Banki Water Turbine Design and Construction Manual

Home - English - French - German - Italian - Portuguese - Spanish SMALL MICHELL (BANKI) TURBINE: A CONSTRUCTION MANUAL BY W.R. BRESLIN a VITA publication ISBN 0-86619-066-X VITA 1600 Wilson Boulevard, Suite 500 Arlington, Virginia 22209 USA Tel: Tel: 703/ 703/276 276-1 -1800 800 * Fax: Fax: 703/2 703/24343-18 1865 65 Inte Intern rnet et: : pr-i pr-inf nfo@ o@vi vita ta.o .org rg [C] 1980 Volunteers in Technical Assistance SMALL MICHELL (BANKI) TURBINE: A CONSTRUCTION MANUAL I. II.

WHAT IT IS AND WHAT IT IS USED FOR DECISION FACTORS Advantages Considerations Cost Estimate Planning

III. IV.

MAKING THE DECISION AND FOLLOWING THROUGH PRE-CONSTRUCTION CONSIDERATIONS Site Selection Expense Alternating or Direct Current Applications Materials Tools

V.

CONSTRUCTION Prepare the End Pieces Construct the Buckets Assemble the Turbine Make the Turbine Nozzle Turbine Housing

VI. VII.

MAINTENANCE ELECTRICAL GENERATION

Generators/Alternators Batteries VIII VIII. . IX. X.

DICT DICTIO IONA NARY RY OF TERM TERMS S FURTHER INFORMATION RESOURCES CONVERSION TABLES

APPE APPEND NDIX IX I.

SITE SITE ANAL ANALYS YSIS IS

APPEN APPENDI DIX X II. II. APPEN APPENDI DIX X III. III. APPEN APPENDI DIX X IV. IV.

SMALL SMALL DAM DAM CON CONSTR STRUC UCTIO TION N DECIS DECISIO ION N MAKIN MAKING G WORK WORKSH SHEET EET RECOR RECORD D KEEP KEEPIN ING G WORKS WORKSHE HEET ET SMALL MICHELL (BANKI) TURBINE

I.

WHAT WHAT IT IS AND AND HOW HOW IT IS USEF USEFUL UL

The Michell or Banki turbine is a relatively easy to build and highly efficient means of harnessing a small stream to provide enough power to generate electricity or drive different types of mechanical devices. 42p01.gif (600x600)

The turbine consists of two main parts--the runner, or wheel, and the the nozzl nozzle. e. Curved Curved horizo horizontal ntal blades blades are are fixed fixed betwe between en the the circular end plates of the runner (see page 17). Water passes from the nozzle through the runner twice in a narrow jet before it is discharged. Once the flow and head of the water site have been calculated, the blades of the 30cm diameter wheel presented here can be lengthened as necessary to obtain optimum power output from the available water source. The efficiency of the Michell turbine is 80 percent or greater. This, along along with with its adaptability adaptability to a variety variety of water water sites and power needs, and its simplicity and low cost, make it very suitable for small power development. The turbine itself

provides power for direct current (DC); a governing device is necessary to provide alternating current (AC). II. II.

DECI DECISI SION ON FACT FACTOR ORS S

Appl Applic icat atio ions ns: :

* *

Elec Electr tric ic gene genera rati tion on (AC (AC or DC) DC) Machi Machine nery ry opera operati tions ons, , such such as thres threshe hers, rs, winnower, water pumping, etc.

Advant antages: es:

*

Very effic ficient and simple ple to bui build and operate. Virt Virtua uall lly y no no mai maint nten enan ance ce. . Can Can opera operate te ove over r a ran range ge of of wate water r flow flow and and head conditions.

* *

Cons Consid ider erat atio ions ns: :

* * * *

Requ Requir ires es a cer certa tain in amo amoun unt t of ski skill ll in in work workin ing g with metal. Special governing device is needed for AC electric generation. Welding Welding equipme equipment nt with with cutting cutting attachme attachments nts are needed. Elect Electri ric c grind grindin ing g machi machine ne is need needed ed. . Access to small machine shop is necessary.

COST ESTIMATE(*) $150 to $600 (US, 1979) including materials and labor. (This is for the the turbi turbine ne only. only. Plannin Planning g and cons construc truction tion costs costs of dam, dam, penstoc penstock, k, etc., etc., must be added. added.) ) (*) Cost estimates serve only as a guide and will vary from country to country. PLANNING Development of small water power sites currently comprises one of the most promising applications of alternate energy technologies. If water power will be used to produce only mechanical energy--for example, for powering a grain thresher--it may be easier and less expensive to construct a waterwheel or a windmill. However, if electrical generation is needed, the Michell turbine, turbine, despite relatively relatively high initial initial costs, costs, may be feasible feasible and indeed economical under one or more of the following conditions: *

Access Access to transmis transmission sion lines lines or to to reliabl reliable e fossil fossil fuel fuel sources is limited or non-existent.

*

Cost Cost of fossi fossil l and and othe other r fuel fuels s is high. high.

*

Availabl Available e water water supply supply is consta constant nt and and reliab reliable, le, with with a head head of 50-100m relatively easy to achieve.

*

Need exists exists for for only only a small small dam dam built built into into a river river or stream stream and for a relatively short (less than 35m) penstock (channel) for conducting water to the turbine.

If one or more of the above seems to be the case, it is a good idea to look further into the potential of a Michell turbine. The final decision will require consideration of a combination of factors, including site potential, expense, and purpose. III. III.

