Chapter 4-7 Flashcards
- What is the main purpose of baffles in the setting of a Boiler?
A) to supply strength to the setting
B) to allow hot gases to make more than one pass through the boiler
C) to produce eddy currents
D) to cause a restriction of gas flow
E) to mix the fuel gas and the combustion air for complete combustion
B) to allow hot gases to make more than one pass through a boiler
- Which of the following are disadvantages of using baffles in a Boiler setting?
1) eddy currents can be produced
2) increased friction can result
3) coal fired boilers can result in pockets of ash accumulation
4) heat transfer is increased.
A) 1,2,3,4
B) 1,2,3
C) 2,4
D) 1,3,4
B) 1,2,3
- In order to direct the flow of combustion gas over the tubes in a watertube boiler, it is necessary to use _____.
A) baffles
B) deflectors
C) fans
D) preheaters
A) baffles
- Baffles can be placed so as to cause the gases to flow at right angles to the tube length, in which case they are called _____ baffles.
A) longitudinal
B) cross
C) back
D) straight
B) cross
- Baffles may be placed so as to cause the gases to flow parallel to the tubes, in which case they are called _____ baffles.
A) longitudinal
B) cross
C) back
D) straight
A) longitudinal
- Baffles are usually constructed of _____ material and may be made up of individual bricks or tiles.
A) steel
B) castable
C) refractory
D) insulation
C) refractory
- Curved or streamlined baffles have the _____ of having no sharp turns to cause eddy currents, increase friction, or form pockets for ash accumulation.
A) disadvantage
B) habit
C) source
D) advantage
D) advantage
- Metal fin bars are welded to adjacent tubes, forming a continuous surface and a pressure tight wall, this is referred to as a welded fin tube wall or a _____ wall.
A) solid
B) membrane
C) screen tube
D) tangent tube
B) membrane
- A wall suitable for severe service, here the tubes are side by side and touching each other, this is called a _____ wall.
A) solid
B) membrane
C) screen tube
D) tangent tube
D) tangent tube
- Flat plates or studs are welded to each side of the tubes, this is called a _____ wall.
A) flat stud tube
B) screen tube
C) tangent tube
D) membrane
A) flat stud tube
- In the watertube boiler, water cooling of the furnace is achieved by arranging tubes to form all or part of the furnace walls. Which of the following refers to this type of construction?
1) tangent tube wall
2) fin welded tubes
3) tube and brick wall
4) flat stud tube wall
A) 1,2,3,4 B) 2,3 C) 2,3,4 D) 1,2 E) 1,3
A) 1,2,3,4
- Steam produced from water in a boiler is at saturation temperature and usually contains a certain amount of moisture. The purpose of the superheater is:
1) to save on chemical make up to the boiler
2) that any moisture present in the steam will be evaporated
3) is to help protect the turbine blades from erosion
4) is to allow more work per kg of steam
A) 1,4 B) 1,2 C) 2,3 D) 2,3,4 E) 2,3
D) 2,3,4
- Which of the following are integral superheaters?
1) high pressure types
2) convection types
3) radiant types
4) high temperature types
A) 1,4 B) 1,3 C) 2,3 D) 3,4 E) 2,4
C) 2,3
- What doe a “rising steam temperature characteristic” mean?
1) at low loads, the steam temperature will be low
2) the superheated steam temperature will rise as the firing rate or boiler output increases
3) at high loads, the steam temperature will be high
4) the temperature of the boiler feedwater rises
A) 1,2,3 B) 2,3 C) 1,3 D) 4 E) 1,4
A) 1,2,3
- Which of the following has a rising steam temperature characteristic?
A) radiant superheater B) pendant superheater C) horizontal superheater D) convection superheater E) separately fired superheater
D) convection superheater
- Which of the following has a falling steam temperature characteristic?
A) radiant superheater B) pendant superheater C) horizontal superheater D) convection superheater E) separately fired superheater
A) radiant superheater
- Which of the following apply to the combination of a radiant superheater and a convection heater?
1) frequently steam generating units have a convection superheater in series with a radiant superheater
2) the steam enters the radiant superheater first and the the convection superheater
3) a fairly steady steam temperature characteristic is produced
4) superheated steam temperatures remain fairly constant at all boiler loads
A) 1,3,4 B) 1,2,3,4 C) 1,2,3 D) 2,3 E) 2,3,4
B) 1,2,3,4
- Which of the following correctly describes the manner in which pendant superheaters are suspended?
A) horizontal B) inclined at an angle of 60 degrees C) vertical D) inclined at an angle of 45 degrees E) inclined at an angle of 30 degrees
C) vertical
- A convection superheater:
A) has the combustion air passing across it
B) is always located in the radiant furnace zone
C) has the hot combustion gases passing over it
D) is located after the economizer
E) is in direct contact with the flame
C) has the hot combustion gases passing over it
- A primary superheater:
A) has the hottest gases passing across it
B) is always located in the radiant furnace zone
C) is the most important superheater
D) receives the saturated steam from the steam drum
E) is always located in the convection zone
D) receives the saturated steam from the steam drum
- Superheated steam:
A) can be produced in the saturated steam drum of a watertube boiler
B) has a temperature that is higher than the saturation temperature for that pressure
C) is almost dry and contains very little moisture
D) cannot be used for sootblowers
E) may cause erosion of turbine blades
B) has a temperature that is higher than the saturation temperature for the pressure
- Which of the following are types of superheaters?
