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21 Cards in this Set
- Front
- Back
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ID fans are? |
Induced draft fans |
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Since furnace pressure is often positive in a packaged watertube boiler, to prevent flue gas leakage A. An induced draft fan is incorporated B. An economizer is used C. Smoke stacks are taller D. A steel casing forms a seal for the furnace |
D. A steel casing forms a seal for the furnace |
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Excessive vibrations caused by inadequate support of a watertube boiler could result in: A) Tube failure B) Combustion control problems C) Drum fracture D) Water level control problems E) Insulation failure
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E) Insulation failure |
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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) Latent heat B) Conduction heat C) Radiant heat D) Convection heat E) Residual heat
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C) Radiant heat |
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A packaged tubular steam boiler often has a steel sheathing in front of the waterwall tubes due to: A) The formation of superheated steam in the tubing B) The erosive action of the flame C) The high radiant energy from the flame D) Overheating of the tubing due to poor circulation E) The high corrosion action of the combustion process |
B) The erosive action of the flame |
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A membrane water wall: A) Is applicable to an externally fired boiler B) Is usually not gas-tight C) Has metal connecting the tubes D) Has firebrick in front of the tubes E) Consists of a metal sheeting in front of the tubes |
C) Has metal connecting the tubes |
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In a longitudinal straight tube boiler the downcomer fed: A) "Hot" water to a riser B) "Cool" water to a rear header C) "Cool" water to a front header D) "Hot" water to the water tubes E) "Cool" water to the steam drum |
B) "Cool" water to a rear header |
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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) Easier waterside maintenance C) Safety due to the low volume of water it contains D) Its lower initial cost E) Its less critical water treatment requireme |
C) Safety due to the low volume of water it contains |
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In order to keep salt concentrations within safe limits, the packaged tubular steam boiler utilizes: A) A water softener after the condensate receiver B) An automatic blow down C) A mixing chamber before the heating coil D) A liquid flow control device E) A desalinater |
B) An automatic blow down |
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A reason for preferring copper tubing in a tubular boiler is: A) Its lower cost than steel B) Because of its good ductility C) Its ability to withstand high temperature D) Scale does not adhere to it E) Faster heat transfer rate |
E) Faster heat transfer rate |
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The bent tube boiler tube design allows the tubes to be attached radially on the outside of the: A) Economizer B) Superheater C) Furnace D) Air pre-heater E) Shell or drum
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E) Shell or drum |
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A problem with a D-type watertube packaged boiler is: A) Ceiling height requirements B) Refractory maintenance for the external furnace C) Excessive vibration D) Its need to be top supported E) Its poor water circulation |
C) Excessive vibration |
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One of the advantages of the low pressure serpentine tube watertube boiler is: A) Ease of replacement of defective tubes B) Excellent water circulation C) Virtually no operational supervision required D) Low cost E) Small amount of feedwater treatment
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A) Ease of replacement of defective tubes |
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The components of a steam generating unit are: 1. Superheater 2. Burners 3. Safety valve 4. Feedwater line A) 2,3,4 B) 1,2,3,4 C) 1,3,2 D) 1,2 E) 1,2,4
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D) 1,2 |
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Large steam generators: A) Are bottom supported B) Have sluggish water circulation C) Are usually of the water tube type D) Are fired by pulverised coal only E) Have beaded tubes
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C) Are usually of the water tube type |
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The most economical fuel to burn in a steam generator is: A) Crushed coal B) Crude oil C) Pulverised coal D) Natural gas E) Heavy fuel oil
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C) Pulverised coal |
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A steam generating unit consists of all the elements which contribute to the efficient production of steam including: Boiler Superheater Reheater Economizer Air heater Fuel equipment Draft fans Ash removal equipment |
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Four components of a heat transfer unit. |
1. Superheater 2. Reheater 3. Economizer 4. Air heater |
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The copper tube tubular boiler: A) Is capable of very large capacities B) Can be gas or oil fired C) Has a one part heating surface D) Is highly susceptible to corrosion E) Has the furnace in the upper section |
B) Can be gas or oil fired |
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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) Radiant walls B) Water walls C) Waterside walls D) Furnace walls E) Fireside walls |
B) Water walls |
