1
Q
- When furnace draft is maintained at atmospheric pressure (or just below), the draft is referred to as:
a. Natural draft
b. Forced draft
c. Induced draft
d. Balanced draft
e. Negative draft
A
d. Balanced draft
2
Q
- Natural draft is the difference in pressure caused by:
a. The height of the furnace
b. The temperature in the furnace
c. The diameter of the stack
d. The atmospheric air conditions
e. The height of the stack
A
e. The height of the stack
3
Q
- Advantages of mechanical draft are:
1) Better purging of boiler
2) Less expensive stack can be used
3) Less supervision during operation
4) Increases unit efficiency
a. 1, 2
b. 1, 2, 3
c. 1, 2, 4
d. 2, 3, 4
e. 1, 4
A
c. 1, 2, 4
4
Q
- Disadvantages of mechanical draft are:
1) Higher initial cost
2) Closer supervision is required
3) More expensive stack must be used
4) Draft is dependent on atmospheric conditions
a. 1, 4
b. 1, 3
c. 2, 3
d. 3, 4
e. 1, 2
A
e. 1, 2
5
Q
- Draft is a term that indicates:
a. Atmospheric pressure
b. Static pressure
c. Absolute pressure
d. Friction pressure
e. Gauge pressure
A
b. Static pressure
6
Q
- In a boiler duct, pressure drop through a restriction is used to:
a. Measure the draft
b. Measure the air flow
c. Measure the density
d. Measure the secondary air pressure
e. Measure air temperature
A
b. Measure the air flow
7
Q
- The instruments used to monitor the air and flue gas system in a boiler consist of instruments that measure:
1) Pressure
2) Temperature
3) Density
4) Flow
a. 1, 2, 3
b. 1, 2, 4
c. 1, 3, 4
d. 1, 2, 3, 4
e. 2, 3, 4
A
b. 1, 2, 4
8
Q
- Draft is measured in:
a. mm of wg
b. mm of mercury
c. cm of mercury
d. cm of wg
e. kPa
A
d. cm of wg
9
Q
- A simple gauge for measuring draft consists of a glass U-tube containing water. This type of gauge is known as a _________.
a. manometer
b. orsat
c. pressure tube
d. diaphragm
A
a. manometer
10
Q
- A type of gauge that has superseded the U-tube for measuring boiler draft is the ________ gauge.
a. manometer
b. orsat
c. pressure tube
d. diaphragm
A
d. diaphragm
11
Q
- The __________ fan provides the volume of combustion air to the boiler.
a. induced draft
b. forced draft
c. cross draft
d. balanced draft
A
b. forced draft
12
Q
- The __________ fan is used to remove the hot flue gases from the boiler.
a. induced draft
b. forced draft
c. cross draft
d. balanced draft
A
a. induced draft
13
Q
- Draft in a furnace depends on:
1) The temperature of atmospheric air
2) The height of the stack
3) The pressure in the furnace chamber
4) The temperature of the gases in the stack
a. 1, 2, 3
b. 1, 2, 4
c. 2, 3, 4
d. 1, 2, 3, 4
e. 1, 3, 4
A
b. 1, 2, 4
14
Q
- Draft fans can be divided into the following types:
1) Backward curved blade
2) Air foil curved blade
3) Straight blade
4) Forward curved blade
a. 1, 4
b. 1, 2, 3
c. 2, 3, 4
d. 1, 2, 3, 4
e. 1, 3, 4
A
d. 1, 2, 3, 4
15
Q
- Draft fan output is controlled by:
1) Variable speed
2) Inlet damper control
3) Outlet damper control
4) Variable area for blades
a. 1, 2, 3
b. 1, 3, 4
c. 2, 3, 4
d. 1, 2, 3, 4
e. 1, 2, 4
A
a. 1, 2, 3
16
Q
- One advantage of inlet vanes to control the output of an I.D. fan is:
a. Less resistance is produced
b. Less control mechanisms are required
c. Air entering the fan receives a spin in the direction of wheel rotation
d. Less maintenance is required
A
c. Air entering the fan receives a spin in the direction of wheel rotation
17
Q
- The most efficient method of controlling an I.D. or F.D. fan on output is:
a. Inlet damper control
b. Outlet damper control
c. Inlet and outlet damper control
d. Variable speed control
e. Constant speed control
A
d. Variable speed control
18
Q
- Which of the following types of fan blades would have the lowest tip velocities?
