Book 11 Flashcards
(100 cards)
The copper tube tubular heating boiler:
Select one:
a.
Are mostly gas fired
b.
Generates high pressure steam
c.
Has the furnace in the upper section
d.
Is highly susceptible to corrosion
Are mostly gas fired
Expanding of tubes into a tube sheet is also called:
Select one:
a.
Beading
b.
Rolling
c.
Flaring
d.
Peening
Rolling
According to ASME VII C2.426, how often should a boiler be blown down if it is not fitted with sampling connections?
a.
Weekly if soft water is used
b.
Once every shift
c.
At least once every 24 h
d.
2–3 times weekly if hard water is used
At least once every 24 h
When an air heater is used in a boiler:
Select one:
a.
The induced draft fan supplies combustion air to the air heater
b.
It increases the efficiency of the boiler
c.
The boiler usually has only a forced draft fan
d.
A balanced draft system cannot be used
It increases the efficiency of the boiler
Packaged boilers:
Select one:
a.
Are shipped in a packing case with the components disassembled
b.
Are completely factory-built
c.
Must not be used over 100 kPa working pressure
d.
Have risers and down comers
Are completely factory-built
High concentrations of dissolved solids can lead to what condition in a boiler?
a.
Foaming
b.
Carryover
c.
Surging
d.
Bubbling
Foaming
Combustion air for the burners is preheated in the _____ by hot flue gases.
Select one:
a.
Economizer
b.
Air heater
c.
Superheater
d.
Windbox
Air heater
A corrugated furnace gives required strength with thinner metal, increases heating surface and:
Select one:
a.
Increases the boiler mass
b.
Adds to the overall material cost of the unit
c.
Decreases combustion turbulence
d.
Allows for differential expansion and contraction
Allows for differential expansion and contraction
Immersion boiler tube bundles:
Select one:
a.
Conduct current through the boiler water
b.
Can be easily removed from the unit for maintenance purposes
c.
Withstand extremely high temperatures and pressures
d.
Have negligible electrical resistance
Can be easily removed from the unit for maintenance purposes
Corrugated furnaces:
Select one:
a.
Permit expansion and contraction with reduced stress
b.
Are cheaper than plain furnaces
c.
Are made from rolled copper
d.
Require fewer stays than plain furnaces
Permit expansion and contraction with reduced stress
What type of furnace is surrounded by brickwork rather than by water?
Select one:
a.
Externally fired
b.
Cyclone furnace
c.
Staged combustion furnace
d.
Internally fired
Externally fired
Tubes for high pressure service are usually:
Select one:
a.
Resistance welded construction
b.
Seamless construction
c.
Lap welded construction
d.
Fin-tube designs
Seamless construction
A reason for preferring copper tubing in a tubular boiler is:
Select one:
a.
Low cost
b.
High metal expansion rate
c.
Ease of replacement of the tubes
d.
Corrosion resistance
Corrosion resistance
In a low-pressure serpentine watertube boiler, the tubes are attached by either _______ or by using ferrules.
Select one:
a.
Welding
b.
Expanding
c.
Threading
d.
Seamless fittings
Threading
One or more steel plates rolled into a cylinder welded together with the ends closed by rounded heads, is called a:
Select one:
a.
Combustion chamber
b.
Packaged boiler
c.
Steam or water drum
d.
Steam header
Steam or water drum
The purpose of a superheater is to:
Select one:
a.
Produce high pressure steam
b.
Increase the steam output
c.
Increase the temperature of the steam
d.
Control the pressure of the steam
Increase the temperature of the steam
Later model HRTs with welded shells could produce up to how much steam?
a.
500 kg/h, 7000 kPa
b.
7000 kg/h, 500 kPa
c.
500 kg/h, 1700 kPa
d.
7000 kg/h, 1700 kPa
Feedback
7000 kg/h, 1700 kPa
Where is watertube boiler feedwater piped to?
a.
Mud drum
b.
Steam drum
c.
Downcomers
d.
Risers
Steam drum
One advantage of cast iron boilers is:
Select one:
a.
Their high factor of brittleness
b.
Reduced vibration due to their heavy foundations
c.
Unlimited operating pressures
d.
Resistance to corrosion
Resistance to corrosion
What is the name for a locomotive boiler with a water leg that extends only down the sides?
a.
Internally fired
b.
Water box
c.
Wet bottom
d.
Dry bottom
Dry bottom
The largest packaged watertube boilers available are around what size?
a.
37 000 kW
b.
72 000 kW
c.
73 000 kW
d.
27 000 kW
73 000 kW
What determines the capacity of a coil tube boiler?
a.
Number of bends
b.
Arrangement of the coils
c.
Number of tubes and overall length of tubes
d.
Size of the drum
Number of tubes and overall length of tubes
The output of an immersion type electric boiler is controlled by __________ one or more elements as required.
Select one:
a.
turning the power on or off
b.
immersing
c.
short-circuiting
d.
controlling the basket level of
turning the power on or off
A _____ is a water filled section, which surrounds the firebox in a locomotive boiler.
Select one:
a.
Crown sheet
b.
Boiler drum
c.
Steam dome
d.
Water leg
Water leg