Fuels and Combustion

Question: Out of the following fuels, the difference between gross and net calorific value will be minimum in case of
[A].

coke oven gas

[B].

water gas

[C].

natural gas

[D].

blast furnace gas

Answer: Option D

Explanation:

No answer description available for this question.

Question: Percentage of nitrogen in blast furnace gas may be around
[A].

5

[B].

25

[C].

55

[D].

80

Answer: Option C

Explanation:

No answer description available for this question.

Question: Flue gas discharge velocity through chimney of a big thermal power plant may be around __________ m/sec.
[A].

0.5

[B].

10

[C].

50

[D].

500

Answer: Option B

Explanation:

No answer description available for this question.

Question: White flue gas (resembling steam) coming out of the chimney of a thermal power plant indicates that the fuel used in the boiler furnace is
[A].

tar

[B].

coke oven gas

[C].

pitch

[D].

pulverised coke

Answer: Option B

Explanation:

No answer description available for this question.

Question: Artificial draught produced by a fan can be controlled by the
[A].

speed of the fan.

[B].

damper.

[C].

variation in the pitch of the fan blades.

[D].

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

Answer: Option D

Explanation:

No answer description available for this question.

Question: Natural draught produced by a chimney depends upon the
[A].

density of the chimney gases.

[B].

height of the chimney.

[C].

both (a) and (b).

[D].

neither (a) nor (b).

Answer: Option C

Explanation:

No answer description available for this question.

Question: Fixed carbon in coal is defined as
[A].

that present in volatile matters.

[B].

the total quantity of carbon present in the coal.

[C].

hundred minus the percentage of volatile matter, ash and moisture.

[D].

the one which is present in the residue after combustion.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Coke oven gas burns with an yellowish flame, because of the presence of
[A].

CO2

[B].

CH4

[C].

H2

[D].

NH3

Answer: Option B

Explanation:

No answer description available for this question.

Question: Blast furnace gas burns with a bluish flame, because of the presence of
[A].

CO

[B].

CH4

[C].

CO2

[D].

S

Answer: Option A

Explanation:

No answer description available for this question.

Question: A coal gasifier opearating at 20 atm. (e.g. Lugri gasifier) as compared to one operating at atmospheric pressure (e.g. Kopper-Totzek or Winkler gasifier) will produce a gas having
[A].

higher methane content and thus higher calorific value.

[B].

higher carbon monoxide content.

[C].

lower carbon dioxide content.

[D].

none of these.

Answer: Option A

Explanation:

No answer description available for this question.