In case of pulverised coal fired steam boiler, the secondary air serves the main purpose of

The main function of primary air in pulverised coal fired burner is to

A

Burn CO to CO₂

B

Dry and transport the coal

C

Have proper combustion by supplying it around the burner

D

Preheat the tertiary air used for complete combustion of CO to CO₂

Function of secondary air in pulverised coal firing is to

A

Transport the coal to the burner

B

Dry the coal

C

Ensure efficient burning of coal around the burner

D

Reduce primary air requirement

The size of a boiler drum in pulverized fuel fired boiler, as its size and capacity, (steam pressure and flow ratings) increase

A

Increases

B

Decreases

C

Remains unchanged

D

Increases/decreases depending on steam temperature requirements

A device used in a boiler to control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required, is known as

A

Blow off cock

B

Fusible plug

C

Superheater

D

Stop valve

Which of the following is the most important deterrants to an extended use of pulverised coal in boiler firing?

A

Ash disposal problem

B

Excessive fly ash discharge from the stack

C

Higher power consumption in its transportation

D

Erosion of induced draft fan blades

Coal is pulverised before burning in large capacity boiler furnaces mainly to

A

Ensure its complete combustion

B

Facilitate easy ash removal

C

Enhance its calorific value

D

Provide trouble free operation

Which of the following is the most important deterrents to an extended use of pulverised coal in boiler firing?

A

Ash disposal problem

B

Excessive fly-ash discharge from the stack

C

High power consumption in its transportation

D

Erosion of induced draft fan blades

Pulverised coal used in boiler firing need not have

A

Less moisture content

B

High fusion point of its ash

C

High bulk density

D

Lower ash content

Use of pulverised coal in boiler furnace provides

A

High calorific value

B

Better combustion

C

Smokeless burning

D

Less erosion on furnace walls

Combustion of pulverised coal as compared to that of lump coal

A

Develops a non-luminous flame

B

Develops a low temperature flame

C

Can be done with less excess air

D

Provides a lower rate of heat release

In case of pulverised coal fired steam boiler, the secondary air serves the main purpose of

Related Questions