1) primary
2) secondary
3) conduction
4) radiant
5) convection
6) pendant
7) attemperator
A) 1,2,3,4 B) 1,2,4,5,6 C) 1,3,4,5,7 D) 3,4,5,6,7 E) 1,2,3,6,7
B) 1,2,4,5,6
- Steam flow from the steam drum is fed to secondary superheater first and then to primary superheater.
A) true
B) false
B) false
- Which of the following are disadvantages in separately fired superheaters?
1) provide a wider range of temperature control
2) higher initial cost
3) lower operating efficiency
4) larger space requirement
A) 1,2 B) 1,2,3 C) 2,3,4 D) 3,4 E) 1,4
C) 2,3,4
- The separately fired superheater is located in a _____ apart from the main steam generator and is independent of the steam generator operating conditions.
A) boiler
B) furnace
C) building
D) enclosure
B) furnace
- The reheater receives steam, which has already expanded through a portion of the turbine and as a result of this expansion has dropped in pressure and in _____.
A) quality
B) volume
C) temperature
D) energy
C) temperature
- In the reheater, the steam has its temperature raised to about the same temperature as was initially provided by the _____.
A) turbine
B) boiler
C) feedwater
D) superheater
D) superheater
- Reheaters are located in the furnace in areas of relatively _____ gas temperatures.
A) high
B) low
C) moderate
D) average
A) high
- The temperature control methods used for reheater temperature control are the same as those used for _____ temperature control.
A) boiler
B) fuel gas
C) superheater
D) preheater
C) superheater
- The steam flow passes through the reheater immediately after the superheater.
A) true
B) false
B) false
- The two basic types of economizers are:
A) radiant and convection B) integral and sensible C) sensible and radiant D) integral and separate E) recuperative and regenerative
D) integral and separate
- An economizers transfers sensible heat to the feedwater before the feedwater is mixed with the circulating boiler water.
A) true
B) false
A) true
- An economizers is:
1) an energy saving device
2) a Boiler feedwater preheater
3) a device that has water inside tubes and hot gases on the outside
4) a device normally located behind the air preheater
A) 1,2,3,4 B) 1,4 C) 1,3,4 D) 2,3,4 E) 1,2,3
C) 1,3,4
- Which of the following are classifications of economizers?
1) gas type
2) integral type
3) vertical type
4) separate type
A) 1,3 B) 2,4 C) 1,2 D) 3,4 E) 1,4
B) 2,4
- Which of the following types of economizers is the most commonly used?
A) horizontal type B) integral type C) vertical type D) separate type E) gas type
D) separate type
- Which of the following tube types are used on economizers?
1) extended surface tubes
2) U bend tubes
3) continuous tube
4) fin tube
A) 1,2 B) 2,3 C) 2,3,4 D) 1,2,3,4 E) 1,3
D) 1,2,3,4
- What is the main purpose of the cast iron fins on the economizers tubes?
A) added strength B) to prevent corrosion C) increase heat transfer D) none of the above E) to allow hot gases to make more than one pass through a boiler
D) none of the above
- What is the purpose of handholes on certain economizers?
1) used for extra strength
2) used for installation
3) used for repair
4) used for inspection
A) 2,3,4 B) 1,2,3 C) 2,3 D) 1,2,3,4 E) 1,3,4
A) 2,3,4
- Which of the following are advantages of an economizer?
1) not as much Boiler feedwater is required
2) there is less thermal shock to the boiler drum
3) there is not as great a pressure drop through the unit
4) there is an increase in boiler efficiency
A) 1,3 B) 2,4 C) 1,2,3 D) 2,3,4 E) 1,3,4
B) 2,4
- Which of the following are disadvantages of economizers?
1) there is more thermal shock
2) there is increased fan power
3) surfaces must be kept clean to provide increased efficiency
4) more fuel is needed if the boiler has an economizer
A) 1,2 B) 2,3 C) 3,4 D) 2,3,4 E) 1,4
B) 2,3
- Which of the following types of boilers use economizers?
1) watertube boiler
2) firetube boiler
3) electric boiler
4) waste heat boiler
A) 1,3 B) 2,4 C) 2,3,4 D) 1,2,4 E) 3,4
D) 1,2,4
- Which of the following statements apply to air heaters?
1) this is another method of recovering heat from flue gases
2) they are often called air preheaters
3) they consist of a heat exchanger surface located in the path of the combustion gases
4) combustion efficiency is improved
A) 1,2 B) 2,3 C) 1,3,4 D) 1,2,3,4 E) 1,2,3
D) 1,2,3,4
- Which of the following are classes of air heaters?
