Fuels and Combustion

Question: In high temperature carbonisation (as compared to low temperature carbonisation) of coal, the
[A].

gas yield is less.

[B].

tar yield is more.

[C].

ignition temperature of coke produced is less.

[D].

aromatic content of tar produced is more.

Answer: Option D

Explanation:

No answer description available for this question.

Question: By-products recovery process from coal carbonisation is termed as direct, indirect and semi direct process depending upon the method of recovery of
[A].

tar

[B].

benzol

[C].

ammonia

[D].

none of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: __________ of the coal is the basis for Seylor’s coal classification.
[A].

Proximate analysis

[B].

Ultimate analysis

[C].

Caking index

[D].

Calorific value

Answer: Option B

Explanation:

No answer description available for this question.

Question: By-products are __________ recovered in ‘Beehive ovens’.
[A].

fully

[B].

partially

[C].

not at all

[D].

negligibly

Answer: Option C

Explanation:

No answer description available for this question.

Question: Function of secondary air in pulverised coal firing is to
[A].

transport the coal to the burner.

[B].

dry the coal.

[C].

ensure efficient burning of coal around the burner.

[D].

reduce primary air requirement.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Coal is pulverised before burning in large capacity boiler furnaces mainly to
[A].

ensure its complete combustion.

[B].

facilitate easy ash removal.

[C].

enhance its calorific value.

[D].

provide trouble free operation.

Answer: Option A

Explanation:

No answer description available for this question.

Question: Bomb calorimeter can be used to determine the __________ of the coal.
[A].

sulphur content

[B].

calorific value

[C].

both(a) & (b)

[D].

neither (a) nor (b)

Answer: Option C

Explanation:

No answer description available for this question.

Question: During combustion of a gaseous fuel, the presence of a non-luminous flame is an indication of the
[A].

incomplete combustion.

[B].

complete combustion.

[C].

high oxygen in flue gas.

[D].

none of these.

Answer: Option B

Explanation:

No answer description available for this question.

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

density

[B].

porosity

[C].

electrical resistivity

[D].

none of these

Answer: Option A

Explanation:

No answer description available for this question.

Question: A travelling grate stoker is meant for the efficient burning of __________ coal.
[A].

caking

[B].

pulverised

[C].

non-caking

[D].

high ash

Answer: Option C

Explanation:

No answer description available for this question.