Fuels and Combustion

Question: The bright glow of a combustion process is the characteristic of __________ temperature oxidation of coal.
[A].

fast & high

[B].

slow & low

[C].

slow & high

[D].

fast & slow

Answer: Option A

Explanation:

No answer description available for this question.

Question: Actual flame temperature is always lower than the adiabatic flame temperature, because there is
[A].

no possibility of obtaining complete combustion at high temperature.

[B].

always loss of heat from the flame.

[C].

both (a) and (b).

[D].

neither (a) nor (b).

Answer: Option C

Explanation:

No answer description available for this question.

Question: C.V. (kcal/Nm3) of gaseous fuels __________ with increase in molecular weight.
[A].

decreases

[B].

increases

[C].

remains constant

[D].

may increase or decrease, depends on combustibles.

Answer: Option D

Explanation:

No answer description available for this question.

Question: If oxygen content in the flue gas rises too high, fuel is being wasted by
[A].

incomplete combustion.

[B].

dry gas/stack gas loss.

[C].

moisture loss.

[D].

none of these.

Answer: Option B

Explanation:

No answer description available for this question.

Question: Fuel combustion is never cent per cent efficient due to
[A].

incomplete combustion

[B].

dry gas/stack gas loss

[C].

moisture loss

[D].

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

Answer: Option D

Explanation:

No answer description available for this question.

Question: Coking time in beehive coke oven is about
[A].

12 hours

[B].

2-3 days

[C].

one week

[D].

two weeks

Answer: Option B

Explanation:

No answer description available for this question.

Question: Coking time in a commercial high temperature coal carbonisation plant is about __________ hours.
[A].

6

[B].

18

[C].

28

[D].

36

Answer: Option B

Explanation:

No answer description available for this question.

Question: Coke ovens in steel plant are heated by
[A].

electricity

[B].

coke oven gas

[C].

mixed gas

[D].

both(b) & (c)

Answer: Option D

Explanation:

No answer description available for this question.

Question: Yield of coke oven gas in low temperature carbonisation of coal is about __________ Nm3 /ton of dry coal.
[A].

60

[B].

160

[C].

500

[D].

750

Answer: Option B

Explanation:

No answer description available for this question.

Question: Calorific value of coke even gas produced by low temperature carbonisation of coal is about __________ Kcal/Nm3.
[A].

4000

[B].

2500

[C].

6500

[D].

10000

Answer: Option C

Explanation:

No answer description available for this question.