1) pendant type
2) recuperative type
3) horizontal type
4) regenerative type
A) 1,3 B) 2,4 C) 1,2 D) 3,4 E) 2,3
B) 2,4
- Which of the following refers to recuperative air heaters?
1) they are rotary heaters
2) the heat from the flue gases passes through a plate or tube wall to the air on the other side
3) they are plate type air heaters
4) they are tubular air heaters
A) 1,2 B) 1,4 C) 2,3,4 D) 2,3 E) 1,3
C) 2,3,4
- What is meant by “counter flow” when referring to air heaters?
A) the flue gas and the air pass through alternate passages in opposite directions
B) the flue gas and air pass through alternate passages in the same direction
C) the flue gas and air pass through he same passages in the same direction
D) the flue gas flows through a bypass around the air heater
E) the flue gas and air pass through the same passages in opposite directions
A) the flue gas and the air pass through alternate passages in opposite directions
- The main purpose of the baffles in the tubular air heaters are:
A) to increase to strength of the heater
B) to help prevent corrosion in the heater
C) to act as a restriction for the air flow
D) to direct the air across the tubes in a number of passes
E) to help prevent erosion in the heater
D) to direct the air across the tubes in a number of passes
- Which of the following statements refers to regenerative air heaters?
1) they are stationary type heaters
2) they are rotary type heaters
3) leakage of gas and air is largely prevented by means of radial and circumferential seals
4) they may be arranged in either a vertical or a horizontal manner
A) 1,3,4 B) 1,4 C) 2,3,4 D) 3,4 E) 1,2,3
C) 2,3,4
- Which of the following are advantages of air heaters?
1) they have a low initial cost
2) they increase the efficiency of the boiler
3) they are easily maintained
4) there is increased combustion efficiency
A) 1,3 B) 1,2 C) 2,4 D) 3,4 E) 2,3
C) 2,4
- Which of the following could contribute to air heater corrosion?
1) if the fuel contains sulphur compounds
2) if the output of the air heater is too hot
3) if the output of the air heater approaches the dew point
4) none of the above
A) 1,3 B) 1,2 C) 2 D) 4 E) 1,4
A) 1,3
- The two basic types of preheaters are:
A) recuperative and regenerative B) recuperative and radiant C) convection and radiant D) plate and tube E) convection and regenerative
A) recuperative and regenerative
- Hot spots on tubes not caused by slag are a more serious problem. They indicate poor heat _____ through the tube walls.
A) distribution
B) transfer
C) flux
D) sensor
B) transfer
- Wet tubes on startup of the boiler are a _____ occurrence, caused by condensation on the tube walls.
A) abnormal
B) emergency
C) normal
D) flooding
C) normal
- When starting up a boiler, a steam flow is needed through the _____ tubes for cooling.
A) superheater
B) preheater
C) boiler
D) turbine
A) superheater
- There is no steam flow through the _____ tubes before the steam turbine has a steam flow through it. Be careful not to increase boiler firing too rapidly and overheat the reheat tubes, during startup.
A) superheater
B) economizer
C) reheater
D) boiler
C) reheater
- When starting the boiler, it may be necessary to keep a flow of BFW through the _____ tubes to prevent overheating and fouling.
A) superheater
B) economizer
C) reheater
D) boiler
B) economizer
- The temperatures of the flue gas leaving the preheater must be kept above the _____ to avoid condensation
A) flash point
B) melt point
C) dew point
D) ambient
C) dew point
- When the boiler is shut down, the air preheater should be inspected for signs of _____.
A) wear
B) distortion
C) overheating
D) corrosion
D) corrosion
- The water _____ of the economizer exit is always below that of the steam drum to prevent steaming in the economizer.
A) temperature
B) pressure
C) flow
D) quality
A) temperature
- The water and water/steam mixture in the steam generation tubes is at _____ temperature.
A) superheat
B) critical
C) saturation
D) normal
C) saturation
- The _____ increases the temperature of the steam from the H.P. Turbine back up to superheater temperature.
