.325 – 0.046 ln [-1.987 (27 +35.703) ln (0.90) = 0.206 or 20.66% moisture dry basis Mw = Md 100 / (100 – Md) = 20.6% x 100 / (100 – 20.6%) = 17.08% Problem 4 If 20 kg of water is removed from a 110-kg paddy, what is the percentage moisture content of paddy in wet basis? Given: Wm Wi

- 20 kg - 110 kg

Required: % MC wet basis Solution: % MCw = ( Wi – Wf ) x 100 / Wi = ( 20 kg / 110 kg ) x 100 = 18.18 %

Moisture Content Problem 5 If a product has 12% moisture content wet basis, what is the equivalent percentage moisture content in dry basis? Given: MCw

- 12%

Required: MCd

Solution: MCd = MCw x 100 / (100 – MCw) = 12 x 100 / ( 100 – 12 ) = 13.64%

Problem 6 A product has 25% moisture content, expressed in dry basis . What is the percentage moisture content of the product in wet basis? Given: MCd

- 25%

Required:

MCw

Solution: MCw = MCd x 100 / (MCd + 100) = ( 25 x 100 ) / (25 + 100 ) = 20%

Moisture Content Problem 7 If 9 tons of a product is to be dried from 24% to 14%, what would be the final weight of the product? Given: Wi MCi MCf

- 9 tons - 24% - 14%

Required:

Weight final

Solution: Wi ( 1 – Mci ) = Wf (1- MCf) Wf = Wi (1-MCi) / (1-MCf) = 9 tons (1-0.24) / (1.014) = 7.9 tons

Problem 8 What is the moisture loss of the product in Problem 7 above? Given: Wf

- 7.9 tons

Required:

Moisture loss

Solution:

ML = Wi – Wf ML = 9 tons – 7.9 tons = 1.05 tons

Moisture Content Problem 9 Shelled corn initially at 24% is to be dried to 14%. If the initial weight of the shelled corn is 1000 kilos, what is its final weight? Given: Grain MC initial MC final Initial weight Required:

-

corn 24% 14% 1000 kg

Final wt. of the corn

Solution: Wi (1 – MCi) Wt. = (1 - MCf) 1000 kg (1 – 0.24) = (1 – 0.14) = 883.72 kg Problem 10 Referring to Problem 9, what is the moisture loss of corn grains? Given: Wt.

- 883.72 kg

Required:

Moisture loss

Solution:

Moisture loss = Wti - Wtf = 1000 kg – 883.72 kg = 116.28 kg

Cleaning, Grading, and Sorting 1. The percentage of grains that are free from foreign matter. a. Percentage foreign matter b. Percentage Cleanliness c. Purity d. None of the above 2. A type of screen cleaners that uses air blast to assist in the cleaning. a. Screen separator b. Fanning mill c. Blower d. None of the above 3. The process of separating lower density materials from grains. a. Aspiration b. Cleaning c. Fanning d. All of the above 4. A primary cleaner which separates larger particles from rice, also known as “rough cleaning” of rough rice. a. Rotary sieve b. Scalper c. Vibrating screen d. All of the above 5. The recommended size of scalper for paddy is ___. a. 0.2-0.25sq.m. per ton b. 0.3-0.35sq.m. per ton c. 0.4-0.45sq.m. per ton d. None of the above 6. The amount of foreign materials in a sample of grains. a. Impurities b. Chalky grain c. Dockage d. None of the above

7. The rough cleaning of paddy removing most foreign materials prior to drying and storage. a. Aspiration b. Scalping c. Sieving d. All of the above 8. A kind of cleaner that uses air in separating lesser-density materials from corn kernel/corn grits such as floured corn, germ and bran. a. Aspirator b. Oscillating screen c. Cleaner d. Cyclone separator e. All of the above

9. The process of removing contaminants from the product. a. Sorting b. Grading c. Cleaning d. None of the above 10. The process of separating cleaned products in various quality fractions that maybe defined based on the size, shape, texture, colors, and other factors. a. Sorting b. Grading c. Cleaning d. None of the above 11. Which of the following parameters are taken into consideration during cleaning and grading products? a. Size b. Weight c. Surface Texture d. Affinity to liquid e. Color f. Shape g. All of the above

Cleaning, Grading, and Sorting 12. The material commonly used in separating grains from chaffs according to size. a. Indented plate b. Perforated sheet c. Steel screen d. All of the above 13. When removing light particles from threshed grains that goes with the chaffs during operation, what would be the best course of action that you can recommend as an Agricultural Engineer in order to achieve better cleaning and separation? a. Install additional perforated sheets in the cleaning system. b. Provide an air blast system using a blower so it can carry light particles. c. Reduce the feeding of threshed grains. d. None of the above 14. When using a cylindrical slotted rotating screen or sheet, the material can be separated in terms of ___. a. weight b. shape c. thickness d. None of the above 15. Indented rotating cylinders are usually used for separating grains in terms of ___. a. thickness b. width and length c. size d. None of the above 16. Air blast separation is effective for separating the product based on ___. a. size b. weight c. length d. None of the above

17. A separator used for particles with low and high terminal velocity. a. Air blast separator b. Aspirator c. Fanning mill d. None of the above 18. Vibrator separator is recommended for separating grains based on ___. a. weight b. surface texture c. size d. none of the above 19. A grain separator for seed based on the affinity for liquid or on the rate at which the surface of the seed absorbs liquid. a. Vibrator separator b. Aspirator c. Magnetic separator d. None of the above 20. The machine used to separate grains according to color or reflectivity. a. Color meter b. Electronic color sorter c. Electric color separator d. None of the above 21. Precleaners are provided for the rice milling plant primarily to ___ and to improve the quality of the final product. a. add for the machine requirement b. protect other processing equipment c. reduce the load d. None of the above

22. In a tray-type paddy separator, brown rice moves at the ___ of the tray. a. bottom b. middle c. top d. None of the above

Cleaning, Grading, and Sorting 23. Self -cleaning sieves used for rice mills basically consist of ___. a. a brush to remove particles that clogs the screen of the cleaner b. one or two balls that continuously hammer the top sieve of the cleaner c. assigned operator to do the cleaning while the machine is operating d. None of the above 24. A machine used to remove hard materials of almost the same size as milled rice through gravity separation using air stream to cause the rice grains to be carried away by the air stream leaving heavy materials behind. a. Aspirator b. De-stoner c. Sifter d. None of the above 25. Magnetic separator basically is installed into the rice milling plant before the ___. a. precleaner b. husker c. whitener d. polisher e. None of the above 26. A separation equipment coupled to the end of a pneumatic conveyor to separate solid particles from the air stream. a. Magnetic separator b. Cyclone Separator c. Vibratory separator d. None of the above

27. Efficiency of ordinary cyclone ranges from ___. a. 80 to 90% b. 95 to 98% c. 98 to 99% d. None of the above

Size Reduction 1. The process of making too-large-tobe-used solid materials usable. a. Size reduction b. Grinding c. Cutting d. All of the above 2. a. b. c. d.

Size-reduction processes include ___. cutting crushing grinding All of the above

3. Raw materials for feeds are processed primarily using a sizereduction equipment to ___. a. increase the surface area of contact of the material to facilitate taking place of reaction b. make it palatable when used as feed for animals c. facilitate conveyance operation at the feed mill f. all of the above 4. A physical mechanism used in sizereduction process. a. Compression b. Impact c. Attrition d. Cutting f. All of the above

5. Which of the following statements is true in relation to size-reduction operation? a. Size reduction is the most inefficient unit operation in terms of energy use. b. Size reduction is the most efficient unit operation in terms of energy use. c. Size reduction is neither efficient nor inefficient unit operation in terms of energy use d. None of the above

6. Which of the following statements is true in relation to reducing particle size of a material? a. Reduction of materials to very fine sizes is more costly in terms of energy as compared with reduction to relatively coarse particles. b. Reduction of materials to very fine sizes is much cheaper in terms of energy as compared with reduction to relatively coarse particles. c. Reduction of materials to very fine sizes has the same cost as compared with reduction to relatively coarse particles. d. None of the above 7. Which of the following is an example of size-reduction processes? a. Chopping corn fodder b. Slicing of sweet potato c. Milling of cassava into flour d. All of the above 8. A trade term used relative to the reduction of grains into meal or flour. a. Shredding b. Crushing c. Milling d. None of the above 9. Size-reduction machines are characterized based on ___. a. capacity b. power required unit material reduce c. size and shape of the product after reduction d. range of size and shape of resulted product. e. All of the above 10. A burr or a plate mill. a. Micro mill b. Attrition mill c. Roller mill d. All of the above

Size Reduction 11. The process of reducing the size of materials by applying force to the product in excess of its strength. a. Shearing b. Crushing c. Milling d. None of the above 12. The process of reducing the size of materials by pushing or forcing a thin sharp knife into it. a. Shearing b. Crushing c. Cutting d. All of the above 13. An indicator of the uniformity of ground materials in the resultant product. a. Uniformity index b. Particle size c. Fineness modulus d. All of the above 14. The process of reducing the size of materials by cutting and crushing actions. a. Milling b. Grinding c. Shearing d. None of the above

15. Hammer mills are designed purposely to ___. a. chop forage materials b. reduce the sizes of granular products c. compact powdered product d. None of the above

16. Vertical-axis hammer mill is more advantageous than horizontal-axis for the reason that: a. It is more effective in grinding grains with higher moisture content of up to 25%. b. The power requirement of the vertical-axis hammer mill is much lower than that of the horizontal-axis hammer mill. c. Less broken grains can be derived from vertical-axis. d. None of the above 17. A grain milling machine consisting of two cast-iron disk plates with teeth or serration on one or on both faces. a. Hammer mill b. Attrition mill c. Roller mill d. All of the above

18. A grain milling machine suitable for grinding grains with moisture content of up to 30%. a. Hammer mill b. Attrition or bar mill c. Roller mill d. All of the above 19. A type of mill used for crushing grains by allowing it to pass through two rotating-cylinder steels, one of which is smaller than the other. a. Hammer mill b. Roller mill c. Plate mill d. All of the above

Size Reduction 20. When reduced material size is between 1/8 in. or more, it is classified as ___. a. microscopic range b. sieve range c. dimension range d. None of the above 21. When reduced material size is between 0.125 to 0.0029 in., it is classified as ___. a. microscopic range b. sieve range c. dimension range d. None of the above 22. When reduced material size is less than 0.0029 in., it is classified as ___. a. microscopic range b. sieve range c. dimension range d. none of the above 23. A device used for classifying granular materials by passing through series of screens. a. Tyler Sieves b. Tyler screen c. Tyler Separator d. None of the above 24. Sieves used in determining the fineness modulus of a material includes 3/8-, 4-, 8-, 14-, 28-, 48-. and ___ -in. mesh. a. 60 b. 80 c. 100 d. None of the above

25. In hammer milling, the fineness of a material is determined by the ___. a. number of hammers b. speed of hammer c. size of hole of the screen d. None of the above 26. The speed of hammer mills. a. 200 to 1000 rpm b. 1500 to 4000 rpm c. 4500 to 6000 rpm d. None of the above 27. The operating speed of burr mills. a. Less than 1200 rpm b. 1200 to 2400 rpm c. 2400 to 3200 rpm d. None of the above 28. Performance characteristics of sizereduction equipment are based on ___. a. size uniformity b. temperature rise c. power requirement d. trouble-free operation e. All of the above 29. The power requirement in reducing the size of grains is ___ for moist grains than for dried grains. a. lesser b. the same c. higher d. None of the above 30. The power requirement of size reduction equipment is ___ for fibrous than crystalline materials. a. lesser b. the same c. higher d. None of the above

Size Reduction 31. The energy requirement of a hammer mill in grinding shelled corn. a. 7.4 kw-hr/ton b. 5.8 kw-hr/ton c. 2.3 kw-hr/ton d. None of the above 32. A cassava processing plant is required to grind fresh cassava into flour, what size-reduction machine would you recommend as an Agricultural Engineer? a. Hammer mill b. Roller mill c. Burr mill d. None of the above 33. The size-reduction machine usually used in feed milling to break dried grains into suitable size for feeds. a. Hammer mill b. Roller mill c. Burr mill d. None of the above 34. In burr milling, the size of grind can be varied by ___. a. varying the size of the screen opening b. varying the pressure on the plates c. varying the opening between rolls d. None of the above 35. During grinding, the temperature of the material ___ when grinding fibrous than granular material. a. decreases b. increases c. does not change d. None of the above

36. The factor affecting the power requirement of grinding mill. a. Type of material b. Moisture content of material c. Fineness of grinding of material d. Rate of feeding the material e. Type and condition of mill f. All of the above 37. The most suitable machine for reducing size of materials like forages, straw, stalks, and weeds. a. Hammer mill b. Roller mill c. Burr mill d. Cutter mill e. All of the above

Mixing and Blending

1. The blending of ingredients or of materials in agricultural processing operation. a. Sorting b. Molding c. Mixing d. All of the above

6. A feed mixer characterized by low capacity, longer mixing time and low power requirement. a. Horizontal mixer b. Inclined mixer c. Vertical mixer d. All of the above

2. The auger that is centrally located in a vertical feed mixer and usually rotates at ___ speed. a. 100-250 rpm b. 250-400 rpm c. 400-650 rpm d. None of the above

7. A feed mixer with an auger that elevates the feed to the top of the mixing bin and spreads them evenly throughout by gravity for another mixing cycle. a. Horizontal mixer b. Vertical mixer c. Inclined mixer d. All of the above

3. Horizontal feed mixer is not advantageous for feed mixing as compared with vertical feed mixer for the reason that ___. a. it has lower capacity b. it has high power requirement c. it has shorter life span d. none of the above 4. If mixing is needed during conveying, the suitable conveyor to use is ___ type. a. bucket b. screw c. belt d. All of the above 5. A feed mixer characterized by high capacity, short mixing time, and high power requirement. a. Horizontal mixer b. Inclined mixer c. Vertical mixer d. All of the above

8. A mixer with U-shaped bin containing a central mixing blade or a ribbon mounted on a rotating shaft. a. Horizontal mixer b. Inclined mixer c. Vertical mixer d. All of the above 9. The assembling and measuring of the needed amount of every solid raw feed material in the formulation of the desired composition of a mixture. a. Mixing b. Blending c. Pelleting d. All of the above 10. The process of combining different materials until a certain degree of homogeneity is achieved. a. Milling b. Mixing c. Feeding d. None of the above

Mixing and Blending 11. Feed materials are purposely mixed to ___. a. obtain a homogenous feed to ensure that animals are given the same proportions of nutrient b. reduce the density of the feed material so that it can be easily transported c. improve the digestability of feeds d. None of the above 12. Basically, the purpose of mixing is ___. a. to promote the transfer of heat between hot and cold products b. to obtain good contact between materials being mixed c. to promote reactions between reactants d. all of the above e. any two of the above 13. A type of mixer suitable for either free flowing or non-free flowing materials. a. Rotating mixer without stirrers b. Rotating mixer with stirrers c. All of the above d. None of the above 14. An indicator of satisfactory mixing. a. Produce uniform mixture b. Less time in mixing materials c. Less cost d. All of the above e. None of the above 15. During mixing, heavier particles tend to remain ___ of the container. a. near the bottom b. away from the bottom c. at the middle d. None of the above

16. During mixing, round or small particles tend to move towards the ___ of the container. a. top b. middle c. bottom d. All of the above 17. Difficulty in mixing may result if the solid particles has ___. a. the same size but of different specific gravity b. different sizes c. different shapes d. All of the above 18. The type of mixer satisfactory for extensively large operations. a. Batch-type mixer b. Semi-continuous type mixer c. Continuous-type mixer d. None of the above 19. The type of mixer suitable for moderate to small operation in which overhead cost is low and labor cost is not critical. a. Batch-type mixer b. Semi-continuous-type mixer c. Continuous-type mixer d. None of the above

Air-Moving Device 1. The measure of the power output of a fan in relation to its power input. a. Fan thermal efficiency b. Fan performance index c. Fan efficiency d. All of the above

7. A Class 1 air-moving device operating at pressure equal to or more than 1 psi. a. Blower b. Fan c. Exhauster d. All of the above

2. An air-moving device that produces high airflow but low head. a. Fan b. Blower c. Compressor d. All of the above

8. A Class 2 air-moving device operating at pressure less than 1 psi. a. Blower b. Fan c. Compressor d. All of the above

3. An air-moving device suitable for grain cleaning. a. Axial fan b. Propeller fan c. Cross-flow fan d. All of the above

9. An air-moving device in which the air flow is at the same axis with the shaft of the device. a. Propeller fan b. Axial flow fan c. Tube axial fan d. Vane axial fan e. All of the above f. None of the above

4. If the diameter of the blower is increased, the pressure will consequently ___. a. increase b. decrease c. be the same d. None of the above 5. An air-moving device commonly used for drying which produces high pressure but low airflow. a. Blower b. Fan c. Compressor d. None of the above 6. Which of the following operations employs air-moving devices? a. Drying b. Material handling c. Refrigerating d. All of the above

10. An axial-type fan that delivers large volume of air at low head and has few narrow blades. a. Propeller fan b. Axial-flow fan c. Tube-axial fan d. Vane-axial fan e. None of the above 11. An axial-type fan with enlarged hubs and warped blades for better efficiency in order to operate against higher pressure than that of the propeller fan. a. Propeller fan b. Axial-flow fan c. Tube-axial fan d. Vane-axial fan e. None of the above

Air-Moving Device 12. An axial-type fan with wider axialflow wheel capable of delivering higher pressure than that of the axial-flow fan and is driven either by belt or by direct drive system. a. Propeller fan b. Axial-flow fan c. Tube-axial fan d. Vane-axial fan e. None of the above 13. An axial-flow-type fan with set of guide vanes located before or after the wheel and is capable to deliver higher pressure than that of the tube-axial fan. a. Propeller fan b. Axial-flow fan c. Tube-axial fan d. Vane-axial fan e. None of the above 14. An air-moving device in which airflow enters the axis of the shaft of the rotating blades and leaves in perpendicular manner. a. Propeller fan b. Axial-flow fan c. Tube-axial fan d. Centrifugal blower e. None of the above 15. A centrifugal-type blower operating at low speed at several inches of pressure than that of the axial-type fan and has a squirrel-cage rotor and large number of blades. a. Forward curved-blade centrifugal blower b. Radial or straight-blade centrifugal blower c. Backward curved-blade centrifugal blower d. All of the above

16. A centrifugal blower with blades positioned at the same plane with the rotating shaft and has larger housing than other types of centrifugal blower and is capable of handle dirty air and conveys materials that go through the fan. a. Forward curved-blade centrifugal blower b. Radial or straight-blade centrifugal blower c. Backward curved-blade centrifugal blower d. All of the above 17. A type of centrifugal blower with few blades tilted backward from the direction of wheel rotation and is inherently high speed with self-limiting horsepower characteristics, and delivers higher pressure than that of the forward and radial-type centrifugal blowers. a. Forward curved-blade centrifugal blower b. Radial or straight- blade centrifugal blower c. Backward curved-blade centrifugal blower d. All of the above 18. A low-pressure high-airflow centrifugal-type blower that delivers uniform airflow along its length. a. Axial-type fan b. Centrifugal blower c. Cross-flow centrifugal blower d. All of the above e. None of the above

Air-Moving Device 19. If the width of the blade of an axialtype fan is increased, the airflow will relatively ___. a. increase b. decrease c. remain the same d. None of the above

24. For the same shaft rpm, which of the following centrifugals delivers higher pressure? a. Forward-curved b. Radial c. Backward-curved d. None of the above

20. If the width of the impeller of a centrifugal-type blower is increased, the airflow will relatively ___. a. increase b. decrease c. remain the same d. None of the above

25. The air-moving device commonly used for refrigeration and ventilation systems. a. Forward-curved b. Radial c. Backward-curved d. None of the above