MAKING MAKING THE DECISION DECISION AND FOLLOWI FOLLOWING NG THROUGH THROUGH

When determining whether a project is worth the time, effort, and expense involved, consider social, cultural, and environmental factors as well as economic ones. What is the purpose of the the effo effort rt? ? Who Who will will bene benefi fit t mos most? t? What What wil will l the the cons conseq eque uenc nces es be if the effort is successful? And if it fails? Having made an informed technology choice, it is important to keep keep good good records records. . It is helpful helpful from from the the beginn beginning ing to to keep keep data on needs, needs, site selection, selection, resource resource availability, availability, constructio construction n progress, labor and materials costs, test findings, etc. The information may prove an important reference if existing plans and methods need to be altered. It can be helpful in pinpointing "what went wrong?" And, of course, it is important to share data with other people. The technologies presented in this and the other manuals in the energy series have been tested carefully and are actually used in many many parts parts of of the world world. . However However, , extensi extensive ve and and control controlled led field tests have not been conducted for many of them, even some of the the most most common common ones ones. . Even though though we know know that that thes these e technol technologie ogies s work well in some situations, it is important to gather specific information on why they perform properly in one place and not in another. Well documented models of field activities provide important information for the development worker. It is obviously important for a development worker in Colombia to have the technical design for a machine built and used in Senegal. But it is even more important to have a full narrative about the machine that provides details on materials, labor, design changes, and so forth. forth. This model model can provide provide a useful useful frame frame of of referen reference. ce. A reliab reliable le bank bank of such such field field inform informatio ation n is now now growi growing. ng. It exists to help spread the word about these and other technologies, lessening the dependence of the developing world on expensive and finite energy resources. A practical record keeping format can be found in Appendix IV. IV. IV.

PRE-C PRE-CON ONSTR STRUC UCTIO TION N CONS CONSIDE IDERA RATIO TIONS NS

Both main parts of the Michell turbine are made of plate steel and requ require ire some some machi machining ning. . Ordinar Ordinary y steel steel pipe pipe is cut cut to form form the blades or buckets of the runner. Access to welding equipment and a small machine shop is necessary. The design of the turbine avoids the need for a complicated and well-se well-sealed aled housing. housing. The beari bearings ngs have have no no contact contact with the water flow, as they are located outside of the housing; they can simply be lubricated and don't need to be sealed.

Figure 2 shows an arrangement of a turbine of this type for 42p07.gif (600x600)

low-head use without control. This installation will drive an AC or DC generator with a belt drive. SITE SELECTION This is a very important factor. The amount of power obtained, the expense of installation, and even, by extension, the applications for which the power can be used may be determined by the quality of the site. The first site consideration is ownership.

Installation of an

electricity-generating unit--for example, one that needs a dam and reservoir in addition to the site for the housing--can require access to large amounts of land. In many developing countries, large lots of land are few and it is likely that more than one owner will have to be consulted. If ownership is not already clearly held, the property questions must be investigated, including any rights which may belong to those whose property borders on the water. Damming, for example, can change the natural water flow and/or water usage patterns in the area and is a step to be taken only after careful consideration. If ownership is clear, or not a problem, a careful analysis of the site is necessary in order to determine: 1) the feasibility of the site for use of any kind, and 2) the amount of power obtainable from the site. Site analysis consists of collecting the following basic data: *

Minimum fl flow.

*

Maximum fl flow.

*

Availabl Available e head head (the (the height height a body body of of water water falls falls befor before e hitting hitting the machine).

*

Pipe line length length (lengt (length h of pensto penstock ck requir required ed to give give desir desired ed head).

* *

Water Water condit condition ion (clear, (clear, muddy, muddy, sand sandy, y, acid, acid, etc.). etc.). Site sketch sketch (with (with evalu evaluatio ations, ns, or or topogra topographic phical al map map with with site site sketched in).

*

Soil conditio condition n (the (the size size of the the ditch ditch and and the the conditi condition on of the soil combine to affect the speed at which the water moves through the channel and, therefore, the amount of power available).

*

Minimum Minimum tailw tailwater ater (determ (determines ines the turbi turbine ne settin setting g and type) type). .

Appendix I contains more detailed information and the instructions needed to complete the site analysis including directions for measuring head, water flow, and head losses. These directions are simple enough to be carried out in field conditions without a great deal of complex equipment. Once such information is collected, the power potential can be determined. Some power, expressed in terms of horsepower or kilowatts (one horsepower equals 0.7455 kilowatts), will be lost because of turbine and generator inefficiencies and when it is transmitted from the generator to the place of application. For a small water power installation of the type considered here, it is safe to assume that the net power (power actually delivered) will be only half of the potential gross power.

Gross power, or power available directly from the water, is determined by the following formula: Gross Power Gross Gross pow power er (En (Engli glish sh uni units ts: :

horse horsepow power er) ) =

Minimum Water Flow (cubic feet/second) X Gross Head (feet) 8.8 Gross power (metric horsepower) = 1,000 Flow (cubic meters/second) X Head (meters) 75 Net Power (available at the turbine shaft) Net Power (English units) = Minimum Water Flow X Net Head(*) X Turbine Efficiency 8.8 Net Power (metric units) = Minimum Water Flow X Net Head(*) X Turbine Efficiency 75/1,000 Some sites lend themselves naturally to the production of electrical or mechanical power. Other sites can be used if work is done to make them suitable. For example, a dam can be built to direct water into a channel intake or to get a higher head than the stream provides naturally. (A dam may not be required if there is sufficient head or if there is enough water to cover the intake of a pipe or channel leading to the penstock.) Dams may be of earth, wood, concrete, or stone. Appendix II provides some information on construction of small dams. EXPENSE Flowing water tends to generate automatically a picture of "free" power in the eyes of the observer. But there is always a (*) Net head is obtained by deducting energy losses from the gross head head (see (see page page 57). 57). A good good assumpt assumption ion for for turbin turbine e effici efficiency ency when calculating losses is 80 percent. cost to producing power from water sources. Before proceeding, the cost of developing low-output water power sites should be checked against the costs of other possible alternatives, such as: *

Electric Electric utili utility-ty--In In areas areas where where transm transmissi ission on lines lines can furni furnish sh unlimited amounts of reasonably priced electric current, it is often uneconomical to develop small or medium-sized sites. However, in view of the increasing cost of utility supplied electricity, hydroelectric power is becoming more cost-effective.

*

Generato Generators-rs--Dies Diesel el engines engines and and interna internal-co l-combus mbustion tion engin engines es are available in a wide variety of sizes and use a variety of fuels-fuels--for for examp example, le, oil, oil, gasol gasoline, ine, or wood. wood. In genera general, l, the the capital expenditure for this type of power plant is low compared to a hydroele hydroelectri ctric c plant plant. . Operatin Operating g costs costs, , on the other other hand, are very low for hydroelectric and high for fossil fuel generated power.

