PEDAL OPERATED WATER PUMPING SYSTEM

SYNOPSIS

Water plays an important role in the material, social and cultural life of man

kind. The water needs are increasing day by day. This is the result of population growth

and increase in the standard of living which is directly proportional to water

consumption.

The lifting of water for drinking or irrigation purposes is of great importance in

widely distributed villages with little or no rural electrification and where under ground

water is available.

INTRODUCTION

The aim of the project is Pedal operated water pumping system. Radial plunger

Pedal operated reciprocating water pumping system are reciprocating pump in which the

piston is provided for the pumping action. The piston is reciprocated with the help of a

pneumatic cylinder, pedal with chain sprocket mechanism and Cam mechanism.

A pump is a Mechanical device which converts mechanical energy into hydraulic

energy. This pump is classified into two types;

i. Positive Displacement and

ii. Non-Positive Displacement pump

In positive displacement pump is the one, in which the liquid is transferred

positively from one stage to another stage by the to and fro motion of the plunger or

piston of the pump.

In non-positive displacement pump the liquid is transferred by the centrifugal

force. This force is cause due to the rotary movement of an impeller. In this, our project,

pedal operated reciprocating water pump is of positive displacement pump. The salient

features of a pedal operated reciprocating water pump have been retained in our project

model and this has been achieved with great care.

Due to high precision work involved in producing pedal operated reciprocating

water pump besides higher cost these pumps are not widely manufactured by most of the

industries. The very name itself indicates that it works with the help of a piston. This

piston is reciprocated with the help of a solenoid valve and electronic timing control unit.

LITERATURE SURVEY

PNEUMATICS

The word ‘pneuma’ comes from Greek and means breather wind. The word

pneumatics is the study of air movement and its phenomena is derived from the word

pneuma. Today pneumatics is mainly understood to means the application of air as a

working medium in industry especially the driving and controlling of machines and

equipment.

Pneumatics has for some considerable time between used for carrying out the

simplest mechanical tasks in more recent times has played a more important role in the

development of pneumatic technology for automation.

Pneumatic systems operate on a supply of compressed air which must be made

available in sufficient quantity and at a pressure to suit the capacity of the system. When

the pneumatic system is being adopted for the first time, however it wills indeed the

necessary to deal with the question of compressed air supply.

The key part of any facility for supply of compressed air is by means using

reciprocating compressor. A compressor is a machine that takes in air, gas at a certain

pressure and delivered the air at a high pressure.

Compressor capacity is the actual quantity of air compressed and delivered and the

volume expressed is that of the air at intake conditions namely at atmosphere pressure

and normal ambient temperature.

The compressibility of the air was first investigated by Robert Boyle in 1962 and

that found that the product of pressure and volume of a particular quantity of gas.

The usual written as

PV = C (or) PıVı = P2V2

In this equation the pressure is the absolute pressured which for free is about 14.7

Psi and is of courage capable of maintaining a column of mercury, nearly 30 inches high

in an ordinary barometer. Any gas can be used in pneumatic system but air is the mostly

used system now a days.

SELECTION OF PNEUMATICS

Mechanization is broadly defined as the replacement of manual effort by

mechanical power. Pneumatic is an attractive medium for low cost mechanization

particularly for sequential (or) repetitive operations. Many factories and plants already

have a compressed air system, which is capable of providing the power (or) energy

requirements and the control system (although equally pneumatic control systems may be

economic and can be advantageously applied to other forms of power).

The main advantage of an all pneumatic system are usually economic and

simplicity the latter reducing maintenance to a low level. It can also have out standing

advantages in terms of safety.

PRODUCTION OF COMPRESSED AIR

Pneumatic systems operate on a supply of compressed air, which must be made

available. In sufficient quantity and at a pressure to suit the capacity of the system. When

pneumatic system is being adopted for the first time, however it wills indeed the

necessary to deal with the question of compressed air supply.

The key part of any facility for supply of compressed air is by means using

reciprocating compressor. A compressor is a machine that takes in air, gas at a certain

pressure and delivered the air at a high pressure.

Compressor capacity is the actual quantity of air compressed and delivered and the

volume expressed is that of the air at intake conditions namely at atmosphere pressure

and normal ambient temperature. Clean condition of the suction air is one of the factors,

which decides the life of a compressor. Warm and moist suction air will result in

increased precipitation of condense from the compressed air. Compressor may be

classified in two general types.