21. If the diameter of the impeller of the centrifugal-type blower is increased, the pressure will relatively ___. a. increase b. decrease c. remain the same d. none of the above

26. The air-moving device commonly used for 6-ton flatbed paddy dryers. a. Forward-curved centrifugal blower b. Propeller fan c. Vane-axial fan d. None of the above

22. If the diameter of the blade of an axial-type fan is increased, the airflow will relatively ___. a. increase b. decrease c. remain the same d. None of the above 23. Noise level is highest for ___ centrifugal blower. a. forward-curved b. radial c. backward-curved d. None of the above

27. The air-moving device commonly used for pneumatic conveyor systems. a. Backward-curved centrifugal blower b. Propeller fan c. Vane-axial fan d. None of the above 28. The air-moving device commonly used for tunnel-ventilated poultry farms. a. Radial centrifugal blower b. Propeller fan c. Vane-axial fan d. None of the above

Air-Moving Device 29. The factor to consider in selecting an air-moving device. a. Quantity of air to be moved per unit time b. Estimated system resistance or head c. Amount of noise permitted d. Space available e. Economic implication f. All of the above g. None f the above

Air-Moving Device Specific Speed Ns = [ N Q 0.5 ] / [Ps 0.75] where: Ns – specific speed, dmls N - speed of air-moving unit, rpm Q - airflow, cfm Ps – pressure requirement, in. H2O

Impeller Diameter (2.35) 108 Ps D = [--------------------------] 0.5  N2 where: D - diameter of impeller, in. Ps – pressure requirement, in. H2O  - pressure coefficient, 0.05 to 2.0 N - speed of impeller, rpm

Pitch Angle for Axial Fan 350 Q –1  = Sin ----------------- N D3 where:  - pitch angle, deg Q - airflow, cfm N - speed of impeller, rpm D - diameter of impeller, in.  - flow coefficient, 0.01 to 0.80

Impeller Width (Centrifugal and Mixed Flow Blower) 175 Q W = ---------------- N D2 where: W – width of impeller, in. Q - airflow, cfm N - speed of impeller, rpm D - diameter of impeller, in.  - flow coefficient, 0.01 to 0.80 Impeller Width (Traverse Flow) 550 Q W = -------------- N D2 for 0.5  W/D  10 where: W – width of impeller, in. Q - airflow, cfm N - speed of impeller, rpm D - diameter of impeller, in.  - flow coefficient, 0.01 to 0.80 Casing Dimension (Forward Curved Centrifugal) Hc = 1.7 D Bc = 1.5 D Wc = 1.25 W + 0.1 D where: Hc – height of casing, in. Bc - breadth of casing, in Wc – width of casing, in. D – diameter of impeller, in W - width of impeller, in

Air-Moving Device Casing Dimension (Narrow Backward Curved Casing Dimension (Wide Backward Curved Centrifugal) Centrifugal) Hc = 1.4 D Hc = 2.0 D Bc = 1.35 D Bc = 1.6 D Wc = W + 0.1 D Wc = W + 0.16 D where: where: Hc – height of casing, in. Hc – height of casing, in. Bc - breadth of casing, in Bc - breadth of casing, in Wc – width of casing, in. Wc – width of casing, in. D – diameter of impeller, in D – diameter of impeller, in W - width of impeller, in W - width of impeller, in Casing Dimension (Mixed Flow) Casing Dimension (Traverse Flow) Hc = 2.0 D Hc = 2.2 D Bc = 2.0 D Bc = 2.2 D Wc = 0.46 D Wc = W + [D/4] where: where: Hc – height of casing, in. Hc – height of casing, in. Bc - breadth of casing, in Bc - breadth of casing, in Wc – width of casing, in. Wc – width of casing, in. D – diameter of impeller, in D – diameter of impeller, in Casing Dimension (Vane-Axial Flow) Wc = 1.2 D where: Wc – width of casing, in. D – diameter of impeller, in Casing Dimension (Partially-Cased Fan) Wc = 0.5 D where: Wc – width of casing, in. D – diameter of impeller, in

Air Horsepower Q V H AHP = ---------------33,000 where: AHP - air horsepower, hp Q - airflow rate, cfm V - specific weight of air, lb/ft3 H - total head, ft

Casing Dimension (Tube-Axial Flow) Wc = 1.0 D where: Wc – width of casing, in. D – diameter of impeller, in Mechanical Efficiency f = AHP / BHP where: f - fan efficiency, decimal AHP - air horsepower, hp BHP - brake horsepower, hp Brake Horsepower Q Pa BHP = -------------6360 f where: BHP - brake horsepower, hp Q - airflow rate, cfm Pa - static pressure, in. water f - fan efficiency, decimal

Air-Moving Device Propeller Fan Pitch P = 2  r tan  where: P - pitch in. r - fan radius, in.  - angle of fan blade twist, deg Fan Laws D2 5 N2 3 HP2 = HP1 -------- --------D 1 5 N1 3 where: HP – fan horsepower, hp D - fan diameter, in. N - speed of impeller, rpm

Fan Laws D2 = D1

H1 1/4 Q2 1/2 --------- --------Q1 1/2 H2 ¼

where: D – impeller diameter, in. H - fan head, in. H20 Q - air flow rate, cfm Fan Laws Q1 1/2 H2 3/4 N2 = N1 --------- --------H1 3/4 Q2 ½ where: N – impeller speed, rpm H - fan head, in. H20 Q - air flow rate, cfm

Air-Moving Device Problem 1 A vane-axial fan for a flat-bed dryer runs at 800-rpm speed. The rate of flow of the fan is 100 cfm at 1 in. of water pressure head. What is the specific speed of the fan? Given: Speed - 800 rpm Rate of flow - 100 ft3

Required: Specific speed of the fan Solution: Ns = N x Q 0.5 / Ps 0.75 = (800 rpm)(100 cfm)0.5 / (1 in.H2O)0.75 = 800 x 10 x 1 = 8,000

Problem 2 A 12inch-diameter fan rotates at 1800-rpm speed. The fan blade has 10-degree pitch angle. What is the fan flow rate if it has 40% static efficiency? Given: Diameter Speed Static efficiency

- 12 in. - 1800 rpm - 40 %

Required: Fan flow rate Solution: Pitch = 2 π ( 6.in) Tan 10 deg = 6.6 in. Q

= 6.6 in per rev x 3.1416 (12 in)2 /4 x 1800 rpm x 40% = 313.35 cfm

Material Handling 1. A machine recommended for use in conveying products with less damage. a. Bucket elevator b. Screw conveyor c. Belt conveyor d. All of the above 2. The part of a belt conveyor used to discharge materials over the end of the belt with the use of a diagonal scraper. a. Scraper b. Tripper c. Head pulley d. None of the above 3. The type of a conveyor feeder used for feeding birds in cages in a poultry farm. a. Flat chain feeder b. Auger feeders c. Round chain feeders d. All of the above 4. A conveyor with high power requirement per unit capacity. a. Bucket b. Belt c. Pneumatic d. All of the above 5. A type of bearing used for tightening the belt of bucket elevators. a. Pillow block bearing b. Flange bearing c. Take-up units d. None of the above 6. The horsepower requirement of belt conveyors includes the power ___. a. to drive empty b. to drive at horizontal c. to drive vertical d. All of the above

7. An electrically-operated device commonly used for automatic bagging of grains or of feeds. a. Solenoid switch b. Transducer c. Load cell d. None of the above 8. What is the theoretical rpm of a bucket elevator with 0.2m-diameter head pulley and and a 0.1-m bucket projection? a. 77 rpm b. 120 rpm c. 160 rpm d. None of the above 9. If the operational efficiency of the bucket elevator in Item 8 above is 85% of the theoretical speed, what is the operation speed of the elevator? a. 65 rpm b. 102 rpm c. 136 rpm d. None of the above 10. What is the theoretical horsepower requirement of a bucket elevator with 545-kg/min capacity and has 10.7-m lift. The elevator is loaded down side. a. 2.19 hp b. 1.92 hp c. 2.91 hp d. None of the above 11. When a bucket elevator is to be fed at the downside section, instead of the upside section of the elevator booth, its power requirement will ___. a. decrease b. increase c. be the same d. None of the above

Material Handling 12. A machine recommended to use in removing metallic elements during conveying. a. Screen separator b. Magnetic separator c. Pneumatic separator d. None of the above

17. An auger which releases conveyed materials uniformly along a substantial portion of its length. a. Feeding auger b. Portable auger c. Distributing auger d. None of the above

13. The commonly used materialhandling equipment. a. Bucket elevator b. Screw conveyor c. Belt conveyor d. All of the above

18. An auger with accessories that include a suitable support system for mobility. a. Feeding auger b. Portable auger c. Distributing auger d. None of the above

14. A conveyor which is essentially made of an endless belt operating between two or more pulleys with load supported by idlers. a. Bucket elevator b. Screw conveyor c. Pneumatic conveyor d. None of the above 15. A conveyor used for fine materials and is made of a helical plate that rotates on a trough and moves the product by dragging. a. Chain conveyor b. Pneumatic conveyor c. Screw conveyor d. None of the above

16. An auger capable of discharging materials to one or more locations. a. Feeding auger b. Portable auger c. Distributing auger d. None of the above

19. The size of an auger is referred to the ___. a. diameter of the auger b. inside diameter of the auger tube c. outside diameter of the auger tube d. none of the above

20. What is the capacity of a 10in.diameter screw conveyor running at 300rpm speed? The screw pitch is equal to its diameter while the shaft diameter is equal to ¼ D. The percentage load is 30% while the density of corn is 45 lbs/ft3. a. 2824 kg/hr b. 3104 kg/hr c. 4231 kg/hr d. None of the above 21. The movement of material in a processing plant in any direction whether it be horizontal, vertical, or any combination. a. Transporting b. Shipping c. Material handling d. All of the above

Material Handling 22. Which of the following is not considered a material handling equipment? a. Bucker elevator b. Screw conveyor c. Belt conveyor d. Lifts, trucks, and carts e. None of the above f. All of the above 23. Pulleys used to hold the belts of a belt conveyor to keep them in place. a. Head pulley b. Booth pulley c. Idlers d. None of the above 24. Pulleys used to drive the belt at the inlet and at the outlet ends of a belt conveyor. a. Head pulley b. Booth pulley c. End pulleys d. None of the above 25. The angle of inclination of belt conveyors for conveying paddy and most grains. a. 9 to 12 degrees b. 16 to 17 degrees c. 20 to 24 degrees d. None of the above 26. The conveyor used to handle finely divided powders, damp , sticky, and heavy viscous materials and hot substances and granular materials of all types. a. Belt conveyor b. Screw conveyor c. Bucket elevator d. Pneumatic conveyor e. None of the above

27. The factor(s) affecting the capacity of belt conveyors. a. Belt width b. Angle of trough c. Belt speed d. All of the above e. Two of the above 28. What is the theoretical rpm of a bucket elevator with 0.4m-diameter head pulley and 0.1-m bucket projection? a. 45.3 rpm b. 55.4 rpm c. 66.7 rpm d. None of the above 29. If the operational speed of the bucket elevator in Item 28 above is 85% of the theoretical speed, what is its operational speed? a. 53.4 rpm b. 62.1 rpm c. 69.3 rpm d. None of the above 30. Which of the following is a characteristic of belt conveyors? a. Self cleaning b. Limited elevating capacity c. Can convey materials in long distance d. Negligible damage to product being conveyed e. Two of the above f. All of the above 31. What is the theoretical horsepower requirement of a bucket elevator with 740-kg/min capacity and 12-m lift and is loaded up side? a. 2.3 hp b. 3.5 c. 4.1 hp d. None of the above

Material Handling

32. If 850 kg of paddy is to be lifted per minute to a 12-m height, what is the horsepower requirement of the elevator? Loading is on the downside of the elevator booth. a. 3.35 hp b. 4.12 hp c. 5.7 hp d. None of the above 33. The type of belt conveyor suitable for conveying grains. a. Flat belt b. Trough belt c. V belt d. None of the above 34. Commonly used belt conveyor for paddy in bag storage. a. Flat belt b. Trough belt c. V belt d. None of the above 35. The trough angle for belt conveyors used for paddy and grains. a. 10 degrees b. 20 degrees c. 45 degrees d. None of the above

36. The pulley diameter of a belt conveyor is 50 cm. It will be ran at 48rpm speed. If the width of the belt is 40 cm with an estimated cross-sectional area of 0.012 m2 and a 20-deg surcharge angle, what will be the speed of the belt? a. 75.4 m/min b. 82.1 m/min c. 93.2 m/min d. None of the above

37. What is the capacity of the belt conveyor in Item 36 above in tons of paddy per hour. Assume a paddy density of 600 kg/m3. a. 29.4 tons per hour b. 32.6 tons per hour c. 41.3 tons per hour d. None of the above 38. What is the capacity of the belt conveyor in Item 36? a. 98.2 tons per hour b. 100.2 tons per hour c. 110.6 tons per hour d. None of the above 39. What is the horsepower requirement of the conveyor in Item 36 running empty? a. 0.72 hp b. 0.81 hp c. 0.89 hp d. None of the above 40. What is the horsepower requirement of the conveyor above in lifting the product? a. 0.32 hp b. 0.48 hp c. 0.53 hp d. None of the above 41. Referring to Item 36, what is the horsepower required to move the product horizontally? a. 0.32 hp b. 0.48 hp c. 0.89 hp d. None of the above 42. Still referring to Item 36, what is the total horsepower requirement of the conveyor? a. 1.22 hp b. 1.69 hp c. 2.15 hp d. None of the above

Material Handling

43. Determine the speed of the belt of a 10m-long belt conveyor needed to deliver shelled corn to a feeder of a storage bin which is 1-m high from the main floor. The pulley diameter and width of the conveyor is 60 cm and 50 cm, respectively, running at 40-rpm speed. The cross-sectional area of the conveyor is 0.031 m2. Assume a 700kg/m3 density for shelled corn. a. 65.7 m/min b. 75.4 m/min c. 81.2 m/min d. None of the above 44. The standard screw pitch for screw conveyors. a. 1/2 of the diameter b. 1 of the diameter c. 1-1/2 of the diameter d. None of the above 45. The type of screw utilized for screw conveyors, which are used to mix materials while conveying. a. Variable pitch screw b. Steeped diameter screw c. Ribbon screw d. None of the above 46. A device used to support long horizontally-oriented screw. a. End bearings b. Hangers brackets c. Trough d. None of the above 47. A U-shaped trough without cover is usually used for screw conveyors ___ oriented in position. a. vertically b. inclined c. horizontally d. None of the above

48. Screw conveyors are seldomly used for conveying rough rice for the reason that ___. a. it is expensive since the materials are difficult to fabricate b. it easily wears out screw and trough because rough rice is abrasive c. it doesn’t look good to convey rough rice using the conveyor d. none of the above 49. Assuming the roughness of the surface of rough rice and corn is equal, which of them requires more power to convey using a screw conveyor? a. Rough rice b. Shelled corn c. Same for both materials d. None of the above

50. If a screw conveyor is inclined, its capacity to convey will ___. a. increase b. decrease c. be the same d. none of the above 51. A 15-degree inclination of conveyor will roughly increase its power by 25% while a 25-degree inclination will increase the power of the conveyor by roughly ___. a. 30% b. 40% c. 50% d. None of the above 52. The type of bucket elevator designed to handle grains. a. Centrifugal b. Positive ( gravity) c. Continuous (direct gravity) d. None of the above

Material Handling 53. Which of the following is a good design feature for bucket elevators. a. Clean out provision for booth b. Belt tension take up c. Replaceable liners at point of wear d. Provision to remove large foreign materials such as metals and stones. e. All of the above f. None of the above 54. Carrying capacity of bucket in bucket elevator is usually calculated by design engineers considering a ___ of the rated capacity. a. 60 to 75% b. 85 to 90% c. 95 to 100% d. None of the above 55. The capacity of a bucket elevator is a function of ___. a. bucket size b. bucket spacing c. belt speed d. all of the above e. None of the above 56. A device used to tighten the belt in order to provide proper tension of the belt of a belt conveyor. a. Belt take up unit b. Belt idler pulley c. Belt tripper d. None of the above 57. The actual horsepower requirement of bucket elevators is ___ higher than the theoretical value due to friction, power transmission and drive losses. a. 5 to 10% b. 10 to 15% c. 15 to 20% d. None of the above

58. Which of the following statements is true in selecting bucket elevator belts. a. As the diameter of the pulley increases, the number of plies required for the belt increases. b. As the diameter of the pulley increases, the number of plies required for the belt decreases. c. As the diameter of the pulley increases, the number of plies required for the belt remains the same. d. None of the above 59. A pneumatic conveyor moves granular materials at a velocity beyond the ___ of the materials. a. superficial velocity b. apparent velocity c. terminal velocity d. none of the above 60. Pneumatic conveyor is used very seldom in conveying rough rice for the reason that ___. a. it is heavy to convey b. the shape is not round c. it is abrasive d. None of the above 61. The main reason that pneumatic conveyor is not preferred over bucket, belt and screw conveyors is because the pneumatic conveyor ___. a. is expensive b. has high power requirement c. requires manpower when loading a material d. None of the above 62. Conveying material can be changed easily when using ___. a. screw conveyor b. bucket elevator c. pneumatic conveyor d. None of the above

Material Handling 63. A pneumatic conveyor system that usually operates below atmospheric pressure. a. High pressure system b. Low pressure system c. Suction system d. All of the above 64. A pneumatic conveyor system that uses low-velocity, high-density air employing a positive displacement blower for which elevator is a function of ___. a. high pressure system b. low pressure system c. suction system d. All of the above 65. For grains, the air conveying capacity required for pneumatic conveyor is ___. a. 15 to 50 ft3/lb b. 55 to 100 ft3/lb c. 105 to 250 ft3/lb d. None of the above 66. The static pressure for fan design in a pneumatic conveyor system is ___ times of the air pressure requirement. a. 1.2 to 1.3 b. 2.2 to 2.3 c. 3.2 to 3.3 d. None of the above 67. The design grain-to-air weight ratio for pneumatic conveyor is ___. a. 1:1.2 to 1:3.7 b. 1:3.8 to 1:4.5 c. 1:4.6 to 1:5.5 d. none of the above 68. A drag, flight or scraper conveyor. a. Screw conveyor b. Chain conveyor c. Belt conveyor d. None of the above

Material Handling Belt Capacity

C = 1710 A S where: C - capacity, bu/hr A - area of cross-section of belt, m2 S - belt speed, m/min

Horsepower to Lift Materials in Belt Conveyor h C HPh = -------- x 1.015 x ---------0.3048 1000 where: HPh – horsepower to lift materials, hp h – lift, m C – capacity, tph Total Horsepower of Belt Conveyor HPt = HPe + HPl + HPh where: HPt – total horsepower, hp HPe – power to drive empty, hp HPl – power to drive in level, hp HPh – power to lift materials, hp

Horsepower Requirement when Screw is Inclined Position HPi = HPh sin  where: HPi – power requirement when screw is in inclined position, hp HPh – power requirement in horizontal position, hp  - inclination of the screw, deg

Horsepower to Drive Empty Belt Conveyor S A+B (3.28L) HPe = --------- + -------------------0.3048 100 where: HPe – horsepower (empty), hp S – belt speed, m/min A – constant, 0.20 to 0.48 @ 36-76 belt width B – constant, 0.00140 to 0.00298 @ 36-76 belt width L – belt length, m Horsepower to Convey Materials in Belt Conveyor on Level Position 0.48 + 0.01 L HPl = C x ---------------------100 where: HPl – horsepower to drive belt conveyor on level position, hp C – belt capacity, tph L – belt length, m

Capacity of Screw Conveyor ( D 2 - d2 ) C = ------------------- x P x N 36.6 where: C – capacity of screw conveyor, ft3/hr D – screw diameter, in. D – shaft diameter, in P – screw pitch, in (normally equal to D) N – shaft speed, rpm Bucket (Elevator) Capacity C = 60 Qb nb Sb where: C – elevator capacity, m3/hr Qb – bucket capacity, m3/1,000,000 nb – number of buckets per meter of belt Sb – belt speed, m/min

