Power Plant Engineering

Fig. 4.42
EXERCISES
1. (a) What is meant by ‘over feed’ and ‘under feed’ principles of firing coal ?
(b) What are the different methods of firing coal ? Discuss the advantages of mechanical
methods of firing coal.
(c) Make neat sketch and explain the working of: (i) Chain grate stoker (ii) Spreader stoker.
(iii) Multi retort stoker.
(d) What is Fluidised Bed Combustion system ? Sketch and describe a Fluidised Bed
Combustion (FBC) system. State the advantages of FBC system.

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STEAM POWER PLANT
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2. Describe the various types of grates used with hand fired furnaces.
3. Name the various methods of ash handling. Describe the pneumatic system of ash handling.
Why it is essential to quench the ash before handling ?
4. (a) Describe the various methods used to fire pulverised coal.
(b) Make a neat sketch of ball and Race mill and explain its working.
(c) State the advantages of pulverised fuel firing.
5. Name the different types of coal-pulverising mills. Describe Ball-Mill.
6. Describe the various types of burners used to burn pulverised coal.
7. Name various draught systems. Describe the operation of a balanced draught system.
8. What is the cause of smoke ? State the factors necessary for its prevention.
9. Name the different types of chimneys used. State the advantages of steel chimney. Derive an
expression for the height of chimney.
10. Describe the various methods used to control the degree of superheat. Name the advantages
gained by using super-heat steam.
11. What is condenser ? Name the different types of condenser. Describe the operation of
(i) Surface condenser (ii) Jet condenser.