Fluid Power Engineering (2151903)...Dr. R.K. Bansal, “Fluid Mechanics & Hydraulic Mechanics”, 9th ed., Laxmi Publications (P) LTD, ND, 2008, Page 376-379, 357-361. Pelton Wheel

A Laboratory Manual for

Fluid Power Engineering

(2151903)

5th Semester

Mechanical Engineering

DARSHAN INSTITUTE OF

ENGINEERING AND TECHNOLOGY,

RAJKOT

Campus: At Hadala, Rajkot-Morbi Highway, Near Water Sump, Rajkot 363650

Phone: +91-2822-293010 Web: www.dashan.ac.in

DARSHAN INSTITUTE OF ENGINEERING

AND TECHNOLOGY

Department of Mechanical Engineering - 5th Semester

Fluid Power Engineering (2151903)

List of Experiments

Sr. No.

Objective Date of

Performance Date of

submission Assessment

Marks Sign &

Remarks

1. To Study of hydraulic force.

2. To Study the operation of a Pelton Turbine.

3. To study the operation of a Francis Turbine.

4. To Study of centrifugal pump characteristics.

5. To Study of reciprocating pumps characteristics.

6. To study the operation of a double stage air compressor.

TOTAL MARKS (Average of 6 Experiment out of 10)

Impact of Jet on Vanes

Fluid Power Engineering (2151903) Department of Mechanical Engineering Darshan Institute of Engineering and Technology, Rajkot

1-1

Experiment No. 1

1.1 Aim

To study the effect of force on following type of vanes:

1. Hemispherical Vane

2. Flat Plate Vane

1.2 Introduction

If a vertical water jet moving with velocity ‘V’ is made to strike a target, which is free to

move in the vertical direction, then a force will be exerted by the jet, according to

momentum equation, this force must be equal to the rate of change of momentum of the

jet flow in the same direction.

Due to impact of the jet on the flat stationary plate, the entire velocity of the jet is

destroyed and due to the rate of change of momentum, force acts on the plate. The jet

after striking will move along the plate. But the plate is at right angles to the jet. Hence

the components of the velocity of the jet in the direction of the jet after striking will be

zero.

The force exerted by the jet on the flat plate in the direction of the jet,

For hemispherical vane,


Fluid Power Engineering (2151903) Department of Mechanical Engineering Darshan Institute of Engineering and Technology, Rajkot 1-2

1.3 Nomenclature

A Area of measuring tank m2

a Cross section area of nozzle m2

d Diameter of nozzle m

Fth Theoretical force N

Fx Rate of change of momentum (Actual force) N

Q Actual discharge m3/sec

R Rise of water level in measuring tank m

R1 Final height of water in measuring tank after time t cm

R2 Initial height of water in measuring tank cm

t Time for flow measurement sec

V Velocity of jet m/sec

W Total weight kg

WA Weight applied on the disc kg

WD+R Weight of aluminum disc with rod kg

WF Weight of flat plate vane kg

WH Weight of hemispherical vane kg

Density of water kg/m3

1.4 Block Diagram

Figure 1.1 Experimental apparatus



1-3

(V1-flow control valve, V2-bypass valve,

V3-drain valve of sump tank, V4-drain valve of measuring tank)

Figure 1.2 Impact of jet on vanes

1.5 Description

The setup consists of a sump tank with centrifugal pump to circulate water. A chamber

with two side glass is provided for visualization of impact of jet on vanes. Water from

sump tank flows through a nozzle and strikes vertically to vane positioned above the

nozzle. Two types of vanes (Hemispherical /Flat) are provided that can be fixed one at a

time. Arrangement is made for the movement of the plate of the vane under the action

of the jet and also because of the weight placed on the loading pan. Measuring tank and

stop watch is provided for flow measurement.

1.6 Utilities Required

Electricity Supply: Single Phase, 220 V AC, 50 Hz, 5-15 Amp. Combined socket

with earth connection.

Water Supply (Initial fill) and floor Drain Required.

Floor Area Required: 1.5 m 0.75 m.



1.7 Experimental Procedure

Starting Procedure:

Close all the valves provided.

Fill sump tank ¾ with water and ensure that no foreign particles are there.

Fix desired vane (Hemispherical /Flat).

Ensure that all on /off switches given on the panel are at OFF position.

Open by pass valve.

Switch on the pump.

Put weight on the pan.

Operate by pass valve and flow control valve to regulate the flow of water

through channel.

Now control the flow of water so that the applied weight on the top is counter

balanced by the impact of jet.

Measure flow rate using measuring tank and stop watch.

Repeat the experiment for different weights.

Repeat the experiment for other vane.

Closing Procedure:

When experiment is over, switch off pump.