Material Handling Power Requirement of Screw Conveyor L (D S + Q K) HP = -------------------1,000,000 where: HP – horsepower requirement, hp L – overall length, ft D – bearing factor, 10 to 106 for ball bearing @ conveyor diameter of 7.5 to 40 cm S – Speed, rpm Q – quantity of materials, lbs/hr K – material factor, 0.4 to 0.7

Motor Horsepower of Screw Conveyor HP P MHP = ---------------0.85 where: MHP – motor horsepower, hp HP – power requirement, hp P – 2 when HP is less than 1; 1.5 when HP is equal to 1 and above

Material Handling Problem 1 What is the theoretical rpm of a bucket elevator with 0.2m-diameter head pulley and 0.1-m bucket projection? Given: Pulley Diameter Bucket projection

- 0.2 m - 0.1 m

Required: Theoretical rpm Solution: Radius

= 0.1 m + 0.05 m = 0.15 m

Nt

= 54.19 / (R)½ = 54.19 / ( 0.15 m x 3.28 ft/m)½ = 54.19 / 0.701 = 77.3 rpm

Problem 2 If the operational efficiency of the bucket elevator in Problem 1 is 85% of the theoretical speed, what is its operating speed? Given: Nt  Required:

- 77.3 rpm - 0.85 Operational Speed

Solution: No

=  x Nt = 0.85 (77.3 rpm) = 65.7 rpm

Material Handling Problem 3 What is the theoretical horsepower requirement of a bucket elevator with 545-kg/min capacity and 10.7-m lift? The elevator is loaded down side. Given: Capacity - 545 kg/min Lift - 10.7 m Loading - downside

Required:

Theoretical Hp

Solution: Hp = Q H F / 4562 = [545 kg/min (10.7 m) (1.5 m)] 4562 = 1.9 hp Problem 4 Compute the theoretical capacity of an 8inch-diameter screw conveyor loaded at 45% of the full load. The screw shaft diameter is 2 inches with 4 inches screw pitch. The speed of the conveyor is 80 rpm. Given: Screw diameter Shaft diameter Screw pitch Screw speed Loading

Required:

- 8 inches - 2 inches - 4 inches - 80 rpm - 45%

Theoretical capacity of the conveyor

Solution: Ct = [(D2 – d2)/36.6][P x N] = [(8 in)2 – (2 in)2 /36.6] [4 in x 80 rpm] = 524.59 ft3/hr @ 45% loading = 524.59 ft3/hr x 0.45 = 236.07 ft3/hr

Material Handling Problem 5 What is the theoretical rpm of a bucket elevator with 0.4m-diameter head pulley and 0.1-m bucket projection? Given: Pulley diameter - 0.4 m Bucket projection - 0.1 m Required:

Theoretical rpm

Solution: Nt

= 54.19 [(0.2 + 0.05)(3.28 ft/m)]0.5 = 54.19 / 0.812 = 66.7 rpm

Problem 6 If the operational speed of the bucket elevator in Problem 5 above is 85% of the theoretical speed, what is its operational speed? Given: Efficiency - 0.80 Theoretical speed - 66.7 rpm Required:

Operational speed

Solution: No

= 0.80 Nt = 0.80 (66.7 rpm) = 53.4 rpm

Material Handling Problem 7 What is the theoretical horsepower requirement of a bucket elevator with 740-kg/min capacity and 12-m lift and is loaded up side? Given: Capacity - 740 kg/min Lift - 12 m Loading - up side

Required:

Theoretical Hp

Solution: Hp = QHF/4562 = (740 kg/min)(12 m)(1.2) / 4562 = 2.3 Hp Problem 8 If 850 kg of paddy is to be lifted per minute to a 12-m height, what is the horsepower requirement of the elevator? Loading is at the downside of the elevator booth. Given: Q - 850 kg/min H - 12 m Loading - downside Required:

Hp requirement

Solution: QHF

Hpe = 4562 850 kg/min (12 m) (1.5) = 4562 = 3.35 hp

Material Handling Problem 9 The pulley diameter of a belt conveyor is 50 cm. It will be ran at 48-rpm speed. If the width of the belt is 40 cm with a 0.012 m2 estimated cross-sectional area and a 20deg surcharge angle, what will be the capacity of the belt conveyor in tons of paddy per hour? Assume a 600 kg/m3 paddy density. Given: Pulley diameter - 50 cm Pulley speed - 48 rpm Belt width - 40 cm Belt cross-sectional area - 0.012 m2 Surcharge angle - 20 deg Paddy density - 600 kg/m3 Required: Belt capacity in tph Solution: (a) V belt = 3.1416 x Dp x Np = 3.1415 x (50 cm/100 cm/m) x 48 rpm = 75.4 m / min (b) Capacity = A x V x 60 = 0.012 m2 x 75.4 m/min x 60 = 54.3 m3/min x 600 kg/ m3 = 32,580 kg/hr x ton/1000 kg = 32.58 tons/hr Problem 10 A screw conveyor discharges grains on a horizontal position at 10 kg per minute. If the conveyor will be inclined at 45-degree position, what will be its output in tons per hour? Given: Q - 10 kg/min Angle - 45° Required: Output in tons/hour Solution: Q inc = Q horizontal Sin 45 = (10 kg/min) x Ton/1000 kg x 60 min/hr x 0.707 = 0.42 ton per hour

Material Handling Problem 11 Determine the power required of a 10m-long belt conveyor needed to deliver shelled corn to a feeder of a storage bin which is 1-m high from the main floor. The pulley diameter and width of the conveyor are 60 cm and 50 cm, respectively, running at 40-rpm speed. The cross-sectional area of the conveyor is 0.031 m2. Assume a 700-kg/m3density for shelled corn. Given: Belt length - 10 m Lift -1m Pulley diameter - 60 cm Belt width - 50 cm Pulley speed - 40 rpm Belt x-area - 0.031 m2 Product - shelled corn Density - 700 kg/m3 Required: Horsepower required to drive the belt conveyor Solution: V = 3.14 D x N = 3.14 x 0.6 m x 40 rpm = 75.4 m/min C = V x A x 60 = 75.4 m/min x 0.031 m2 x 60 = 140.24 m3/hr x 700 kg/m3 x ton/1000 kg = 98.17 ton/hr (a) Hpe = [(S/0.3048) (A + B (3.28 L))] / 1000 = [[(75.4 m3/min)/0.3048] [0.3+0.00187(3.281x10 m)]]/100 = 0.89 hp (b) Hpv = C (0.48 + 0.01 L) / 100 = 98.17 (0.48 + 0.01 (1m) / 100 = 0.48 hp (c) Hph = (L/0.3048) (1.015) (C/1000) = (1/0.3048) (1.015) (98.17 ton/hr) = 0.32 hp Total Hp = Hpe + Hpv + Hph = 0.89 hp + 0.48 hp + 0.32 hp = 1.69 hp (use 2 hp)

Material Handling Problem 12 Calculate the theoretical power required to drive a 10meter-long screw conveyor having 6-inches diameter. The conveyor shaft is supported by a roller-type bearing and is used to convey ground lime at 10-tph rate. The conveyor speed is 40 rpm. Also, compute the power required for the motor. Given: Screw length - 10 meters Screw diameter - 6 inches Type of bearing - roller Product - ground lime Capacity - 10 tons per hour Screw speed - 40 rpm Required: Theoretical Power Motor Power Solution: HP = L (DS + Q k) / 1,000,000 = 10 m x 3.28 ft/m ( 18 x 40 rpm + 10,000 kg/hr x 2.2 lb/kg x 0.6) / 1,000,000 = 32.8 ft/min (720 rpm + 1320 lb/hr) / 1,000,000 = 0.456 hp MHP = H x P / 0.85 = 0.456 x 2 / 0.85 = 1.074 hp

Problem 13 A screw conveyor discharges 10 kg per minute of grains on a horizontal position. It consumes 2 hp of power during operation. If the conveyor will be inclined at 45 degree position, what will be its power consumption? Given:

Q Angle

Required:

Output in tons/hour

Solution: HPinc

- 10 kg/min - 45°

= HPhor x Sin  = 2 hp x sin 45 deg = 1.4 hp

Crop Drying 1. The minimum drying efficiency requirement for mechanical dryers based on standard performance criteria. a. 90% b. 75% c. 50% d. None of the above 2. The minimum heating efficiency requirement for direct-fired biomassfueled grain dryers. a. 75% b. 65% c. 50% d. None of the above 3. The minimum heat utilization efficiency requirement for direct-fired petroleum-fueled mechanical dryers based on standard performance criteria. a. 90% b. 80% c. 70% d. None of the above 4. The warranty period requirement for mechanical grain dryers. a. 6 months b. 12 months c. One year d. Two of the above 5. The ratio of the heat released by the fuel to the theoretical heat available in it. a. Burner efficiency b. Thermal efficiency c. Combustion efficiency d. None of the above

6. The pressure built up in the plenum chamber used to maintain uniform distribution of airflow throughout the mass of grains. a. Velocity pressure b. Static pressure c. Dynamic pressure d. Any combination of the above 7. The temporary holding of grains between drying passes to allow the moisture in the center of the grain to equalize with that on its surface. a. Tempering b. Static drying c. Dryaeration d. None of the above 8. If 20 kg of water is removed from a 110-kg paddy, what is the percentage moisture content of the paddy in wet basis? a. 12% b. 18% c. 22% d. None of the above 9. What is the percentage moisture content of the paddy in Item 8 when expressed in dry basis? a. 22% b. 30% c. 12% d. None of the above 10. What is the amount of moisture to be removed from a material with 14.5% moisture content and 76 kg dry matter weight? a. 12.9kg b. 24.1kg c. 14.5kg d. None of the above

Crop Drying 11. If 9 tons of a product is to be dried from 24 to 14% moisture content, what would be the final weight of the product? a. 7953.4 kg b. 8837.3 kg c. 9741.4 kg d. None of the above 12. What is the weight of moisture to be removed from the product in Item 11? a. 1046.5 kg b. 2285.6 kg c. 2634.4 kg d. None of the above 13. The recommended depth of grains in a shallow-bed dryer. a. Up to 12 inches b. Up to 18 inches c. Up to 24 inches d. All of the above 14. A 45°C drying temperature is equal to ___. a. 113°F b. 131°F c. 121°F d. none of the above 15. Two tons of paddy was dried in a mechanical dryer from 24 to 14% in 8 hours. What is the final weight of the product after drying? a. 1767.4 kg b. 1677.4 kg c. 1776.4 kg d. None of the above 16. What is the drying capacity of the dryer in Item 15? a. 200 kg/hr b. 250 kg/hr c. 125 kg/hr d. None of the above

17. Referring to Item 15, what is the moisture reduction per hour? a. 29.07 kg/hr b. 27.09 kg/hr c. 20.97 kg/hr d. None of the above 18. The divisional layer between the dried and the undried products in a drying system. a. Drying layer b. Drying zone c. Drying front d. All of the above 19. The amount of heat required to raise one gram of water one degree centigrade. a. One BTU b. One calorie c. One joule d. All of the above 20. A solar dryer is used to reduce the moisture content of 4 tons of paddy rice from 25 to 15% wet basis. How much is the amount of moisture removed? a. 471 kilos b. 417 kilos c. 714 kilos d. None of the above 21. A device that generally removes excess moisture by forced ventilation either with or without addition of heat. a. Fryer b. Dehydrator c. Dryer d. None of the above 22. A batch-type dryer with vertical holding bin used for deep-bed drying. a. Recirculating dryer b. Vertical bin dryer c. Batch-type dryer d. None of the above

Crop Drying 23. A mechanical dryer equipped with series of holding bins that allow grains to continuously pass through its drying chamber until their moisture content is reduced to a desired level. a. Batch dryer b. Continuous-flow dryer c. Recirculating dryer d. None of the above 24. A batch-type dryer that circulates or mixes the grains during drying. a. Vertical-bin dryer b. Recirculating dryer c. Flat-bed dryer d. None of the above 25. An air chamber maintained under pressure and is usually connected to one or more distribution ducts in a drying system. a. Drying bin b. Plenum chamber c. Air duct d. None of the above 26. The component of a dryer that converts the velocity pressure of the fan to static pressure. a. Drying bin b. Plenum chamber c. Manometer d. None of the above 27. What is the relative humidity of the air if the psychrometer measures 40°C for both the dry bulb and the wet bulb temperatures? a. 40% b. 80% c. 100% d. All of the above

28. If the point is moved horizontally to the left of the psychrometric chart, the process is ___. a. heating b. cooling c. drying d. None of the above 29. Shelled corn initially at 24% is to be dried to 14%. If the initial weight of the corn is 1000 kilos, what would be its final weight? a. 782 kg b. 827 kg c. 872 kg d. None of the above 30. What is the weight of moisture removed from the corn grains in Item 29 above? a. 128 kg b. 173 kg c. 218 kg d. None of the above 31. The usual depth of grains in a deepbed batch dryer. a. 18 inches b. 2 to 8 ft c. 8 to 10 ft d. None of the above 32. In grain drying theory, drying occurs when ___. a. the vapor pressure of grains is higher than the vapor pressure of the air b. the vapor pressure of grains is lower than the vapor pressure of the air c. the vapor pressure of grains is equal with the vapor pressure of the air d. None of the above

Crop Drying 33. Compute the drying efficiency of a one-ton capacity flat-bed dryer used to dry paddy from 21 to 14% in 8 hrs. The fuel consumption rate of the dryer is 7 lph. Assume a 600 kCal/kg heat of vaporization and a 9,000 kCal/kg heating value of fuel. The density of fuel is 0.76. a. 10.24% b. 11.35% c. 12.75% d. None of the above 34. What is the fuel consumption rate of a 2-ton grain dryer required to dry paddy from 22 to 14% in 8 hrs. The dryer efficiency is 45%. Assume a 600kCal/kg heat of vaporization for paddy. a. 4.53 lph b. 3.56 lph c. 2.78 lph d. None of the above 35. What is the required dimension for a square bin with 1-ton paddy load if the dryer requires 0.45-m thickness. Assume a 576-kg/m3 grain density. a. 2 m b. 3 m c. 4 m d. None of the above 36. Compute the theoretical heat requirement for a 1-ton flat-bed dryer operating on the following conditions: enthalpy of drying air, 46 BTU/ lbda.; enthalpy of outlet air, 40 BTU/lbda; specific volume of air, 0.9 m3/kg. Airflow rate is 100m3/min. a. 25,920 kCal/hr b. 26,640 kcal/hr c. 27,543 kcal/hr d. None of the above

37. A flatbed dryer is using a direct fired biomass furnace for heating paddy. As an Agricultural Engineer, what would you recommend to eliminate entirely fly ashes that goes with the hot air in the bin during drying? a. Increase the height of the plenum chamber to slow down the velocity of the air in the bin b. Reduce the rpm of the blower to slow down the air velocity of the hot air c. Install a heat exchanger in the furnace d. None of the above 38. The dryer is equipped with optimum size of blower and furnace to push the air into a metal drying bin. As an Agricultural Engineer, what would you recommend to improve the pressure draft of air at the plenum chamber? a. Replace the bin with bigger plenum chamber b. Reduce the drying temperature of the air when operating the dryer c. Seal the bin plenum chamber d. None of the above

Crop Drying

Drying Capacity Cd = (Wi / Td) where: Cd – drying capacity, kg/hr Wi – initial weight of material, kg Td – drying time, hr

Moisture Reduction Rate per Hour Wi – Wf MRR = ------------Td where: MRR – moisture reduction rate, kg/hr Wi – initial weight, kg Wf – final weight, kg Td – drying time, hr Heat Available in the Fuel Qaf = FCR HVf where: Qaf – heat available in the fuel, KJ/hr FCR – fuel consumption rate, kg/hr HVf – heating value of fuel, KJ/hr Heat Utilization HU = (Qsd x Td / MR) 100 where: HU – heat utilization, KJ/kg Qsd – heat supplied to the dryer, KJ/hr Td – drying time, hr MR – amount of moisture removed, kg Volume of Grain to be Dried Vg = 1000 Wi / Dg where: Vg – volume of grain to be dried, m3 Wi – initial weight of grain, tons Dg – grain density, kg/m3

Final Weight of Dried Material Wi (100 – Mci) Wf = ------------------------(100 – MCf) where: Wf – final weight of dried material, kg Wi – initial weight of material, kg Mci – initial moisture content, % MCf – final moisture content, % Heat Supplied to the Dryer 60 (h2-h1) AR Qsd = ------------------------ where: Qsd – heat supplied to the dryer, KJ/hr H2 – enthalpy of drying air, KJ/kg da H1 – enthalpy of ambient air, KJ/kg da AR – airflow rate, m3/min  - specific volume, m3/kg da Heat System Efficiency hs = (Qsd / Qaf) 100 where: hs – heating system efficiency, % Qsd – heat supplied to the dryer, KJ/hr Qaf – heat available in the fuel, KJ/hr Heat Utilization Efficiency THU hu = ----------- x 100 Qsd where: hu – heat utilization efficiency, % THU – total heat utilized, KJ/hr Qsd – heat supplied to the dryer, KJ/hr Drying Floor Area Af = Vg / Dg where: Af – floor area of bin, m2 Vg – volume of grain in bin, m3 Dg – depth of grain in bin, m

Crop Drying Airflow Requirement Af = C SAF where: Af – air flow rate, m3/min C – dryer capacity, tons SAF – specific air flow rate, m3/min-ton

Apparent Air Velocity in Grain Bed Vapp = AF / Af where: Vapp – apparent air velocity, m/min AF – total airflow, m3/min Af – dryer floor area, m2

Blower Pressure Draft Requirement Pd = Ps Dg where: Pd – blower pressure draft, cm of water Ps – specific pressure draft, cm water per meter depth of grain Dg – depth of grain in bed, m Theoretical Heat Required Hn AF Qr = ---------------Vs where: Qr – theoretical heat required, KJ/min Hn – net enthalpy, KJ/kg Vs – specific volume of air, m3/kg

Theoretical Weight of Fuel WF = Qr / HVF where: WF – theoretical weight of fuel, kg/min Qr – total heat required, KJ/min HVF – heating value of fuel, KJ/kg

Theoretical Volume of Fuel Vf = WF / Df where: Wf – theoretical volume of fuel, lpm WF – total weight of fuel, kg/min Df – density of fuel, kg/liter Drying Time WMR DT = -------------AF Vs HR where: DT – drying time, min WMR – weight of moisture to be removed, kg AF – airflow rate mg/min Vs – air density, kg/m3 HR – humidity ratio, kg moisture/kg da

Weight of Moisture Removed 1 - Mci WMR = Wi (1 - --------------- ) 1 – MCf where: WMR – weight of moisture removed, kg Wi – initial weight of grain to be dried, kg MCi – initial moisture content, decimal MCf – final moisture content, decimal Actual Volume of Fuel FVa = Vf / t where: FVa – actual volume of fuel, lph Vf – theoretical volume of fuel, lph t – thermal efficiency, decimal

Crop Drying Problem 1 A two-ton mechanical dryer dries paddy from 24 to 14% in 8 hours. What is the final weight of the product after drying? Given: Capacity MCi MCf Time

- 2 tons - 24% - 14% - 8 hours

Required: Final weight Solution: Wf = Wi (1-MCi) / (1 – MCf) = 2 tons (1-0.24) / (1-0.14) = 1.767 tons

Problem 2 What is the percentage moisture reduction per hour in Problem 1 above? Given: MC initial - 24 % MC final - 14 % Drying time - 8 hours Required:

% moisture reduction per hour

Solution: % moisture = (24% – 14%) / 8 = 1.25 % per hour

Crop Drying Problem 3 Referring to Problem 1, what is the drying capacity of the dryer? Given: Wt initial - 2 tons Drying time - 8 hours Required:

Drying Capacity

Solution: Cd = Wi / Td = 2 tons / 8 hours = 0.25 ton / hour

Problem 4 Still referring to Problem 1, what is the rate of moisture reduction per hour? Given: Wt initial - 2 tons Wt final - 1.767 tons Drying time - 8 hours Required:

Moisture reduction per hour

Solution: Wt. of moisture removed = 2 tons – 1.767 tons = 0.233 ton Moisture reduction per hr = 0.232 ton / 8 hours = 0.029 ton/hr

Crop Drying Problem 5 Compute the apparent air velocity in a 1-ton capacity flat-bed dryer with 2.4m-x2.4m dimension square bin. The specific airflow rate of the dryer is 50 m3 per minute of air per m3 of grain. Assume a 500-kg/m3 density of grain. Given: Total airflow - 50 m3/min Area - 2.4 m x 2.4 m Grain density - 500 kg/m3

Required:

Apparent air velocity

Solution: Volume= 1 ton x 1000 kg/ton x m3/500kg = 2 m3 Q = 50 m3/min-m3 x 2 m3 = 100 m3/min Vapp = 100 m3/min / 2.4 m x 2.4 m = 17.36 m/min

Crop Drying Problem 6 Compute the drying efficiency of a one-ton capacity recirculating-type dryer used to dry paddy from 21 to 14% in 8 hrs. The fuel consumption rate of the dryer is 7 lph of diesel. Assume a 600 kcal/kg heat of vaporization and a 9,000 kcal/kg heating value of fuel. The density of fuel is 0.76. Given: Capacity - 1 ton FCR - 7 lph diesel MC i - 21% Hv - 600 kcal/kg MC f - 14% HVF - 9,000 kcal/kg Td - 8 hours δf - 0.76 Required: Drying Efficiency Solution: Wf = 1 ton (1-.021)/(1-.14) Qf = 7 liters/hr x 9,000 kcal/kg = 0.918 ton x 0.76 kg/liter WR = 1 ton – 0.918 ton = 47,880 kcal/hr = 81.4 kg Ed = 6,104 kcal/hr x 100/ Qo = 81.4 kg x 600 kcal/kg 47,880 kcal/hr = 48,840 kcal/8 hours = 12.75% = 6,104 kcal/hr Problem 7 What is the fuel consumption rate of a 2-ton grain dryer required to dry paddy from 22 to 14% in 8 hrs.? The dryer efficiency is 45%. Assume a 600 kcal/kg heat of vaporization for paddy. Given: Capacity - 2 tons ξd - 45% Mci - 22% Hv - 600 kcal/kg MCf - 14% Drying Time = 8 Required: Fuel Consumption Rate Solution:

Wf = 2 (1-0.22)/(1-0.14) = 1.81 tons WR = 2 tons - 1.81 tons = 186 kg Qr = 186 kg x 600 kcal/kg = 111,627 kcal/8 hr = 13,953 kcal/hr Qf = 13,953 kcal/hr / 0.45 = 31,007 kcal/hr

FCR = (31,007 kcal/hr) / (9,000 kcal/kg x 0.76 kg/liter) = 4. 53 liters per hour

Crop Storage 1. The process in which air moves through the mass of stored grains at a low rate to maintain grain quality. a. Cooling b. Aeration c. Fanning d. None of the above

7. If 5000 bags of paddy are to be piled 20-bags high, how many square meters of floor space is required? (0.23 m/bag) a. 111 sqm b. 121 sqm c. 211 sqm d. None of the above

2. The maximum allowable safe height of sack pile in bag storage. a. 12-16 sacks b. 18-25 sacks c. 28-30 sacks d. None of the above

8. A storage method in which the concentration of gas in the storage atmosphere is changed. a. Sealed storage b. Modified atmosphere c. Controlled atmosphere d. All of the above

3. The recommended stacking density for paddy per cubic meter of space. a. 5 bags b. 10 bags c. 15 bags d. None of the above 4. The recommended stacking density for corn per cubic meter of space. a. 12 bags b. 14 bags c. 16 bags d. None of the above 5. The recommended stacking density for rice per cubic meter of space. a. 10 bags b. 15 bags c. 20 bags d. None of the above 6. If a pile of rice is 8-m long, 6-m wide, and 3.6-m high, how many bags of rice are safe to be piled? a. 2592 bags b. 2952 bags c. 2295 bags d. None of the above

9. A storage practice in which grains are stored in loose form in a large container. a. Bag storage b. Bunker storage c. Bulk storage d. All of the above 10. A small metal probe used for taking samples of paddy from a sack. a. Sampling tube b. Trier c. Sampler d. None of the above 11. A wooden frame used in staking bags of rice. a. Dunnage b. Loading platform c. Bag holder d. All of the above 12. A warehouse used for storing paddy or rice, either in bulk or in bags. a. Silo b. Godown c. Farmstead d. None of the above

Crop Storage 13. The optimum relative humidity for storing fruits and vegetables is ___. a. 60-70% b. 80-90% c. 90-100% d. All of the above 14. What is the peak storage capacity of a 5m-diameter grain storage bin with 6m average height and 28-deg minimum angle of fill? a. 126.5m³ b. 162.5m³ c. 156.2m³ d. None of the above 15. The recommended overall height by ASAE for an agricultural pallet bin. a. 72 or 133 cm b. 62 or 122 cm c. 52 or 112 cm d. None of the above 16. A storage system for holding buffer stocks and is usually located at the shipping receiving terminals. a. Village level storage system b. Commercial level storage system c. Centralized storage system d. All of the above 17. A storage structure made of prefabricated reinforcement concrete with metal siding and with either a hopper bottom or a flat bottom. a. Warehouse b. Silo c. Bulk container d. All of the above

18. The size of wire mesh used in storage to protect stored product from insects and rodents. a. ¼ inch mesh b. ½ inch mesh c. ¾ inch mesh d. All of the above 19. Changes in texture, odor, flavor, and nutritive value of grains during prolonged storage, even in the absence of insects and microorganisms, are due to ___. a. moisture and temperature b. vapor pressure and temperature c. vapor pressure and moisture d. all of the above e. None of the above 20. The recommended dimension for maximum piling of stacks to conform with the fumigating sheets in situations where warehouses cannot be made airtight. a. 7.3 m x 21.9 m x 4.5 m b. 6.3 m x 20.9 m x 4.5 m c. 5.3 m x 19.8 m x 4.5 m d. None of the above 21. The recommended stack height in a warehouse should not exceed the height of the walls plus a space of at least ___ between the top of the stacks and the roof frame. a. 1 meter b. 1.5 meters c. 2.0 meters d. None of the above 22. The rrecommended optimum stock height for paddy stored in a warehouse. a. 16 layers b. 18 layers c. 20 layers d. All of the above

Crop Storage 23. The recommended optimum stock height for maize stored in a warehouse. a. 16 layers b. 18 layers c. 20 layers d. All of the above

27. Safe storage moisture content of copra for use as feed ingredient. a. 5.8 % b. 11% c. 13% d. None of the above

24. The method of piling grains that provides ventilation space between bags and allows circulation of convective air current which, in turn, becomes the medium for heat dissipation. a. Chinese Method b. Japanese Method c. Philippine Method d. None of the above

28. Safe storage moisture content of copra for use as feed ingredient. a. 5.8 % b. 11% c. 13% d. None of the above

25. The allowable space between the top of the stocks and the roof truss of a warehouse. a. 1.0 meter b. 1.5 meters c. 2.0 meters d. None of the above 26. In storing paddy, which of the following statements is true? a. More paddy can be stored in a warehouse when it is placed in jute sacks. b. More paddy can be stored in a warehouse when it is placed in woven polypropylene bags. c. The same volume of paddy can be stored in a warehouse whether they are stored in jute sacks or in woven polypropylene bags. d. None of the above

Crop Storage Loss Due to Resp Lres = Wp x DML DML = 1-exp[[-AtC exp[D(T-60)] Exp [E (W-0.14)]] where: Lres – weight loss due to respiration, kg Wg – weight of grain stored, kg DML – dry mater loss, decimal t – storage time, hr/1000 T – temperature, F W – moisture content, decimal wb A – constant, 0.000914 C – constant, 0.6540 D – constant, 0.03756 E – constant, 33.61 Loss Due to Insect Li = 0.003 Id where: Li - weight loss due to insects, kg Id - percent insect damaged kernels at the end of the storage period, %

Loss Due to Birds Lb = 0.005 D P where: Lb - weight loss due to birds, kg D - storage period, days P - bird population Total Weight Loss Lt = Lr + Lm + Li + Lr + Lb + Ls where: Lt - total weight loss, kg Lr - weight loss due to respiration, kg Lm - weight loss due to microorganism, kg Li - weight loss due to insect, kg Lr - weight loss due to rodents, kg Lb - weight loss due to birds, kg Ls – weight loss due to spillage, kg

Loss Due to Microorganism Wi(100-Mi) Lm = [---------------- + 0.68x10 0.44Mi-11.08 ] D 100 where: Lm - weight loss due to microorganism, kg Wi - weight of incoming stock, tons Mi - moisture content of incoming stock, % w.b. D - storage period, days

Loss Due to Rodents Lr = C D where: Lr - weight loss due to rodents, kg C – coefficient, 0.0036, 0.020, 0.035 kg/day for mice, small rats, and big rats respectively D - storage period, days Loss Due to Spillage Ls = 0.005 Wg Hf where: Ls - weight loss due to spillage, kg Wg - weight of grain handled, kg Hf – number of times of handling

Crop Storage Problem 1 If a pile of rice is 8-m long, 6-m wide and 3.6-m high, how many bags of rice are safe to be piled? Given: Length of pile - 8 m Width of pile - 6 m Height of pile - 3.6 m Required:

Number of bags of rice

Solution: No. of bags = [ L x W x H ] / 15 bags / m3 = [8m x 6m x 3.6 m]/15 bags/m3 = 2,592 bags Problem 2 If 5000 bags of palay is to be piled 20-bags high, how many square meters of floor space is needed? (0.23 m/bag) Given: No of bags - 5000 bags Height of pile - 20 bags Height of bag - 0.23 m/bag Required:

Floor area

Solution: Volume of pile = 5000 bags/ 10 bags/m3 = 500 m3 Height of pile = 20 bags x 0.23 m/bag = 4.6 m Area of pile

= 500 m3 / 4.6 m = 108.69 m2

Crop Storage Problem 3 What is the peak storage capacity of a 5-m diameter grain-storage bin with 6-m average height and 28-deg. minimum angle of fill? Given: Diameter of grain Average height Angle of fill Required:

- 5m - 6m - 28°

Peak storage capacity

Solution: D/2 tanθ V = (πD2/4) EH + (πD2/4) 3

=

π(5m)2/4)

π(5m)2

5m/2 tan 28

4

3

6m +

= 117.8 m3 + 8.70 m3 = 126.50 m3

Crop Storage Problem 4 Two piles of shelled corn in bags will be stored in a warehouse having a dimension of 15-m wide by 30-m long and 6-m high. How many bags of the product would be contained per pile inside the warehouse? Given: Length - 30 m Width - 15 m Height - 6m Required: No. of bags per pile Solution: Volume = 30 m x 15 m x 6 m = 2,700 m3 number of bags = 2,700 m3 12 bags/m3 = 32,400 bags Problem 5 A 100,000-bag capacity pile will be constructed to stack paddy in a warehouse using jute bags to a height of 20 ft. What will be the probable floor area of the stack if a rectangular pile (2W=L) will be constructed? Assume a 0.23 m/bag height and 10bags-per-m3 stacking density. Given: Capacity Height Bag ht. Ρ

- 100,000 bags - 20 ft - 0.23 m/bag - 10 bags/m3

Required:

Floor area

Solution: Volume = 100,000 bags / 10 bags per m3 = 10,000 m3 Floor Area = 10,000 m3 / 6 m = 1,667 m2 2W x W = 1,667 m2 W2 = 1,667 m2/2 W = 28.8 m L = 57.6 m No. of Layers = 6 m / 0.23 m per bag = 26 bags

Rice Milling 1. The hydrothermal treatment of paddy before milling is called ___. a. parboiling b. drying c. water treatment d. None of the above 2. A machine that converts paddy to milled rice. a. Paddy husker b. Rice whitener c. Rice mill d. All of the above 3. A kind of rice mill that employs only one whitening machine. a. “Kiskisan” rice mill b. Single-pass rice mill c. Rubber roll rice mill d. None of the above 4. A multi-pass rice mill is characterized by ___. a. having two or three separate hullers in the system b. having a series of two or three whitening machines c. having the paddy loaded in the rice mill several times d. None of the above 5. The ratio of the weight of milled rice to the weight of paddy multiplied by one hundred. a. Percentage head rice recovery b. Percentage milling recovery c. Percentage milling capacity d. None of the above 6. The maximum percentage of milling recovery from rice mills. a. 69% b. 75% c. 80% d. None of the above

7. If five tons of paddy is milled in 6 hours produces 3950 kg of brown rice and 3250 kg of milled rice, what is the milling recovery? a. 60% b. 65% c. 70% d. None of the above 8. Referring to Item 7 above, what is the hulling coefficient of the huller? a. 0.79 b. 0.89 c. 0.99 d. None of the above 9. If the head rice recovery of paddy in Item 7 is equal to 85%, what is the amount of broken grains? a. 487.50 kg b. 478.50 kg c. 475.85 kg d. None of the above 10. Referring to Item 7, what is the amount of rice hull produced during milling? a. 1000 kg b. 1050 kg c. 1100 kg d. None of the above 11. Broken rice is a quality deterioration index during ___. a. drying b. threshing c. milling d. None of the above 12. A fraction of grain with its length equal to or greater than an average of three-fourths. a. Large broken grain b. Small broken grain c. Head grain d. None of the above

Rice Milling 13. A rice processing plant operates at 5 tons per hour. The milling and head rice recoveries of the rice mill are 69% and 95%, respectively. What is its input capacity? a. 7.24 tons per hour b. 3.45 tons per hour c. 4.75 tons per hour d. None of the above 14. Referring to Item 13, what is the throughput rate of the rice mill in kg broken grains per hour? a. 0.172 ton per hour b. 0.250 ton per hour c. 0.350 ton per hour d. None of the above 15. If a rice huller has 0.90 hulling coefficient and 0.80 wholeness coefficient, what is the output per hour of the rice huller in Item 13 in kg of brown rice? a. 6.52 tons per hour b. 4.50 tons per hour c. 4.00 tons per hour d. None of the above 16. An example of a rice huller. a. Steel-fluted huller b. Rubber-roll c. Disk d. Centrifugal e. All of the above 17. A rice mill huller that has high milling recovery. a. Steel huller b. Rubber huller c. Stone disk d. All of the above

18. The measure of the machine’s ability to remove hulls with minimum breakage. a. Coefficient of hulling b. Coefficient of breakage c. Coefficient of wholeness d. All of the above 19. A dehulled paddy but with bran layer remaining intact. a. Rough rice b. Milled rice c. Brown rice d. All of the above 20. If the end-product in milling is brown rice, the grain has just passed through a ___. a. paddy cleaner b. rubber roll huller c. whitener d. sifter e. None of the above 21. The minimum hulling efficiency requirement for rice mill based on standard performance criterion. a. 90% b. 80% c. 70% d. None of the above 22. The recommended peripheral speed of a rubber roller for hulling operation. a. 10 m/s b. 14 m/s c. 18 m/s d. None of the above 23. The percentage speed difference between rubber rollers. a. 15% b. 20% c. 25% d. None of the above

Rice Milling 24. The speed of the fixed rubber roll in a rubber roll huller is slower by ___ compared to that of the adjustable roller. a. 20 % b. 25 % c. 30 % d. None of the above 25. The husking ratio of a rubber roll huller is about ___. a. 60-70 % b. 80-90 % c. 95-98 % d. None of the above 26. If the rubber roll huller wears out, the peripheral speed of the roller will ___. a. decrease b. increase c. be the same d. None of the above 27. In a disk huller, the stationary disk is located at the ___. a. top of the huller b. bottom of the huller c. side of the huller d. None of the above 28. The manufacturers’ prescribed peripheral velocity for a disk huller is ___. a. 10 m/s b. 14 m/s c. 18 m/s d. None of the above 29. The manufacturers’ recommended speed for a horizontal abrasive whitener is ___. a. 800 rpm b. 1000 rpm c. 1200 rpm d. All of the above

30. A machine used to remove the bran from brown rice. a. Polisher b. Husker c. Whitener d. All of the above 31. The extent by which the bran layer of the brown rice is removed as a result of whitening. a. Milling degree b. Degree of whitening c. Milling recovery d. All of the above

32. A type of whitener consisting of a flutted-roller rotating inside a hexagonal chamber with slot-type perforations. a. Abrasive-type whitener b. Frictional-type whitener c. All of the above d. None of the above 33. The manufacturers’ recommended speed for the rotating cone in a vertical abrasive whitening cone must not exceed ___. a. 13 m/s b. 14 m/s c. 15 m/s d. None of the above 34. The recommended clearance for a disk huller in order to achieve high brown rice recovery with less breakage. a. ¼ of the length of the paddy grain b. ½ of the thickness of the paddy grain c. ¾ of the length of the paddy grain d. None of the above

Rice Milling 35. The adjustment clearance for rubber brakes in a vertical abrasive whitening cone is ___. a. 1 to 2 mm from cone coating b. 2 to 3 mm from cone coating c. 3 to 4 mm from cone coating d. None of the above 36. The auxillary device in a rice mill that receives the fine bran particles from milled rice and gives a glossy appearance to the product. a. Whitener b. Grader c. Polisher d. All of the above 37. A machine that smoothens the surfaces of milled rice after removing the bran making it shiny. a. Whitener b. Polisher c. Sifter d. Grader e. All of the above 38. A machine used to segregate various fractions/sizes of milled rice. a. Whitener b. Grader c. Whitener d. None of the above 39. The process of compressing mash feeds with the use of live steam to produce small chunks or cylindrical feeds. a. Mixing b. Crumbling c. Pelleting d. All of the above

40. The process of grinding pellets into coarse granular form. a. Coarse pelleting b. Crumbling c. Milling d. None of the above 41. Grinding feeds will basically ___. a. make the feed attractive to the animals b. improve its digestability c. prolong its storage period d. None of the above 42. A machine that separates paddy from brown rice. a. Screen sifter b. Paddy separator c. Paddy husker d. Rice whitener e. None of the above 43. The capacity of a compartment- type separator is ___. a. 20-30 kg. brown rice per hour b. 40-60 kg. brown rice per hour c. 70-80 kg. brown rice per hour d. None of the above 44. A one-ton-per-hour rice mill is to be designed. The milling recovery is 68% while the hulling efficiency is 90%. What size of paddy separator will you recommend? a. 26 compartments b. 32 compartments c. 40 compartments d. None of the above

Rice Milling

Hulling Coefficient Ch = Wbr / Wp where: Ch – hulling coefficient, decimal Wbr – weight of brown rice, grams Wp – weight of paddy, grams Hulling Efficiency h = Ch Cw where: h – hulling efficiency, decimal Ch – hulling coefficient, decimal Cw – wholeness coefficient, decimal Percentage Broken Milled Rice %BR = (Wbr / Wmr) 100 where: %BR – percentage broken rice, % Wbr – weight of broken rice, kg Wmr – weight of milled rice, kg Percentage Brewer’s Rice %BrR = (Wbrr / Wmr ) 100 where: %BrR – percentage brewer’s rice, % Wbrr – weight of brewer’s rice, kg Wmr – weight of milled rice, kg Milling Recovery % MR = ( Wmr / Wp ) 100 where: % MR – milling recovery, % Wmr – weight of milled rice, % Wp – weight of paddy, kg

Wholeness Coefficient Cw = Wwbr / Wbr where: Cw – wholeness coefficient, decimal Wwbr – weight of whole brown rice, grams Wbr – weight of brown rice, grams Percentage Brown Rice Recovery % BRR = (Wbrr / Wp ) x 100 where: %BRR – percentage brown rice recovery, % Wbrr – weight of brown rice, kg Wp – weight of paddy, kg Throughput Capacity Ct = 0.2 Wp / To : brown rice Ct = [Wp MR]/To: milled rice where: Ct - throughput capacity, kg/hr Wp - weigh t paddy input, kg To - operating time, hr MR – milling recovery, decimal 0.60 to 0.69 Head Rice Recovery %HR = (Whr / Wmr ) 100 where: %HR – head rice recovery, % Whr – weight of head rice, kg Wmr – weight of milled rice Speed of Low Speed Rubber Roller Ns = Nh - [0.25 / Nh] where: Ns - speed of slower rubber roller, rpm Nh - speed of faster rubber roller, rpm

Rice Milling Number of Compartments for Paddy Separator NC = Cb / 40 : long grain NC = Cb / 60 : short grain where: NC - number of compartments Cb - throughput capacity, kg brown rice per hour

Number of Brake for Vertical Abrasive Whitener NB = [D / 100] : Germany NB = [D / 100] : Italy where: NB – number of brakes, units D - cone diameter, mm

Rice Milling Problem 1 A single-pass rice mill was tested for 30 min. and gave the following results: input paddy, 1000 kg; milled rice produced, 650 kg; broken rice produced, 150 kg; and weight of head rice, 200 kg. Compute the following: (a) Throughput capacity, (b) % Milling recovery, (c) % Broken grains, and (d) % Head rice recovery. Given: Wp Wmr Whr Wbr Time Required:

-

1000 kg 650 kg 200 kg 150 kg 30 min.

