FUELS AND COMBUSTION QUIZ

1kg mole

22.4 Nm³

32 kg

All of these

Moisture

Volatile matter

Ash

Sulphur (4-6%)

29

19

23

21

Completely burn the volatile matter

None of these

Burn the lumpy coal

Pneumatically convey the pulverised coal

Equal

More or less ; (depends on the state of fuel.)

Less

More

Both CO and CO₂

Only CO

All of these

Both CO and O₂

None of these

Flame temperature

Calorific value of the fuel

Scale losses of the furnace stock

All of these

Flue gas has lower dew point thereby facilitating more waste heat recovery

Emissivity factor is higher

Sulphur content is lower

Is desirable in producer gas manufacture

None of these

Has poor strength and abrasion resistance

Produces more slag when used in the blast furnace

The ash in molten condition gets absorbed in the pores of the refractory lining of the furnace and causes its spalling due to different co-efficient of expansion/contraction of the refractory and the

The ash retains the sulphur & phosphorus and thus affects the quality of products in metallurgical furnace apart from increasing the slag volume. Besides, it may fuse and stick to the boiler tubes

All of these

It is abrasive to the coal pulveriser (ie.g. ball mill) and the combustion chamber