Switch off power supply to panel.

Drain water from all tanks with the help of drain valves.

1.8 Observation & Calculation

Given Data:

Acceleration due to gravity, g = 9.81 m/sec2

Diameter of nozzle, d = 0.01 m

Area of measuring tank, A = 0.074 m2

Density of water = 1000 kg/m3

Weight of aluminum disc with rod, WD+R = 0.198 kg

Weight of Flat plate vane, WF = 0.024 kg

Weight of Hemispherical vane, WH = 0.043 kg



1-5

Observation Table:

For Flat Plate Vane For Hemispherical Vane

Sr. No.

WA (kg)

R1 (cm)

R2 (cm)

t (sec)

Sr. No.

WA (kg)

R1 (cm)

R2 (cm)

t (sec)

1. 1.

2. 2.

3. 3.

Calculations:

(A) Flat Plate Vane

1. Area of Nozzle,

2. Rise of water level in measuring tank,

3. Actual flow rate,

4. Velocity of jet,

5. Actual force acting on flat plate vane,

6. Total weight,

7. Theoretical force,

8.



(B) Hemispherical Vane

1. Area of Nozzle,


3. Actual flow rate,

4. Velocity of jet,

5. Actual force acting on hemispherical vane,

6. Total weight,

7. Theoretical force,

8.

Result Table:

(A) For Flat Plate Vane

Sr. No.

R (m)

Q (m3/sec)

V (m/sec)

Fx (N)

W (Kg)

Fth (N)

Error (%)

1.

2.

3.



1-7

(B) For Hemispherical Plate Vane

Sr. No.

R (m)

Q (m3/sec)

V (m/sec)

Fx (N)

W (kg)

Fth (N)

Error (%)

1.

2.

3.

1.9 Conclusion

1.10 Precaution & Maintenance Instructions

Never run the apparatus if power supply is less than 200 Volts and above 230

Volts,

Never switch on main power supply before ensuring that on/off switch given on

the panel is at OFF position.

Always use clean water.

Never fully close the delivery valve and by-pass Valve at a time.

Always keep apparatus free from dust.

1.11 Troubleshooting

If pump gets jammed, open the back cover of pump and rotate the shaft

manually.

If pump gets heated up, switch off the main power for 30 minutes and avoid

closing the flow control valve (V1) and By Pass Valve (V2) at a time.

1.12 References

Dr. R.K. Bansal, “Fluid Mechanics & Hydraulic Mechanics”, 9th ed., Laxmi

Publications (P) LTD, ND, 2008, Page 376-379, 357-361.

Pelton Wheel Turbine Test Rig


2- 1

Experiment No. 2

2.1 Aim

To Study the operation of a Pelton Turbine:

1. To determine the output power of Pelton turbine.

2. To determine the efficiency of the Pelton turbine.

2.2 Introduction

A turbine is a machine which converts the fluid energy into mechanical energy which is

then utilized to run the electric generator of a power plant. Pelton turbine is an impulse

turbine. In an impulse turbine, all the available energy of water is converted into kinetic

energy or velocity head by passing it through a contracting nozzle provided at the end of

the penstock. The water coming out of the nozzle is formed into a free jet, which strikes

on a series of buckets of the runner thus causing it to revolve. The runner revolves

freely in air and the pressure at the inlet and outlet of the turbine is atmosphere. The

water is contact with only a part of the runner at a time, and throughout its action on

the runner. The turbine is used for high head.

2.3 Nomenclature

A Cross section area of pipe m2

Cv Co-efficient of pitot tube.

D Diameter of pipe M

dB Diameter of brake drum m

dR Diameter of rope m

Ei Input power kW

Eo Output power kW

g Acceleration due to gravity m/sec2

H Total head m

h Manometer difference m

h1,h2 Manometer reading at both points cm

N RPM of runner shaft RPM

P Pressure gauge reading kg/cm2

Re Equivalent Radius m



2-2

Q Discharge m3/sec

T Torque N m

V Velocity of water m/sec

W1 Spring balance weight kg

W2 Adjustable weight kg

W3 Weight of Rope kg

w Density of Water kg/m3

m Density of Manometer fluid i.e. Hg kg/m3

ηt Turbine efficiency %

2.4 Block Diagram

(V1 – bypass valve, V2 – valve for cooling water or brake drum, V3 – drain valve for

sump tank, V4 & V5 – valve for manometer for pressure tapping,

V6 & V7 – valve on manometer for air vent)

Figure 2.1 Pelton wheel turbine test rig



2- 3

Fig 2.2 Experimental apparatus

2.5 Description

The set up consists of centrifugal pump, turbine unit, and sump tank, arranged in such a

way that the whole unit works as re-circulating water system. The centrifugal pump

supplies the water from sump tank to the turbine. The loading of the turbine is achieved

by rope brake drum connected with weight balance. The turbine unit can be visualize by

a large circular transparent window kept at the front. A bearing pedestals rotor

assembly of shaft, runner and brake drum, all mounted on suitable cast iron base plate.




