Design of Plate and Frame Filter Press

PAMANTASAN NG LUNGSOD NG MAYNILA (University of the City of Manila) College of Engineering and Technology Department of Chemical Engineering PLATE AND FRAME FILTER PRESS

DESIGN DESCRIPTION A filter press may be square or circular, vertical or horizontal. This type of equipment is consists of series of compartments arranged alternately and supported on a pair of rails with a filter cloth over each side of the plates. The slurry is fed to each compartment under pressure. The slurry passes through the filter medium and out a discharge pipe leaving solids behind. They are simple to operate, very versatile and flexible in operation. DESIGN SELECTION Plate and frame filter press was selected among the other types because the process requires high recovery of filtrate after extraction. Basically plate and frame filter press is used in batch processes. It is easy to operate and very useful whether the filtrate or the cake is the product. DATA AND ASSUMPTIONS 1. Mass flow rate of the slurry = 2,534.84 kg/batch (based from material balance) 2. Mass flow rate of the cake = 356.74 kg/batch (based from material balance) 3. Mass flow rate of the filtrate = 2,176.83 kg /batch (based from material balance) 4. Density of the filtrate = 1040.175 kg/m3 (average density composition of the filtrate) 5. Density of Cake = 3,304.01 kg/ m3(average density composition of the cake) 1 | Phosphatization of Calcined Tahong (Perna Viridis) Shells for the Production of Calcium Phosphate

PAMANTASAN NG LUNGSOD NG MAYNILA (University of the City of Manila) College of Engineering and Technology Department of Chemical Engineering 6. Feed Temperature = 90OC DESIGN CONSIDERATIONS 1. Operating pressure is assumed to be 5.0 atm since pressure ranges from 3 to 10 atm in a plate and frame media (Unit Operations and Chemical Engineering by McCabe, 7th ed, pg.1008) 2. The 1.0 in thick plates and 3.0 in thick frames are assumed since thickness of plates ranges from ¼ to 2 in. and thickness of frame ranges from ¼ to 8in (Unit Ops. of Chem. Eng’g by McCabe, 7th ed, pg.1008) 3. The most commonly used medium for plate frames filter press is polypropylene fabric for filtering and is usually diatomaceous silica (Perry’s Chemical Eng’g Handbook, 7th ed., pg. 19-65) 4. Plate size is assumed to be 24 by 24 inches since the square plates range from 6 to 78 in. (Unit Operations by McCabe 7th ed. pg. 1008) 5. Safety factor is 20% (Plant Design and Economics for Chemical Engineers by Timmerhaus, 5th Ed., Table 3-1, pg.82-83) 6. The filter resistance (RC) is much less than the cake resistance (RM). 7. The time of filtration (tf) is 30 minutes (based on experimental). 8. The time of washing (tw) is 10minutes (Brown, Unit Operations p. 229) DESIGN REQUIREMENTS 1. Filter rate 2. Plate area 3. Frame dimension 4. Number of frames 5. Mass of wash water 6. Power requirement

2 | Phosphatization of Calcined Tahong (Perna Viridis) Shells for the Production of Calcium Phosphate

PAMANTASAN NG LUNGSOD NG MAYNILA (University of the City of Manila) College of Engineering and Technology Department of Chemical Engineering

1. Filter Rate

Using 20% safety factor (from Plant Design and Economics by Timmerhaus p. 82-83, table 3-1) (

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2. Plate Area Since the plate is square, the area can be solved by: A=

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3. Frame Dimension Thickness = Lf = 3.0 in = 0.0762m Height = H = plate size + 2Lf = 24 in + 2(3 in) = 26 in = 0.7620 m Width = W = H (since the frame is a square) = 0.7620 m Dimension = 0.7620 m x 0.7620 m x 0.0762 m Use: 0.8 m x 0.8 m x 0.08 m 4. Number of Frames

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5. Mass of Wash Water

3 | Phosphatization of Calcined Tahong (Perna Viridis) Shells for the Production of Calcium Phosphate

PAMANTASAN NG LUNGSOD NG MAYNILA (University of the City of Manila) College of Engineering and Technology Department of Chemical Engineering

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, Use 41.7 kg/batch

6. Power Requirement Using mechanical energy balance:

Thus,

4 | Phosphatization of Calcined Tahong (Perna Viridis) Shells for the Production of Calcium Phosphate

PAMANTASAN NG LUNGSOD NG MAYNILA (University of the City of Manila) College of Engineering and Technology Department of Chemical Engineering

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Use: 1.0 hp

5 | Phosphatization of Calcined Tahong (Perna Viridis) Shells for the Production of Calcium Phosphate

PAMANTASAN NG LUNGSOD NG MAYNILA (University of the City of Manila) College of Engineering and Technology Department of Chemical Engineering DESIGN SPECIFICATIONS

PLATE AND FRAME FILTER PRESS Identification Item: Plate and Frame filter press Number of Required Units: 1 Materials Handled: Calcium Oxide together with Calcium Chloride Functions: Filters the slurry to recover the filtrate after extraction Design Data PARAMETERS

Proposed Design

Existing Design

Filter Rate

2.6 m3

3 m3

Filter Media

Polypropylene Fabric

Polypropylene Fabric

Plate Area

0.3716 m2

0.3716 m2

Frame Dimension

0.8 m x 0.8 m x 0.08 m

0.9x 0.9 x 0.1 m

Number of Frames

13

34

Mass of Wash Water

41.7 kg

Pressure Head

5 atm

6.82 atm

Power Requirement

0.9 hp

1.0 hp

Accessories Hydraulic Pump Feed Tank Product Collecting Vessel Flexible Hose

Soruce: Pacific Processing Equipment

6 | Phosphatization of Calcined Tahong (Perna Viridis) Shells for the Production of Calcium Phosphate

PAMANTASAN NG LUNGSOD NG MAYNILA (University of the City of Manila) College of Engineering and Technology Department of Chemical Engineering DESIGN CONFIGURATIONS

Capacity: 2.6 m3/batch Pressure: 5.0 atm Power Requirements: 0.9 hP

24 in

24 in

Plate Area: 0.37161 m2 Filter Media: Polypropylene Fabric Plate Thickness: 1 in. 7 | Phosphatization of Calcined Tahong (Perna Viridis) Shells for the Production of Calcium Phosphate