Throughput capacity % Milling recovery % Broken grains % Head rice recovery

Solution: Throughput Capacity = Wp x MR / To = 1000 kg x 0.65 / 30 min/60 min/hr = 1300 kg milled rice per hr % Milling recovery = Wmr 100 / Wp = 650 kg x 100 / 1000 kg = 65% % Broken rice = Wbr 100 / Wmr = 150 kg x 100 / 650 kg = 23% % Head rice recovery = Whr 100/Wmr = 200 kg x 100 / 650 kg = 31%

Rice Milling Problem 2 Five tons of paddy milled in 6 hours produces 3950 kg of brown rice and 3250 kg of milled rice. What is the milling recovery? Given: Wt of paddy Milling time Wt of brown rice Wt of milled rice

Required:

-

5 tons 6 hors 3950 kg 3250 kg

Milling Recovery

Solution: MR = Wt milled rice x 100 / wt of paddy = 3250 kg x 100 / 5000 kg = 0.65 x 100 = 65%

Problem 3 What is the hulling coefficient of the huller in Problem 2? Given: Weight of brown rice Weight of paddy Required:

- 3950 kg - 5000 kg

Hulling Coefficient

Solution: Coef. of hulling = Wt of brown rice/Wt of paddy = 3950 kg / 5000 kg = 0.79

Rice Milling Problem 4 If the head rice recovery of the paddy in Problem 2 is equal to 85%, what is the amount of broken grains? Given: Head rice recovery Required:

- 85%

Weight of milled rice

Solution: Wt. of broken grains = Wt mr (100 – HRR) = 3250 (100 – 0.85) = 487.5 kg

Problem 5 Referring to Problem 2, what is the amount of rice hull produced during milling? Given: Wt. of paddy - 5000 kg Required:

Weight of rice hull

Solution:

Wt. of RH = Wt. of paddy x 20% = 5000 kg x 0.20 = 1000 kg

Rice Milling Problem 6 A disk huller with 600-mm diameter will be installed as return huller for a rice milling plant. As an Agricultural Engineer, determine the diameter of the pulley required for the huller. The motor for the huller will have 4-inches pulley diameter and is expected to run at 1740 rpm. Given: Diameter of huller Motor pulley Motor speed Required:

- 600 mm - 4 in. - 1740 rpm

Huller pulley diameter

Solution: Huller rpm = (14 m/s ) (60 s/min) /[ 3.14 (0.6 m)] = 445.8 rpm Huller Pulley D = 4 in (1740 rpm) / 445.8 rpm = 15.6 in. use 16 in. Problem 7 A rice milling plant is to be designed to run at 5tons-per-hour throughput rate. The design milling recovery is 69% while the hulling efficiency is 95%. How many compartments are needed for the paddy separator of the rice mill? Assume a 50-kg br/hr-comp. Given: Throughput capacity Milling recovery Hulling efficiency Required:

- 5 tph - 69% - 95%

No. of compartments

Solution: C p = 5 tph / 0.69 = 7.25 tph of paddy C br = 7.25 tph x 0.95 = 6.9 tph brown rice No. of compartments = 6.9 tph x 1000 kg/ton x 1 comp/50 kg-hr = 138 compartments

Rice Milling Problem 8 A rubber roll husker was tested to determine its performance. The husker ran for 2 hours at a rate of 1000 kg of input paddy. The weight of brown rice obtained after passing the husker was 805 kg. The weight of whole brown rice obtain per kg of sample was 900 grams. What is the hulling coefficient, wholeness coefficient, and hulling efficiency of the huller? What is the throughput capacity of the husker, in kilogram per hour of brown rice? Given: Weight of paddy - 1000 kg Operating time - 2 hours Weight of brown rice - 805 kg Weight of whole brown rice - 900 g per kg of brown rice Required: Hulling coefficient, wholeness coefficient, husking efficiency, and throughput rate Solution: Hulling coefficient = 805 kg/1000 kg = 0.805 Wholeness coefficient = (900 g brown rice x 1kg/1000 g) x 805 kg brown rice / 805 kg brown rice = 0.9 Hulling efficiency = (0.805 x 0.90) x 100 = 72.45% Throughput capacity = 805 kg / 2 hours = 402.5 kg/hr

Corn Milling 1. The process of reducing corn kernel into grits, germ, and pericarp with or without conditioning. a. Dry milling b. Hammer milling c. Attrition milling d. None of the above

7. The minimum main product recovery requirement based on the performance criteria for corn mill. a. 44% b. 54% c. 64 % d. None of the above

2. The major component of a corn mill that reduces corn kernels into grits. a. Burr mill b. Hammer mill c. Steel roller mill d. All of the above

8. The minimum by-product recovery requirement based on the performance criteria for corn mills. a. 21 % b. 31% c. 41% d. None of the above

3. The milled corn kernel where the outer covering and germs have been removed and with particle size of not less than 0.86 mm. a. Broken corn kernel b. Cracked corn kernel c. Corn grits d. None of the above 4. a. b. c. d. e.

The main product in milling corn. Corn grit # 10 Corn grit # 12 Corn grit # 14 Corn grit # 16 All of the above

5. The ratio of the weight of corn kernel input to the total operating time. a. Input capacity b. Output capacity c. Milling capacity d. All of the above 6. The ratio of the weight of corn grits to the total weight of corn kernel input expressed in percent. a. % input capacity b. % main product recovery c. % milling recovery d. All of the above

9. The machine used to remove germs and pericarp from the corn kernel. a. Conditioner b. De-germinator c. Corn mill d. None of the above 10. A kind of shelled corn kernels in which the germ and pericarp have been removed. a. Milled corn kernel b. Degerminated corn kernel c. Polished corn kernel d. None of the above 11. The process of rewetting dried corn kernels to about 18 to 22% moisture content and tempering them to make the pericarp and the germ become more pliable and easier to remove during degermination process. a. Wet milling b. Degermination process c. Conditioning d. None of the above

Corn Milling 12. The starch component of corn kernel. a. 11-23% b. 4-8% c. 2-4% d. 61-68% e. 2-16% f. None of the above

17. The process of softening and conditioning corn kernels for subsequent milling and for preventing germination and fermentation. a. Cleaning b. Steeping c. Grinding d. None of the above

13. The fiber component of corn kernel. a. 11-23% b. 4-8% c. 2-4% d. 61-68% e. 2-16% f. None of the above

18. In steeping process, corn kernel is soaked in water at a controlled temperature of ___ for 30 to 50 hours. a. 35C b. 48C c. 64C d. None of the above

14. The protein/gluten component of corn kernel. a. 11-23% b. 4-8% c. 2-4% d. 61-68% e. 2-16% f. None of the above

19. The process of milling corn kernels by soaking them first in chemicals before subjecting them to a size- reduction equipment and other successive processes. a. Dry milling process b. Wet milling process c. Wet and dry milling process d. None of the above

15. The oil component of corn kernel. a. 11-23% b. 4-8% c. 2-4% d. 61-68% e. 2-16% f. None of the above 16. The shrinkage component of corn kernel. a. 11-23% b. 4-8% c. 2-4% d. 61-67% e. 2-16% f. None of the above

20. A chemical added to prevent bacterial growth and to reduce the bond between the gluten and starch in corn kernels during steeping process. a. Sulphur dioxide (SO2) b. Sodium chloride (NaCl) c. Sodium hydroxide (NaOH) d. None of the above 21. The process of milling corn kernels by subjecting them into size-reduction processes after cleaning. a. Dry milling process b. Wet milling process c. Wet and dry milling process d. None of the above

Corn Milling 22. The major product(s) produced during corn wet-milling process. a. Condensed Corn Fermented Extractive b. Corn Germ Meal c. Corn Gluten Feed d. Corn gluten Meal f. All of the above

23. The corn step liquor which is a highenergy liquid feed ingredient with protein value of 25% on a 50% solid basis and also a source of B-vitamins and mineral when used as pellet fiber. a. Condensed Corn Fermented Extractive b. Corn Germ Meal c. Corn Gluten Feed d. Corn gluten Meal f. All of the above 24. The product of corn wet-milling process that consists of 20% protein, 2% fat and 9.5% fiber and contains amino acid balance that makes it valuable in poultry and swine rations, also used as carrier of liquid feed nutrients. a. Condensed Corn Fermented Extractive b. Corn Germ Meal c. Corn Gluten Feed d. Corn gluten Meal f. All of the above 25. A medium protein ingredient composed of bran and fibrous portions which is widely used in complete feeds for dairy and beef cattle, poultry, swine, and pet foods. a. Condensed Corn Fermented Extractive b. Corn Germ Meal c. Corn Gluten Feed d. Corn gluten Meal f. All of the above

26. The product of corn wet-milling process that has high protein concentrate typically supplied at 60% protein, 2.5% fat, and 1% fiber and is considered an excellent cattle feed. a. Condensed Corn Fermented Extractive b. Corn Germ Meal c. Corn Gluten Feed d. Corn gluten Meal f. All of the above

Coconut Flour Processing 1. A screened food-grade product obtained after drying, expelling and/or extracting most of the oil or milk from sound coconut meat. a. Copra b. Virgin coconut oil c. Coconut flour d. All of the above

2. A natural oil obtained from fresh mature kernel of the coconut by mechanical extraction. a. Coconut oil b. Virgin coconut oil c. Copra d. All of the above 3. A coconut flour prepared from unpared dehydrated and edible coconut kernel by pre-pressing and solvent extraction. a. Whole full fat coconut flour b. Defatted coconut flour c. Paring Flour f. All of the above 4. The coconut flour prepared from the paring or the testa of the coconut. a. Whole full fat coconut flour b. Defatted coconut flour c. Paring Flour f. All of the above 5. The coconut flour obtained from food-grade copra meal. a. Whole full fat coconut flour b. Defatted coconut flour c. Paring Flour f. All of the above

6. The coconut meat obtained after extracting oil for granulated copra. a. Copra b. Copra meal c. Copra meat d. None of the above 7. The process of drying of grinded coconut meat, oil extraction and pulverizing the meal. a. Dry process b. Wet process c. Wet and dry process d. None of the above. 8. The process wherein the meat is extracted with milk, drying of residue and grinding to produce flour. a. Dry process b. Wet process c. Wet and dry process d. None of the above 9. Virgin coconut oil can be obtained in ___ process. a. dry process b. wet process c. wet and dry processes d. none of the above 10. The advantage of dry process over wet process is that it gives ___ oil recovery and 0.1% free fatty acid. a. low b. medium c. high d. All of the above

Coconut Flour Processing 11. In virgin coconut-oil processing, the coconut milk and oil will separate and a layer of curd will appear at the top of the jar for at least ___ hour. a. 12 b. 24 c. 36 d. All of the above

12. Which of the following products is not a by-product of coconut processing? a. Virgin coconut oil b. Desiccated coconut powder c. Coconut vinegar d. Nata de coco e. None of the above 13. A cellulosic white cream yellow substance formed by the bacteria Xylinium on the surface of sugarenriched coconut water. a. Cocosugar b. Virgin coconut oil c. Nata de coco f. All of the above 14. A by-product of drying finely particles of homogenized coconut milk mixed with maltodextrins and other emulsifiers. a. Desiccated coconut powder b. Spray dried coconut milk powder c. Heated air dried coconut powder d. All of the above

Sugar Processing 1. In sugarcane processing, water at 43 to 48C is applied into the sugarcane tables to ___ it before milling. a. cool and soften b. wash and remove dirt from c. increase the moisture content of d. All of the above 2. Machines used in braking and removing fibers from the steam cells of the sugarcane. a. Chippers b. Oscillating mincers c. Fiber removers d. All of the above 3. Sugarcane passes through a series of v-stripped roller mills to ___. a. soften the cane before subjected for extraction process b. extract juices c. chop it into pieces before extracting the juice d. All of the above 4. The by-product from sugarcane juice extraction and is usually used as fuel for the boiler of the sugar mill. a. Molasses b. Bagasse c. Filter cake d. All of the above 5. In sugarcane processing, clarifiers are used primarily to ___. a. reduce odor of sugarcane juice b. separate out suspended particles in sugarcane juice c. ensure that white sugar can be produce during the process d. None of the above

6. The process of separating sugarcane juice from the water vapor by heating in a vacuum container to produce raw and white sugar. a. Extraction b. Evaporation c. Crystallization d. All of the above e. None of the above 7. Sugar crystals formed after evaporation are separated from sugar honey using a ___, which rotates at a very high speed. a. rotary dryer b. centrifuge c. extractor d. None of the above

8. After separating sugar crystals from sugar honey, which of the following needs to undergo drying and cooling processes? a. Sugar crystal b. Sugar honey c. Sugar crystal and honey d. None of the above 9. Materials used for further refinement of white or raw sugar. a. Activated charcoal and diatomaceous earth b. Bleaching solution, such as chlorine c. Solution of caustic soda d. All of the above 10. The moisture content requirement for raw sugar before storage and packaging. a. 20.% b. 2.0% c. 0.2% d. None of the above

Sugar Processing 11. The storage moisture content requirement for white sugar. a. 3.0% b. 0.3% c. 0.03% d. None of the above 12. White and refined white sugars are packed in standard sizes which is ___, respectively. a. 50 and 46 kg b. 60 and 40 kg c. 60 and 50 kg d. All of the above 13. Sticking together of two or more crystals during centrifuging and drying operations. a. Crystallization b. Agglomeration c. Coagulation d. All of the above 14. The residue derived from cane milling after extraction of juice. a. Molasses b. Bagasse c. Filter cake d. All of the above 15. The apparatus used for the separation of suspended-solid sediments from turbid-sugar solutions. a. Centrifuge b. Clarifier c. Extractor d. None of the above 16. The material retained on the filter screen and is discharged from the filters after filtering clarifier muds. a. Filter Scum b. Filter Sediments c. Filter cake d. None of the above

17. The mother liquor separated from crystals by centrifuging. a. Sugar honey b. Molasses c. Syrup d. All of the above e. None of the above 18. The brown sugar produced from a sugar mill generally destined for further processing to white sugar in a refinery. a. Molasses b. Raw sugar c. White sugar d. None of the above 19. The concentrated juice from the evaporator. a. Molasses b. Syrup c. Extracted juice d. None of the above 20. Insoluble solids in juice or in other liquids which can only be removed by mechanical means. a. Suspended solids b. Sugar crystals c. Bagasse d. All of the above 21. The treatment of raw sugar to remove the film of adhering molasses. a. Clarification b. Extraction c. Affination d. None of the above 22. The by-product of sugarcane processing. a. Bagasse b. Molasses c. Filter cake d. All of the above

Sugar Processing 23. The fine fraction of bagasse obtained by screening or by pneumatic separation generally used as a filter aid in filtration. a. Mud press b. Bagacillo c. Trash d. None of the above 24. The term that refers to cane tops, leaves, dead stalks of cane, and any other vegetable matters delivered with the cane. a. Mud press b. Bagacillo c. Trash d. All of the above 25. The measure of dissolved solids in sugar liquor or syrup using refractometer also known as the percentage sugar by mass. a. Glycemic index b. Brix c. Brix index d. All of the above 26. The process involving introduction of carbon dioxide gas into limed juice or syrup to remove color and non-sugar solids. a. Color extraction b. Carbonization c. Extraction d. All of the above 27. The type of molasses used primarily as animal feed and is also used to produce ethanol, compressed yeast, citric acid, and rum. a. Edible molasses b. Blackstrap molasses c. Organic molasses d. None of the above

28. The type of molasses used as food syrup and blended with other syrups. a. Edible molasses b. Blackstrap molasses c. Organic molasses d. None of the above

29. The process of heating the juice and adding lime after passing the milling rollers to form coagulants from impurities and then allowed to settle in a large tank. a. Filtration b. Clarification c. Extraction d. None of the above 30. The process of separation of sugar crystals from dark syrup after crystalizing with the use of a high-speed rotating cylindrical basket. a. Fugalling b. Filtering c. Clarifying d. All of the above 31. The process after clarification of sugar juices before subjecting them to evaporation. a. Coagulation b. Extraction c. Filtration d. None of the above 32. Coconut sugar contains ___ sucrose than sugarcane. a. the same amount of b. lesser amount of c. more amount of d. None of the above

Sugar Processing 33. Coconut sugar contains ___ of macro and micro nutrients than sugar cane. a. the same amount b. more amount c. less amount d. None of the above

39. An instrument used to reduce the relative humidity of air in coconut sugar storage. a. Pyschrometer b. Dehumidifier c. Hydrometer d. None of the above

34. The collection time requirement for harvesting coconut sap for coco sugar processing. a. 4 to 5 hours b. 6 to 9 hours c. 10 to 14 hours d. None of the above

40. An instrument used to measure the sugar level of coconut sap. a. Refractometer b. pH meter c. Glycimeter d. All of the above

35. The cooking temperature for coconut sap for sugar processing. a. 80C b. 90C c. 100C d. All of the above

41. The dark-brown color of coconut sugar is basically the result of drying sugar crystals at ___ temperature. a. low b. medium c. high d. None of the above

36. Coconut sap brix requirement for coconut sugar. a. 9.1 to 10.5 b. 11.0 to 12.9 c. 13.0 to 14.5 d. All of the above 37. The recommended temperature for drying coconut sugar. a. 40 to 50C b. 51 to 60C c. 65 to 70C d. None of the above 38. The recommended relative humidity in drying coconut sugar. a. 80 to 95 % b. 50 to 75 % c. 35 to 45 % d. None of the above

Food Process Engineering 1. The prevention or protection of products against spoilage. a. Preservation b. Drying c. Dehydration d. None of the above 2. The process of preservation by means of heating the product at a temperature below 100°C to kill pathogenic bacteria. a. Drying b. Dehydration c. Pasteurization d. All of the above 3. The process of preserving food materials in a hermetically-sealed container which has been sterilized using heat. a. Drying b. Canning c. Steaming d. None of the above 4. The process of subjecting food products to a temperature of about 65°C for 30 min causing the death of many, but not all, of the organisms present. a. Dehydration b. Sterilization c. Pasteurization d. None of the above 5. The process of removing solid particles from a liquid such as wine, fruit juices, vinegar, and vegetable oil. a. Screening b. Filtration c. Leaching d. None of the above