Water supply (Initial fill)

Drain Required.

Floor Area required:

Mercury (Hg) for manometer: 250 gms

Tachometer for RPM measurement.



2-4


Starting Procedure:

Close all the valves provided.

Fill sump tank ¾th with clean water and ensure that no foreign particles are

there.

Fill manometer fluid i.e. Hg. in manometer by opening the valves of manometer

and one PU pipe from pressure measurement point of pipe.

Connect the PU pipe back to its position and close the valves of manometer.

Open the by-pass valve and ensure that there is no load on the brake drum.

Switch on the pump with the help of starter.

Close the by-pass valve.

Open pressure measurement valves of the manometer.

Open the air release valve provided on the manometer, slowly to release the air

from manometer. (This should be done very carefully)

When there is no air in the manometer, close the air release valves.

Now turbine is in operation.

Load the turbine with the help of hand wheel attached on the top of weight

balance.

Note the manometer reading and pressure gauge reading.

Measure the load applied and RPM of the turbine.

Repeat the experiment at different load.

Repeat the experiment for different discharge by regulating the nozzle position

by the hand wheel provided for same.

Closing Procedure:

When the experiment is over, first of all remove the load on dynamometer.

Open the by-pass valve.

Close the ball valves provided on manometer.

Switch OFF Pump with the help of starter.

Switch OFF main power supply.

Drain the sump tank by the drain valve provided.



2- 5

2.8 Observation & Calculation Given Data:


Diameter of pipe, D = 0.052 m

Density of water, w = 1000 kg/m3

Diameter of brake drum, dB = 0.2 m

Density of Manometer fluid Hg, m = 13600 kg/m3

Diameter of rope, dR = 0.012 m

Co-efficient velocity for pitot tube, Cv = 0.98

Weight of Rope, W3 = 0.116 kg

Observation Table:

Sr. No

N RPM

P kg/cm2

h1 (cm)

h2 (cm)

W1 (kg)

W2 (kg)

1.

2.

3.

4.

5.

Calculations:

1. Total head,

2. Cross section area of pipe,

3. Manometer difference,

4. Velocity of water,



2-6

√ ( )

5. Discharge,

6. Input power,

7. Equivalent radius,

8. Torque,

( )

9. Output power,

10. Turbine efficiency,

Result Table:

Sr. No

H, (m of WC)

Q (m3/sec)

EI

(kW) T

(Nm) Eo

(kW) ηt

(%)

1.

2.

3.

4.

5.

2.9 Conclusion



2- 7


Never run the apparatus if power supply is less than 390 volts and above 420

volts.

To prevent clogging of moving parts, run pump at least once in a fortnight.



If pump does not lift the water, the revolution of the motor may be reverse.

Change the electric connection to change the revolutions.

If panel is not showing input, check the main supply.

2.12 References

Streeter, Wylie, Bedford, “Fluid Mechanics”, 9th ed., McGraw Hill., NY, 2007, Page

529-532.

Y.A.Cengel, J.M. Cimbala, “Fluid Mechanics”, 2nd ed., Tata McGraw-Hill, ND, 2007,

Page 783-785.

Francis Turbine Test Rig


3- 1

Experiment No. 3

3.1 Aim

To study the operation of a Francis Turbine:

1. To determine the output power of Francis Turbine.

2. To determine the efficiency of the Francis Turbine.

3.2 Introduction

Francis Turbine, named after James Bichens Fransis, is a reaction type of turbine for

medium high to medium low heads and medium small to medium large quantities of

water. The reaction turbine operates with its wheel submerged in water. It is a mixed

flow type in which water enters the runner radially inwards towards the centre and

discharges out axially. The water before entering the turbine has pressure as well as

kinetic energy. The moment on the wheel is produced by both kinetic and pressure

energies. The water leaving the turbine has still some of the pressure as well as kinetic

energy.