A) superheater
B) economizer
C) furnace
D) reheater
D) reheater
- The popping pressure of a safety valve must be:
A) lower on the economizer than the main steam drum
B) higher on the main steam drum than the air preheater
C) lower on the main steam drum than the superheater
D) higher on the main steam drum than on the superheater
E) the same on the main steam drum as on the superheater
D) higher on the main steam drum than on the superheater
- Safety valves should be opened manually to:
A) release internal pressure B) remove sludge C) lower boiler water level D) test the operation of the valve E) test the lower water fuel cutoff
D) test the operation of the valve
- Safety valves:
1) prevent loss of production in a plant
2) prevent bursting of the boiler drum
3) release steam to the atmosphere
4) are not required on boilers
A) 1,2,3,4 B) 1,2 C) 2,3 D) 3,4 E) 1,3
C) 2,3
- To increase the popping pressure of a safety valve:
A) the adjusting spring is spewed upward B) the adjusting screw is moved upward C) the adjusting ring is screwed downward D) the adjusting screw is moved downward E) the spring is replaced
D) the adjusting screw is moved downward
- To increase the blowdown of a safety valve:
1) increase the spring tension
2) increase the port openings
3) screw the adjusting spring upwards
4) decrease the port opening
A) 1,2 B) 2,3 C) 2,4 D) 1,3 E) 3,4
E) 3,4
- The purpose of the lip or feather on a safety valve seat:
1) increases the force of steam acting on the seat
2) allows the valve to pop open
3) allows simpler construction of the valve
4) makes no difference in operation
A) 1,2,3,4 B) 1,2 C) 2,3 D) 3,4 E) 1,2,3
B) 1,2
- Safety valves:
1) shall be attached as close as possible to the boiler drum
2) shall be attached in an upright position with the spindle vertical
3) shall have a discharge line attached
4) shall have no valve placed between the boiler and the safety valve
A) 1,2,3,4 B) 1,2,3 C) 1,2,4 D) 2,3,4 E) 1,3,4
C) 1,2,4
- A safety valve:
1) which discharges shall be located or piped clear of platforms or running boards
2) must have a gravity drain installed in the discharge line where condensate may collect
3) shall have an open gravity drain in the valve casing below the seat
4) has no discharge pipes in some cases
A) 1,2,3,4 B) 1,2,3 C) 2,3,4 D) 1,3,4 E) 1,2,4
A) 1,2,3,4
- Every boiler must be fitted with at least one pressure gauge:
A) to indicate the steam flow from the boiler
B) to indicate that it is on or offline
C) to indicate the pressure in the boiler
D) to indicate the pressure in the steam header
E) to indicate the water level in the boiler
C) to indicate the pressure in the boiler
- A water gauge glass:
1) indicates how much steam is in the boiler
2) may be connected directly to the boiler
3) must have a water column connected to the boiler first
4) indicates how much water is in the boiler
A) 1,2,4 B) 2,3,4 C) 1,2 D) 2,4 E) 1,3,4
D) 2,4
- During the operation of a boiler, it is extremely important to maintain the correct water level:
1) to prevent the gas burner from fluctuating
2) to prevent water carry over
3) to prevent hot spots
4) to protect the alternator
A) 1,2,3,4 B) 1,2 C) 1,4 D) 2,3 E) 1,2,3
D) 2,3
- The water column:
1) acts as a reservoir
2) dampens the agitation
3) tends to trap any sludge or sediment
4) provides a place for the installation of alarm floats
A) 1,2,3,4 B) 1,2,3 C) 2,3,4 D) 1,3,4 E) 1,2,4
A) 1,2,3,4
- Water gauge glasses have:
1) quick closing type valves in the steam and waterside
2) valves with convenient handles, that could be remotely operated if needed
3) drain valves, which are slow opening
4) no drain valves
A) 1,2,3,4 B) 1,2,3 C) 1,2,4 D) 2,3,4 E) 1,3,4
B) 1,2,3
- Flat glass gauges;
1) are used for pressures above 2750 kPa
2) are used on water tube boilers only because they are cooler
3) consist of two glass plates, which are bolted to a steel forged housing
4) are lined with him sheets of mica
A) 1,2,3,4 B) 1,2,3 C) 1,3,4 D) 2,3,4 E) 1,2,4
C) 1,3,4
- When repairing a gauge glass:
1) the boiler gauge glass should not be under pressure
2) the steam and water connections should be closed and the drain valve should be open
3) the operator should wear a face shield before pressuring up the glass
4) the steam and water connection should be blown out before installing the new glass
A) 1,2,3,4 B) 1,2,3 C) 2,3,4 D) 1,3,4 E) 1,2,4
A) 1,2,3,4
- Low water fuel cutoffs:
A) cannot be automatically reset B) do not act as an interlock device C) may have a float or electrode chamber D) cannot be adversely effected by heat E) not required on automatically fired steam boilers
C) may have a float or electrode chamber
- A boiler explosion due to overheating of the heating surfaces may result from:
A) improper furnace purge B) a faulty low gas pressure switch C) a low water cutoff malfunction D) combustion air switch failure E) a faulty flame scanner
C) a low water cutoff malfunction
- Low water fuel cutoffs:
1) are required when a boiler is not under continuous attendance by a certified operator
2) are required on firetube boilers only
3) must be installed so that they cannot be rendered inoperative
4) must be tested under operating conditions
A) 1,2,3,4 B) 1,2,3 C) 1,3,4 D) 2,3,4 E) 1,2,4
C) 1,3,4
- A low water level fuel cutoff device:
1) shuts the fuel off to the boiler when the air flow drops
2) shuts the fuel off when the burner pressure is low
3) protects the boiler from overheating
4) shuts the main fuel valve during a low water condition
A) 1,2,3 B) 1,2 C) 2,3 D) 3,4 E) 1,2,4
D) 3,4
- Low water fuel cutoff devices:
1) usually have mercury switches
2) are usually float operated
3) may be used to activate alarms as well as shutting off the fuel supply
4) are usually located in float chambers
A) 1,2,3,4 B) 1,2,3 C) 2,3,4 D) 1,3,4 E) 2,3
A) 1,2,3,4
- The low water level fuel cutoff device:
1) should be blown down every shift
2) should be blown down once a week
3) has a drain valve installed at the bottom connection
4) is blown down to prevent sediment buildup
A) 1,2,3,4 B) 1,3,4 C) 1,2,3 D) 2,3,4 E) 1,2,4
B) 1,3,4
- Which of the following do not require steam stop valves?
