Superheater arrangements

Question 1

Steam leaving the steam drum is called?

Answer 1

Saturated

Question 2

What is the function of a spray desuperheater?

Answer 2

located between the primary and secondary superheater banks it lowers the steam temperature by injecting a fine spray of water into the steam.

Question 3

Why is it vital steam flow through the superheater tube is maintained when the boiler is firing?

Answer 3

the flow of steam conducts heat away from the tub walls and keeps the tube metal temperature down to safe metalurgical limits

Question 4

The pendant superheater is non-drainable how can residual condensate be removed during start up?

Answer 4

By slow application of heat to evaporate the condensate in all tubes

Question 5

What is the advantage of using superheated steam?

Answer 5

It contains more heat energy than saturated steam, and therefore can perform more work.

Question 6

What is attemperation?

Answer 6

control of steam temperature

Question 7

What is the convection zone?

Answer 7

The zone of the boilwer where primary superheater and reheater tubes are located. It is out of sight of the fireball and thus no radiant heat.