3.3 Nomenclature

A Cross section area of pipe m2

Cv Co-efficient of pitot tube

D Diameter of pipe m

dB Diameter of brake drum m

dR Diameter of rope m

Ei Input power kW

Eo Output power kW

g Acceleration due to gravity m/sec2

H Total head m

h Differential pressure of manometer m

h1,h2 Manometer reading at both points cm

N RPM of runner shaft RPM

Pd Delivery pressure kg/cm2

PS Suction pressure mmHg



Q Discharge m3/sec

Re Equivalent Radius m

T Torque N m

V Velocity of water m/sec

W1 Applied weight kg

W2 Dead weight (obtain from spring balance) kg

W3 Weight of hanger kg

W4 Weight of Rope kg

w Density of Water kg/m3

m Density of Manometer fluid i.e. Hg kg/m3

ηt Turbine efficiency %

3.4 Block Diagram

(V1 - valve for discharge pressure, V2 - valve for suction pressure, V3 & V4 - valve for

pitot tube, V5 & V6 – Air bleeding valve, V7 – Drain valve for sump tank,

V8 – valve for cooling water of brake drum)

Figure 3.1 - Francis turbine test rig



3- 3

Figure 3.2 – Experimental apparatus

3.5 Description

The present set-up consists of a runner. The water is fed to the turbine by means of

Centrifugal Pump, radially to the runner. The runner is directly mounted on one end of a

central SS shaft and other end is connected to a brake arrangement. The circular

window of the turbine casing is provided with a transparent acrylic sheet for

observation of flow on to the runner. This runner assembly is supported by thick cast

iron pedestal. Load is applied to the turbine with the help of brake arrangement so that

the efficiency of the turbine can be calculated. A draught tube is fitted on the outlet of

the turbine. The set-up is complete with guide mechanism. Pressure and vacuum gauges

are fitted at the inlet and outlet of the turbine to measure the total supply head on the

turbine.


Electricity Supply: Three Phase, 440 V AC, 50 Hz, 5kW with earth connection.

Water supply (200 liters.)

Drain required.

Floor Area required: 2 m x 1 m



Mercury for manometer, 250 gm.

Tachometer to measure RPM


Starting Procedure:

Clean the apparatus and make tank free from Dust.

Close the drain valve provided.

Fill Sump tank ¾ with Clean Water and ensure that no foreign particles are there.

Fill manometer fluid i.e. Hg. in manometer by opening the valves of manometer

and one PU pipe from pressure measurement point of pipe.

Connect the PU pipe back to its position and close the valves of manometer.

Ensure that there is no load on the brake drum.

Switch on the Pump with the help of Starter.

Open the Air release valve provided on the Manometer, slowly to release the air

from manometer. (This should be done very carefully.)

When there is no air in the manometer, close the air release valves.

Now turbine is in operation.

Apply load on hanger and adjust the spring balance load by hand wheel just to

release the rest position of the hanger.

Note the manometer reading, pressure gauge reading and vacuum gauge reading.

Measure the RPM of the turbine.

Note the applied weight and spring balance reading.

Repeat the same experiment for different load.

Regulate the discharge by regulating the guide vanes position.

Repeat the experiment for different discharge.

Closing Procedure:

When the experiment is over, first remove load on dynamometer.

Open the by-pass valve.

Close the ball valves provided on manometer.

Switch OFF Pump with the help of starter.

Switch OFF main power supply.



3- 5


Given Data:

Acceleration due to gravity g = 9.81 m/sec2

Diameter of pipe, D = 0.08 m

Density of water w = 1000 kg/m3

Diameter of brake drum, dB = 0.2 m

Density of Manometer fluid Hg, m = 13600 kg/m3

Diameter of rope, dR = 0.012 m

Co-efficient of velocity for pitot tube, Cv = 0.98

Weight of hanger, W3 = 0.246 kg

Weight of Rope, W4 = 0.104 kg

Observation table:

Sr. No.

N RPM

Pd kg/cm2

PS mmHg

h1 (cm)

h2 (cm)

W1 (kg)

W2 (kg)

1.

2.

3.

4.

5.

Calculations:

1. Total head,

(

)


3. Manometer difference,

4. Velocity of water,



√ ( )

5. Discharge,

6. Input power,

7. Equivalent radius,

8. Torque,

( )

9. Output power,

10. Turbine efficiency,

Result Table:

Sr. No

H, (m of WC)

Q (m3/sec)

EI

(kW) T

(Nm) Eo

(kW) ηt

(%)

1.

2.

3.

4.

5.

3.9 Conclusion



3- 7



volts

To prevent clogging of moving parts, Run Pump at least once in a fortnight.


Drain the apparatus completely after experiment is over.



If pump does not lift the water, the revolution of the motor may be reverse.

Change the electric connection to change the revolutions.

If panel is not showing input, check the main supply.

3.12 References

Streeter, Wylie, Bedford, “Fluid Mechanics”, 9th ed., McGraw Hill., NY, 2007, Page

518-520.

Y.A. Cengel, J.M. Cimbala,”Fluiod Mechanics”, 2nd ed., Tata McGraw-Hill, ND,

2007, Page 786-795.