*

Solar--E Solar--Exten xtensiv sive e work work has has been been done done on the the utili utilizati zation on of solar solar energy energy for for such such things things as water water pumpi pumping. ng. Equipme Equipment nt now now available may be less costly than water power development in regions with long hours of intense sunshine.

If it seems to make sense to pursue development of the small water power site, it is necessary to calculate in detail whether the site will indeed yield enough power for the specific purposes planned. Some sites will require investing a great deal more money than others. others. Constru Constructio ction n of dams dams and pensto penstocks cks can can be very very expensiv expensive, e, depending upon the size and type of dam and the length of the chan channel nel requi required. red. Add to to these these const construct ruction ion expen expenses, ses, the cost of the electric equipment--generators, transformers, transmission lines--and related costs for operation and maintenance and the cost can be substantial. Any discussion of site or cost, however, must be done in light of the purpose for which the power is desired. It may be possible possible to justify justify the expense expense for one one purpose purpose but not for for another. ALTERNATING OR DIRECT CURRENT A turbine can produce both alternating (AC) and direct current (DC). (DC). Both types types of curre current nt cannot cannot always always be used for the the same same purposes and one requires installation of more expensive equipment than the other. Several factors must be considered in deciding whether to install an alternating or direct current power unit. The demand for power will probably vary from time to time during the day. day. With With a const constant ant flow of water water into the turbine turbine, , the power output will thus sometimes exceed the demand. In producing AC, either the flow of water or the voltage must be regulated because AC cannot be stored. Either type of regulation requires additional equipment which can add substantially to the cost of the installation. The flow of water to a DC-producing turbine, however, does not have have to be be regula regulated. ted. Excess Excess power power can be be stored stored in in storage storage batteri batteries. es. Direct Direct current current gene generato rators rs and stor storage age batter batteries ies are are relatively low in cost because they are mass-produced. Direct current is just as good as AC for producing electric

light light and and heat. heat. But elect electrica rical l equipme equipment nt havin having g AC moto motors, rs, such as farm machinery and household appliances, have to be changed changed to DC moto motors. rs. The cost cost of of conver converting ting applianc appliances es must must be weighed against the cost of flow regulation needed for producing AC. APPLICATIONS While a 30.5cm diameter wheel has been chosen for this manual because this size is easy to fabricate and weld, the Michell turbine has a wide range of application for all water power sites providing head and flow are suitable. The amount of water to be run through the turbine determines the width of the nozzle and the width of the wheel. These widths may vary from 5cm to to 36cm. 36cm. No other other turb turbine ine is is adaptab adaptable le to as large large a range range of water flow (see Table 1). Imp uls e o r Pe lto n Banki

Michell or

Centrifugal Pump

Used as Turbine Head Range (feet ) Flow Range (cubic) feet per second Application Available for any

50 to 1000

3 t o 6 50

0.1 to 10 high head

0.5 to 250 medium head

desired condition Power (horsepower) Cost per Kilowatt low Manufacturers Turbin binenfab fabrik Warenburg

1 t o 50 0 lo w

James Leffel & Co. Any reputa utable dealer ler Spr ingfi eld , Ohi o or manufacturer. 455 0 1 US A

1 t o 10 00 low

Omberger88 32 Bayern, Germany

Dre s s & Co .

Can be do-it-

Warl. Germany

project if small

Offices Bubler Taver Taverne ne, , Switz Switzer erlan land d

machine shops are avail availabl able. e.

yourself weld and

Table 1. Small Hydraulic Turbines The size of the turbine depends on the amount of power required, whether electrical or mechanical. Many factors must be considered to determine what size turbine is necessary to do the the job job. . The The fol follo lowi wing ng example illustrates the decision-making process for the use of a turbine to drive a peanut huller (see (see Figu Figure re 3). 3). Step Steps s will will

42p13.gif (540x540)

be similar in electrical power applications. *

Powe Power r eno enoug ugh h to to rep repla lace ce the motor for a 2-1/2 hp 1800 revolutions per minute (rpm) peanut thresher.

*

Gross Gross power power needed needed is about about 5 hp hp (rough (roughly ly twice twice the the horsep horsepower ower of the motor to be replaced assuming that the losses are about one-half of the total power available).

*

Village Village strea stream m can be dammed dammed up and and the water water channel channeled ed through a ditch 30m (100 ft) long.

*

Total Total differ differenc ence e in elevatio elevation n is 7.5m (25 ft). ft).

*

Avai Availa labl ble e min minim imum um flow flow rate rate: :

2.8 2.8 cu cu ft/ ft/se sec. c.

*

Soil of ditch ditch permi permits ts a water water velo velocity city of 2.4 2.4 ft/sec ft/sec (Appe (Appendix ndix I, Table 2 gives n = 0.030).

*

Area Area of flow flow in ditc ditch h = 2.8/ 2.8/2. 2.4 4 - 1.2 1.2 sq sq ft. ft.

*

Bott Bottom om widt width h = 1.2 1.2 ft. ft.

*

Hydrauli Hydraulic c radius radius = 0.31 x 1.2 = 0.37 0.37 ft (see (see Appendix Appendix I).

Calculate results of fall and head loss. Shown on nomograph (Appendix I) as a 1.7 foot loss for every 1,000 feet. Therefore the total loss for a 30m (100 ft) ditch is: 1.7 10

= 0.17 0.17 feet feet

Since 0.17 ft is a negligible loss, calculate head at 25 ft. Power produced by turbine at 80% efficiency = 6.36 hp Net power = Minimum water flow x net head x turbine efficiency 8.8 2.8 x 25 x 0.80 8.8

= 6.36 horsepower

Formulas for principal Michell turbine dimensions: ([B.sub.1]) = width of nozzle =

210 x flow -------------------------------------

------Runner outside diameter x [square root] head =

210 x 2.8 = 9.8 inches --------12 x [square root] 25

([B.sub.2]) ([B.sub.2]) = width width of runner runner between between discs - ([B.sub.1]) ([B.sub.1]) = 1/2 to to 1 inch = 9.8 + 1 inch = 10.8 inches Rotational speed (revolutions per minute) =