a. Straight blades
b. Backward curved blades
c. Forward curved blades
d. Round blades
e. Axial blades
A
c. Forward curved blades
19
Q
- When a boiler is burning solid fuels, the secondary air is usually admitted:
a. Under the fuel bed
b. Through the fuel bed
c. Over the fuel bed
d. With the primary air
e. Around the fuel bed
A
c. Over the fuel bed
20
Q
- When a boiler is burning solid fuels, the primary air is usually admitted:
a. Under the fuel bed
b. By the I.D. fan
c. Over the fuel bed
d. With the secondary air
e. Around the fuel bed
A
a. Under the fuel bed
21
Q
- The most commonly used acid in boiler cleaning is:
a. 5% inhibited sulfuric
b. 5% inhibited citrus
c. 5% inhibited hydrochloric
d. 5% inhibited carbonic
e. 5% inhibited nitric
A
c. 5% inhibited hydrochloric
22
Q
- Mechanical cleaning tools used in cleaning boilers are driven by:
1) Air
2) Steam
3) Water
4) Electricity
a. 1, 2, 3
b. 1, 3, 4
c. 2, 3, 4
d. 1, 2, 3, 4
e. 1, 2, 4
A
d. 1, 2, 3, 4
23
Q
- The windbox is an extension of the air ducts and serves as a __________ chamber for the air.
a. stilling
b. distributing
c. expansion
d. cooling
A
b. distributing
24
Q
- Louvers are installed in the ________ to direct the air to the base of the flame.
a. fan
b. burner
c. windbox
d. ducts
A
c. windbox
25
439. Solid pollutants are dust particles known as ash, consisting mainly of the __________ parts of the fuel.
a. combustible
b. solid
c. metal
d. non-combustible
d. non-combustible
26
440. In modern pulverized coal firing facilities, the high __________ between the coal and the combustion air stream causes most of the ash to be carried over with the stack effluents.
a. turbulence
b. temperatures
c. quality
d. flow
a. turbulence
27
441. The theory of particle precipitation is based on the fact that, when a moving particle changes its ________, a force is generated as a consequence.
a. direction
b. velocity
c. humidity
d. charge
b. velocity
28
442. In a cyclone precipitator a spray of water turns the individual dust particles into heavy mud particles.
a. True
b. False
a. True
29
443. Dust laden flue gas from the boiler enters the _________ precipitator that contains a charging electrode. The dust particles receive a charge of electricity and become electrified.
a. electrostatic
b. electric
c. cyclone
d. mist
a. electrostatic
30
444. The __________ use several filter bags, in parallel, and the principle is the same as that of the domestic vacuum cleaner. The fabric of the bags is large enough to allow the flue gas molecules to pass through but small enough to catch the dust particles.
a. electrostatic
b. electric
c. cyclone
d. bag houses
d. bag houses
31
445. The type of _____ _____ system used at a plant depends upon the method of firing and the size of the plant.
a. partical percipitator
b. ash handling
c. distributed control
d. water washing
b. ash handling
32
446. A small plant firing with ______ may be arranged so that trucks can be driven into the basement and the ash from the ash pit dumped directly into them.
a. stokers
b. burners
c. coal
d. methane
a. stokers
33
447. __________ systems often use jet pumps to move a mixture of water and ash to the disposal area, via a closed pipeline.
a. Ash
b. Mechanical
c. Pneumatic
d. Hydro
d. Hydro
34
448. A __________ system moves the ash in a stream of air, or flue gas.
a. ash
b. mechanical
c. pneumatic
d. hydro
c. pneumatic
35
449. A __________ system moves the ash in a stream of air, or flue gas.
a. ash
b. mechanical
c. pneumatic
d. hydro
c. pneumatic
36
450. The __________ system involves the use of solids handling equipment, such as scraper conveyors, bucket elevators, and conveyor belts.
a. ash
b. mechanical
c. pneumatic
d. hydro
b. mechanical
37
451. Recovery systems, for the removal of SO2 can be classified into two major types the ______ and the ______.
a. solid, liquid
b. wet, dry
c. large, small
d. adsorption, absorption
b. wet, dry
38
452. In the ____ scrubbing system, a solution of lime/limestone slurry contacts the sulphur dioxide laden flue gas.
a. dry
b. wet
c. liquid
d. absorption
b. wet
39
453. In the ____ scrubbing process, the heat of the flue gas is used to dry finely atomized slurry of alkaline reactants.
a. dry
b. wet
c. liquid
d. absorption
a. dry