1) safety valve
2) main steam header
3) reheater
4) superheater
A) 1,3,4 B) 1,2,3 C) 2,3,4 D) 1,2,3,4 E) 1,2,4
A) 1,3,4
- Steam stop valves:
1) can be of the gate or globe type
2) can be high or are high pressure valves
3) may have drain valves located on the lower part of the valve body
4) can be of flanged type construction
A) 1,2 B) 2,3 C) 2,3,4 D) 1,2,3,4 E) 1,2,4
D) 1,2,3,4
- When two or more boilers are connected to a common main:
1) it is recommended that each boiler be equipped with an automatic stop and check valve
2) the automatic stop and check valve should be located closest to the boiler
3) they should have stop valves located between the main and the automatic stop and check valve
4) the space between. Stop and check valve and boiler stop valve shall be provided with an adequate drain
A) 1,2,4 B) 1,2,3 C) 2,3,4 D) 1,3,4 E) 1,2,3,4
E) 1,2,3,4
- A non return valve:
1) can be a globe type valve
2) can be an angle type valve
3) is the same as a stop and check valve
4) prevents a backflow of steam from the header to the boiler
A) 1,2,3,4 B) 1,2,3 C) 2,3,4 D) 1,3,4 E) 1,2,4
A) 1,2,3,4
- A non return valve:
1) can use a piston to cushion the valve upon opening
2) can use a spring to cushion the valve upon opening
3) does not need anything to cushion the valve upon opening
4) opens when the Boiler pressure exceeds the main steam header pressure
A) 1,2,4 B) 1,2 C) 1,4 D) 3,4 E) 2,4
A) 1,2,4
- The purpose of the non return valve is:
A) to drain water out of the main steam header
B) to prevent the backflow of steam
C) to prevent water from entering the steam header
D) to prevent the safety valve from popping
E) to prevent steam from entering the steam header
B) to prevent the backflow of steam
- The piping between the non return valve and the stop valve has a drain valve:
1) to help warm up the header
2) to indicate if there is steam flowing from the boiler
3) to indicate the pressure of the line
4) to drain the condensate out of the header
A) 1,2,3,4 B) 1,2 C) 1,3 D) 1,4 E) 1,2,4
D) 1?4
- The blow off connection to a boiler:
1) is made to the lowest point of the boiler
2) is used to drain the boiler
3) is used to blow out mud and sediment
4) is used to lower the concentration of dissolved impurities
A) 1,2,3,4 B) 1,2,3 C) 1,3,4 D) 1,2,4 E) 2,3,4
A) 1,2,3,4
- The ASME code required that the blowoff piping:
1) shall be painted to indicate a hot pipe
2) shall not be less than 25 mm and not greater than 64 mm in size
3) is exposed to direct furnace heat so it shall be protected by heat resistant material
4) shall be of flanged connections
A) 1,2 B) 2,3,4 C) 3,4 D) 1,2,3,4 E) 2,3
E) 2,3
- Every steam boiler having a working pressure exceeding 103 kPa:
1) shall be equipped with two approved blowoff valves
2) must have at least one slow opening blowoff valve
3) must have two slow opening blowoff valves
4) must have two quick opening blowoff valves
A) 1,4 B) 1,2,4 C) 1,2 D) 3,4 E) 1,3
C) 1,2
- Steam boilers:
1) normally do not have blowoff valves
2) are normally equipped with one slow opening and one quick opening blowoff valve
3) may be equipped with one slow opening and one quick opening blowoff valve
4) normally have two quick opening blowoff valves
A) 1,2,3 B) 1,2 C) 2,3 D) 3,4 E) 1,3
C) 2,3
- When a boiler has a quick opening and a slow opening blowoff valve:
1) the slow opening valve is next to the boiler
2) the quick opening valve is next to the boiler
3) it does not matter which one is next to the boiler
4) it does matte which one is next to the boiler
A) 1,2,4 B) 3 C) 1,4 D) 2,4 E) 1,2,3
D) 2,4
- A slow opening blowoff valve:
1) refers to the amount of time taken to open it
2) refers to the amount of time taken to close it
3) is one which requires at least five 360 degree turns to fully open or to fully close it
4) is located downstream of a quick opening blowoff valve
A) 1,3,4 B) 3,4 C) 1,3 D) 1,4 E) 2,3,4
B) 3,4
- A slow opening blowoff valve:
1) creates less water hammer than a quick opening blowoff valve
2) creates more water hammer than a quick opening blowoff valve
3) creates the same amount of water hammer as a quick opening type
4) is opened after the quick opening valve
A) 1,4 B) 2,4 C) 3,4 D) 4 E) 3
A) 1,4
- Which of the following is the correct procedure, when blowing down a boiler with both a quick opening and a slow opening valve?
