Sootblowers

Question 1

In addition to reducing heat transfer, soot and ash on
fireside tubes also
a) lessens the chance of furnace explosions
b) increases draft fan power
c) results in the formation of CO in the flue gases
d) raises superheater temperatures
e) results in smoke emissions from the stack

Answer 1

b) increases draft fan power

Question 2

Relative to Figure 1, in the module the radiant zone is

a) downstream of the economizer
b) downstream of the air preheater
c) between the primary superheater and economizer
d) between the reheater and primary superheater
e) upstream of the reheater

Answer 2

e) upstream of the reheater

Question 3

The steam used for sootblowing is usually

a) greater than boiler drum pressure
b) wet unsaturated steam
c) the same as boiler drum pressure
d) superheated at the sootblower nozzle
e) mixed with compressed air

Answer 3

d) superheated at the sootblower nozzle

Question 4

A furnace wall sootblower sequence of operation is

a) rotate & blow, extend, retract
b) extend, blow, retract, rotate
c) rotate, extend, blow, retract
d) extend, rotate & blow, retract
e) retract, blow, rotate, extend

Answer 4

d) extend, rotate & blow, retract

Question 5

A long retractable sootblower will

a) have nozzles throughout its full length
b) be used to clean furnace walls
c) blow during extension and retraction as it rotates
d) not blow until fully extended
e) require less exterior room than a furnace wall unit

Answer 5

c) blow during extension and retraction as it rotates

Question 6

During a sootblowing operation the boiler firing rate should
be at least
a) 15%
b) 30%
c) 20%
d) 80%
e) 70%

Answer 6

b) 30%

Question 7

While a steam sootblower is in operation it is cooled by

a) air
b) flue gases
c) steam
d) water
e) none of the above

Answer 7

c) steam

Question 8

A stationary sootblower

a) has two opposing nozzles at the end of its lance
b) has a row of nozzles throughout the lance length
c) does not rotate while blowing
d) is cooled by air while not in use
e) is cooled by water while not in use

Answer 8

b) has a row of nozzles throughout the lance length

Question 9

Shot cleaning pellets have a diameter of approximately

a) 2 cm
b) 6 cm
c) 0.6 cm
d) 0.6 mm
e) 2 mm

Answer 9

c) 0.6 cm

Question 10

Shot cleaning pellets are transported to the top of the
boiler
a) by using an air stream
b) manually
c) in a steam injection system
d) by a hydraulic hoisting system
e) and are not recycled

Answer 10

a) by using an air stream

Question 11

Soot and ash are undesirable on tube surfaces because they

a) increase heat transfer through the heating surfaces
b) cause overheating of the tubes
c) reduce boiler efficiency
d) reduce draft for power requirements
e) reduce the heating surface of the boiler

Answer 11

c) reduce boiler efficiency