Centrifugal Pump Test Rig


4- 1

Experiment No. 4

4.1 Objective

Study of centrifugal pump characteristics.

4.2 Aim

1. To determine : (i) Power input, (ii) Shaft output, (iii) Discharge, (iv) Total head,

(v) Pump Output, (vi) Overall efficiency, (vii) Pump efficiency

2. To plot the following performance characteristics: (i) Head Vs Discharge, (ii)

Pump efficiency Vs Discharge

4.3 Introduction

The hydraulic machines, which convert the mechanical energy into hydraulic energy,

are called pumps. The hydraulic energy is in the form of pressure energy. If the

mechanical energy is converted into pressure energy by means of centrifugal force

acting on the fluid, the hydraulic machine is called centrifugal pump.

The centrifugal pump acts as a reversed of an inward radial flow reaction turbine. This

means that the flow in centrifugal pumps is in the radial outward directions. The

centrifugal pump works on the principle of forced vortex flow, which means that an

external torque rotates a certain mass of liquid, the rise in pressure head of the rotating

liquid takes place. The rise in pressure head at any point of the rotating liquid is

proportional to the square of tangential velocity of (i.e. rise in pressure head = V2/ 2g or

2r2/2g) the liquid at that point. Thus at the outlet of the impeller where radius is more,

the rise in pressure head will be more and the liquid will be discharged at the outlet

with a high- pressure head. Due to this high-pressure head, the liquid can be lifted to a

high level.

Centrifugal Pump is a mechanical device, which consists of a body, impeller and a

rotating mean i.e. motor, engine etc. Impeller rotates in a stationary body and sucks the

fluid through its axes and delivers through its periphery. Impeller has an inlet angle,

outlet angle and peripheral speed, which affect the head and discharge. Impeller is

rotated by motor or i.c. engine or any other device.



4-2

4.4. Nomenclature


EMC Energy meter constant Pulses/kW hr

Ei Pump input kW

ES Shaft output kW

Eo Pump output kW

g Acceleration due to gravity m/s2

H Total head m

hpg Height of pressure gauge from vacuum gauge m

N Speed of pump RPM

P Pulses of energy meter



Q Discharge m3/s


R1 Final level of water in measuring tank cm

R2 Initial level of water in measuring tank cm

t Time taken by R sec

tp Time taken by P sec

Density of fluid kg/m3

ηm Motor efficiency %

ηo overall efficiency %

ηp Pump efficiency %



4- 3

4.5 Block Diagram

(V1 – flow control valve at discharge of pump, V2 - control valve at suction of pump, V3 –

valve for delivery pressure, V4 – valve for suction pressure, V5 – drain valve of

measuring tank, V6 – Drain valve for sump tank)

Figure 4.1 Centrifugal pump test rig




4-4

4.6 Description

Centrifugal Pump Test Rig consists of a sump, a centrifugal pump, a DC motor and

measuring tank. To measure the head, pressure and vacuum gauges are provided. To

measure the discharge, a measuring tank is provided. Flow diversion system is provided

to divert flow from sump tank to measuring tank and from measuring tank to sump

tank. A valve is provided in pipeline to change the rate of flow.


Electricity Supply: Single Phase, 220 V AC, 50 Hz, 5-15 Amp.

Combined socket with earth connection.

Water Supply (Initial Fill).

Floor Drain Required.

Floor Area Required:


Starting Procedure:

Clean the apparatus and make tanks free from dust.

Close the drain valves provided.

Fill sump tank ¾ with clean water and ensure that no foreign particles are there.

Open flow control valve given on the water discharge line and control valve

given on suction line.

Ensure that all On/Off switches given on the panel are at OFF position.

Set the desired RPM of motor / pump with the speed control knob provided at

the control panel.

Operate the flow control valve to regulate the flow of water discharged by the

pump.

Operate the control valve to regulate the suction of the pump.

Record discharge pressure by means of pressure gauge, provided on discharge

line.

Record suction pressure by means of vacuum gauge, provided at suction of the

pump.

Record the power consumption by means of energy meter, provided in panel

with the help of stop watch.



4- 5

Measure the discharged by using measuring tank and stop watch.

Repeat the same procedure for different speeds of pump.

Repeat the same procedure for different discharge with constant speed.

Closing Procedure:

When experiment is over, open gate valve properly provided on the discharge

line.

Reduce the RPM of the pump with the help of DC drive.

Switch OFF the pump first.

Switch OFF power supply to panel.


Given Data:

Area of measuring tank A = 0.125 m2


Motor Efficiency, ηm = 0.8 (assumed)


Energy Meter Constant, EMC = 3200 Pulses / kW hr

Height of pressure gauge from vacuum gauge, hpg = 1 m

Observation Table:

Sr. No

N (RPM)

Pd (kg/cm2)

PS (mmHg)

R1 (cm)

R2 (cm)

t (sec)

tP (sec)

P

1.

