Power Engineering - 4A12 (Elements of Boiler Systems)
Practice Questions With Complete Solutions
(4-051-1.15) Blowoff valves are used to:
a. Drain or remove sediment from the bottom of the steam drum
b. Drain or remove sediment from the bottom of the boiler
c. Drain or remove sediment from the continuous blowdown
d. Reduce the steam pressure on the boiler Correct Answers b.
Drain or remove sediment from the bottom of the boiler
(4-051-1.16) The low water fuel cutoff is a device fitted to the
boiler to shut the:
a. Feed water supply if the fuel supply is too low
b. Feed water supply if the boiler water level becomes too high
c. Fuel valve if the water level becomes too high
d. Fuel valve if the water level becomes too low Correct
Answers d. Fuel valve if the water level becomes too low
(4-051-1.18) An induced draft fan handles:
a. Air from the combustion chamber
b. Air going to the combustion chamber
c. Flue gases going to the combustion chamber
d. Flue gases from the combustion chamber Correct Answers d.
Flue gases from the combustion chamber
(4-051-1.21) A device that normally uses air or steam to do its
job is the:
,a. Siphon
b. Operating control
c. Burner
d. Soot blower Correct Answers d. Soot blower
(4-051-1.26) Water formed from the condensing of steam is
called:
a. Water
b. Wet steam
c. Condensate
d. Waste water Correct Answers c. Condensate
(4-051-1.29) Water that is fed into the boiler to replace water
that has been converted into steam is called:
a. Condensate
b. Fresh water
c. Return water
d. Feedwater Correct Answers d. Feedwater
(4-056-1.10) A characteristic of mechanical draft is that the
draft:
a. Varies with atmospheric pressure
b. Varies with chimney height
c. Varies with chimney temperature
d. Is properly regulated during all firing conditions Correct
Answers d. Is properly regulated during all firing conditions
(4-056-1.11) Natural draft is produced in a boiler furnace when:
, a. Hot flue gases contract so that each cubic meter has more
mass
b. Gases in the stack have less mass than an equal column of
outside air
c. Gases in the stack have more mass than an equal column of
outside air
d. Hot flue gases condense Correct Answers b. Gases in the
stack have less mass than an equal column of outside air
(4-056-1.14) A boiler with only an induced draft fan:
a. Will have a furnace pressure that is below atmospheric
pressure
b. Is extremely inefficient
c. Needs a very tall stack
d. Will have a positive furnace pressure Correct Answers a.
Will have a furnace pressure that is below atmospheric pressure
(4-056-1.15) An induced draft fan:
a. Is physically smaller than a forced draft fan
b. Has less expensive materials of construction than an FD fan
c. Operates at higher temperatures than an FD fan
d. Discharges air to the wind box Correct Answers c. Operates
at higher temperatures than an FD fan
(4-056-1.3) The advantage of a steel stack over a reinforced
concrete stack is that a steel stack:
a. Is more durable
Practice Questions With Complete Solutions
(4-051-1.15) Blowoff valves are used to:
a. Drain or remove sediment from the bottom of the steam drum
b. Drain or remove sediment from the bottom of the boiler
c. Drain or remove sediment from the continuous blowdown
d. Reduce the steam pressure on the boiler Correct Answers b.
Drain or remove sediment from the bottom of the boiler
(4-051-1.16) The low water fuel cutoff is a device fitted to the
boiler to shut the:
a. Feed water supply if the fuel supply is too low
b. Feed water supply if the boiler water level becomes too high
c. Fuel valve if the water level becomes too high
d. Fuel valve if the water level becomes too low Correct
Answers d. Fuel valve if the water level becomes too low
(4-051-1.18) An induced draft fan handles:
a. Air from the combustion chamber
b. Air going to the combustion chamber
c. Flue gases going to the combustion chamber
d. Flue gases from the combustion chamber Correct Answers d.
Flue gases from the combustion chamber
(4-051-1.21) A device that normally uses air or steam to do its
job is the:
,a. Siphon
b. Operating control
c. Burner
d. Soot blower Correct Answers d. Soot blower
(4-051-1.26) Water formed from the condensing of steam is
called:
a. Water
b. Wet steam
c. Condensate
d. Waste water Correct Answers c. Condensate
(4-051-1.29) Water that is fed into the boiler to replace water
that has been converted into steam is called:
a. Condensate
b. Fresh water
c. Return water
d. Feedwater Correct Answers d. Feedwater
(4-056-1.10) A characteristic of mechanical draft is that the
draft:
a. Varies with atmospheric pressure
b. Varies with chimney height
c. Varies with chimney temperature
d. Is properly regulated during all firing conditions Correct
Answers d. Is properly regulated during all firing conditions
(4-056-1.11) Natural draft is produced in a boiler furnace when:
, a. Hot flue gases contract so that each cubic meter has more
mass
b. Gases in the stack have less mass than an equal column of
outside air
c. Gases in the stack have more mass than an equal column of
outside air
d. Hot flue gases condense Correct Answers b. Gases in the
stack have less mass than an equal column of outside air
(4-056-1.14) A boiler with only an induced draft fan:
a. Will have a furnace pressure that is below atmospheric
pressure
b. Is extremely inefficient
c. Needs a very tall stack
d. Will have a positive furnace pressure Correct Answers a.
Will have a furnace pressure that is below atmospheric pressure
(4-056-1.15) An induced draft fan:
a. Is physically smaller than a forced draft fan
b. Has less expensive materials of construction than an FD fan
c. Operates at higher temperatures than an FD fan
d. Discharges air to the wind box Correct Answers c. Operates
at higher temperatures than an FD fan
(4-056-1.3) The advantage of a steel stack over a reinforced
concrete stack is that a steel stack:
a. Is more durable