A) open the slow opening valve, then open the quick opening valve. After blowing down, close the quick opening valve, then close the slow opening valve
B) open the quick opening valve, then open the slow opening valve. Air blowing down, close the quick opening valve, then close the slow opening valve
C) open the quick opening valve, then open the slow opening valve. After blowing down, close the slow opening valve, then close the quick opening valve
D) open the slow opening valve, then open the quick opening valve. After blowing down, close the slow opening valve, then close the quick opening valve
E) it does not matter which valve is opened first. After blowing down, it does not matter which valve is closed first
C) open the quick opening valve, then open the slow opening valve. After blowing down, close the slow opening valve, then close the quick opening valve
- All blowoff pipes, valves and fittings must be:
1) painted to prevent corrosion
2) of heavy construction corresponding to the Boiler pressure
3) installed without sharp bends
4) able to expand and contract without being constricted
A) 1,2,3,4 B) 1,2,3 C) 1,3,4 D) 2,3,4 E) 1,2,4
D) 2,3,4
- The purpose of the blowoff tank:
1) is to measure the amount of water being blown down from the boiler
2) is to prevent steam and hot water from going directly to the sewer
3) is to reduce the pressure and temperature of the water entering the sewer
4) is to prevent damage to the sewer system
A) 1,2,3,4 B) 1,2,3 C) 2,3,4 D) 1,3,4 E) 1,2,4
C) 2,3,4
- What are drum internals?
A) the riser tubes
B) the downcomers
C) the fittings located within the boiler drum
D) the internal shell
E) the fittings attached to the boiler drum or shell
C) the fittings located within the boiler drum
- The removal of impurities from the steam is extremely important because:
1) the boiler uses too much fuel
2) they will form deposits in the superheater tubes
3) the overheating of the tubes will result
4) deposits will be formed on the turbine blades
A) 1,2,3,4 B) 1,2,3 C) 1,2,4 D) 1,3,4 E) 2,3,4
E) 2,3,4
- The purpose of removing moisture from steam:
1) is to lower the solids concentration of the steam
2) is to lower the erosion effect on the turbines
3) is to save water makeup to the boiler
4) is to save money on the operation of the boiler system
A) 1,2,3,4 B) 1,2,3 C) 1,2,4 D) 1,3,4 E) 2,3,4
C) 1,2,4
- The purpose of the steam washer is:
1) to scrub the incoming water
2) to absorb any gaseous impurities in the steam
3) to prevent excessive water makeup to the boiler
4) to prevent silica buildup in the superheater tubes
A) 2,3,4 B) 2,4 C) 2,3 D) 1,3 E) 1,4
B) 2,4
- The internal feed pipe:
1) serves to distribute the incoming feedwater uniformly along the length of the drum
2) helps prevent scale buildup
3) prevents temperature shock
4) helps prevent turbulence
A) 1,3,4 B) 2,3,4 C) 1,2,3 D) 2,3 E) 1,2,4
A) 1,3,4
- The purpose of the continuous blowdown connection is to _____.
A) lower the concentration of dissolved solids in the boiler wate
B) keep the water at the correct level in the gauge glass
C) keep the steam pressure correct
D) blow the sludge out of the mud drum
E) lower the Boiler feedwater flow to the boiler
A) lower the concentration of dissolved solids in the boiler water
- The advantage of the continuous blowdown as compared to the bottom blowoff:
1) is that the valve is smaller to operate
2) is that it is much more accurate to control the water concentration
3) is that it can be used with a heat exchanger for economy
4) is that it replaces the bottom blowoff completely
A) 1,2 B) 2,3 C) 1,2,3 D) 2,3,4 E) 1,2,4
B) 2,3
- A gate valve:
1) has less restriction in a line than a globe valve
2) should be operated either fully open or fully closed
3) is used to throttle flow
4) is used for different applications than a globe valve
A) 1,2,3,4 B) 1,2,3 C) 1,3,4 D) 1,2,4 E) 2,3,4
D) 1,2,4
- The gas pilot pressure regulator _____ the incoming header gas pressure, ensuring a satisfactory pilot flame.
A) reduces
B) increases
C) controls
D) samples
A) reduces
- The main gas pressure regulator _____ the gas pressure at a higher setting than the pilot regulator.
A) reduces
B) increases
C) controls
D) samples
C) controls
- A low gas pressure cutoff switch _____ the burner from operating when the gas pressure in the supply line drops below the pressure necessary to maintain a stable flame at the burner.
A) promotes
B) prevents
C) opens
D) raises
B) prevents
- The high gas pressure switch contacts are normally _____ whenever the main gas line pressure s below a preset pressure.
A) open
B) stable
C) frozen
D) closed
D) closed
- The main gas valves are ON/OFF, normally open, single seated gas valves, when the electric motors on the valves are energized.
A) true
B) false
B) false
- Most burners have the fuel entering the combustion air stream at or near a _____ angle to promote good mixing.
A) cross
B) right
C) upward
D) down
B) right
- The multi spud burner has _____ spuds or jets connected to a circular manifold.