6. The process of segregating alcohol, sugar, and some soluble materials with the use of water. a. Leaching b. Hydrolysis c. Water adsorption d. None of the above 7. An equipment either in the form of sheets, rods, or other shapes used in food industry for feeding solid/liquid mixture into a screw press or wringers. a. Extruder b. Screw press c. Screw feeder d. All of the above 8. The machine used for mixing solids and liquids at a ratio that forms a very viscous mixture, like pastes and doughs. a. Kneader b. Roller c. Mixer d. None of the above 9. The termination of the entire organisms in the product using heat at a temperature of about 50° to 100°C. a. Pasteurization b. Heat sterilization c. Dehydration d. None of the above 10. The process applied in the manufacture of chocolates and other similar products producing a very marked effect on the product’s appearance and flavor through the elimination of moisture, harshness, and acidity. a. Conching b. Roasting c. Frying d. None of the above

Food Process Engineering 11. The process of heating the product to nearly boiling point achieving stability of the food product against spoilage due to microorganism. a. Cooking b. Sterilization c. Pasteurization d. None of the above 12. The process often used in heating cans and their content under vacuum condition to remove air and other entrapped gases before sealing. a. Exhausting b. Sterilizing c. Heating d. All of the above 13. A drying technology that has the ability to maintain the original appearance of the product with no shrinkage, retain shape and structure. a. Heated air drying b. Conduction drying c. Freeze drying d. All of the above 14. A type of dryer commonly used in food industry where dried materials are injected into it in an automized form to produce powdered product. a. Spray dryer b. Drum dryer c. Pneumatic dryer d. All of the above 15. The complete destruction of all forms of life in the product being processed. a. Cooking b. Sterilization c. Pasteurization d. None of the above

15. The process of pumping the product against a steel plate through a very small opening of 0.0001 diameter at a pressure of about 3500 psi to reduce the size of fat globules such as those in milk, mayonnaise, and others to a point that fats have no tendency to rise. a. Homogenizing b. Conching c. Pressing d. None of the above

16. The process used in many food products by giving deaeration treatment to improve the color and flavor, to retain the aroma, and to reduce the volume of the product. a. Degassing b. Blending c. Exhausting d. All of the above 17. The process usually applied to nuts and beans of various sorts in order to bring about the desired flavor. a. Drying b. Blanching c. Roasting d. Pasteurization e. None of the above 18. Brown spots on dried vegetables are caused by ___. a. too high drying temperature used b. low drying temperature used c. optimum drying temperature used d. None of the above 19. An indicator of food quality which determines its acceptability to the consumers. a. Taste b. Flavor c. Palatability d. None of the above

Food Process Engineering 20. The process used in canning in which there is a rigid regulation on the cooking temperature in such a manner that packages are not misshapen or broken by too rapid cooling. a. Tempering b. Freezing c. Refrigeration d. None of the above 21. An example of Newtonian fluid with low viscosity. a. Soup b. Chocolate c. Juices d. All of the above 22. An example of Non-Newtonian fluid with high viscosity. a. Juices b. Drinks c. Mashed vegetables d. All of the above 23. The pre-drying temperature requirement for mushroom. a. 80-90F b. 120-125F c. 250-300F d. None of the above e. All of the above 24. The roasting temperature for pumpkin seeds, sunflower seeds, and peanuts. a. 200 - 250F b. 250 - 300F c. 300 - 350F d. None of the above 25. The recommended temperature for drying vegetables. a. 125F b. 150F c. 175F d. 200F e. All of the above

26. A pretreatment method used for vegetables to destroy enzymes that can cause undesirable changes in color and flavor during drying and storage. a. Cleaning b. Blanching c. Drying d. None of the above 27. A pretreatment method for fruits and vegetables to retard spoilage and darkening of skins. a. Blanching b. Sulfuring c. Sterilizing d. All of the above 28. Pretreatment of fruits and vegetables are recommended to ___. a. stop enzymatic activity which results in color, flavor, and nutrient losses or changes b. stop ripening and spoilage c. hasten drying rate and improve storability of the product d. None of the above 29. The formation of a “case” like a leathery material outside of a very highsugar food, such as fruit, which doesn’t allow water to pass through during drying is a factor of ___. a. slow drying b. rapid drying c. normal drying d. None of the above 30. The requirement(s) for a good dehydrator: a. Some forms of temperature control. b. A fan to circulate air and remove moisture. c. Easy to remove and wash trays. d. All of the above

Food Process Engineering 31. Sulfured foods are recommended for storage using ___. a. metal can container b. plastic container c. bottle with can cover container d. All of the above 32. Conditioning dried fruits after drying is basically done to ___. a. allow the moisture to equalize throughout the entire fruit so that there will be no damp spots where molds may grow b. increase the quality of dried fruit prior to packaging c. improve the color and taste of the fruit d. none of the above 33. Sulfur treatment on fruits and vegetables can be replaced by ___. a. sulfite dips b. steam blanching c. water blanching d. All of the above e. None of the above 34. An example of chemicals used as sulfite dip. a. Sodium bisulfite b. Sodium sulfite c. Sodium metabisulfite d. None of the above e. All of the above 35. The use of rotating or exchanging trays in a dehydrator is recommended when drying fruits and vegetables ___. a. to reduce drying time b. to increase the efficiency of the dryer c. to promote even drying of product d. None of the above

36. Another term used for citric acid. a. Table salt b. Lemon salt c. Acid salt d. All of the above 37. These are fruit rolls characterized by tasty chewy dried fruit made by pouring pursed fruit into a flat surface for drying. a. Fruit rolls b. Dried fruit c. Fruit leathers d. All of the above 38. Which of the following statements is true? a. Different foods requiring similar drying times and temperature can be dried together. b. Vegetables with strong odor or flavor should be dried separately. c. Don’t dry strong-smelling vegetables in an electric dehydrator because dehydrators are not screened and insect may invade the food. d. All of the above e. None of the above 39. The commonly used methods for pasteurizing foods. a. Freezing and oven drying b. Steaming and Blanching c. Boiling and drying d. All of the above e. None of the above 40. The recommended storage time for dried foods. a. 2 – 4 months b. 4 – 12 months c. 12 – 24 months d. All of the above

Food Process Engineering 41. Pasteurizing is recommended for foods that had been contaminated or used as second treatment for vegetables held in storage if the vegetables do not have any mold on them ___. a. before drying b. before and during storage c. after storage d. All of the above e. None of the above

42. The drying time requirement for solid yellow or slightly brown-flecked bananas in a dehydrator. a. 4 - 8 hours b. 8 - 10 hours c. 10 - 16 hours d. All of the above 43. The process of decomposition of carbohydrates by microorganism or enzyme. a. Fermentation b. Spoilage c. Preservation d. None of the above 44. Preservation of food in brine or in vinegar, with or without bacterial fermentation. a. Pickling b. Salting c. Blanching d. None of the above 45. The process of boiling whole fruits or pieces of fruit pulp with sugar to a moderate-thick consistency, without retaining the shape of the fruit. a. Jams b. Jellies c. Marmalades d. All of the above

46. A product prepared by extracting the juice from boiled fruits, and then boiled with sugar and cooked to such consistency that gelatinize when cooled. a. Jam b. Jellies c. Marmalade d. All of the above 47. A clear jelly which contains evenly suspended slices of fruits or peel. a. Jam b. Jellies c. Marmalades d. All of the above

48. The aseptic practice in the preparation, processing and packaging of food products. a. Cleaning b. Sanitation c. Housekeeping d. None of the above 49. Substances used to preserve food by retarding deterioration, rancidity or discoloration due to oxidation. a. Additives b. Antioxidants c. Emulsifiers d. None of the above 50. Any tag, brand, mark, pictorial, or other descriptive matter written, printed, marked, embossed or impressed on, or attached to a container of food. a. Nutrition facts b. Label c. Trademark d. None of the above

Food Process Engineering

51. A pretreatment procedure to keep the color and the quality of vegetables before drying. a. Trimming b. Blanching c. Salting d. None of the above 52. Substances that modify surface tension in the component phase of an emulsion to establish a uniform dispersion. a. Additives b. Antioxidants c. Emulsifiers d. None of the above 53. Any substance, including food additive, used as a component in the manufacture or preparation of food and is present in the final product. a. Nutrient b. Microelement c. Ingredient d. None of the above

57. Chilling injury of banana occurs at a temperature ___. a. below 27C b. below 14C c. below 5C d. None of the above 58. The lowest temperature that is safe for storing banana is ___. a. 14C b. 5C c. 0C d. All of the above

59. The process of heating vegetables in steam or in boiling water to inactivate enzymes and to reduce microbial population thereby prolonging storage at subfreezing temperature. a. Dehydration b. Blanching c. Drying d. None of the above

54. The cooking temperature that destroys most bacteria in foods. a. 115°C b. 100°C c. 74°C d. None of the above

60. Factors that change during cold storage of fish due to oxidation of fish oils and pigments, particularly in more fatty fish species. a. Color and flavor b. Color and texture c. Flavor and texture d. All of the above

55. The canning temperature for fruits, tomatoes, and pickles in a water bath canner. a. 115°C b. 100°C c. 74°C d. None of the above

61. The most favorable cold storage temperature for eggs. a. 29 – 30C b. 29 – 30F c. 28F d. None of the above

56. The canning temperature for lowacid vegetables, meat and poultry in a pressure canner. a. 115°C b. 100°C c. 74°C d. None of the above

62. The freezing temperature for eggs. a. 29 – 30C b. 29 – 30F c. 28F d. None of the above

Food Process Engineering 63. A frozen product made from pasteurized mixture of sugar, solid milk, stabilizer, food acid, and flavorings such as fruits, fruit juices or extracts, and water. a. Ice cream b. Sherbet c. Frozen milk d. All of the above 64. Which of the following material is used for packaging frozen poultry products? a. Plastic b. Edible coating c. Aluminum foil d. Waxed cardboard e. All of the above

65. Changes in the flavor of meat, fish or poultry during freezing is due to the ___. a. change in temperature of the product b. microorganisms that were killed during storage c. oxidation of fats d. none of the above 66. In order to minimize darkening of carcass of poultry meat, it is recommended that before cold storage poultry meat should be ___. a. slowly be frozen and undergo scalding process b. frozen rapidly c. undergo scalding process d. None of the above 67. The term used for internal organs of poultry suitable for cold storage. a. Carcass b. Giblets c. Gills d. None of the above

68. Tenderness of poultry meat can be maintained during cold storage by ___. a. storing it in aluminum foil b. storing it in plastic net c. storing it unpacked d. All of the above 69. The process of hanging meat at a temperature between 0° to 3C to create tenderizing effect before freezing. a. Aging b. Freezing c. Tempering d. None of the above 70. Frozen poultry products are only good for a period of ___. a. 1 to 6 months b. 6 to 12 months c. 1 to 2 years d. All of the above

71. If a poultry product is stored at a temperature between 35°- 40°F, the product quality can be maintained within ___. a. 1 to 2 months b. 1 to 2 days c. 1 to 2 hours d. none of the above 72. The flesh obtained from domesticated animals. a. Carcass b. Meat c. Giblets d. None of the above 73. The meat from rabbit. a. Lapan b. Venison c. Chevon d. None of the above

Food Process Engineering 74. The meat of sheep that is less than one year old. a. Lamb b. Mutton c. Chevon d. None of the above 75. The method used in preserving meat. a. Smoking process b. Refrigeration c. Freeze drying d. Irradiation e. All of the above 76. Which of the following statements is true? a. When beef is stored at a lower temperature, it will have longer storage life than when it is stored at higher temperature. b. Storing beef at lower temperature will shorten its storage life. c. Storing beef at higher temperature will prolong its storage life. d. All of the above 77. The meat of a less-than-one year old cattle. a. Beef b. Veal c. Carabeef d. All of the above 78. Myoglobin content in meat is responsible for ___. a. odor of meat after cold storage b. appearance of meat c. color of meat d. All of the above e. Two of the above f. None of the above

79. Which of the following statements is true in cold storage of meat? a. Extreme temperature fluctuation during defrosting contributes to shorter storage life of the meat. b. Freezing meat and its subsequent frozen storage improve the quality of meat products. c. Proper handling of meat prior to freezing reduces the quality of frozen products. d. None of the above 80. The process in heating copra to facilitate the removal of oil during pressing. a. Drying b. Steaming c. Conditioning d. None of the above 81. One thousand nuts, at 800 grams per nut, will produce ___ of copra. a. 220 kg b. 320 kg c. 420 kg d. None of the above

Feed Milling 1. Any substance or product including additives, whether processed, partially processed or unprocessed, intended for oral feeding to animal. a. Food b. Feed c. Feed materials d. None of the above

6. Which of the following is not a feed ingredient? a. Corn bran b. Blood meal c. Cassava meal d. Fish mill e. Brown sugar f. None of the above

2. This refers to various products from vegetable or animal origin in their natural state, fresh or preserved, products derived from industrial processing, and organic or organic substances, whether or not containing additives, which are intended for oral animal feeding either directly as such or after processing, in the preparation of compound feeding stuff or as carriers of premixtures. a. Feed b. Feed material c. Feedstock d. None of the above

7. Which of the following is not a mineral supplement in the production of feeds? a. Calcium phosphate b. Oyster shell c. Steamed bone meal d. Limestone e. All of the above f. None of the above

3. Which of the following grain processing methods is a dry process? a. Grinding b. Pelleting c. Extruding d. Popping e. All of the above 4. Which of the following grain processing methods is a wet process? a. Soaking b. Steam flaking c. Exploding d. All of the above 5. The process of converting agricultural materials into suitable kind of feeds for animal use. a. Feed milling b. Food processing c. Feed preservation d. None of the above

8. The basic function(s) to be performed in the production of animal feeds. a. Collection of raw materials b. Modification of raw materials c. Blending and mixing of ingredients d. Delivering of compound feed produced e. All of the above f. Two of the above g. None of the above 9. The process in feed milling operation in order to obtain the desired formulation that includes such operation as weighing and volumetric dosing of feed materials. a. Milling and flaking b. Blending and mixing c. Weighing and bagging d. None of the above

Feed Milling 10. Pelleting of feeds in the feed milling plant is done after ___. a. cleaning b. grinding c. mixing d. None of the above 11. Cleaning and drying of feed material are done in the milling plant after ___. a. grinding the feed material b. pelleting the feed material c. reception of raw material d. None of the above 12. The assembling and measuring of the required qualities of raw material into batch of desired operation. a. Mixing b. Blending c. Grinding d. None of the above 13. The process of obtaining a homogenous mixture of feeds so that animal can be offered with different nutrients in the desired proportion. a. Mixing b. Blending c. Grinding d. None of the above 14. The process of making feeds into acceptable solid particles so nutrients is properly distributed. a. Mixing b. Pelleting c. Grinding d. None of the above

15. The process of preparing raw materials for mixing and making them digestible to the animals. a. Blending b. Grinding c. Pelleting d. None of the above 16. The usual storage period for mixed feed. a. 2 to 7 days b. 8 to 15 days c. 16 to 30 days d. None of the above 17. Quality control in feed milling plant is basically done ___. a. at the receiving center b. after pelleting process c. both at the receiving center and after pelleting process d. None of the above 18. The standard size of pallet for 25-kg bag feeds. a. 120 cm x 80 cm b. 120 cm x 100 cm c. 120 cm x 160 cm d. None of the above

19. The standard size of pallet for 50-kg bag feeds. a. 120 cm by 80 cm b. 120 cm by 100 cm c. 120 cm x 160 cm d. None of the above 20. The principal liquid ingredient in feed milling plant. a. Water b. Molasses c. Coconut oil d. None of the above

Feed Milling 21. In feed milling plant, gravity conveyors for dry grains require a minimum slope of ___. a. 26 degrees b. 35 degrees c. 60 degrees d. None of the above 22. In feed milling plant, gravity conveyors for meal and light ingredients require a minimum slope of _____. a. 26 degrees b. 35 degrees c. 60 degrees d. None of the above 23. The conveyor used in feed milling plants for distributing materials over silos. a. Belt conveyor b. Screw conveyor c. Chain conveyor d. None of the above 24. For the same size of a conveyor unit, chain conveyors has ___ capacity over screw conveyors. a. lower b. higher c. the same d. None of the above 25. The typical speed requirement for chain conveyor in a feed milling plant. a. 10 to 20 m/min b. 20 to 30 m/min c. 30 to 40 m/min d. None of the above 26. The most commonly used grinding equipment in feed milling plants. a. Roller mill b. Attrition mill c. Hammer mill d. None of the above

27. A mechanical feeding device that controls the flow of feeds through the amplitude of the vibration and by regulating the thickness of the layer of feed by means of a slide. a. Rotating lock feeder b. Feed rolls c. Vibratory feeder d. None of the above 28. A mechanical feeding device that controls the flow of feeds through the speed of rotation of the compartment valve . a. Rotating lock feeder b. Feed rolls c. Vibratory feeder d. None of the above 29. Homogeneity of particles during mixing can be achieved more for ___ materials. a. smaller particles b. large particles c. small and large d. None of the above 30. The more uniform is the particle size the ___ is the homogeneity. a. easier b. difficult c. harder d. None of the above 31. Segregation of feed materials and ingredients is facilitated when there is ___ variation on the specific density of materials to be mixed. a. lower b. higher c. lower and higher d. None of the above

Feed Milling 32. The approximate rpm of a batch-type feed mixer. a. 25 rpm b. 100 rpm c. 150 rpm d. None of the above 33. Vertical mixer has ___ mixing time compared with batch mixer. a. shorter b. longer c. the same d. None of the above 34. The power requirement of a vertical mixer is ___ than that of the batch-type feed mixer. a. lower b. higher c. the same with d. None of the above 35. The mixing time of vertical mixer. a. 15 to 30 min b. 30 to 60 min c. 60 to 120 min d. None of the above 36. The steam is used in feed milling plant during ___ process. a. bending b. mixing c. grinding d. pelleting e. None of the above

Refrigeration and Cold Storage 1. The process of removing heat from a substance or from a space at a lower temperature. a. Sublimation b. Heat of fusion c. Refrigeration d. All of the above 2. The heat moves from one substance to another naturally ___. a. from higher temperature to lower temperature b. at lower temperature to higher temperature c. at either temperature d. None of the above 3. The intensity of the molecular movement of matter. a. Energy b. Heat c. Work d. All of the above 4. a. b. c. d.

A substance is said to be cold if ___. heat is present heat is absent heat is higher All of the above

5. The quantity of heat in the substance is described in terms of ___. a. BTU b. calories c. pascal d. two of the above e. None of the above 6. a. b. c. d.

