Madurai Sail Windmill Marcus Sherman 1975

25 Pages·1975·0.19 MB·English

Appropriate Technologies
for Semiarid Areas:

Wind and Solar Energy
for Water Supply

Gorman Foundation
{or Internallonal Developmesat
‘Seminar Centre lor Economic
and Social evelopment
see fest)
AN INTERIM REPORT: TRE DESIGN AND CONSTRUCTION OF AN
APPROPRIATE WATER PUMPING WINDMILL FOR INDIAN AGRICULTURE

Marcus M. Sherman

I. Introduction

In many parts of India there are adequate supplies of
aroundwater which are unavailable to faruers for Srrigation
during the dry season because of inadequate power sources
for pumping. Electricity is commonly avatlable for only
four hours of pumping par day, due to heavy energy consump~
tion (n the cities and overespansion of the rural power
grid without @ corresponding increase in generating capa-
bility. Many farmers can never use electric pumps because
Governnent regulations prohibit installation af electric
Pumps within 128 metres of each other,

Three to eight horsepower diasal off pumps ure frequently
used for irrigation but are very expensive to operate be-
cause of the nigh cost of Imported ofl and high maintenance
costs, The traditianal bullack-cperated pumps remain the
most common and reliable source of (reigation water for
Subsistence farning. Water far domestic use is usually
Vifted by hand with rope and bucket from open walls.

During the early 19602 the Wind Power Division of the Ma-
tional Aaronautical Laboratory2/ developed, tested, and
produced 200 12-bladed- fon-type windmills which demonstret—
ed the feasibility of using wind power to pump vater fn In-
dia. Several tyoes of imported European and American multi-
bladed windmf11s have also been used to harness India's
abundant Wind enersy resources. However, dua to high capt-
ta) cost of the windnills and bigh level of technical
skills required for maintenance of industrially produced
aNl-metal windmi 11s, windpower 1s not commonly exploited tn
India.2f

In 1973 the Indian Nationa Council of Sefance and Tech-
nology Expert Committee on Hind Power?/ in their project on
water punping windnills stated that great posstbitities
exist in further development of windatlls for irrigation as
well a5 water supply, even In areas haying low wind veloct-
tar of 8-10 k.p.h. They concluded that fabrication of wa
ter pumping windmills by indigenous manufacturers is possi-
ble and should be encouraged and popularized.

Having observed what appeared to be a classical “take off”
OF wind pump technology tn Crete and Cyprus, Duncan Allse-
brook.t/ OXFAW water technology advisor, noted that the
elements Involved seen to be:

8) the private import of a fen sophisticated, effictent
windnt11s2

b) an agricultural economy without the benefit of nechans-
cal implements;

c) rainfall totalling less than 30 Inches per annum, with
a pronounced dry season;

a) large, flattish basins or plateaus with fertile soils
and shallow water tablas (15-60 feet below surface):

e) Farmers willing to experiment with more intensive egri>
culture, particularly vegetable gardening and orchards,
than has bean possible under conditions of limited fr-
rigations

f) tha existance of a large corps of Jocal craftsmen, par-
ticularly carpenters, masons and blacksmiths.

II. Design céiteria

In order to surmount many of the difficulties encountered
by pravious wind power development efforts in India, the
following design criteria were chosen for an appropriate
windmit) prototyp:

2) Low wind

The windwii1 must operate {n low wind speeds of 6-8 k.
characteristic of many areas of India during the dry winter
and must ba adjustable te operate in higher wind velocities
up to 40 k.p.h.
b) Paap

The windn(11 must have high starting torque and low r.p-m,
to operate a large bore piston pump or 2 large diameter
dtaphraga pump.
€) Iprtgatton

The windwill must lift 28,570 litres per day frome ten-
netre-deep well at an average daily wind velocity of 4~
k.p.h. in order to irrigate one hectare of field with 2 cn
water per week.
4) Low cost

The capital cost must be below Rs 3,000 to be competitive
with the capital cost of a diesel or electric pump set.

e) Local materials

ADL windmil construction should be of common sizes of
locally available materials to minimize cost and simplify
repairs.

f) Local skits

AIL construction ski11s should be those of local crafts-
men in order to stimulate tne rural economy and increase
the degree of tnvolvement of the village people:

9) Operator
Tt was assumed that the operator would be at the site
each day, therefore automatic blade adfustment would not be

required.

fh) Low natatenance
Maintenance costs and skills should be low.
4} Traditional pump

The windmill should not interfere with the continued op-
eration of the traditional pumping device on the same well.