73.1 x [square root] head ---------------------------Runner outside diameter (ft) 73.1 x [square root] 25

rpm ----------------------1

= 365.6

The horsepower generated is more than enough for the peanut huller but the rpm is not high enough. Many peanut threshers will operate at varying speeds with proportional yield of hulled peanuts. So for a huller which gives maximum output at 2-1/2 hp and 1800 rpm, a pulley arrangement will be needed for stepping up speed. In this example, the pulley ratio needed to step up speed is 1800 .365 or approx approxima imately tely 5:1. Therefo Therefore re a 15" 15" pulley pulley atta attached ched to the turbine shaft, driving a 3" pulley on a generator shaft, will give [+ or -] 1800 rpm. MATERIALS Although Although materials materials used in construction construction can be be purchased purchased new, many of these materials can be found at junk yards. Materials for 30.5cm diameter Michell turbine: *

Stee Steel l plat plate e 6.5m 6.5mm m X 50c 50cm m X 100 100cm cm

*

Steel Steel plate plate 6.5mm 6.5mm thick thick (quantit (quantity y of mater material ial depe depends nds on on nozzle width)

*

10cm 10cm ID wate water r pipe pipe for for turb turbine ine bucke buckets ts(*) (*)

*

Chicken Chicken wire wire (1.5c (1.5cm m X 1.5cm 1.5cm weave weave) ) or 25mm 25mm dia dia steel steel rods rods

*

4 hub flanges flanges for attac attaching hing end piece pieces s to steel steel shaft shaft (found (found on most car axles)

*

4.5c 4.5cm m dia dia soli solid d ste steel el rod rod

*

two two 4.5 4.5cm cm dia dia pil pillo low w or or bus bush h bea beari ring ngs s for for high high spee speed d use use. . (It (It is possib possible le to fabr fabricat icate e wooden wooden beari bearings ngs. . Because Because of the the high high speed, such bearings would not last and are not recommended.)

*

eight eight nuts nuts and bolts, bolts, approp appropriat riate e size size for hub flang flanges es

TOOLS * * * * * * * * *

Weldi Welding ng equip equipme ment nt with with cutti cutting ng atta attachm chmen ents ts M eta l file Elec Electr tric ic or manu manual al grin grinde der r Dril Drill l and and meta metal l bits bits Comp Compas ass s and and Pro Protr trac acto tor r T-square T-square (templat (template e includ included ed in the back of this this manual manual) ) Hammer C-clamps W or k b ench

(*) Measurements for length of the pipe depend on water site conditions. V. CONSTRUCTION PREPARE THE END PIECES

An actual size template for a 30.5cm turbine is provided at the end of of this this manual manual. . Two of of the bucket bucket slots slots are are shaded shaded to show show how the buckets are installed. Figure 4 shows the details of a Michell runner. 42p17.gif (600x486)

*

Cut out out the the half half circle circle from from the the templa template te and and mount mount it on cardboard or heavy paper.

*

Trace Trace around around the the half half circle circle on the the steel steel plate plate as as shown shown in Figure 5.

42p18a.gif (393x486)

*

Turn the templ template ate over over and and trace trace again again to comple complete te a full full circle (see Figure 6.

42p18b.gif (353x353)

*

Draw the bucke bucket t slots slots on the templ template ate with with a clockwis clockwise e slant slant as shown in Figure 7.

42p19a.gif (393x393)

*

Cut out out the the bucket bucket slots slots on the the templat template e so that that there there are 10 10 spaces.

*

Place Place the the templ template ate on the the stee steel l plate plate and trace trace in in the the bucket slots.

*

Repeat Repeat the the tracing tracing process process as as before before to to fill fill in the the area area for for the shaft (see Figure 8).

42p19b.gif (353x353)

*

Drill Drill a 2mm 2mm hole hole in the the steel steel plate plate in the the center center of the the wheel wheel where where the cross cross is is forme formed. d. The hole hole will will serv serve e as a guide for cutting the metal plate.

42p20a.gif (353x353)

*

Take Take a pie piece ce of scra scrap p met metal al 20cm 20cm long long x 5cm 5cm wide wide. . Dril Drill l a hole the width of the opening in the torch near one end of the metal strip.

*

Drill Drill a 2mm 2mm dia hole hole at the the other other end end at a point point equal equal to the the radius radius of the wheel wheel (15. (15.25cm 25cm). ). Measure Measure careful carefully. ly.

*

Line up the the 2mm hole hole in the the scrap scrap metal metal with the 2mm 2mm hole hole in the metal plate and attach with a nail as shown in Figure 10.

42p20b.gif (243x486)

*

Cut both both end end plates plates as shown shown (in (in Figure Figure 10) using using the torch torch. .

*

Cut the bucket bucket slot slots s with with the the torc torch h or a metal metal saw. saw.

*

Cut out out a 4.5c 4.5cm m dia circle circle from from the the center center of of both both wheels. wheels. This prepares them for the axle.

CONSTRUCT THE BUCKETS Calculate the length of buckets using the following formula: Width Width of Buckets Buckets Bet Between End Plates tes root] Head (ft)

=

210 x Flow (cu/ft/s (cu/ft/sec) ec) + (1 .5in) Outsi tside Diamete eter of Turbi rbine (in) x [square are

*

Once the bucke bucket t length length has has been been determ determined ined, , cut the 10cm 10cm dia dia pipe to the required lengths.

*

When cutting cutting pipe pipe lengt lengthwis hwise e with with a torch, torch, use a piece piece of angle iron to serve as a guide, as shown in Figure 11.

42p21.gif (353x353)

(Bucket measurements given in the template in the back of this manual will serve as a guide.) *

Pip Pipe ma may als also o be be cu cut using an electric circular saw with a metal cutting blade.

*

Cut Cut fou four r buc bucke kets ts from from each each sect sectio ion n of of pip pipe. e. A fif fifth th piec piece e of of pipe will be left over but it will not be the correct width or angle for use as a bucket (see Figure 12).

42p22a.gif (393x393)

*

File File each each of the the buck bucket ets s to meas measur ure e 63mm 63mm wide wide. . (NOT (NOTE: E: Cutt Cuttin ing g with a torch torch may may warp warp the buckets buckets. . Use a hammer hammer to straight straighten en out any warps.)

ASSEMBLE THE TURBINE *

Cut Cut a sha shaft ft from from 4.5c 4.5cm m dia dia stee steel l rod rod. . The The tot total al leng length th of the the shaft should be 60cm plus the width of the turbine.