Ten BTU is equivalent to ___. 2520 calories 2250 calories 2045 calories None of the above

7. One-hundred calories is equivalent to ___. a. 418.7 Joules b. 481.7 Joules c. 471.8 Joules d. None of the above 8. The instrument used to measure heat is ___. a. thermometer b. watt meter c. calorimeter d. None of the above 9. The measurement of the heat level of a substance. a. Thermometer b. Temperature c. Calorimeter d. All of the above 10. Which of the following statements is true? a. The freezing point of water is 0°F. b. The boiling point of water is 212°C. c. That 32°F and 0°C is the same temperature level. d. None of the above 11. The quantity of heat required to raise the temperature of a substance one degree scale. a. Sensible heat b. Specific heat c. Latent heat d. None of the above 12. The specific heat of water is ___. a. 1 BTU/lb-°F b. 1 kcal/kg-°C c. 1 cal/g-°C d. All of the above

Refrigeration and Cold Storage 13. The amount of heat added to or removed from a substance without changing its temperature. a. Sensible heat b. Latent heat c. Specific heat d. All of the above

18. The quantity of heat required to change a unit mass of solid to gas without change in temperature. a. Latent heat of fusion b. Latent heat of vaporization c. Latent heat of sublimation d. None of the above

14. The heat added to or removed from a substance causing a change in its state but without changing its temperature. a. Sensible heat b. Latent heat c. Specific heat d. All of the above

19. The latent heat of fusion of water is ___. a. 336 kJ/kg b. 144 BTU/lb c. All of the above d. None of the above

15. The quantity of heat required to change a unit mass of a liquid into gaseous state without change in temperature. a. Latent heat of vaporization b. Latent heat of fusion c. Latent heat condensation d. None of the above 16. The quantity of heat required to change a unit mass of solid to liquid state without change in temperature. a. Latent heat of vaporization b. Latent heat of fusion c. Latent heat of sublimation d. All of the above 17. The quantity of heat required to change a unit mass of gas to liquid state without change in temperature. a. Latent heat of vaporization b. Latent heat of condensation c. Latent heat of fusion d. All of the above

20. At higher elevation, ___. a. water will boil at 100C b. water will boil above 100C c. water will boil below 100C d. water will not boil e. None of the above 21. The amount of heat transmitted to a wall is a factor of ___. a. wall thickness b. temperature difference c. resistance of heat flow of the wall materials d. all of the above 22. A material with high emissivity ___. a. will collect more heat b. will not collect heat c. will transmit heat d. None of the above 23. The basic use of insulating materials for a refrigeration system is ___. a. to retard heat flow b. to prevent surface condensation c. to control noise and vibration d. All of the above

Refrigeration and Cold Storage 24. Which of the following insulating materials for a refrigeration system is efficient and less expensive? a. Asbestos b. Styrofoam c. Aluminum foil d. All of the above

30. One ton refrigeration is the amount of heat required to melt one ton of ice in ___. a. 12 hours b. 24 minutes c. one day d. None of the above

25. The cooling coil of a refrigeration system. a. Condenser b. Evaporator c. Compressor d. None of the above

31. One ton refrigeration is equal to ___. a. 288,000 BTU/day b. 12,000 BTU/hr c. 200 BTU/min d. All of the above

26. The basic part of a refrigeration system which is characterized by high pressure side. a. Condenser b. Evaporator c. Expansion valve d. All of the above

32. An example of a refrigerant. a. Ammonia b. Carbon monoxide c. Methyl bromide d. All of the above

27. The part of a refrigeration system that causes the refrigerant to circulate. a. Condenser b. Expansion valve c. Compressor d. None of the above 28. The part of a refrigeration system that causes the reduction of pressure of the refrigerant. a. Evaporator b. Compressor c. Expansion valve d. All of the above 29. A fluid that easily boils at lower temperature. a. Water b. Oil c. Refrigerant d. All of the above

33. The commonly used refrigerant in ice plants. a. Ammonia b. Carbon dioxide c. Methyl chloride d. None of the above 34. A refrigeration appliance that operates at higher temperature. a. No-frost refrigerator b. Air-conditioner c. Domestic freezer d. All of the above 35. The introduction of fresh ambient air to an air-conditioned or refrigerated space. a. Cooling b. Air changes c. Air filtration d. None of the above

Refrigeration and Cold Storage 36. The removal of accumulated ice from the surface of cooling coils that operates below freezing point. a. Dehumidification b. Defrosting c. Ice melting d. None of the above 37. A refrigeration system used to either cool or heat a given space normally by exchanging the functions of the evaporator and the condenser. a. Heat pump b. Humidifier c. Dehumidifier d. None of the above 38. The air that flows through the gaps around doors, windows and others. a. Air intake b. Air changes c. Infiltration d. None of the above 39. The difference between the dry bulb and the wet bulb temperatures. a. Wet bulb depression b. Relative humidity c. Dew point temperature d. None of the above 40. The temperature at which liquid is converted to solid state upon the removal of its latent heat of fusion. a. Cooling point b. Solid point c. Freezing point d. None of the above

41. To reduce the relative humidity of air, it is recommended to use a ___. a. humidifier b. dehumidifier c. psychrometer d. None of the above 42. In a domestic refrigerator, the condenser can be found ___. a. inside the refrigerator cabinet b. outside the refrigerator cabinet c. beneath the freezer d. None of the above 43. Freezers in a refrigerator compartment are normally found at the upper section of the cabinet for the reason that ___. a. it is easy to load a product b. it is easy to install in the cabinet c. heat will efficiently be distributed throughout the refrigerator compartment d. None of the above 44. When a product is termed as frozen, it is ___. a. chilled and stored above freezing point b. stored between –10F to 10F c. stored at 10F to 50F d. All of the above 45. Another important factors in cold storage of perishable products are: a. Energy and power requirement inside the storage room. b. Temperature and heat loss in the storage room. c. Humidity and air motion inside the storage room. d. None of the above

Refrigeration and Cold Storage 46. The use of plastic polyethylene sheet as packaging material for cold storage is ___. a. to provide heat insulating effect on the product b. to make the product attractive to the customer c. to prevent moisture loss in the product d. None of the above 47. The purpose of refrigeration in storing perishable products is ___. a. to improve the quality of the product b. to arrest or retard the natural process of deterioration c. to hasten ripening or maturity of product, such as fruits and vegetables d. All of the above 48. The process of exposing freshlyharvested product and carefullyprepared food to subzero temperatures and holding them at 32C during storage period to maintain their quality. a. Cold storage b. Quick freezing c. Sharp freezing d. All of the above 49. If vegetables are stored at a temperature between 0° to 30°C, the product is under ___. a. frozen storage b. refrigerated storage c. All of the above d. None of the above

50. An important factor that contributes in proper refrigeration of perishable crops is ___. a. constant temperature b. free air circulation c. control of relative humidity d. All of the above 51. The process of retarding moisture and oxidation loss from the product during cold storage by continuously providing a film or a coating that adheres to the product’s surface. a. Blanching b. Thawing c. Glazing d. None of the above 52. A type of freezer that operates at 30°F and below air temperature and at 500 to 100 fpm velocity. a. Sharp freezer b. Air-blast freezer c. Contact plate freezer d. All of the above 53. A type of freezer used for fish products in which the products are placed in shelves or in aluminum pans or plates covered by pipe coils or evaporators at a temperature of –20° to 29°C. a. Sharp freezer b. Air-blast freezer c. Contact plate freezer d. All of the above

Refrigeration and Cold Storage 54. The method of freezing the surface of poultry meat using mist of liquid prior to storage in an air-blast freezer or cold storage room. a. Liquid immersion freezing b. Liquid spray freezing c. Conveyor tunnel freezing d. All of the above

59. The method of freezing shrimp in an agitated cold brine solution with fixed concentration and temperature. a. Blast freezing b. Immersion freezing c. Tunnel freezing d. None of the above

55. The freezing point of milk. a. -0.545°C b. -0.545°F c. 0. 545°C d. None of the above

60. At –18C, scallop meat has a frozen storage life of ___. a. 1 - 2 months b. 3 - 6 months c. 7 - 12 months d. None of the above

56. Freezer-burn in meat products is a result of ___. a. storing meat products in a freezer with plastic sheet to prevent moisture loss b. storing meat products without plastic sheet at high relative humidity b. storing meat products without plastic sheet at low relative humidity d. None of the above

61. ASHRAE is the acronym for ___. a. Association of Heat, Refrigeration, and Air Conditioning Engineers b. American Society of Heating, Refrigerating, and Air Conditioning Engineers c. Association of Sensible Heating, Refrigeration, and Air Cooling Engineers d. None of the above

57. The recommended time for storing beef cuts at –18C is ___. a. 6 to 12 months b. 3 to 4 months c. 1 to 2 months d. None of the above

62. An equipment used to clean, cool, heat, humidify, or dehumidify air. a. Air heat exchanger b. Air conditioner c. Air-cooled condenser d. All of the above

58. Ground beef can be safely stored at –18C within a period of ___. a. 6 to 12 months b. 3 to 4 months c. 1 to 2 months d. None of the above

63. The process of removing moisture from the air. a. Dehydration b. Air suction c. Dehumidify d. All of the above

Refrigeration and Cold Storage 64. The most popular refrigerant used for a refrigeration system. a. R-12 (Dichlorodifluoromethane) b. R-22(Monochlorodiflouromethane) c. R-502 d. All of the above 65. The most popular refrigerant for air-conditioning. a. R-12 (Dichlordifluoromethane) b. R-22 (Monochlorodiflouromethane) c. R-502 (mixture of R-22 and R115) d. All of the above 66. The popular refrigerant for lowtemperature refrigeration systems. a. R-12 (Dichlordifluoromethane) b. R-22 (Monochlorodiflouromethane) c. R-502 (mixture of R-22 and R115) d. All of the above 67. The process in which the air is cooled, cleaned and circulated. a. Air conditioner b. Air conditioning c. Air cooling and cleaning d. All of the above 68. An air-conditioning system in which the condenser is located separately from the evaporator and uses interconnecting refrigerant lines. a. Split-system air conditioning system b. Package- equipment air conditioning system c. All of the above d. None of the above 69. The cooling equipment of an air conditioner. a. Condenser b. Evaporator c. Compressor d. Expansion valve e. None of the above

70. The condenser efficiency of an air conditioner can be increased by ___. a. reducing the condenser surface area b. increasing the condenser surface area c. increasing the amount of refrigerant flowing in the condenser d. None of the above 71. The operating temperature of an evaporator in an air-conditioning system. a. 20F b. 40F c. 60F d. All of the above 72. Refrigerated air-conditioning is used in ___. a. hot temperature with high humidity b. hot temperature with low humidity c. hot temperature with either high or low humidity d. None of the above 73. Which of the following statements is true? a. The motor and the compressor of a refrigeration system is separately installed. b. The motor and the compressor of a refrigeration system are housed in the same compartment. c. The compressor and the motor of a refrigeration system is non-hermetic type. d. None of the above 74. A refrigerated system that cleans, dehydrates and cools a compartment. a. No frost refrigerator b. Chiller c. Freezer d. Air conditioner e. None of the above

Refrigeration and Cold Storage 75. The highest pressure in the refrigeration system is found at ___. a. the capillary tube b. the entrance of the evaporator coil c. the entrance of the condenser tube d. the evaporator coil, immediately before the compressor e. None of the above 76. The component of a refrigeration system positioned next to the condenser. a. Capillary tube b. Filter c. Compressor d. None of the above 77. The component of a refrigeration system located after the capillary tube. a. Evaporator b. Compressor c. Condenser d. None of the above 78. A refrigeration system component found before the condenser. a. Filter b. Evaporator c. Capillary tube d. Compressor e. None of the above 79. The lowest temperature zone in a refrigeration system. a. Condenser b. Capillary tube c. Evaporator d. None of the above

80. The state of the refrigerant at the condenser side immediately after leaving the compressor. a. Superheated gas b. Lukewarm liquid c. Saturated gas d. None of the above 81. The state of the refrigerant at the evaporator side immediately before the compressor. a. Superheated gas b. Lukewarm liquid c. Saturated gas d. None of the above 82. A newly discovered refrigerant not harmful to the ozone layer and also known as “ozone-friendly gas.” a. R12 b. Ammonia c. Suva Mp 52 (R-134a) d. All of the above 83. A term used to describe overcharging of refrigerant. a. Back frost b. Sweating c. Supercharging d. None of the above 84. A device used mostly in large cooling units to cool the water that absorbs the heat from the condenser. a. Cold storage room b. Cooling Tower c. Heat Exchanger d. None of the above

Refrigeration and Cold Storage 85. The mixture of ½ vapor and ½ liquid. a. Saturated gas b. Saturated liquid c. Superheated gas d. None of the above 86. The mixture of ½ liquid and ½ gas. a. Saturated gas b. Saturated liquid c. Superheated gas d. None of the above

87. The charging pressure for refrigerator and for freezer using R-12 refrigerant. a. 19 psi b. 65 psi c. 75 psi d. None of the above 88. The charging pressure for air conditioning unit using R-12 refrigerant. a. 19 - 45 psi b. 65 - 75 psi c. 80 - 90 psi d. None of the above 89. A dry ice is ___. a. solid H2O b. solid CO c. solid CO2 d. None of the above 90. When a condenser of a refrigeration system is cooling, what is the common trouble? a. Too much refrigerant b. Lacks refrigerant c. No refrigerant d. None of the above

91. A passage from the outside of a leaky room caused by cracks in windows, doors and other possible sources. a. Heat loss b. Air infiltration c. Air gap d. None of the above 92. The primary refrigerant for refrigerators known as Dichlorodifluoromethane. a. R-11 b. R-12 c. R-22 d. None of the above 93. The primary refrigerant for airconditioning systems known as Monochlorodifluoro-methane. a. R-11 b. R-12 c. R-22 d. None of the above 94. An extruded foam used for lowtemperature systems such as refrigeration, building and sub-zero insulation. a. Polystyrene foam b. PVC foam c. Plastic foam d. All of the above

Refrigeration and Cold Storage

Heat Gain on Walls Qw = A Rt (To – Ti) where: Qw - heat gain from walls, W A - wall surface area, m2 Rt - thermal transmittance, W/m-C To – wall outside temperature, C Ti - wall inside temperature,  C Product Load Qp = Wp Cp (Ti – Tf) / 86400 where: Qp - product load, W Wp - weight of the product, kg Cp - specific heat of the product, J/kg-C Ti – product initial temperature, C Tf – product final temperature, C Light Load Ql = Lr where: Ql - light load, W Lr - lamp rating, W Human Heat Load Qh = Nh HRh / 86400 where: Qh - human heat load, W Nh - number of human HRh - heat of respiration of human, J/man-day

Air Infiltration Load Vr Hf AC Qai = ------------------------86400 where: Qai - air infiltration loss, W Vr - room volume, m3 Hf - heat factor, J AC - Air changes, KJ/m3 Heat of Respiration Load Qr = Wp HRp / 86400 where: Qr - heat of respiration load, W Wp – weight of the product, kg HRp – product heat of respiration, J/kg-day

Tons of Refrigeration TR = TL / 12,000 where: TR - refrigeration capacity, tons of ref TL – total load, BTU/hr Latent Heat of Freezing Qlf = Mw LHF where: Qlf - latent heat of freezing water, KJ Mw - mass of water, kg LHF - Latent heat of freezing, 336 KJ/kg

Refrigeration and Cold Storage Problem 1 Compute the amount of heat needed to drop the temperature of 100 cans of milk from 32C to 25C. Assume a specific weight of milk equal to 0.99 kg/liter. The specific heat of milk is 0.93 BTU/lb-F. Given: No. of cans = 100 Volume per can = ¼ liter Temp initial = 30C Temp final = 25C Cp = 0.93 BTU/lb-F Required: Amount of heat to be removed Solution: Qs = (00.99kg/li x ¼ li x 100 cans) x (0.93 BTU/lb-F) (86F – 79F) = 455.75 BTU Problem 2 Compute the cooling load of a 150-kg carabeef if it is to be cooled from 28°C to -2.2 °C, after which it is frozen and cooled to -20°C. The specific heat of carabeef above and below freezing are 3.5 kJ/kg-°C and 1.75 kJ/kg-°C, respectively. The freezing point is -2.2°C and the latent heat of fusion is 250 kJ/kg. Given: m Te Tf Ts Cb Ca h1

- 150 kg - 28°C - -2.2°C - -20°C - 3.5 kJ/kg-°C - 1.75 kJ/kg-°C - 250 kJ/kg

Required:

Cooling load (Qt)

Solution: Qt = m Cb (Te – Tf) + mh1 + m Ca (Tf – Ts) = 150 kg (3.5 kJ/kg-°C) [28 - (-2.2)°C] + 150 kg (250 kJ/kg) + 150 kg (1.75 kJ/kg-°C) [-2.2 – (-20)°C] = 58, 027.5 kJ

Refrigeration and Cold Storage Problem 3 One ton of poultry meat is put in a chiller at 8°C and frozen to -18°C in 10 hours. Compute the product load if the latent heat is 235 kJ/kg and the freezing temperature is -4°C. The specific heat of poultry meat is 3.5 kJ/kg-°C above freezing and 1.5 kJ/kg-°C below freezing. Given: Cb - 3.5 kJ/kg-°C Ca - 1.5 kJ/kg-°C Solution: Te - 8°C Tf - -4°C Qt = [m Cb (Te – Tf) + mh1 + m Ca (Tf – Ts)] / T Ts - -18°C = 1000 kg (3.5 kJ/kg-°C) [8 - (-4)] + 1000 kg h1 - 235kJ/kg (235 kJ/kg) + 1000 kg (1.5 kJ/kg-°C) [.-4 – m - 1 ton (= 1000 kg) (-18)] / 10 hrs x 3600 sec/hr time - 10 hrs = 278,000 kJ / 10 hrs x 3600 sec/hr = 7.72 kJ/sec or 7.72 kW Required: Product load (Qt)

Problem 4 How many units of 1-hp air conditioning system is required to maintain the temperature of a farm house at 27 C? The floor dimension of the house is 10-m wide x 30-m long. The height of ceiling of the room is 8 ft . Given:

Structure Dimension Ceiling Height Temperature

- Farm house - 10-m W x 30-m L - 8 ft - 27C

Required: No. of units of 1-hp air conditioner Solution: No. of Units = 10 m x 30 m / 20 m2 per 1-hp unit = 5 units of 1-hp air conditioner

Refrigeration and Cold Storage Problem 5 Determine the heat load of a proposed walk-in cooler having 6-ft x 8-ft floor space and 7 ft height. It is designed to have a 4-in cork insulation (6.5 BTU/hr-ft2) on all surfaces and an inside temperature of 35F. The products to be cooled are: cabbage, 100 lb/day (0.9 BTU/lb-F) and fresh beef, 200 lbs/day (0.5 BTU/lb-F). Assume the products are to be cooled from 85 to 35F in 24 hours. Given: Cooler Type Floor Space Height Insulation Heat insulating cap Temp inside Product Temp for cooling Time of cooling

- Walk-in - 6 ft x 8 ft - 7 ft - 4-in. thick cork - 6.5 BTU/hr-ft2 - 35F - 100-lb/day cabbage, 200-lbs fresh beef - 85F to 35F - 24 hours

Required: Heat Load Solution: Product load: 0.9 x 100 x (85-35)/24

= 187 BTU/hr

0.75 x 200 x (85-35)/24

= 312 BTU/hr

Space Load:

6 x 8 + 6 x 7 x 2 + 8 x 7 x 2 + 6 x 8 = 292 ft2 Using 6.5 BTU/ft2-hr 292 ft2 x 6.5 BTU/ ft2-hr

= 1,898 BTU/hr

Total Heat Load: 187 + 312 + 1,898

= 2,397 BTU/hr

Heat Transfer and Thermal Insulation 1. The transfer of heat from one part of a solid body to the other parts under the influence of temperature gradient. a. Convection b. Conduction c. Radiation d. All of the above

7. A proportionality factor that represents the property of a material through heat conduction. a. Thermal resistivity b. Thermal conductivity c. Thermal coefficient d. None of the above

2. The transfer of heat by mixing one parcel of fluid with another. a. Convection b. Conduction c. Radiation d. All of the above

8. Cooling meat, fruits and vegetables are examples of heat transmission by ___. a. unsteady state conduction b. steady state conduction c. free convection d. None of the above

3. The shape factor for heat by conduction is expressed as ___. a. A/dx b. K A/dx c. dt/dx d. none of the above

9. The factor influencing thermal conductivity of a material. a. Chemical composition of materials b. Temperature of materials c. Surrounding pressure d. All of the above

4. The amount of heat transferred per unit temperature per unit length. a. Emissivity b. Thermal conductivity c. Heat transfer coefficient d. None of the above

10. If the temperature surrounding the material is reduced, the thermal conductivity also ___. a. changes in a decreasing manner b. changes in increasing manner c. does not change d. None of the above

5. When heat is transmitted through molecular waves, it is transmitted by ___. a. Convection b. Conduction c. Radiation d. None of the above

11. Fluids with low molecular weight have ___. a. high thermal conductivity b. low thermal conductivity c. no thermal conductivity d. None of the above

6. The amount of heat required to raise one pound of water one degree Farenheight. a. Thermal capacity b. Specific heat c. British Thermal Unit d. None of the above

12. Heat basically transfers from ___. a. lower temperature to high temperature b. high temperature to lower temperature c. lower pressure to high pressure d. None of the above