A) two
B) five
C) six
D) eight
D) eight
- In a multi spud burner, each spud is equipped with a _____ valve so that it may be removed for cleaning.
A) cleaning
B) shutoff
C) globe
D) regulating
B) shutoff
- The nitrogen and oxygen in the combustion air _____ at high temperature to form NOx.
A) react
B) unite
C) combine
D) mix
A) react
- The thermal NOx reaction occurs rapidly above _____ degrees C.
A) 1000
B) 2500
C) 15000
D) 1535
D) 1535
- To achieve lower NOx the flame temperature must be kept as low as possible. This is achieved by:
A) flue gas recirculation B) adding more O2 to the main flame C) air staging D) fuel conditioning E) A & C F) B & D G) C & D
E) A & C
- The main function of a gas burner is to:
A) provide for intimate mixing of gas and combustion air
B) admit the gas into the furnace
C) regulate the gas flow into the furnace
D) assist in the control of air flow to the furnace
E) admit combustion air into the furnace
A) provide for intimate mixing of gas and combustion air
- The above ground storage tanks must have an earth or concrete dyke around the tank of such a size as to contain the total volume of oil stored plus one _____.
A) quarter
B) third
C) half
D) meter
B) third
- An oil storage tank must not have galvanized pipe, as sulphur in the oil will react with the galvanizing zinc causing _____.
A) sludge
B) corrosion
C) water
D) ignition
A) sludge
- The tank steam smothering line is used in the event of _____.
A) freezing
B) spills
C) fire
D) entry
C) fire
- The heating of heavy fuel oil takes place in _____ stages.
A) three
B) five
C) many
D) two
D) two
- The second stage of heating, to allow atomization of the oil, involves heating the oil to between _____ C.
A) 5 and 25
B) 30 and 50
C) 70 and 100
D) 200 and 300
C) 70 and 100
- The steam atomizer type burners operate on the principle of producing a steam fuel emulsion that atomizes the oil through the rapid _____ of the steam when released into the furnace.
A) expansion
B) velocity
C) temperature
D) movement
A) expansion
- Failure to burn a fuel oil at the correct pressure and temperature and with the correct atomizer will result in:
1) flame sputtering
2) carbon formation
3) flashback
4) soot
A) 1,2,3 B) 1,2,4 C) 2,3,4 D) 1,2,3,4 E) 1,3,4
D) 1,2,3,4
- Which of the following burners supplies oil under high pressure?
A) air atomizing B) rotary cup burner C) steam atomizing D) mechanical atomizing E) rotary atomizing
D) mechanical atomizing
- In steam atomizing the steam supply pressure is:
A) the same as the oil pressure
B) slightly higher than the oil pressure
C) slightly lower than the oil pressure
D) must be twice as high as the oil pressure
E) must be half as high as the oil pressure.
B) slightly higher than the oil pressure
- The advantages of steam atomizing are:
1) a low turn down ratio is possible
2) a high turn down ratio is possible
3) low pressure may be used
4) a constant pressure may be maintained from low to high firing condition
A) 1,3 B) 1,4 C) 2,3 D) 2,4 E) 1,2
C) 2,3
- Steam atomizing burners require cleaning:
A) more often than the air atomizer B) more often than mechanical atomizers C) less often than mechanical atomizers D) usually only about twice a year E) just as often as mechanical atomizers
C) less often than mechanical atomizers
- In an air atomizing oil burner the air is called:
A) tertiary air B) combustion air C) secondary air D) primary air E) excess air
D) primary air
- The cup of a rotary cup oil burner rotates at:
A) 3200 rpm B) 3400 rpm C) 3500 rpm D) 3800 rpm E) 4000 rpm
C) 3500 rpm
- The purpose served by the coal _____ is to receive the incoming coal supply, place it on stock, and then transport it from stock to boilers at the time and in the form required.
A) pulverizer
B) plant
C) scale
D) hopper
B) plant
- The coal is fed to the surge bin, where inline _____ remove any metal.
A) filters
B) screens
C) magnets
D) shovels
C) magnets
- A belt scale operates by measuring the speed of the belt and the weight on a suspended section of the carrying run. An _____ relates running weights to belt travel and records the tonnage of coal handled.
A) integrator
B) controller
C) electromagnetic
D) elevator
A) integrator
- Screens are fitted in the coal route to the bunkers to remove tinder, stone, and oversize coal so that the supply to the _____ mills is kept free.
A) supply
B) pulverizing
C) storage
D) grading
B) pulverizing
- Reserve storage coal, stocked for extended periods in the open air it will _____ by weathering and also there is an ever present danger of spontaneous combustion
A) mature
B) vaporize
C) deteriorate
D) solidify
C) deteriorate
- The temperature of the stock should be monitored as temps of _____ C and above indicate threat of fire.
A) 100
B) 50
C) 200
D) 70
D) 70
- There are three general firing arrangements:
A) horizontal firing B) vertical firing C) tangential firing D) cross firing E) multi firing F) a,b,c G) c,d,e
F) a,b,c
- The secondary air is admitted to the burner housing surrounding the central nozzle through adjustable _____.