*

Place Place the the met metal al hub hubs s on the the cent center er of of each each end end piec piece, e, mat matchi ching ng the hole of the hub with the hole of the end piece.

*

Drill Drill four four 20mm 20mm holes holes throu through gh the the hub hub and and end end piec piece. e.

*

Atta Attach ch a hub hub to each each end end piece using 20mm dia x 3cm long bolts and nuts.

*

Slid Slide e sha shaft ft thro throug ugh h the the hubs and space the end pieces to fit the buckets.

42p22b.gif (393x393)

*

Make certain certain the the distan distance ce from from each each end end piece piece to the end end of the shaft is 30cm.

*

Insert Insert a bucke bucket t and align align the end piece pieces s so that that the the blade blade runs perfectly parallel with the center shaft.

*

Spot weld the bucke bucket t in place place from the outsi outside de of the end end piece (see Figure 14).

42p23.gif (540x540)

*

Turn the turbi turbine ne on the shaft shaft half a revolut revolution ion and and insert insert another bucket making sure it is aligned with the center shaft.

*

Spot Spot weld weld the the sec secon ond d buc bucke ket t to to the the end end pie piece ces. s. Once Once thes these e buckets are placed, it is easier to make sure that all the buckets will be aligned parallel to the center shaft.

*

Weld the hubs to the the shaf shaft t (check (check measurem measurement ents). s).

*

Weld the remai remaining ning buckets buckets to to the end end pieces pieces (see Figure Figure 15). 15).

42p24a.gif (353x353)

*

Moun Mount t the the turb turbin ine e on on its its bear bearin ings gs. . Clam Clamp p each each bear bearin ing g to to the the workbench so that the whole thing can be slowly rotated as in a lathe. The cutting tool is an electric or small portable hand grinder mounted on a rail and allowed to slide along a second second rail, rail, or or guide guide (see (see Figure Figure 16). The slide slide rail should should

42p24b.gif (353x353)

be carefully clamped so that it is exactly parallel to the

turbine shaft.

*

Grin Grind d awa away y any any unev uneven en edge edges s or or joi joint nts. s. Rota Rotate te the the tur turbi bine ne slowly so that the high part of each blade comes into contact with with the the gri grind nder er. . Low Low par parts ts will will not not qui quite te touc touch. h. This This process takes several hours and must be done carefully.

*

Make sure the bucke bucket t blades blades are are ground ground so that that the the edges edges are are flush with the outside of the end pieces.

*

Balance Balance the the turbin turbine e so it it will will turn turn evenly evenly (see (see Figur Figure e 17). 17).

42p25.gif (393x393)

It may be necessary to weld a couple of small metal washers on the the top top of of eithe either r end end of the turbine. turbine. The turbine turbine is balanced when it can be rotated in any position without rolling. MAKE THE TURBINE NOZZLE *

Determin Determine e nozzl nozzle e size size by by using using the followin following g formu formula: la: 210 X flow (cubic feet/second -----------------------------------------------------runner outside diameter (in) x [square root] head (ft) The nozzle should be 1.5cm to 3cm less than the inside width of the turbine.

Figure 18 shows a front view of a properly positioned nozzle in 42p26.gif (393x393)

relationship to the turbine. *

From a 6.5mm 6.5mm steel steel plate plate, , cut side section sections s and flat flat front front and back sections sections of the the nozz nozzle. le. Width Width of of front front and back back pieces will be equal to the width of the turbine wheel minus 1.5 to 3cm. Determine other dimensions from the full-scale diagram in Figure 19.

42p28.gif (600x600)

*

Cut curve curved d section sections s of the the nozzle nozzle from 15cm (OD) steel steel pipe pipe if available. Make sure that the pipe is first cut to the correct correct width width of the the nozzle nozzle as as calcula calculated ted previ previous ously. ly. (Bend (Bend steel plate to the necessary curvature if 15cm pipe is unavailable. The process will take some time and ingenuity on the part part of of the builder builder. . One way way of bending bending steel steel plate plate is to to sledge hammer the plate around a steel cylinder or hardwood log 15cm 15cm in in diamete diameter. r. This may be be the only only way to constr construct uct the nozzle if 15cm steel pipe is unavailable.)

*

Weld Weld all all sec secti tion ons s toge togeth ther er. . Foll Follow ow ass assem embl bly y inst instru ruct ctio ions ns given in "Turbine Housing" on page 29.

The diagram in Figure 19 provides minimum dimensions for proper turbine installation.

TURBINE HOUSING Build the structure to house the turbine and nozzle of concrete, wood, wood, or steel steel plate plate. . Figur Figure e 20 20 show shows s a side side view view and and 42p29.gif (600x600)

front view of a typical installation for low head use (1-3m). Be sure housing allows for easy access to the turbine for repair and maintenance. *

Attach Attach the the nozzle nozzle to to the housing housing first first and then then orien orient t the turbine to the nozzle according to the dimensions given in the diagr diagram am in Figure Figure 19. 19. This should should ensure ensure correct correct turbi turbine ne placement. Mark the housing for the placement of the water seals.

*

Make Make wate water r seal seals. s. In 6.5 6.5mm mm stee steel l plat plate, e, dri drill ll a hole hole sli sligh ghtl tly y larger larger than than the the shaft shaft diamet diameter er (about (about 4.53cm) 4.53cm). . Make Make one for each side. Weld or bolt to the inside of the turbine housing. The shaft must pass through the seals without touching them. Some water will still come through the housing but not enough to interfere with efficiency.

*

Make the found foundatio ation n to which which the the bearin bearings gs will will be atta attached ched of of hardwood pilings or concrete.

*

Move the turbi turbine, ne, with with beari bearings ngs attac attached hed, , to the the prope proper r nozzle/turbine placement and attach the bearings to the foundation with bolts. The bearings will be on the outside of the turbine turbine housing housing (see (see Figure Figure 21). (Note: (Note: The drive drive pulley pulley is

42p30.gif (600x600)

omitted from the Figure for clarity.) Figure 22 shows a possible turbine installation for high head 42p31.gif (600x600)

applica application tions. s. A water water shut-o shut-off ff valve valve allow allows s control control of the the flow flow of water water. . Never Never shut shut off the water water flow suddenly suddenly as a ruptu rupture re in the penstock is certain to occur. If maintenance on the turbine is necessary, reduce the flow gradually until the water stops. VI.

