FUELS AND COMBUSTION QUIZ

During the carbonisation of coal

Hard semi-coke starts shrinking at 600°C

All of these

Evolution of H₂ and formation of methane and aromatics occur at > 700°C

All tar is evolved at < 600°C

TRUE ANSWER : ?
YOUR ANSWER : ?

To avoid fire by spontaneous combustion of coal due to its low temperature oxidation, it should be stored in

Shallow and small piles

Large heaps with small surface to volume ratio

Closed space without any ventilation facility

Fine sizes without the presence of any lump

TRUE ANSWER : ?
YOUR ANSWER : ?

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

50

500

0.5

10

TRUE ANSWER : ?
YOUR ANSWER : ?

Heat penetration rate in narrow coke ovens in high temperature carbonisation of coal is around __________ cm/hr.

10

2.5

0.5

20

TRUE ANSWER : ?
YOUR ANSWER : ?

Oxygen percentage (by weight) in atmospheric air is

21

19

29

23

TRUE ANSWER : ?
YOUR ANSWER : ?

Moisture loss is determined by the

Humidity of combustion air

Moisture content of fuel

Both A and B

The water formed by combustion reaction

TRUE ANSWER : ?
YOUR ANSWER : ?

The average molecular weight of a flue gas having the composition by volume as CO₂ = 25%, O₂ = 25%, N₂ = 50% will be

42.9

23

27.6

47.3

TRUE ANSWER : ?
YOUR ANSWER : ?

When the coal is heated in absence of air, it is called its

Deoxidation

Coalification

Carbonisation

Gasification

TRUE ANSWER : ?
YOUR ANSWER : ?

Presence of __________ in a dry gaseous fuel does not contribute to its calorific value.

Oxygen

Sulphur

Hydrogen

Carbon

TRUE ANSWER : ?
YOUR ANSWER : ?

The calorific value of producer gas is around __________ kcal/Nm³

500

4500

1300

9000

TRUE ANSWER : ?
YOUR ANSWER : ?

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