Chemical Engineering

Question: The advantage of firing pulverised coal in the furnace lies in the fact, that it
[A].

permits the use of high ash content coal.

[B].

permits the use of low fusion point ash coal.

[C].

accelerates the burning rate and economises on fuel combustion.

[D].

all (a), (b) and (c).

Answer: Option C

Explanation:

No answer description available for this question.

Question: In case of pulverised coal fired steam boiler, the secondary air serves the main purpose of
[A].

transportation of coal.

[B].

drying of coal.

[C].

combustion of coal by supplying it around the burner.

[D].

preheating the primary air.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Commercial production of petrol from coal (as practised in a factory at Sasol in South Africa) is done by the __________ of coal.
[A].

hydrogenation

[B].

gasification

[C].

carbonisation

[D].

none of these

Answer: Option A

Explanation:

No answer description available for this question.

Question: Fischer-Tropsch method aims at the
[A].

gasification of coal.

[B].

synthesis of gasoline (from water gas).

[C].

hydrogenation of coal to produce gasoline.

[D].

none of these.

Answer: Option B

Explanation:

No answer description available for this question.

Question: “Overfire burning” in a furnace is a phenomenon characterised by the
[A].

supply of excess fuel.

[B].

supply of excess air.

[C].

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

[D].

none of these.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Emission of dense white smoke out of the chimney of a thermal power plant is an indication of the use of
[A].

less air for combustion.

[B].

correct amount of air for combustion.

[C].

too much air for combustion.

[D].

pulverised coal in boilers.

Answer: Option C

Explanation:

No answer description available for this question.

Question: As time passes, the calorific value of stored coal
[A].

decreases

[B].

increases

[C].

remains unaltered

[D].

may increase or decrease (depends on the method of storage).

Answer: Option A

Explanation:

No answer description available for this question.

Question: A particular coal is said to be free burning when it
[A].

burns completely.

[B].

gives smokeless burning.

[C].

shows little or no fusing action.

[D].

none of these.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Oxygen percentage (by weight) in atmospheric air is
[A].

19

[B].

21

[C].

23

[D].

29

Answer: Option C

Explanation:

No answer description available for this question.

Question: For maximum discharge through a chimney, its height should be
[A].

200 meters.

[B].

infinitely long.

[C].

more than 105.7 metres.

[D].

equal to the height of the hot gas column producing draught.

Answer: Option D

Explanation:

No answer description available for this question.