FUELS AND COMBUSTION QUIZ

Which of the following is not used as a binder in coal briquetting?

Line

Pitch

Molasses

Tar

TRUE ANSWER : ?
YOUR ANSWER : ?

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

500

50

0.5

10

TRUE ANSWER : ?
YOUR ANSWER : ?

A coal having higher volatile matter content, has lower

Smoking tendency on burning

Coke oven gas yield on carbonisation

Chance of catching fire during storage in open space

Ignition temperature

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following would require least amount of secondary air for combustion?

Semi-bituminous coal containing 25% ash and 20% volatile matter

Anthracite containing 10% volatile matter and 8% ash

Coke breeze containing 25% ash and 2% volatile matter

Bituminous coal containing 20% ash and 25% volatile matter

TRUE ANSWER : ?
YOUR ANSWER : ?

Presence of phosphorous in metallurgical coal

Increases its caking power

Is not undersirable

Reduces its calorific value

Badly affects the quality of steel

TRUE ANSWER : ?
YOUR ANSWER : ?

Hardgrove grindability index of four coal samples are given below. Which of them is the easiest to grind?

50

100

85

70

TRUE ANSWER : ?
YOUR ANSWER : ?

'Wobbe index' is a characteristic of

Liquid fuels

Fat coals

Solid fuels

Gaseous fuels

TRUE ANSWER : ?
YOUR ANSWER : ?

A fuel with high heat release rate will

Require smaller combustion chamber

None of these

Have high calorific value

Have high adiabatic flame temperature

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 oxygen has been used for combustion

No excess air has been used for combustion

Complete combustion of fuel has taken place

21% excess air has been used for combustion

TRUE ANSWER : ?
YOUR ANSWER : ?

Calorific value of

Light paraffinic fuel oils is lower than that of equivalent olefins

Light paraffinic fuel oils is higher than that of equivalent olefins

Light paraffinic fuel oils is equal to that of equivalent olefins

N-paraffin is lower than that of iso-paraffins of the same compounds

TRUE ANSWER : ?
YOUR ANSWER : ?