FUELS AND COMBUSTION QUIZ

In high temperature carbonisation (as compared to low temperature carbonisation) of coal, the

Tar yield is more

Gas yield is less

Aromatic content of tar produced is more

Ignition temperature of coke produced is less

TRUE ANSWER : ?
YOUR ANSWER : ?

Fuel consumption in coke making can be reduced by

Preheating, blending and de-ashing the coal

All of these

Stamped charging of coal

Dry quenching of coke

TRUE ANSWER : ?
YOUR ANSWER : ?

Washing of coal

All of these

Controls its ash fusibility and increases its calorific value

Reduces its sulphur and ash content

Improves its coking properties

TRUE ANSWER : ?
YOUR ANSWER : ?

Naphthalene is used for making

Insecticides (e.g. moth balls)

All of these

Unsaturated polyesters

Drug intermediates e.g. β-naphthol

TRUE ANSWER : ?
YOUR ANSWER : ?

Fusion point of coal ash generally varies from 1000 to 1700° C. Ash having fusion point less than __________ °C is liable to form clinker.

1400

1100

1250

1350

TRUE ANSWER : ?
YOUR ANSWER : ?

A carbonaceous fuel (containing no H₂ or hydrocarbons) is burnt and the resulting flue gas contains 21% CO₂. It means that

21% excess air has been used for combustion

No excess air has been used for combustion

Complete combustion of fuel has taken place

21% excess oxygen has been used for combustion

TRUE ANSWER : ?
YOUR ANSWER : ?

Anthracite coal

Ignites more easily than bituminous coal

Is essentially a coking coal

Contains more volatile matter than bituminous coal

Burns with short, bluish, yellow-tipped flame producing very little smoke

TRUE ANSWER : ?
YOUR ANSWER : ?

Net calorific value is the gross calorific value less the __________ heat of water in the product of combustion when cooled to 15°C.

Sensible and latent

Sensible

None of these

Latent

TRUE ANSWER : ?
YOUR ANSWER : ?

Abel apparatus is used for those oils, whose flash points are___°F.

>120

300-600

>280

TRUE ANSWER : ?
YOUR ANSWER : ?

Improper storage condition results in the weathering of coal and spontaneous combustion, which increases its

Caking index

Yield of carbonised products

Friability & oxygen content

Calorific value

TRUE ANSWER : ?
YOUR ANSWER : ?

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