MAINTENANCE

The Michel Michell l (Banki) (Banki) turbin turbine e is relati relatively vely main maintena tenancence-free free. . only wearable parts are the bearings which may have to be replaced from time to time.

The

An unbalanced turbine or a turbine that is not mounted exactly will wear the bearings very quickly. A chicken wire screen (1.5cm x 1.5cm weave) located behind the

control gate will help to keep branches and rocks from entering the turb turbine ine housi housing. ng. It may may be nece necessar ssary y to clean clean the scree screen n from from time time to time time. . An altern alternati ative ve to chicken chicken wire is the the use of thin steel rods spaced so that a rake can be used to remove any leaves or sticks. VII. VII.

ELEC ELECTR TRIC ICAL AL GENE GENERA RATI TION ON

It is beyond the scope of this manual to go into electrical generation using the Michell (Banki) turbine. Depending on the generator and accessories you choose, the turbine can provide enough rpm for direct current (DC) or alternating current (AC). For information on the type of generator to purchase, contact manufac manufacture turers rs direct directly. ly. A list list of compa companies nies is provid provided ed here. here. The manufacturer manufacturer often will will be able to to recommend recommend an appropriate appropriate generator, if supplied with enough information upon which to make make a recom recommend mendatio ation. n. Be prepar prepared ed to supply supply the the follow following ing details: *

AC or DC operatio operation n (incl (include ude voltage voltage desired desired). ).

*

Long range range use of of electr electrical ical energy energy (futur (future e consump consumption tion and addition of electric devices).

*

Climatic Climatic conditio condition n under under which which gene generato rator r will will be used used (i.e. (i.e., , tropical, temperate, arid, etc.).

*

Power Power availab available le at water water site site calcula calculated ted at at lowest lowest flow flow and and maximum flow rates.

* Power Power availab available le to the gener generator ator in watts watts or or horsepo horsepower wer (conservative figure would be half of power at water site). *

Revoluti Revolutions ons per per minute minute (rpm) (rpm) of turbin turbine e without without pulleys pulleys and and belt.

*

Intended Intended or presen present t consump consumptio tion n of elect electrica rical l energy energy in in watts watts if possible (include frequency of electrical use).

GENERATORS/ALTERNATORS *

Lima Electric Electric Co., 200 East East Chapm Chapman an Road, Road, Lima, Lima, Ohio 45802 45802 USA.

*

Kato, Kato, 3201 3201 Third Third Avenue Avenue North, North, Mankat Mankato, o, Minne Minnesota sota 56001 56001 USA. USA.

*

Onan, Onan, 1400 1400 73rd 73rd Avenue Avenue NE, NE, Minnea Minneapoli polis, s, Minnes Minnesota ota 55432 55432 USA.

*

Winco Winco of Dyna Dyna Techn Technolog ologies, ies, 2201 East 7th Stree Street, t, Sioux Sioux City City, , Iowa 51102 USA.

*

Kohler, Kohler, 421 High High Street Street, , Kohle Kohlen, n, Wisco Wisconsin nsin 53044 53044 USA. USA.

*

Howelite Howelite, , Rendale Rendale and Nelso Nelson n Street Streets, s, Port Port Cheste Chester, r, New New York York 10573 USA.

*

McCulloc McCulloch, h, 989 989 South South Brookl Brooklyn yn Avenu Avenue, e, Wellsv Wellsville ille, , New York York 14895 USA.

*

Sears, Sears, Roebu Roebuck ck and Co., Chicago, Chicago, Illinoi Illinois s USA. USA.

*

Winpower Winpower, , 1225 1225 1st Avenue Avenue East, East, Newto Newton, n, Iowa Iowa 50208 50208 USA. USA.

*

Ideal Ideal Electri Electric, c, 615 615 1st Street, Street, Mansf Mansfiel ield, d, Ohio Ohio 44903 44903 USA. USA.

*

Empir Empire e Elect Electri ric c Compan Company, y, 52005200-02 02 Firs First t Avenue Avenue, , Brook Brooklyn lyn, , New York 11232 USA.

BATTERIES *

Bright Bright Star, Star, 602 602 Getty Getty Avenu Avenue e Clifton Clifton, , New Jersey, Jersey, 0701 07015 5 USA.

*

Burgess Burgess Divis Division ion of of Clevite Clevite Corp., Corp., Gould Gould PO PO Box 3140, 3140, St. Paul, Minnesota 55101 USA.

*

Delco-Re Delco-Remy, my, Divis Division ion of of GM, PO Box Box 2439, 2439, Anders Anderson, on, India Indiana na 46011 USA.

*

Eggle-Pi Eggle-Pichen chen Industr Industries, ies, Box 47, 47, Joplin Joplin, , Missour Missouri i 64801 64801 USA. USA.

*

ESB Inc., Inc., Willard Willard Box Box 6949, 6949, Cleve Cleveland land, , Ohio Ohio 44101 44101 USA. USA.

*

Exide Exide, , 5 Penn Penn Cente Center r Plaza, Plaza, Phil Philad adelp elphi hia, a, Penns Pennsyl ylvan vania ia 19103 19103 USA.

*

Ever-Rea Ever-Ready dy Union Union Carbi Carbide de Corpo Corporati ration, on, 270 270 Park Park Avenue Avenue, , New York, New York 10017 USA.

VIII VIII. .

DICT DICTIO IONA NARY RY OF TERM TERMS S

AC (Alternating Current)--Electrical energy that reverses its directio direction n at regular regular interva intervals. ls. These These inter intervals vals are called cycles. BEARING--Any part of a machine in or on which another part revolves, slides, etc. DIA (Diameter)--A straight line passing completely through the center of a circle. DC (Direct (Direct Current)--E Current)--Electrica lectrical l current current that flows flows in one one direction without deviation or interruption. GROSS POWER--Power available before machine inefficiencies are subtracted. HEAD--The height of a body of water, considered as causing pressure. ID (Inside Diameter)--The inside diameter of pipe, tubing, etc.

