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18 Cards in this Set
- Front
- Back
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The combustion chamber of a serpentine tube watertube boiler is
a) equipped with gas power burners b) located above the tube c) surrounded by the tube d) located below the tube e) enclosed by a non-insulated metal casing |
D
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One of the reasons that industrial type watertube boilers are seldom selected for low pressure heating plants is a) high fuel consumption b) low overall efficiency c) poor water circulation d) high cost e) poor steam production |
D
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A membrane waterwall a) is usually not gas-tight b) consists of a metal sheeting in front of the tubes c) has metal connecting the tubes d) has firebrick in front of the tubes e) is applicable to an externally fired boiler |
C
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What limits the height of a packaged boiler is a) building ceiling height b) internal furnace dimensions c) firing capacity d) boiler design e) transportation requirements |
E
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The use of bent tube boiler designs allows the furnace wall to be lined with tubes, thereby exposing more of the heating surface to a) convection heat b) conducted heat c) radiant heat d) residual heat e) latent heat |
C
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The bent tube boiler design allows the tubes to be attached radially on the outside of the a) furnace b) superheater c) economizer d) shell or drum e) air preheater |
D
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In a low pressure serpentine tube watertube boiler, the serpentine tubes are attached to upper and lower headers with __________ connections. a) welded b) pressure sealed c) threaded d) seamless e) nozzle |
C
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The furnace walls in a bent-tube watertube boiler are formed by water filled tubes and these walls are called a) furnace walls b) water walls c) fireside walls d) waterside walls e) radiant walls |
B
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A reason for preferring copper tubing in a tubular boiler is a) low cost b) high metal expansion rate c) ease of replacement of the tubes d) corrosion resistance e) elimination of feedwater treatment |
D
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An initial problem with the tubular boiler being used as a steam unit was a) metals which would not stand up to the temperatures involved b) dissolved impurities forming scale on the tube c) metals not standing up to the pressures involved d) inadequate capacities e) inability to maintain pressure |
B
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An advantage of a packaged low pressure tubular or watertube boiler is a) its ability to meet load changes due to its heat reserve b) its less critical water treatment requirement c) its lower initial cost d) easier waterside maintenance e) safety due to the low volume of water it contains |
E
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One of the advantages of the low pressure serpentine tube watertube boilers is a) ease of feedwater treatment b) excellent water circulation c) low cost d) ease of replacement of defective tubes e) virtually no operational supervision required |
D
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One of the advantages of the low pressure serpentine watertube boiler is a) virtually no maintenance required b) virtually eliminates feedwater treatment c) virtually eliminates expansion and contraction stresses d) virtually no operational supervision required e) virtually no need for tubes replacement |
C
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A reason for preferring copper tubing in a tubular boiler is a) faster heat transfer rate b) because of its good ductility c) its ability to withstand high temperature d) scale does not adhere to it e) its lower cost than steel |
A
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A packaged tubular steam boiler often has a steel sheathing in front of the waterwall tubes due to a) the high radiant energy from the flame b) overheating of the tubing due to poor circulation c) the erosive action of the flame d) the high corrosion action of the combustion process e) the formation of superheated steam in the tubing |
C
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In order to keep salt concentrations within safe limits the packaged tubular steam boiler utilizes a) an automatic blowdown b) a desalinator c) a water softener after the condensate receiver d) a mixing chamber before the heating coil e) a liquid flow control device |
A
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A disadvantage of the watertube or tubular boiler is a) its long warm-up period b) water treatment monitoring c) its thermal stresses d) the foundation requirements due to mass e) its high maintenance cost |
B
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The copper tube tubular boiler a) can be gas or oil fired b) has a one part heating surface c) has the furnace in the upper section d) is highly susceptible to corrosion e) is capable of very large capacities |
A
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