1. Positive displacement compressor.

2. Turbo compressor

Positive displacement compressors are most frequently employed for

compressed air plant and have proved highly successful and supply air for pneumatic

control application.

The types of positive compressor

1. Reciprocating type compressor

2. Rotary type compressor

Turbo compressors are employed where large capacity of air required at low

discharge pressures. They cannot attain pressure necessary for pneumatic control

application unless built in multistage designs and are seldom encountered in

pneumatic service.

RECIPROCATING COMPRESSORS

Built for either stationary (or) portable service the reciprocating compressor is by

far the most common type. Reciprocating compressors lap be had is sizes from the

smallest capacities to deliver more than 500 m³/min. In single stage compressor, the air

pressure may be of 6 bar machines discharge of pressure is up to 15 bars. Discharge

pressure in the range of 250 bars can be obtained with high pressure reciprocating

compressors that of three & four stages.

Single stage and 1200 stage models are particularly suitable for pneumatic

applications , with preference going to the two stage design as soon as the discharge

pressure exceeds 6 bar , because it in capable of matching the performance of single stage

machine at lower costs per driving powers in the range .

COMPONENTS AND DESCRIPTION

Pneumatic cylinder

An air cylinder is an operative device in which the state input energy of

compressed air i.e. pneumatic power is converted in to mechanical output power, by

reducing the pressure of the air to that of the atmosphere.

Single acting cylinder

Single acting cylinder is only capable of performing an operating medium in only

one direction. Single acting cylinders equipped with one inlet for the operating air

pressure, can be production in several fundamentally different designs.

Single cylinders develop power in one direction only. Therefore no heavy

control equipment should be attached to them, which requires to be moved on the piston

return stoke single action cylinder requires only about half the air volume consumed by a

double acting for one operating cycle.

Double acting cylinders:

A double acting cylinder is employed in control systems with the full

pneumatic cushioning and it is essential when the cylinder itself is required to retard

heavy messes. This can only be done at the end positions of the piston stock. In all

intermediate position a separate externally mounted cushioning derive most be provided

with the damping feature.

The normal escape of air is out off by a cushioning piston before the end of the stock

is required. As a result the sit in the cushioning chamber is again compressed since it

cannot escape but slowly according to the setting made on reverses. The air freely enters

the cylinder and the piston stokes in the other direction at full force and velocity.

4.4.1. Parts of Pneumatic Cylinder

Piston

The piston is a cylindrical member of certain length which reciprocates inside the

cylinder. The diameter of the piston is slightly less than that of the cylinder bore

diameter and it is fitted to the top of the piston rod. It is one of the important part which

converts the pressure energy into mechanical power.

The piston is equipped with a ring suitably proportioned and it is relatively soft

rubber which is capable of providing good sealing with low friction at the operating

pressure. The purpose of piston is to provide means of conveying the pressure of air

inside the cylinder to the piston of the oil cylinder.

Generally piston is made up of

Aluminium alloy-light and medium work.

Brass or bronze or CI-Heavy duty.

The piston is double acting type. The piston moves forward when the high-

pressure air is turned from the right side of cylinder. The piston moves backward when

high pressure acts on the piston from the left side of the cylinder. The piston should be as

strong and rigid as possible.

The efficiency and economy of the machine primarily depends on the working of

the piston. It must operate in the cylinder with a minimum of friction and should be able

to withstand the high compressor force developed in the cylinder and also the shock load

during operation.

The piston should posses the following qualities.

a. The movement of the piston not creates much noise.

b. It should be frictionless.

c. It should withstand high pressure.

Piston Rod

The piston rod is circular in cross section. It connects piston with piston of other

cylinder. The piston rod is made of mild steel ground and polished. A high finish is

essential on the outer rod surface to minimize wear on the rod seals. The piston rod is

connected to the piston by mechanical fastening. The piston and the piston rod can be

separated if necessary.

One end of the piston rod is connected to the bottom of the piston. The other end

of the piston rod is connected to the other piston rod by means of coupling. The piston

transmits the working force to the oil cylinder through the piston rod. The piston rod is

designed to withstand the high compressive force. It should avoid bending and withstand

shock loads caused by the cutting force. The piston moves inside the rod seal fixed in the

bottom cover plate of the cylinder. The sealing arrangements prevent the leakage of air

from the bottom of the cylinder while the rod reciprocates through it.