3) Labour-intensive

Basically, 2 labour-intensive, capital-conservattve de
sign was required.
UIT, Description of the Windai1!

This windmit1 1s the fourth in a sertes of prototypes
that have been built near Madurat, South India, by members
of the Madurat Windmill Committee, Rev. C, P. Hefneman,

T, 0, Heineman, Nanoharan Selvaraj, 4. 5. Piltaf, 5. T.
Arasu, M. HM. Sherman! 8/ Ff re 4g an adaptation of the
traditional Greek satl-wing windmill design which is widely
used on Crete.2/ 2/ 4 25-foot sail-wing windn{}1 with six
sails in the classical Greek configuration has been de-
signed by Hans Keyer”/ and tested by Brace Research Insti-
tute.

Loca? purchase of materials commenced on 2 February 1975,
and construction of the windm{11 by the author, &, Nanoharan
Selvaraj, $. N. Thirunavakarasu, and various local craftsmen
continued at a regular daily pace until completion on
25 March when the firet pumping trial wat made. A public
demonstration was given on 29 March:

When the author eft Madurai on 19 Apri? 1975, the wind-
wS11 was operating well, pumping 1,635 litres per hour from
a depth of 9.2 netres at an average operating speed of 12
rop.m. in low winds, estimated ta be 6-8 k.p.h. Maxinun
spuad observed was 25 r.p.m.; minimum speed before stopping
was 8 r.p.m.; starting speed was 12 r.p.m.

The conponents of this Indo-Greek windmi!1 pumping system
are: well, storage tank, foundation, puep, variable stroke
pump lever, tower, turntable base, turntable carriage, tail
Wane, crankshaft connecting rod, crankshaft, shaft bearings,
hub, arms, safts, and operator,

ay Mall

The prototype was erected over the corner of 25 mx 50
% 8m deep well dug into 4 fractured rock aquifer. The well
was also Fitted with a traditional kunalee bullock pump and
a5 hip. electric pump. The windni}? 1s located over one
corner of the wel? so it does not interfere with tha opera~
tion of Gither of these pumps.
6) Storage tank
A conarete or stone storage tank with at Teast 30,000-
Mitre capacity 18 necessary to provide » large quantity of
water 1n a short period of time once daily for flooding tha
felds, A storage tank may serve as 2 multipurpose struce
ture by being used for aquaculture and partially as found

than for shelter.

6) Foundation

The foundation of the windmill consists of six heavy
steel anchors, four of which ara imbedded in concrete in
lenetre-deep, -5 m-dianeter holes outside the corner of the
well and two of which are fastened to a larga stone pitlar
Taid across the corner of the wel).

4) Pump

The puap used in the first testing of this windmill fs a
piston pump with a 10 em bore an 4 61 cn waxtaum stroke.
The punp 45 attached in the botten of the well at the end
of 9.1m of 5 cm steel pipe suspended from the stone pillar.
The top of the pump piston connecting rod passes up through
and out of the top end of the pipe and ts secured to the
tnd of the variable stroke puxp lever.

e) Yariable stroke pump layer
Because the seasonal intensity of the wind vartes, {t ts
desirable to vary the tend on a windmtI1 for optimum use of
the availabte wind. This ts accomplished with a 7.5 m long
5 cm x 20 em teak beam mounted at the base of the windnill
by a fixed axis point at one end and attached to tha punp
piston rod at the other end, The battom end of the wooden
crankshaft connecting rod 1s fixed to this Tever by a steal

bracket at a point between the ends of the lever. This

point can be varied to change tha length af stroke deliv-
arad to the pump connacting rod. The pump lever is also t
portant because {t fncreasas the stroke of tha crankshaft
from 13 en at the crankshaft to a minimum of 18 cm and a
Baxinum of 36 cm at the pump connecting rod. Increasing the
stroke is useful because it permits the use of a snaller
bore piston pump which is available im the local market.
*) Tower

The tover {s made of s4x S-m-long teak poles balted at
the bottom to the steel anchors in the foundation ind bolt-
ed at the top to the base of the turntable. The base of the
tower 1 1.8 min diameter. There are twa sets of crass
braces matted to che inside of the tover and a set of ine
ternal guy wires. Ladder steps are nailed to the inside.
Five additional steps nailed around the toner one etre
above ground provide a standing platform for the operstor

while he is adjusting the sails.