NET HEAD--Height of a body of water minus the energy losses caused by the friction of a pipe or water channel. OD (Outside Diameter)--The outside dimension of pipe, tubing, etc. PENSTOCK--A conduit or pipe that carries water to a water wheel or turbine. ROLLED EARTH--Soil that is pressed together tightly by rolling a steel or heavy wood cylinder over it. RPM (Revolutions Per Minute)--The number of times something turns or revolves in one minute. TAILRACE (Tailwater)--The discharge channel that leads away from a waterwheel or turbine. TURBINE--Any of various machines that has a rotor that is driven by the pressure of such moving fluids as steam, water, water, hot hot gase gases, s, or or air. air. It is is usual usually ly made made with a series of curved blades on a central rotating spindle. WEIR--A dam in a stream or river that raises the water level. IX. FURTHER Brow Brown, n, Gut Guthr hrie ie J. J. (ed. (ed.). ). Hydr Hydro o Elec Electr tric ic Eng Engin inee eeri ring ng Prac Practi tice ce. . New York: Gordon & Breach, 1958; London: Blackie and Sons, Ltd., 1958. A complete treatise covering the entire field of hydr hydroe oele lect ctri ric c engi engine neer erin ing. g. Thre Three e volu volume mes. s. Vol. Vol. 1: Civi Civil l Enginee Engineering ring; ; Vol. Vol. 2: Mechani Mechanical cal and and Electr Electrical ical Enginee Engineering ring; ; and Vol. 3: Economics, Operation and Maintenance. Gordon & Breach Science Publishers, 440 Park Avenue South, New York, New York 10016 USA. Crea Creage ger, r, W.P W.P. . and and Just Justin in, , J.D. J.D. Hydr Hydro o Ele Elect ctri ric c Hand Handbo book ok, , 2nd 2nd ed. New York: York: John Wiley Wiley & Son, Son, 1950. 1950. A most complet complete e handboo handbook k coverin covering g the entire entire field. field. Especia Especially lly good good for for reference. John Wiley & Son, 650 Third Avenue, New York, New York 10016 USA. Davi Davis, s, Calv Calvin in V. V. Hand Handbo book ok of App Appli lied ed Hyd Hydra raul ulic ics, s, 2nd 2nd ed. ed. New New York: McGraw-Hill, 1952. A comprehensive handbook covering all phases phases of appl applied ied hydrauli hydraulics. cs. Several Several chapter chapters s are are devoted devoted to hydroe hydroelect lectric ric appli applicat cation. ion. McGraw-H McGraw-Hill, ill, 1221 Avenue of the Americas, New York, New York 10020 USA. Durali, Durali, Mohammed Mohammed. . Design Design of of Small Small Water Water Turbi Turbines nes for for Farms Farms and and Small Small Communi Communities ties. . Tech. Tech. Adaptat Adaptation ion Program Program, , MIT, MIT, Cambrid Cambridge, ge, Massach Massachuset usetts ts 0213 02139 9 USA. USA. A Highly Highly technica technical l manua manual l of the designs of a Banki turbine and of axial-flow turbines. Also contains technical drawings of their designs and tables tables of fric friction tion losses, losses, efficie efficiences nces, , etc. etc. This This manual is far too technical to be understood without an enginee engineering ring backgrou background. nd. Probably Probably only useful useful for for univer university sity projects and the like. Haimerl Haimerl, , L.A. L.A.

"The Cross Cross Flow Flow Turbin Turbine," e," Water Water Power Power (London (London), ),

January January 1960. 1960. Reprint Reprints s availabl available e from Ossber Ossberger ger Turbin Turbinen-f en-fabr abrik, ik, 8832 8832 Weiss Weissenb enburg, urg, Bayern, Bayern, Germany Germany. . This This arti article cle describes a type of water turbine which is being used extensively in small power stations, especially in Germany. Available from VITA. Hamm, Hamm, Hans Hans W. Low Cost Cost Devel Developm opment ent of of Small Small Water Water Power Power Sites. Sites. VITA 1967. Written expressly to be used in developing areas, this manual contains basic information on measuring water power potential, building small dams, different types of turbines and water wheels, and several necessary mathema mathematica tical l table tables. s. Also Also has has some some informat information ion on manufac manufacture tured d turbi turbines nes availabl available. e. A very very usef useful ul book. book. Langhor Langhorne, ne, Harry Harry F. "Hand-Ma "Hand-Made de Hydro Hydro Power Power," ," Alter Alternati native ve Sources Sources of Energy, Energy, No. 28, October October 1977, 1977, pp. 7-11. 7-11. Describes how one man built a Banki turbine from VITA plans plans to to power power and heat heat his his home. home. useful useful in in that that it it gives gives a good account of the mathematical calculations that were necessary, and also of the various modifications and innovations he built built into into the the system. system. A good good real-lif real-life e accou account nt of build building ing a low-cos low-cost t water water power power syste system. m. ASE, Route Route #2, Box 90A, Milaca, Minnesota 59101 USA. Mock Mockmo more re, , C.A. C.A. and and Merr Merryf yfie ield ld. . F. The The Bank Banki i Wate Water r Turb Turbin ine. e. Corvall Corvallis, is, Oregon Oregon: : Oregon Oregon State State College College Engi Engineer neering ing Experi Experiment ment Station Station, , Bullet Bulletin in No. No. 25, 25, Febru February ary 1949. 1949. A trans translati lation on of a pap paper er by by Donat Donat Banki Banki. . A high highly ly tec techni hnica cal l description of this turbine, originally invented by Michell Michell, , togethe together r with with the results results of of tests. tests. Oregon Oregon State State University, Corvallis, Oregon 97331 USA. Paton, on, T.A. .A.L. Power wer From rom Wate ater, London: on: Leonar nard Hill, 1961. concise general survey of hydroelectric practice in abridged form.

