Drum Internals

Question 1

The component of a boiler which allows a space for the
introduction of chemicals is the
a) mud drum
b) steam drum
c) injection tank
d) internal feed pipe
e) deaerator

Answer 1

b) steam drum

Question 2

A boiler steam drum will
a) allow load increases to be accomplished more quickly
b) always be the highest component of a boiler
c) not distribute feedwater to cold sections of the boiler
d) have no bearing or effect on water circulation
e) contain a steam space which will be at higher pressure
than the water space

Answer 2

a) allow load increases to be accomplished more quickly

Question 3

At lower pressures, steam

a) has higher densities
b) is more difficult to separate from the water
c) readily rises and separates from the water
d) cannot be separated from water with mechanical devices
e) requires large volume spaces in order to separate

Answer 3

c) readily rises and separates from the water

Question 4

Steam separation in a modern boiler usually occurs in

a) 1 step
b) 2 steps
c) 3 steps
d) 4 steps
e) 5 steps

Answer 4

c) 3 steps

Question 5

Cyclone separators are used to

a) separate water droplets from the steam
b) accelerate the steam leaving the boiler
c) heat the steam coming out of the drum
d) separate impurities from the water
e) separate water from the steam drum

Answer 5

a) separate water droplets from the steam

Question 6

Relative to steam drum internals, a boiler water test is
conducted to
a) ensure scrubbers have not corroded away
b) adjust or set the continuous blowdown valve (CBD)
c) ensure the water is not attacking the separators
d) inform us when maintenance is required on drum equipment
e) ensure chemicals are entering the boiler

Answer 6

b) adjust or set the continuous blowdown valve (CBD)

Question 7

The CBD valve is usually a

a) gate valve with a metering device
b) ball valve with a metering device
c) stop/check valve with a metering device
d) butterfly valve with a metering device
e) needle valve with a metering device

Answer 7

e) needle valve with a metering device

Question 8

A drum internal which acts to reduce thermal shock and
turbulence is the
a) cyclone separator
b) drip-collector baffle
c) corrugated plate drier
d) internal feed pipe
e) chevron drier

Answer 8

d) internal feed pipe

Question 9

Some smaller boilers have a pipe and baffle device in the
steam drum which acts as
a) a separator
b) a chemical injection device
c) a scrubber
d) a drip collector baffle
e) an internal feed pipe

Answer 9

e) an internal feed pipe

Question 10

Chemicals are injected into the boiler to

a) prevent corrosion
b) keep sludge dispersed
c) prevent sludge
d) prevent scale
e) all the above

Answer 10

e) all the above

Question 11

The chemical injection line is located

a) near the normal water level
b) close to the CBD line
c) in the steam space
d) near the internal feed pipe
e) close to the riser tubes

Answer 11

d) near the internal feed pipe