Cylinder Cover Plates

The cylinder should be enclosed to get the applied pressure from the compressor

and act on the pinion. The cylinder is thus closed by the cover plates on both the ends

such that there is no leakage of air. An inlet port is provided on the top cover plate and

an outlet ports on the bottom cover plate. There is also a hole drilled for the movement

of the piston.

The cylinder cover plate protects the cylinder from dust and other particle and

maintains the same pressure that is taken from the compressor. The flange has to hold

the piston in both of its extreme positions. The piston hits the top plat during the return

stroke and hits the bottom plate during end of forward stroke. So the cover plates must

be strong enough to withstand the load.

Cylinder Mounting Plates:

It is attached to the cylinder cover plates and also to the carriage with the help of

‘L’ bends and bolts.

SPRACKET AND CHAIN DRIVE MECHANISM:-

This is a cycle chain sprocket. The chain sprocket is coupled with another

generator shaft.

The chain converts rotational power to pulling power, or pulling power to

rotational power, by engaging with the sprocket.

The sprocket looks like a gear but differs in three important ways:

1. Sprockets have many engaging teeth; gears usually have only one or two.

2. The teeth of a gear touch and slip against each other; there is basically no slippage in a

sprocket.

3. The shape of the teeth is different in gears and sprockets.

Figure Types of Sprockets

HOUSE AND FITINGS:

It is provided for the passage of compressed air from the compressor outlet to the

operating valve.

Two separate pipes also connect the operating valve with the working cylinder

pressure drop through and air line depends on the flow rate, pipe diameter, pipe length

and pipe geometry. It can be determined directly for straight pipes of any given length.

A small chaining bore size can have marked effect on pressure drop, where as even

doubling the pipe length, will only result in doubling the pressure drop.

Pressure drop through bends and fittings can only be determined by empirical

tests, since it is specific to the internal geometry involved. Rigid pipes however are less

manipulated through remain form of bends with arrangements increase and variable air

have to flow and the flow itself may be of fluctuating or pulsating nature. In this case it

is thus normally based on practical recommendation.

SEALS:

Seal is an important component of a pneumatic system and is used to prevent the

air leakage through the joint.

This project passes the static seal which are used to prevent the leakage through

the stationary surface.

Material of the seal is Teflon tape. Teflon has the following properties

Withstand the system pressure and temperature without any damage.

Resist the wear and abrasion.

Recover from deformation.

Resists the adverse effects such as deterioration and shrinking

caused by the system air.

Seals are devices for closing gaps to prevent leakage or make pressure joints and

also to prevent the entry of air and dirt from outside into the system. The material of seal

must be compatible with the fluid medium. It is a circular ring made of synthetic rubber.

It is used for providing tight sealing between the piston and the cylinder wall. It prevents

air leakage from the top and bottom of the cylinder.

Seals for air cylinder and valves are not normally called upon to seal pressure

higher than about 2 bars. Since the fluid to be seated is a gas, (in our case air) rubbing

speeds tends to be high and the seal the seal may have to be operated under dry

conditions with minimal lubrication.

NON-RETURN VALVE:-

THEORY OF OPERATION

The non-return valve is employed in all those circuits where the fluid must flow in

one way only, avoiding the flow in the opposite direction.

TO OBTAIN PERFECT SEALING

1. Make sure that all tubes are perfectly clean

and that there are no impurities in the system

where the fluid will flow.

2. Remove protective caps only when ready to

assemble, making sure that in the assembly

phase no impurities enter the system.

TECHNICAL CHARACTERISTICS

1. The non-return valve assures a perfect tightness of the circuit, provided that the

indicated nominal working pressures are kept as recalled in this catalogue.

2. The particular profile of its inner elements assures the correct flow with a minimum

pressure drop.

3. The valve is a compact, particularly sturdy element; the seal is obtained by a plain seat

metal to metal plug with an electrometric seal gasket assuring tightness at low working

pressures.

4. A basic body allows to interchange different types of non return valves applying from

time to time the different engaged stud ends as chosen by the customer allowing an easy

logistic of the stock.