A

Zerb Zerban an, , A.H. A.H. and and Nye, Nye, E.P. E.P. Powe Power r Plan Plants ts, , 2a ed. ed. Scra Scrant nton on, , Pennsyl Pennsylvani vania: a: Interna Internation tional al Text Text Book Book Compan Company, y, 1952 1952. . Chapter Chapter 12 gives gives a concis concise e present presentatio ation n of hydrauli hydraulic c power power plants plants. . Interna Internation tional al Text Text Book Book Compan Company, y, Scrant Scranton, on, Pennsylvania 18515 USA. X. CONVERSION TABLES UNITS OF LENGTH 1 1 1 1 1 1 1

Mile Kilometer Mile Foot Meter Inch Centimeter

= = = = = = =

1760 Yards 1000 Meters 1.607 Kilometers 0.3048 Meter 3.2808 Feet 2.54 Centimeters 0.3937 Inches

= 5280 Feet = 0.6214 Mile

= 39.37 Inches

UNITS OF AREA 1 Square Mile

= 640 Acres

= 2.5899 Square

Kilometers 1 Squa Square re Mile 1 Acre 1 Square Meter 1 Square 1 Square 1 Square Square

Kilo Kilomet meter er

= 1,000 1,000,0 ,000 00 Squar Square e Meter Meters s

= 0.386 0.3861 1 Squar Square e

Foo t

= 43,560 Square Feet = 144 Square Inches

= 0.09 2 9 Sq uare

Inc h Mete r Centime Centimeter ter

= 6.452 Square Centimeters = 10.764 Square Feet = 0.155 0.155 Square Square Inch

UNITS OF VOLUME 1.0 Cubic Cubic Foot Gallons 1.0 British Imperial Gallon 1.0 Cubic Meter Gallons 1.0 Liter Gallons

= 1728 1728 Cubic Cubic Inches Inches

= 1.2 US Gallons = 35.314 Cubic Feet

= 7.48 US

= 264.2 US

= 1000 Cubic Centimeters

= 0.2642 US

= 1000 Kilograms = 1000 Grams = 2000 Pounds

= 2204.6 Pounds = 2.2046 Pounds

UNITS OF WEIGHT 1.0 Metric Ton 1.0 Kilogram 1.0 Short Ton UNITS OF PRESSURE

1. 0 1. 0 1. 0 1. 0 1.0 (PSI) 1.0 1.0 1.0 1.0 1. 0

Pound per square Pound per square Pound per square Pound per square Atmosphere

i nc h i nc h i nc h i nc h

Atmosphere Foot Foot of wate water r = 0.43 0.433 3 PSI PSI Kilog Kilogram ram per per square square centime centimeter ter Pound per square inch

= 1 4 4 Po un d p e r sq uar e foot = 27.7 Inches of water* = 2 .3 1 F ee t o f wat er* = 2.042 Inches of mercury* = 14.7 Pounds per square inch = 33.95 Feet of water* = 62.3 62.355 55 Poun Pounds ds per per squa square re foot foot = 14.223 14.223 Pound Pounds s per squar square e inch inch = 0.0703 Kilogram per square centimeter

UNITS OF POWER 1. 0 (KW) 1. 0 1.0 1.0 1. 0

Horsepower (English)

= 7 4 6 Wa t t

Horsepower (English) Horsepower (English) Kilowat Kilowatt t (KW) (KW) = 1000 1000 watt watt Horsepower (English)

= 550 Foot pounds per second = 33,000 Foot pounds per minute = 1.34 1.34 Horsepo Horsepower wer (HP) (HP) English English = 1.0139 Metric horsepower (cheval-vapeur) = 75 Meter X Kilogram/Second = 0.736 Kilowatt = 736 Watt

1.0 Metric horsepower 1.0 Metric horsepower

(*) At 62 degrees Fahrenheit (16.6 degrees Celsius). APPENDIX I

= 0.746 Kilowatt

SITE ANALYSIS This Appendix provides a guide to making the necessary calculations for a detailed site analysis. Data Sheet Measuring Gross Head Meas Measur urin ing g Flow Flow Measuring Head Losses DATA SHEET 1.

Minimum Minimum flow of water water availab available le in in cubic cubic feet feet per second (or cubic meters per second).

_____

2.

Maximum flow of water available in cubic feet per second (or cubic meters per second).

___ __

3.

Head or fall of water in feet (or meters).

_____

4.

Length Length of pipe pipe line line in feet (or meters) meters) needed needed to get the required head.

_____

5.

Describ Describe e water water conditi condition on (cle (clear, ar, muddy, muddy, sand sandy, y, acid).

_____

6.

Describe soil condition (see Table 2).

_____

7.

Mini Minimu mum m tail tailwa wate ter r elev elevat atio ion n in feet feet (or (or mete meters rs). ).

____ _____ _

8.

Approxi Approximate mate area of pond pond above above dam dam in in acres acres (or square kilometers).

_____

9.

10.

Appr Approxi oxima mate te dept depth h of the the pon pond d in feet feet (or meters).

_____

Distanc Distance e from from powe power r plant plant to where where electric electricity ity will be used in feet (or meters).

___ __

11.

Approximate distance from dam to power plant.

_____

12.

Minimum air temperature.

_____

13.

Maximum air temperature.

_____

14.

Estimate power to be used.

___ __

15.

ATTACH ATTACH SITE SITE SKETC SKETCH H WITH WITH ELEVATI ELEVATIONS, ONS, OR TOPOGR TOPOGRAPH APHICAL ICAL MAP WITH SITE SKETCHED IN.

The following questions cover information which, although not necessary in starting to plan a water power site, will usually be neede needed d later. later. If it can can possib possibly ly be given given early early in the the project project, ,

this will save time later. 1.

Give the type, power, and speed of the machinery to be driven and indicate indicate whether direct, belt, or gear drive drive is desired or acceptable.

2.

For electric current, indicate whether direct current is accepta acceptable ble or alte alternat rnating ing current current is requi required. red. Give the desired voltage, number of phases and frequency.

3.

Say whether manual flow regulation can be used (with DC and very small AC plants) or if regulation by an automatic governor is needed. MEASURING GROSS HEAD

Method No. 1 1.

Equipment

42p51.gif (353x353)

a.

b. 2.

Surveyor's leveling instrument--consists of a spirit level fastened parallel to a telescopic sight. Scale--use wooden board approximately 12 ft in length.

Procedure a.

Surveyor's level on a tripod is placed downstream from the power reservoir dam on which the headwater level is marked.

b.

After taking a reading, the level is turned 180[degrees] in a horizont horizontal al circle circle. . The scal scale e is plac placed ed downst downstream ream from it at a suitable distance and a second reading is taken. This process is repeated until the tailwater level is reached.