2.

3.

4.

5.

Calculations:

1. Pump input,

2. Shaft output,



4-6


4. Discharge,

⁄

5. Total head,

[

]

6. Pump output,

7. Pump efficiency,

8. Overall efficiency,

Result Table:

Sr. No

N (RPM)

H (m of

water)

Q (m3/sec)

EI

(kW) Es

(kW) Eo

(kW) ηp

(%) ηo

(%)

1.

2.

3.

4.

5.



4- 7

4.10 Conclusion


Never run the apparatus if power supply is less than 200Volts and above 230

Volts

Never fully close the Delivery line and By-Pass line Valves simultaneously.

To prevent clogging of moving parts, Run Pump at least once in a fortnight


If apparatus will not in use for more than half month, drain the apparatus

completely.



If pump does not lift the water, open the air vent provided on the pump to

remove the air from pump.

If still water is not lifting the revolution of the DC motor may be reverse. Change

the electric connection of motor to change the revolutions.

If panel is not showing input, check the fuse and main supply.

If field failure (FF) indicates on the control panel and the motor is not moving,

check the fuses if burnt, change it.

If overload (OL) indicates on the panel and motor stop moving, reduce the load.

4.13 References

R.S Khurmi, “Hydraulics, Fluid Mechanics and Hydraulic Machines”, 11th ed.,

S.Chand & Company LTD., ND, 2008, Page 582-585, 587, 590.

Y.A. Cengel, J.M. Cimbala, ”Fluid Mechanics”, 2nd ed., Tata McGraw-Hill, ND, 2007,

Page180-182.

Reciprocating Pump Test Rig


5- 1

Experiment No. 5

5.1 Objective

Study of reciprocating pumps characteristics.

5.2 Aim

1. To determine: (i) Power input, (ii) Shaft output, (iii) Total head, (iv) Discharge,

(v) Pump Output, (vi) Overall efficiency, (vii) Volumetric efficiency, (viii) Pump

efficiency

2. To plot the following performance characteristics: (i) Head Vs Discharge, (ii)

Pump efficiency Vs Discharge

5.3 Introduction

A pump is a device which lifts water from a lower level to a higher level at the expense

of mechanical energy. Pump can be broadly classified into two categories, Positive

Displacement & rotodynamic or dynamic pressure pump. In a positive displacement

pump a small quantity of liquid is taken inside the pump and is bodily displaced and

forced out of the pump under pressure. The liquid inside a positive displacement pump

may be subjected either to a reciprocating motion (reciprocating pump) or to a

rotary/circular motion (gear pump, screw pumps etc.).

Reciprocating Pump consists a piston having a reciprocatory motion inside a cylinder

with the help of connecting rod and a crank rotated by a electric motor, I.C. Engine, or

any another suitable means. The cylinder is connected to the sump by the suction pipe

and to the reservoir by the delivery pipe. Valves are provided at suction and delivery

side and are non-returnable so that to allow the fluid in direction only.

These pumps are applied where the fluid is required in a small quantity but at a higher

pressure. Reciprocating pumps are applied for vehicle washing, for the water supply for

the multi-stories buildings, industries etc.



5-2

5.4 Nomenclature


a Area of cylinder m2

d Diameter of cylinder m

EMC Energy meter constant Pulses/kW hr

Ei & Eo Pump input & output kW

ES Shaft output kW


H Total head m

hpg Height of pressure gauge from vacuum gauge m

L Length of stroke m

N Speed of pump RPM

P Pulses of energy meter



Qa & Qt Actual & Theoretical discharge m3/s


R1 & R2 Final & Initial level of water in measuring

tank

cm

t & tp Time taken by R & P sec

Density of fluid kg/m3

ηm, ηo, ηp Motor, Overall & Pump efficiency %

ηt & ηvol Transmission & Volumetric efficiency %



5- 3

5.5 Figure

(V1 – flow control valve, V2 – valve for suction, V3 – valve before pressure gauge, V4 –

valve before suction gauge, V5 – drain valve for measuring tank, V6 – drain valve for

sump)

Figure 5.1 Reciprocating pump test rig




5-4

5.6 Description

The apparatus consists of a double acting-single cylinder reciprocating pump is

operated on closed circuit basis. A DC motor is provided to regulate the rpm of the

pump. Suction and delivery head can be varied by the valves provided and Pressure &

vacuum gauges can measure it. To find out the Input power to the pump an electronic

energy meter is fitted. Sump tank, measuring tank and stop watch is provided with the

set-up. Discharge can be calculated with the help of measuring tank and stop watch.