9) Turoteble base

The base of the turntable consists of a steel truck tire
rim with an inside diameter of 23 cm, The truck rim $5
drilled and bolted to the tops af the teak poles. The
snooth circular platforn formed by the inside of the rin fs
the bearing surface upon which the turntable carriage sits
and rotates

hy Turatabt

¢ carriage

The turntable carriage 1s a 1.5 m x 36 cm rectangular
jron angle frame which Is secured to the turntable base by
four bolts which are fixed to two 26 cm pteces of angle
iron which rotate on tha bottom inside surface of the turn-
table base. This arrangement keaps the carriage firmly at-
tached to the top of the tower white at the same time al-
lowing {t and the attached tail, crankshaft, sails, atc.s
to turn when the wind direction changes.

1) Tait vane

A 1.30 x 2.5 m rectangular tail made of bamboo matting
fn a light teakwood frame is supported by a 3.7 » long
piece of heavy duty bamboo pole from the rear of the turn~
table carriage with two "U" bolts and is braced with guy
wires. The tail keeps tne satls always facing the wind.
4) Crankshaft connecting rod

This connecting red was made of two Scmx Somx le
teak poles bolted together end to end. The bottom of the
red is bolted to a hinged steel bracket which can be moved
te different positions along the puap lever. The top of the
red $s bolted to a steel swivel which in turn $s belted to
a wooden bearing attached to the crank. Since the connact-
ing rod $3 always in tension and never in compression there
are no braces or guides necessary. The swivel allows the
crankshaft, ete., to turn in response te changing wind di-
rection without twisting the connecting rod or pump lever.
k) Crankshaft

The crankshaft fs the main shaft hich directly transfers
the horfzantal rotary motion from the windnill satis foto
the vertically reciprocating motion necessary to operate
the piston pump. There are no gears or pulleys in the driv-
ing mechanism. The crankshaft is nade of 3.2 cm m{1d steel
rod which has a crank of 3.2 cm mild steel rod welded at
the centre to give a total stroke of 13 cm. A cotter pin at
the tall end of the shaft keeps the shaft from sIiding for-
ward out of the bearings.

1) hate, bearings

The crankshaft {5 cupported directly behind the hub and
directly behind the crank with two § om thick Blocks of
hardwood, each with a steel ball bearing tn the centre to
hold the crank, Thess Wooden bearing Blocks are both bolted
to the turntable carriage. The front bearing 4s slightly
elevated so that the front of the crankshatt 1s raised 6°
up from the hartzontal, thus preventing the tips of the
bamboo ars from hitting the legs of the toxer.
a} Mob

The hub functions as 4 connector between the arms of the
windaitY’ and the crankshaft. It consists of an ardinary ox
cert wheel hud with eight wooden spokes, The spokes are
braced to each other with wood, A bamboo arn 1s attached to
each spoke with two “UT bolts, A hole in the centre of the
hub fits onte the front end of the crankshaft and {s secured
by a 1.6 cm bolt “cotter pin.

ny Arms

Eight 4.5-n-long bamboo poles radiate cut from the hub to
form a total windnill diameter of ten metres. & centrat sup~
porting spar of bamboo extends out two metres in front of
the hub along the main axis of the crankshaft. Humber etght
gauge single-strand ste] wires radiating out and back fron
the tip ef this central spar to the tip of each banboo aro
provides bracing against strong winds. Wires between the
tips of all the radial arms provide additional bracing.
Banboo arms have the advantage of High flexibitity and ten
stle strength as well as widespread availability and low
cost. Village craftsmen are familiar with bamboo as a buitd~
ing material. Oisadvantage of bamboo is that it W511 split
over a long period of tine or iF mishandled.

©) Satis

Cloth was chosen for the wind-catching surface of the
windm{1] because {t 1s Ifghtweight, essy to hande, readily
and cheaply available and it forms a strong uniform surface
for catching the wind when supported at three or more
points, The efant right-triangular sails were stitched by a
local tailor from khaki cloth normatly used for bus conduc-
tor uniforms. & 10-cm-wide sleeve on the hypotenuse side of
each sa4] allows ft to stip on and off the bamboo arms. The
tip and hub ends of the sleeve are tied securely to thefr
respective ends of the bamboo arms. The 90° corner of each
#417 15 secured by « rope of coconut husk fibre to the tip
of the adjacent arm.

p) Dperator
It 45 taportant to have a tra(ned person daily at the site

to control the windwill, divect water flow, and make ninor
repairs.