Heat Transfer and Thermal Insulation 13. If more heat is to be transmitted from one side of a solid body to the other side, which of the following would you recommend as an Engineer? a. Increase the thickness of material. b. Decrease the thickness of material. c. Maintain the thickness of material. d. None of the above

14. The shape factor for conduction heating on a cylindrical wall is ___. a. 6.3 L/ (ln r2/r1) b. 3.14 L/ (ln r2/r1) c. 3.14 kL/ (ln2/r1) d. None of the above 15. The amount of heat transmitted per unit time and temperature for a given surface area of a fluid. a. Heat coefficient b. Specific heat c. Heat transfer coefficient d. None of the above 16. If a boiling water is pumped from a boiler to a heat exchanger, heat is transmitted by ___. a. natural convection b. forced convection c. radiation d. None of the above 17. Heat transfer coefficient is lower for ___. a. liquids b. gases c. boiling water d. condensing vapors e. None of the above

18. An example of heat conductor. a. Silica brick b. Refractory cement c. Asbestos fiber d. None of the above

19. In a vacuum condition, heat transfer by conduction moves ___. a. faster b. slower c. at constant rate d. None of the above 20. In sundrying, heat is released to a material by ___. a. radiation b. force convection c. natural convection d. None of the above 21. The amount of heat required to raise a kilogram of water one degree centigrade. a. Kilo Calories b. Joules c. Watts d. None of the above

22. Dimensionless numbers used in determining heat transfer coefficient by natural convection. a. Nusselt/Grashof/Prantdl b. Nusselt/Reynolds/Prantdl c. Prantdl/Reynolds/Grashof d. None of the above 23. The unit of energy in SI system is ___. a. Newton-meter b. Joules c. W-sec d. All of the above 24. The insulating ability or resistance of a material to the flow of heat. a. Thermal resistance b. Thermal conductivity c. Thermal insulator d. All of the above

Heat Transfer and Thermal Insulation 25. The ability of a material to give up or to receive heat. a. Resistance b. Thermal conductance c. All of the above d. None of the above

30. Which of the following fluids has the highest heat transfer coefficient? a. Gases b. Liquids c. Boiling water d. All of the above

26. The temperature of the surrounding air. a. Dry bulb temperature b. Wet bulb temperature c. Ambient temperature d. All of the above

31. The heat transfer coefficient of liquids, in kcal/m²-hr-°C , ranges from ___. a. 3 to 20 b. 100 to 600 c. 1000 to 2000 d. None of the above

27. The form of energy that provides the difference in temperature among molecular materials. a. Heat b. Temperature c. Thermal resistance d. None of the above 28. Nusselt number is a function of ___. a. convection coefficient, pipe diameter, and thermal conductivity b. thermal conductivity, viscosity, and diameter of pipe c. convection coefficient, velocity of fluid, diameter of pipe d. None of the above 29. A thick-walled stainless-steel tube (k = 19 w/m-°C, with 2 cm ID and 4 cm OD) is covered with a 3-cm layer of asbestos insulation (k = 0.2 w/m-°C). If the inside wall temperature of the pipe is maintained at 600°C and the temperature outside of the insulation is at 100°C, what would be the heat loss per foot length of the tube? a. 600 w/m b. 680 w/m c. 720 w/m d. None of the above

32. Which of the following statements is true? a. The thermal conductivity of aluminum is higher than that of silver. a. Silver is faster to transmit heat than aluminum. c. Aluminum and silver transfer heat at the same rate. d. All of the above 33. What is the heat loss per ft² of the 9-inch-thick wall of a brick kiln made from a material with thermal conductivity of 0.18 BTU/hr-ft-°F? The outside and inside temperatures are 1500°F and 400°F, respectively. a. 224 BTU/hr-ft² b. 264 BTU/hr-ft² a. 246 BTU/hr-ft² d. None of the above 34. If the flow of fluid is on streamline characteristics, the fluid is at ___. a. turbulent condition b. laminar condition c. Eddies d. All of the above

Heat Transfer and Thermal Insulation 35. What is the heat transfer loss per foot of a 2-inch nominal pipe (OD=2.37 in.) covered with 1-inch-thick insulating material having an average thermal conductivity of 0.037 BTU/hr-ft-°F. The inner and outer temperatures of the insulation are 380° and 80°F, respectively. a. 161 BTU/hr-ft b. 111 BTU/hr-ft c. 125 BTU/hr-ft d. None of the above 36. The Prantdl number is a function of ___. a. viscosity, specific heat, and thermal conductivity a. specific heat, heat transfer coefficient, and thermal conductivity c. viscosity, diameter of pipe, thermal conductivity d. None of the above 37. Heat transfer coefficient by force convection is determined by what dimensionless numbers? a. Nusselt, Prantdl, Reynolds b. Nusselt, Prantdl, Grashof c. Reynolds, Grashof, Prantdl d. None of the above 38. One British thermal unit (BTU) is equal to ___. a. 1055 J b. 1505 J c. 1550 J d. None of the above 39. If the heated pipe is changed with a higher pipe schedule, the transfer of heat will ___. a. increase b. decrease c. remains the same d. All of the above

40. Basically, the thermal conductivity of a material will increase if the ___. a. thickness is increased b. temperature is increased c. temperature is decreased d. All of the above 41. Which of the following statements is true? a. Heat transfer rate is higher on edges of boxes. b. Heat transfer rate is higher on corners of boxes. c. Heat transfer rate is lower on walls of boxes. d. None of the above 42. A good insulator for kiln dryer. a. Rice husk b. Brick c. Concrete d. None of the above 43. A material that is poor conductor of heat or has low thermal conductivity. a. Conductor b. Insulator c. Resistor d. All of the above 44. A good example of hightemperature insulating material. a. Iron b. Wood c. Asbestos d. All of the above 45. Which of the following materials has low thermal conductivity? a. Building brick b. Asbestos c. Firebrick d. Concrete e. None of the above

46. Insulators used for steam lines are classified as ___. a. low temperature range insulator b. medium temperature range insulator c. high temperature range insulator d. None of the above

47. A good example of a dualtemperature insulator. a. Expanded silica b. Cellular glass c. Vermiculite d. All of the above 48. A form of insulants used in industrial insulation application. a. Flexible strips b. Foil c. Flexible pipe section and mattresses d. All of the above 49. Which of the following statements is true? a. In insulation, heat gain is more costly than heat loss. b. The cost of extracting heat from refrigerated space is the same with the cost of heat losses from a high temperature system. c. The cost of insulating high temperature system is the same with that of low temperature system. d. All of the above 50. The presence of moisture in a lowtemperature insulation material may cause ___. a. reduction in the insulating value of the material a. improvement in the insulating value of the materials c. reduction in the cost of the insulating materials d. All of the above

Heat Transfer and Thermal Insulation 51. An extruded foam used for lowtemperature systems such as refrigeration, building and sub-zero insulation. a. Polystyrene foam b. PVC foam c. Plastic foam d. All of the above 52. A ceramic material designed to be resistant to high temperature, i.e., 1000° to 1800°C. a. Refractory b. Asbestos c. Fiber glass d. None of the above 53. The factor(s) that need(s) to be considered in selecting an insulant. a. Operating temperature b. Maintenance cost c. Ability to resist mechanical and heat damage d. All of the above 54. To protect the insulant from mechanical damage, it must be provided with ___. a. metal sheet cladding b. nets and asbestos cement c. wire net and bituminous compound d. All of the above 55. The Stefan–Boltzmann constant is equal to ___. a. 0.147 x 10-8 BTU/hr-ft2-F4 b. 0.174 x 10-8 BTU/hr-ft2-F4 c. 0.174 x 10-8 BTU/hr-ft2-F3 d. None of the above 56. The equation for heat transfer by radiation in gray bodies is ___. a. Qr = λAT4 b. Qr = ελAT4 c. Qr = ε AT4 d. None of the above

Heat Transfer and Thermal Insulation 57. A device used in transferring heat. a. Insulator b. Heat absorber c. Heat exchanger d. All of the above 58. The overall heat transfer coefficient includes ___. a. thermal conductivity and heat transfer coefficient of the materials b. heat transfer coefficient and emissivity of the materials c. thermal conductivity and emissivity of the materials d. None of the above 59. Which of the following statements is true? a. When radiant energy falls on a body, portion of it may be reflected, absorbed and the remainder transmitted. b. When radiant energy falls on a body, part of it may be reflected and absorbed. c. When radiant energy falls on a body, all of the energy are absorbed. d. None of the above 60. When two fluids in a heat exchanger move in opposite direction, the device is classified as ___. a. parallel flow HE b. cross flow HE c. constant flow HE d. None of the above 61. In heat transfer by radiation, configuration factor for parallel planes is ___. a. higher than perpendicular planes b. lower for perpendicular planes c. equal to perpendicular planes d. None of the above

Heat Transfer and Thermal Insulation Conduction (Homogenous Wall) Qk = k A (To – Ti) / x where: Qk - heat transfer rate, W k - thermal conductivity, W / K-m A - surface area, m2 To - outside wall temperature, K Ti - inside wall temperature, K x - wall thickness, m

Conduction (Homogenous Cylindrical Wall) 2  k L (Ti - To) Qk = ----------------------------Ln ro/ri where: Qk - heat transfer rate, W K - thermal conductivity, W / K-m A - surface area, m2 L - length of cylinder, m To - outside wall temperature, K Ti - inside wall temperature, K r - radius of wall, m o, i – outside and inside wall surfaces Radiation

Qr =   A T 4 where: Qr - heat trabsfer rate, W  - emmisivity  - Stefan-Boltzman constant, 5.7x104 W/m2-K4 A - surface area, m2 T - temperature of the surface of the material, K

Conduction (Composite Wall) A (T1 – T4) Qk = -----------------------------------------x12/k12 + x23/k23 + x34/k34 where: Qk - heat transfer rate, W k - thermal conductivity, W / K-m A - surface area, m2 T4 - outside wall temperature, K T1 - inside wall temperature, K x - wall thickness, m 1,2,3,4 - represent wall surfaces Convection Qh = h A (To – Ti ) where: Qh - heat transfer rate, W h - heat transfer coefficient, W-m2-K A - surface area, m2 Tf - fluid temperature, K Ts - surface temperature, K

Heat Transfer and Thermal Insulation Problem 1 The temperature inside a rice hull furnace is maintained at 1500 F by means of suitable control apparatus. The wall of the furnace is 9 in. in thickness and constructed from a material having 0.18 Btu/hr-ft-F thermal conductivity. Calculate the heat loss for each square foot of wall surface per hour. Assume that the inside and outside wall temperatures are 1500F and 400F, respectively. Given: Furnace inside wall temperature - 1500F Wall thickness - 9 in. K material - 0.18 BTU/hr-ft-F Outside wall temperature - 400F Required: Heat transfer loss per square foot Solution: dt = 1500F – 400F = 1100F dx = 9 in. x ft.12 in = 0.75 ft Qk/A = (0.18 BTU/hr-ft-F)(1100F) / 0.75 ft = 264 BTU/hr-ft2 Problem 2 Calculate the thermal conductivity of a 4’ x 8’ test panel, 1-in. thick if during a 3-hour test period it conducted 900 BTU of heat through the panel with 15F temperature differential between its surfaces. Given: Area of the wall Wall thickness Heat conducted Difference in temp

- 4 ft x 8 ft - 1 in. - 900 BTU - 15F

Required: thermal conductivity Solution: Qk = 900 BTU/ 3 hours = 300 BTU/hr K = (300 BTU/hr) (0.083 ft) / (32 ft2) (15F) = 0.052 BTU/hr-ft-F

Heat Transfer and Thermal Insulation Problem 3 The wall of a kiln is made up of 9-in fire bricks (k=0.72 BTU/hr-ft-F), 5-in insulating bricks (k=0.08 BTU/hr-ft-F), and 7.5-in red bricks (K=0.5 BTU/hr-ft-F). The inner (t1) and outer surface temperatures (t4) are 1500F and 150F, respectively. Neglecting the residences of the mortar joints, compute the temperatures t2 and t3 at the contact surface. Given: Fire brick - 9 in. K - 0.72 BTU/hr-ft-F Insulating Brick - 5 in. K - 0.08 BTU/hr-ft-F Red brick - 7.5 in. K - 0.5 BTU/hr-ft-F t1 - 1500F t4 - 150F Required: Temperatures at t2, t3, and at the contact surface area

Solution: Qk1-4 = 1 ft2 (1500F-150F) / [(9in/12in/ft/0.72 BTU/hr-ft-F) + (5in/12in/ft/0.08BTU/hr-ft-F) + (7.5in/12in/ft/0.5BTU/hr-ft-F)] = 180 BTU/hr 180 BTU/hr = 0.72 BTU/hr-ft-F x 1 ft2 (1500 – t2) / (9 in/12 in/ft) t2 = 1312F 180 BTU/hr = 0.08 BTU/hr-ft-F x 1 ft2 x (1312F – t3) / (5 in/12in/ft) t3 = 375F

Heat Transfer and Thermal Insulation Problem 4 A biomass furnace with 1-in. horizontal-plate steel wall is covered by a 2-in.-thick insulation. The temperature of the upper side of the steel wall is 450F while at the lower side of the insulation is 100F. If the k for steel is 29 BTU/hr-ft-F and the k for the insulation is 0.5 BTU/hr-ft-F, what is the temperature at the junction between the steel plate and the insulation? Given: Material Thickness Insulation T1 T3 K steel K insulation

- steel plate - 1 in - 2 in. - 450F - 100F - 29 BTU/hr-ft-F - 0.5 BTU/hr-ft-F

Required: Temperature between the steel plate and the insulation

Solution: Qk = 1 ft2 x (450F – 100F) / (1in./12 in./ft/29 BTU/hr-ft-F) + (2 in./12 in/ft/0.5 BTU/hr-ft-F) = 1041 BTU/hr 1041 BTU/hr = 29 BTU/hr-ft-F x 1 ft2 x (450-T2) / 1 in./12 in./ft T2 = 447F

1 in.

2 in.

Heat Transfer and Thermal Insulation Problem 5

What is the heat loss per ft2 of a 9-inch-thick brick-kiln wall made of a material with 0.18 BTU/hr-ft-F thermal conductivity? The outside and inside temperatures are 1500F and 400F, respectively. Given:

k To Ti x

Required:

Heat loss per ft2

Solution: Qk

- 0.18 BTU/ hr-ft-°F - 1500 °F - 400° F - 9 in.

= kA(To-Ti)/x = 0.18 BTU/hr-ft-°F (1500°F – 400°F) / 9 in x 12 ft/in = 264 BTU/hr-ft2

Problem 6

1 in.

What is the heat transfer loss per foot of a 2inch nominal pipe (OD=2.37 in.) covered with 1-in.-thick insulating material having of 0.037 BTU/hr-ft-F average thermal conductivity. The inner and outer temperatures of the insulation are 380 and 80F, respectively. Given: Required: Solution:

To= 80 F

Ti= 380F

K = 0.037 BTU/hr-ft-F Heat transfer lose per foot

Qk = 2π kL (Ti – To) / ( ln ro/ri ) = 2π (0.037 BTU/hr-ft-°F) (380F – 80F) / ln 2.187/1.1875 = 114.16 BTU/hr-ft

2.37 in.

Heat Transfer and Thermal Insulation Problem 7 A thick-walled stainless-steel tube (k = 19 w/m-°C, with 2 cm ID and 4 cm OD) is covered with a 3-cm layer of asbestos insulation (k = 0.2 w/m-°C). If the inside wall temperature of the pipe is maintained at 600°C and the outside of the insulation at 100°C, what is the heat loss per foot length of the tube? Given: Pipe inside diameter - 2 cm Pipe outside diameter - 4 cm Thickness of asbestos - 3 cm K pipe - 19 W/m-C K asbestos - 0.2 W/m-C Temperature inside the pipe - 600C Temperature outside the asbestos - 100C Required: Heat transfer rate per foot length of pipe Solution: Qk = 2 π x L x (600C – 100C) / [[(ln 2 cm/1 cm)/19 W/m-C] + [(ln 5 cm/2 cm)/0.23 W/m-C)]] = 680 W per m or 207 W/ft Problem 8 What is the heat loss per ft² of the 9-inch-thick wall of a brick kiln made from a material with 0.18 BTU/hr-ft-°F thermal conductivity? The outside and inside temperatures are 1500°F and 400°F, respectively. Given: Brick wall thickness - 9 in. Thermal conductivity - 0.18 BTU/hr-ft-F Inside temperature - 1500F Outside temperature - 400F Required: Heat loss per ft 2 Solution: Qk = A x [0.18 BTU/hr-ft-F x (1500F – 400F)] / (9 in/12 in/ft) = 264 BTU/hr-ft2

Heat Transfer and Thermal Insulation

Problem 9 Calculate the energy transfer rate across a 6-in. firebrick wall of a farm house with 50C temperature difference across the wall. The thermal conductivity of the firebrick is 0.65 BTU/hr-ft-F. Given: Thickness of wall Temperature difference Heat transfer coefficient

- 6 in. - 50C - 0.65 BTU/hr-ft-F

Required: Heat transfer rate by conduction Solution: Qk = A 0.65 BTU/hr-ft-F (50 C) / 6 in. = 0.65 BTU/hr-ft-F (122F) / (6 in./12 in./ ft) = 158.6 BTU/hr-ft2

The Authors: Alexis T. Belonio is a Professional Agricultural Engineer and a registered ASEAN Engineer. He is an Senior Research Fellow at the Philippine Rice Research Institute, Science City of Munoz, Nueva Ecija. He also serves as Affiliate Professor at the College of Engineering, Central Luzon State University (CLSU), Science City of Munoz, Nueva Ecija and a former Associate Professor of the Department of Agricultural Engineering and Environmental Management, College of Agriculture, Central Philippine University, Iloilo City. He finished his Bachelor of Science in Agricultural Engineering and Master of Science degrees from CLSU. Since 1983, he has been deeply involved in teaching, research, technology development, and entrepreneurial activities related to the fields of agricultural engineering. He was awarded by the Philippine Society of Agricultural Engineers (PSAE) as the Most Outstanding Agricultural Engineer in the field of Farm Power and Machinery, in 1993. In that same year, he was named by the Professional Regulation Commission (PRC) as the Outstanding Professional in the field of Agricultural Engineering. And in 1997, he was awarded by the TOYM Foundation and the Jerry Roxas Foundation as the Outstanding Young Filipino (TOYF) in the field of Agricultural Engineering. He was also awarded as Associate Laureate of the Rolex Awards for Enterprise 2008 (Geneva, Switzerland) and as a Laureate in Economic Business Development Category of The Tech Awards 2010 (San Jose, California). He was adjudged as one of the Inspiring Modern-Day Filipino Heroes by Yahoo Southeast Asia in 2011 and one of the 25 Heroes for Better of Western Union. As a dedicated professional, he serves as technical consultant to various agricultural companies and machinery manufacturers in the country and abroad. He also serves as a Reviewer for the Agricultural Engineering Board Examination to TGIM, CLSU, BUCAF, CBSUA, and SPAMAST Review Centers, in the fields of Agricultural Power, Machinery and Allied Subjects, and Agricultural Processing, Structures and Allied Subjects. He has written and published several research and technical papers, including instructional and review materials. Daniel Alexis H. Belonio is a Professional Agricultural Engineer. He finished his BS in Agricultural Engineering degree at Central Luzon State University (CLSU) in 2014. He worked as project assistant at Vinasilic SJ in Vietnam and at PT Minang Jordanindo in Indonesia on the development of ric e husk gasifiers. He also worked as assistant engineer at Agribio Philippines in Palawan on the design, construction, and operation of 100 kW rice husk gasifier power generating unit, rotary flash combined with instore dryer, and re-circulating bin type dryers. While working at CNC Design Lab as assistant engineer, he is presently taking up BS in Civil Engineering through the ETEEAP Program at CLSU.