FUELS AND COMBUSTION QUIZ

A coal having high volatile matter content will

Burn with a small non-smoky flame

Have a very high calorific value

Give less yield of tar and gas on carbonisation

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

During its calorific value determination by bomb calorimeter, coal is combusted by

Air

Oxygen enriched air

Oxygen

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

Out of the following fuels, the difference between gross and net calorific value will be minimum in case of

Water gas

Coke oven gas

Blast furnace gas

Natural gas

TRUE ANSWER : ?
YOUR ANSWER : ?

Temperature of coke oven gas just before entering into saturator (for recovery of NH₃) is about __________ °C.

180

65

120

30

TRUE ANSWER : ?
YOUR ANSWER : ?

Presence of free moisture in coal during its high temperature carbonisation

Increases the loss of fine coal dust from the ovens when charging

Reduces the coking time

Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

Coalification means the

Complete combustion of coal

Process of conversion of lignite into anthracite

Direct hydrogenation of coal

Underground gasification of coal

TRUE ANSWER : ?
YOUR ANSWER : ?

Preheating of coal charge for the coke ovens reduces the

Time of carbonisation

Fuel consumption in coking

Yield of gas and tar

All of these

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following will be unsuitable for dust cleaning from flue gas at 400°C from a pulverised coal fired boiler ?

Bag filter

Hydrocyclones

Wet scrubber

Multicyclones

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following has the highest flame speed?

C₂H₆

CH₄

H₂

CO

TRUE ANSWER : ?
YOUR ANSWER : ?

During coal carbonisation process, the conversion of semi-coke to coke is accompanied by an increase in the __________ of the mass.

Electrical resistivity

None of these

Density

Porosity

TRUE ANSWER : ?
YOUR ANSWER : ?

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