Water Supply (Initial Fill).

Floor Drain Required.

Floor Area Required:


Starting Procedure:

Clean the apparatus and make all tanks free from dust.

Close the drain valves provided.

Fill Sump Tank ¾th with clean water and ensure that no foreign particles are

there.

Open flow control valve given on the water discharge line and control valve

given on suction line.

Ensure that all On/Off switches given on the panel are at OFF position.

Set the speed of motor / pump with the help of 3 speed step cone pulley.

Now switch ON the main power supply and switch ON the Pump.

Operate the flow control valve to regulate the flow of water discharged by the

pump.

Operate the control valve to regulate the suction of the pump.

Record discharge pressure by means of pressure gauge, provided on discharge

line.

Record suction pressure by means of vacuum gauge, provided at suction of the

pump.



5- 5

Note down the time required for 10 pulses with the help of stop watch to

calculate the power consumption.

Note down the RPM.

Measure the flow of water, discharged by the pump, using stop watch and

measuring tank.

Repeat the same procedure for different pressure head.

Repeat the same procedure for different RPM with the help of step cone pulley.

Closing Procedure:

When experiment is over, gate valve is proper open provided on discharge line.

Switch OFF the pump first.

Switch OFF power supply to panel (MCB).


Given Data:

Area of measuring tank, A = 0.075 m2

Energy Meter Constant, EMC = 3200 Pulses / kW hr

Acceleration due to gravity, g = 9.81m/sec2

Height of pressure gauge from vacuum gauge, hpg = 0.650 m

Motor Efficiency, ηm = 0.8 (assumed)

Efficiency of transmission, ηt = 0.7 (assumed)


Diameter of cylinder, d = 0.055 m

Length of stroke, L = 0.04 m

Observation Table:

Sr. No

N (RPM)

Pd (kg/cm2)

PS (mm of Hg)

R1 (cm)

R2 (cm)

t (sec)

tP (sec)

P

1.

2.

3.

4.

5.



5-6

Calculations:

1. Pump input,

2. Shaft output,


4. Actual discharge,

⁄

5. Area of cylinder,

6. Theoretical discharge,

⁄

7. Total head,

[

]

8. Pump output,

9. Volumetric efficiency,

10. Pump efficiency,



5- 7

11. Overall efficiency,

Result Table:

Sr. No

N (RPM)

Qa (m3/sec)

Qt (m3/sec)

EI

(kW) Es

(kW) Eo

(kW) ηvol (%)

ηp (%)

ηo (%)

1.

2.

3.

4.

5.

5.10 Conclusion


Never run the apparatus if power supply is less than 200Volts and above 230

Volts.

Never fully close the Delivery Valve and By-Pass Valves at a time.

To prevent clogging of moving parts, Run Pump at least once a fortnight.


If apparatus is not in use for more than half month, drain the apparatus

completely.




5-8


If pump does not lift the water, open the air vent provided on the pump to

remove the air from pump.

If still water is not lifted, the revolution of the DC motor may be reverse. Change

the electric connection of motor to change the revolutions.

If panel is not showing input, check the fuse and main supply.

If field failure (FF) indicates on the control panel and the motor is not moving,

check the fuses, if burnt, change it.

If overload (OL) indicates on the panel and motor stop moving, reduce the load.

5.13 References

R.S Khurmi, “Hydraulics Fluid Mechanics and Hydraulic Machines”, 11th ed.,

S.Chand & Company LTD., ND, 2008, Page 602-604, 605, 606.

Dr. P.N. Modi, Dr. S. M. Seth, “Hydraulics & Fluid Mechanics”, 15th ed., Standard

Book House, ND, 2005, Page1020-1022.

Double Stage Air Compressor Test Rig


6- 1

Experiment No. 6

6.1 Objective

To study the operation of a double stage air compressor.

6.2 Aim

1. To find out the volumetric efficiency

2. To find out isothermal efficiency

3. To calculate the compression ratio

6.3 Nomenclature

ao Cross section area of orifice m2

ap Cross section area of pipe m2

Cd Co-efficient of discharge of orifice

d Diameter of bore m

do Diameter of orifice m

dp Diameter of pipe m

EMC Energy meter constant Pulses / kW hr

Ei Power input kW

Eiso Isothermal power kW

ES Shaft power kW


ΔH Total head m of air

h Manometer pressure difference m

h1, h2 Manometer reading at both points cm

L Length of stroke m

N RPM of compressor rpm

Nm RPM of motor rpm

Pa Atmospheric pressure N/m2

P Number of pluses from Energy Meter

Pd Gauge pressure kg/cm2

Qa Actual volume of air m3/sec



6-2

Qt Swept volume of compressor m3/sec

R Radius of swinging field dynamometer m

r Compression ratio

T Torque N-m

tp Time of P pulses sec

W Weight kg

m Density of water kg/m3

a Density of air kg/m3

ηv Volumetric efficiency %

ηiso Isothermal efficiency %

6.4 Introduction

Air Compressor is a device, which sucks the air from atmosphere and compresses it and

delivers in reservoir tank. It compresses the air by means of a reciprocating piston,

which reciprocates in a stationary cylinder. It can be single stage or multi stage. It can

be single acting or double acting.

