EXPERIMENT- 1
Objective: Trace the flue gas path and water – steam circuit with help of boiler model.
Babcock and Wilcox boiler
Babcock and Wilcox is a water-tube boiler is an example of horizontal inclined tube boiler it also
a High Pressure Boiler.
Construction: Babcock and Wilcox boiler with longitudinal drum. It consists of a drum
connected to a series of front end and rear end header by short riser tubes. To these headers are
connected a series of inclined water tubes of solid drawn mild steel. The angle of inclination of
the water tubes to the horizontal is about 15° or more.
Working: The fire door the fuel is supplied to grate where it is burnt. The hot gases are forced to
move upwards between the tubes by baffle plates provided. The water from the drum flows
through the inclined tubes via down take header and goes back into the shell in the form of water
and steam via uptake header. The steam gets collected in the steam space of the drum. The steam
then enters through the antipriming pipe and flows in the superheater tubes where it is further
heated and is finally taken out through the main stop valve and supplied to the Steam turbine or
Steam engine when needed.
The pressure of steam in case of cross drum boiler may be as high as 100 bar and steaming
capacity upto 27000 kg/h.
At the lowest point of the boiler is provided a mud collector to remove the mud particles through
a blow-dawn-cock.
Cochran boiler
It is one of the best types of vertical multi-tubular boiler, and has a number of horizontal fire
tubes it also a Low Pressure Boiler.
Construction: Cochran boiler consists of a cylindrical shell with a dome shaped top where the
space is provided for steam. The furnace is one piece construction and is seamless. Its crown has
a hemispherical shape and thus provides maximum volume of space.
Working: The fuel is burnt on the grate and ash is collected and disposed of from ash pit. The
gases of combustion produced by burning of fuel enter the combustion chamber through the flue
tube and strike against fire brick lining which directs them to pass through number of horizontal
tubes, being surrounded by water. After which the gases escape to the atmosphere through smoke
box and chimney.
Specifications:
Shell diameter 2.75 m
Height 5.79 m
Working pressure 6.5 bar (max. pressure = 15 bar)
Steam capacity 3500 kg/hr (max. capacity = 4000 kg/hr)
Heating surface 120 m2
Efficiency 70 to 75% (depending on the fuel used)
EX.NO: 2 DISMANTLING AND ASSEMBLING OF FOUR STROKE PETROL
ENGINE AND IDENTIFICATION OF PARTS
AIM: To dismantle and assemble the given four stoke petrol engine and to identify the parts.
TOOLS REQUIRED:
1. Double end spanner set.
2. Ring end spanner set.
3. Box spanner set.
4. Hammer
5. Cutting plier.
6. Torque wrench
7. Feeler gauge
8. Screw driver
9. Emery paper
PROCEDURE:
1. Remove the connection from the battery.
2. Remove the drain cock from the radiator and drain the water.
3. Remove the drain plug from the oil sump and drain the oil.
4. Remove the air cleaner, valve, carburettor, rock arm assembly, push rod, and rocker arm
lubrication tube.
5. Then loose the engine head bolts and remove the gaskets carefully. Then remove the
engine head and place it on a workbench.
6. Punch the valves and with the help of lock washer valve spring compressor remove the
valve spring, valve lock cup and remove the valves from the head.
7. Clean the valves, rocker arm, pushrod, tappet, valve guide, valve spring, valve lock cup
etc. if any parts are damaged replace it with new one.
8. After removing the carburettor from the engine body, dismantle all the parts from the
carburettor and clean it using petrol and compressed air.
9. Remove the inlet manifold and exhaust manifold from the engine block and remove the
gaskets carefully.
10. Clean the inlet manifold using petrol and remove the carbon from the exhaust manifold
with the help of wire brush and finally clean the manifold by kerosene.
11. Then assemble all the parts by reverse of dismantling procedure. And check timing and
adjust the distributor for correct advance.
12. Then start the engine and correct the low speed screw, needle screw and fit the air filter.
RESULT: Thus the given four-stroke petrol engine was dismantled, parts are identified and
assembled
EXPERIMENT NO- 3
NAME OF EXPERIMENT: LOAD TEST ON A SINGLE CYLINDER FOUR
STROKE DESEL ENGINE (WITH ROPE BRAKE DYNAMOMETER)
OBJECT:
1. To determine the B.P, F. P. And I. P at different load.
2. To determine the fuel consumption, air consumption, air-fuel ratio and s .f .c at different
load.
3. To calculate mechanical and thermal efficiency of the engine at different load.
4. To plot the graphs of fuel consumption in vs. B .P, and s. f. c vs. AFR.
APPARATUS WITH SPECIFICATION :
1. Single cylinder water cooled diesel engine.
Make.
Rated Horsepower: 5 H P, 1500 r p.m.
Stroke: 110 mm.
2. Dynamometer
Make
Type: Mechanical (Rope Drum)type
3. Tachometer
Make
4. Fuel measuring tank. Mounted on a sturdy iron stand, burette tube three way cock with
connecting tube.
5. Air intake measurement.
Make:
Size:
6. Stopwatch.
THEORY: In theoretical cycle, we assume that there is no friction loss or exhaust gas loss,
cooling water heat loss or there is no variation of sp. heat of gases with temperature.
Therefore the efficiency of the cycle is independent of these. But in actual cycle on which the
engine works must depend on these factors and due to these losses the efficiency of the
engine is less than that of theoretical cycle. Engines are required to be tested mainly for on a
production line of engines and in research of design purposes the basic measurements which
usually should be undertaken to evaluate the performance of an engine
are
• Speed
• Fuel and Air consumption.
• Air- Fuel ratio.
• B.P, f. p and I. p .
• Heat going to cooling water.
• Heat going to exhaust gases.
• Sp. Fuel consumption.
• Mechanical and Thermal efficiency.
EXPERIMEENT PROCEDURE:
1. Check the level of the diesel in tank and lime up with the fuel pump through fuel
measuring apparatus.
2. Start the engine by hand cranking with no load condition.
3. As the engine pick up speed, start water to the brake drum.
4. Put a light Load in the engine with loading screw.
5. Achieving steady state condition, note down all the necessary data (fuel consumption,
cooling water flow rate, brake drum speed with tachometer, manometer difference,
difference temperatures).
6. After noting down repeat the steps 4 and 5 for different load.
7. Before stop the Engine remove the load and run the engine on no-load for two minutes.
8. Stop the engine.
9. Turn off cooling water supply to engine after one minute.
PRECAUTION:
The following precautions should be taken during the experiment:
• Before starting engine, grease cups and lubricating oil should be checked.
• It should be checked that air is not present in the pump.
• The water line should also be checked.
CONCLUSION AND REMARKS:
To be written by student