5. The valve may be used for convoying mineral oils, fuels, compressed air or gases.

6. The nominal working temperature is between –20° and +120° Celsius degrees for

carbon steel, and between –60° and +200° Celsius degrees for stainless steel. The limit

may change according to the type of gasket used.

COMPONENT TESTING

Valves are checked for leakages at low

pressure and at high pressure (nominal

working pressures plus 33%).

SAFETY FACTORS

Safety factor is 2.5:1 at static load with temperature within range.

FINISH TREATMENT

All valves are treated with a chemical polishing with steel spheres which eliminate

all oxides and burrs due to the machining phase, without altering or damaging the

product. All valves are plugged to avoid internal damages.

DESIGN OF EQUIPMENT AND DRAWING

Pneumatic components and its specification

The pneumatic cutting and Filing machine consists of the following components to

full fill the requirements of complete operation of the machine.

1. Double acting pneumatic cylinder

2. Connectors

3. Hoses

1. Double acting pneumatic cylinder

Technical Data

Stroke length : Cylinder stoker length 160 mm = 0.16 m

Piston rod : 18 mm = 18 x 10ˉ³ m

Quantity : 2

Seals : Nitride (Buna-N) Elastomer

End cones : Cast iron

Piston : EN – 8

Media : Air

Temperature : 0-80 º C

Pressure Range : 8 N/m²

2. Connectors

Technical data

Max working pressure : 10 x 10 ⁵ N/m²

Temperature : 0-100 º C

Fluid media : Air

Material : Brass

3. Hoses

Technical date

Max pressure : 10 x 10 ⁵ N/m²

Outer diameter : 6 mm = 6 x 10 ˉ ³m

Inner diameter : 3.5 mm = 3.5 x 10 ˉ ³m

DESIGN CALCULATION

PNEUMATIC CYLINDER:

Design of Piston rod:

Load due to air Pressure.

Diameter of the Piston (d) = 40 mm

Pressure acting (p) = 6 kgf/cm²

Material used for rod = C 45

Yield stress (σy) = 36 kgf/mm²

Assuming factor of safety = 2

Force acting on the rod (P) = Pressure x Area

= p x (Πd² / 4)

= 6 x {( Π x 4² ) / 4 }

P = 73.36 Kgf

Design Stress(σy) = σy / F0 S

= 36 / 2 = 8 Kgf/mm²

= P / (Π d² / 4 )

∴ d = √ 4 p / Π [ σy ]

= √ 4 x 75.36 / {Π x 18}

= √ 5.33 = 2.3 mm

∴ Minimum diameter required for the load = 2.3 mm

We assume diameter of the rod = 15 mm

DISTRIBUTION CHAMBER:

Design of cylinder thickness:

Material used = Cast iron

Assuming internal diameter of the cylinder = 75 mm

Ultimate tensile stress = 250 N/mm² = 2500 gf/mm²

Working Stress = Ultimate tensile stress / factor of safety

Assuming factor of safety = 4

Working stress ( ft ) = 2500 / 4 = 625 Kgf/cm²

According to ‘LAMES EQUATION’

Minimum thickness of cylinder ( t ) = ri {√ (ft + p) / (ft – p ) -1 }

Where,

ri = inner radius of cylinder in cm.

ft = Working stress (Kgf/cm²)

p = Working pressure in Kgf/cm²

∴ Substituting values we get,

t = 3.75 { √ (625 + 6) / ( 625 – 6) -1}

t = 0.036 cm = 0.36 mm

We assume thickness of cylinder = 7.5 mm

Inner diameter of barrel = 75 mm

Outer diameter of barrel = 75 + 2t

= 75 + ( 2 x 7.5 ) = 90 mm

Design of Piston rod:

Diameter of Piston Rod:

Force of piston Rod (P) = Pressure x area = p x Π/4 (d²)

= 6 x (Π / 4) x (7.5)²

= 265 Kgf

Also, force on piston rod (P) = (Π/4) (dp)² x ft

P = (Π/4) x (dp)² x 625

256 = (Π/4) x (dp)² x 625

∴ dp² = 256 x (4/Π) x (1/625)

= 0.52

dp = 1.87 cm = 18.7 mm

By standardizing dp = 20 mm

Length of piston rod:

Approach stroke = 50 mm

Length of threads = 2 x 20 = 40mm

Extra length due to front cover = 12 mm

Extra length of accommodate head = 20 mm

Total length of the piston rod = 50 + 40 + 12 + 20

= 12.2 cm

By standardizing, length of the piston rod = 120 mm

WORKING PRINCIPLE

Initially starting with cycle pedaling operation is manually. The sprocket is

coupled to another sprocket with the help of chain drive. The second sprocket shaft is

coupled to the Cam plate with the help of End bearings. The Cam plate is coupled to the

pneumatic cylinder with the help of Cam shaft

The 2 outlet ports are connected to an actuator (Cylinder). The pneumatic

activates is a double acting, single rod cylinder. The cylinder output is coupled to further

purpose. The piston end has a water horning effect to prevent sudden thrust at extreme

ends. The end of the cylinder two Non return valve is connected for both of the side. One

Non return valve for suction side and another one non return valve are for delivery side.

The pedaling operation done by manually with the help of man and this power is

transferred to the Cam mechanism. This Cam and cam shaft is used to activate the

pneumatic cylinder. The pneumatic cylinder forward stroke is suction the water and

return stroke will deliver the water.

FABRICATION

COMPONENTS:

Piston

Actuating rod

Base Plate

Bush

Flexible hoses

Cylinder block

Piston:

The piston is fitted in the cylinder block and reciprocates inside. When the

solenoid valve supplies the air in the front end of the piston, the piston is pushed forward.

This moves the hacksaw and the cutting stroke takes place.

Then the solenoid valve supplies air to the rear end of the piston. The pressure is

same but the contact area is less due to the presence of the piston rod and pushes the

piston at a greater pressure thus resulting in a fast return stroke. The material for the

piston is Aluminum.

Actuating Rod:

The actuating rod is fitted inside the bush. It is connected at one end to the piston

rod and at the other end it is connected to the hacksaw frame. It reciprocates inside the

bush. The material for the actuating rod is mild steel.

Base Plate:

All the components of the machine are mounted on the base plate. It withstands

the vibrations encountered during machining. It is mounted on the bench.

Flexible Hose:

The flexible hoses connect the solenoid valve and the cylinder block. Hoses are

made of in layer of elastomer (or) synthetic rubber and braided fabric which takes up the

higher pressure. If the hose is subjected to rubbing, it should be enclosed in a protective

sleeve.

Cylinder block:

The cylinder block has two opening for admitting air inside the block for

achieving the reciprocation motion of the piston. The material for cylinder block is

Aluminium.

Bush:

It is cylindrical in shape with a central hole. It supports the actuating rod. The

actuating rod reciprocates in the bore at the bush. The material for the bush is mild steel.

APPLICATIONS

Since the Pedal operated reciprocating water Pump is more efficient it is used for

pumping the water or oil mostly.

Domestic Applications

Industrial Applications

It is widely applicable in industrial practices. It is used,

1. In hydraulic lifts and Jacks

2. In hydraulic press

3. In load transfer applications

4. In hydraulic puller

5. In service centers

6. In mechanical clamping applications

7. In deep drawing, shearing etc

8. In machine shops for actuating various machines

9. In wheel mechanism of an aero crafts

And it is used in all places wherever positive displacement is required. There it

has a wide range of application in all fields.

NEED FOR AUTOMATION

Nowadays almost all the manufacturing process is being atomized in order to

deliver the products at a faster rate. The manufacturing operation is being atomized for

the following reasons.

To achieve mass production

To reduce man power

To increase the efficiency of the plant

To reduce the work load

To reduce the production cost

To reduce the production time

To reduce the material handling

To reduce the fatigue of workers

To achieve good product quality

Less Maintenance

ADVANTAGES AND LIMITATIONS

ADVANTAGES:

Even if all the other pumps are similar in use the Pedal operated reciprocating

water pump is more advantageous than the other pumps.

1. This is of compact in size

2. Less Maintenance is enough

3. The oil or water pumped is of higher pressure

4. Quite running and smooth operation is achieved.

5. Higher efficiency

6. Full efficient positive displacement pump

7. Effective working principle

8. It does not have any Prime mover, like electric motor related to

the unit.

9. As the air is freely available, we can utilize the air to pumping

the water and hence it is economical.

10. Less Maintenance

LIMITATIONS

It is costlier than the other types of pump because of compressor unit.

Less efficiency when compressed to other device.

Leakage of air affects the working of the unit.