In two-stage compression, air is partially compressed in low-pressure cylinder. This air

is passed through intercooler between first stage and second stage so that air at inlet of

second stage is at lower temperature than the first stage outlet. This is done to reduce

the work of compression in second stage. Final compression is completed in second

stage i.e. in high-pressure cylinder. Also, the compressors are provided with clearance

volume, two stage compressors can achieve higher volumetric efficiency than single

stage compressors, because of lower compression per stage.

As the compressed air is used in a wide range in industrial, domestic, aeronautics fields

etc. so compressors are applied in wide range. Compressors are used where the air is

required at high pressure.



6- 3

6.5 Block Diagram

(V1-air discharge control valve, V2-water inlet valve, V3-water drain valve)

Figure 6.1 Double stage air-compressor test rig




6-4

6.6 Description

Double stage air compressor test rig consists of two cylinders and pistons, a reservoir

tank, Driven by an A.C. motor. Temperature sensors are provided at inlet and outlet.

To find out the inlet volume of air, an orifice meter is provided. To stream line the

intake, a diaphragm base manifold is provided. Pressure Gauge is provided at reservoir

tank. Safety valve and auto power out switch is provide for the safety factor.


Electricity Supply: Single Phase, 220 V AC, 50 Hz, 5-15 Amp.

Combined socket with earth connection.

Water Supply: Continuous @ 2 LPM at 1 bar.

Floor Area required:


Close the outlet valve of tank and start the compressor.

Let the receiver pressure rise up to around 2 kg/cm2. Now open the delivery

valve so that constant delivery pressure is achieved.

Wait for some time and see that delivery pressure remain constant. Now note

down the pressure.

Record the time for 10 pulses of energy meter.

Record the manometer reading.

Record the temperature of air at inlet, before second stage and after second

stage.

Find out the RPM of compressor with the help of RPM indicator.

Repeat the same procedure for different delivery pressure.


Given Data:

Bore diameter, d = 0.0935 m

Density of water, w = 1000 kg/m3

Length of stroke L = 0.078 m

Density of air, a = 1.21 kg/m3

Diameter of orifice do = 0.011 m



6- 5

Co-efficient of discharge of orifice, Cd = 0.64

Diameter of pipe dP = 0.022 m

Energy meter constant, EMC = 3200 pulses / kW-hr

Atmospheric pressure Pa = ⁄

RPM of motor, Nm = 1440

Radius of swinging Field Dynamometer, R = 0.173 m

Observation Table:

Sr. No

N RPM

Pd kg/cm2

h1 (cm)

h2 (cm)

W (kg)

P tp

(sec) T1

(OC) T2

(OC) T3

(OC) T4

(OC)

1.

2.

3.

4.

5.

Calculations:

1. Manometer pressure difference,

2. Total head,

( )

3. Cross section area of orifice,




6-6

5. Actual volume of air,

√ √

6. Swept volume of compressor,

7. Volumetric efficiency,

8. Power input,

9. Torque,

10. Shaft power,

11. Compression ratio,

(

)

12. Isothermal power,

13. Isothermal efficiency,



6- 7

Result Table:

Sr. No

H, (m)

∆H, (m of air)

Qa (m3/s)

Qt (m3/s)

ηv (%)

EI

KW T

(Nm) Es

KW r

Eiso

KW ηiso (%)

1.

2.

3.

4.

5.

6.10 Conclusion



volts

Check the oil before starting the Air Compressor.

Close the delivery valve of Tank before starting the experiment.

Always keep the apparatus free from dust.


If control panel does not show input, main supply.

If pressure gauge is not showing the pressure, there may be a leakage of air.

Check the suction line and valves provided on delivery line.

6.13 References

W.L. McCabe J C. Smith, “Unit Operations Of Chemical Engineering”, 7th ed.,

McGraw Hill International Edition, NY, 2005, Page 216-222.

Documents

Fluid Power Engineering (2151903)...Dr. R.K. Bansal, “Fluid Mechanics & Hydraulic Mechanics”, 9th ed., Laxmi Publications (P) LTD, ND, 2008, Page 376-379, 357-361. Pelton Wheel