FUELS AND COMBUSTION QUIZ

Volatile matter content in coking coal may be about __________ percent.

1

7

22

46

TRUE ANSWER : ?
YOUR ANSWER : ?

When the coal is heated in absence of air, it is called its

Deoxidation

Gasification

Coalification

Carbonisation

TRUE ANSWER : ?
YOUR ANSWER : ?

Blast furnace gas compared to coke oven gas has

Higher calorific value

Lower ignition temperature

Lower theoretical flame temperature

Narrower limit of inflammability

TRUE ANSWER : ?
YOUR ANSWER : ?

Overfire burning in a furnace is a phenomenon characterised by the

Supply of excess air

Supply of excess fuel

Burning of carbon monoxide and other incombustibles in upper zone of furnace by supplying more air

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

A good metallurgical coke should have very low

Fusion point of its ash

Hardness & strength

Sulphur & phosphorous content

Porosity

TRUE ANSWER : ?
YOUR ANSWER : ?

Combustion of pulverised coal compared to the lumpy coal

Provides higher thermal efficiency & flame temperature

Provides better control of furnace temperature

All of these

Facilitates combustion with lower excess air

TRUE ANSWER : ?
YOUR ANSWER : ?

Fuel combustion is never cent per cent efficient due to

Dry gas/stack gas loss

Incomplete combustion

Moisture loss

All of these

TRUE ANSWER : ?
YOUR ANSWER : ?

A coal with high ash content

Is not subjected to washing

Has higher calorific value

Is harder and stronger

Has low quantity of mineral matter

TRUE ANSWER : ?
YOUR ANSWER : ?

Use of preheated air for combustion of fuel in the furnace, increases the

None of these

Calorific value of the fuel

Scale losses of the furnace stock

Flame temperature

TRUE ANSWER : ?
YOUR ANSWER : ?

Bomb calorimeter can be used to determine the __________ of the coal.

Calorific value

Neither A nor B

Both A & B

Sulphur content

TRUE ANSWER : ?
YOUR ANSWER : ?

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