FUELS AND COMBUSTION QUIZ

Tar yield is more

Ignition temperature of coke produced is less

Gas yield is less

Aromatic content of tar produced is more

Preheating of fuel gases & combustion air

Reducing sulphur content in the fuel

Supplying correct amount of combustion air

Adopting proper fuel firing technique & fuel preparation

Density

Porosity

Electrical resistivity

None of these

Pulverised coal in boilers

Too much air for combustion

Correct amount of air for combustion

Less air for combustion

None of these

Scrubbing with wash oil (a petroleum product)

Absorbing in vetro-coke solution

Adsorbing on bog iron bed

Using low c.v. fuels

Maintaining proper draft in the furnace

Oxygen enrichment of combustion air

Controlling the excess air

Removing ash from the coal based on difference in specific gravity of coal and ash

All of these

Washing lump coal (> 80 mm size)

Washing fine coal dust (< 0.5 mm size)

40 and 70

80 and 97

25 and 97

95 and 100

Increases the time of carbonisation

May damage its walls due to abrupt excessive swelling of coal

Produces larger size coke

None of these

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36

8

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