FUELS AND COMBUSTION QUIZ

Very little excess air

High amount/current of combustion air

Low amount/current of combustion air

Preheated secondary air

None of these

Hardness

Strength

Reactivity

High heat transfer rate

Reduced NOx formation in flue gas

Lower furnace operating temperature

All of these

All tar is evolved at < 600°C

Hard semi-coke starts shrinking at 600°C

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

All of these

C₂H₆

H₂

CO

CH₄

Lower hydrogen content

Neither A nor B

Both A & B

Higher calorific value

Both B & C

Reduces the combustion efficiency by limiting the permissible temperature reduction

Increases the dew point

Decreases the dew point

None of these

Under pressurising

Banking

Back draughting

Fixed carbon

Total carbon

Hydrogen

Nitrogen

Oxygen content

Calorific value

Caking power

None of these