A) vanes
B) orifices
C) louvers
D) openings
A) vanes
- In a vertical firing arrangement the burners are located in the furnace arch (top) and fire vertically _____.
A) upward
B) downward
C) inside
D) left
B) downward
- The tangential firing arrangement has burners installed in each of the _____ of the furnace.
A) walls
B) sides
C) corners
D) arches
C) corners
- The cyclone furnace is an arrangement whereby crushed coal of _____ mm size, rather than pulverized coal, is burned.
A) 50
B) 10
C) 25
D) 6
D) 6
- A tube (or ball) mill is a hollow cylindrical shell, filled approximately half full, with forged steel or cast alloy balls, racing in diameter from _____ mm to _____ mm.
A) 1,25
B) 25,51
C) 30,40
D) 50,100
B) 25,51
- High speed impact pulverizers (turning at 1200 to 1800 rpm) consist of a series of hinged or fixed _____ revolving in a chamber.
A) balls
B) weights
C) hammers
D) wheels
C) hammers
- The ball race pulverizer is used for grinding all grades of coal.
A) true
B) false
A) true
- The bowl mill has _____ to grind the coal between themselves and a slowly rotating horizontal table.
A) rollers
B) balls
C) hammers
D) grinders
A) rollers
- An overfeed stoker uses the _____ flow of fuel and air, with fuel flowing downward and air flowing upward.
A) concurrent
B) crosscurrent
C) countercurrent
D) undercurrent
C) countercurrent
- A spreader stoker distributes the coal onto the surface of a traveling grate with ash discharged at the _____ of the furnace.
A) back
B) front
C) side
D) bottom
B) front
- In a _____ stoker, altering the position of the spill plate or the speed of the rotor changes the distance the coal is thrown.
A) overfeed
B) crossfeed
C) traveling
D) spreader
D) spreader
- In a _____ stoker, air for combustion is supplied by a forced draft fan and passes up through openings in the grate to the fuel.
A) overfeed
B) crossfeed
C) traveling
D) spreader
B) crossfeed
- Using preheated air with pulverized coal:
A) dries the coal
B) helps reduce ash buildup
C) reduces air pollution
D) allows lower grades of fuel to be used
E) increases the heating value of the coal
A) dries the coal
- In an underfed stoker, air for combustion is supplied to a chamber below the grates, then it passes through the grates via:
A) varying the ram stroke B) variable veins C) tuyeres D) dampers E) nozzles
C) tuyeres
- The types of grates used on a crossfeed stoker are:
1) roller grate type
2) chain grate type
3) bar grate type
4) mesh
A) 1,2 B) 1,3 C) 2,3 D) 2,4 E) 1,4
B) 1,3
- 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
D) balanced draft
- 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
E) the height of the stack
- Advantages of mechanical draft are:
1) better purging of the 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
C) 1,2,4
- 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
E) 1,2
- Draft is a term that indicates:
A) atmospheric pressure B) static pressure C) absolute pressure D) friction pressure E) gauge pressure
B) static pressure
- In a Boiler duct, the pressure drop thigh 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
B) measure the air flow
- 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
B) 1,2,4
- Draft is measure in:
A) mm of wg B) mm of mercury C) cm of mercury D) cm of wg E) kPa
D) cm of wg
- 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) manometer
- 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
D) diaphragm
- The _____ fan provides the volume of combustion air to the boiler.
A) induced draft
B) forced draft
C) cross draft
D) balance draft
B) forced draft
- 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) induced draft
- 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) 1,4
B) 1,2,4
- 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
D) 1,2,3,4
- 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) 1,2,3
- 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
C) air entering the fan receives a spin in the direction of wheel rotation
- 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
D) variable speed control
- 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
C) forward curved blades
- 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
C) over the fuel bed
- 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) under the fuel bed
- The most commonly used acid in boiler cleaning is:
A) 5% inhibited sulphuric B) 5% inhibited citrus C) 5% inhibited hydrochloric D) 5% inhibited carbonic E) 5% inhibited nitric
C) 5% hydrochloric
- 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
D) 1,2,3,4
- The wind box is an extension of the air ducts and serves as a _____ chamber for the air.
A) stilling
B) distributing
C) expansion
D) cooling
B) distributing
- Louvers are installed in the _____ to direct the air to the base of the flame.
A) fan
B) burner
C) windbox
D) ducts
C) windbox
- Solid pollutants are dust particles known as ash, consisting mainly of the _____ parts of the fuel.
A) combustible
B) solid
C) metal
D) noncombustible
D) noncombustible
- 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
- 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
- In a cyclone precipitator a spray of water turns the individual dust particles into heavy mud particles.
A) true
B) false
A) true
- 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
- 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 molecule to pass through but small enough to catch the dust particles.
A) electrostatic
B) electric
C) cyclone
D) bag houses
D) bag houses
- The type of _____ _____ system used at a plant depends upon the method of firing and the size of the plant.
A) particle precipitator
B) ash handling
C) distributed control
D) water washing
B) ash handling
- 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
- _____ 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
- A _____ system moves the ash in a stream of air, or flue gas.
A) ash
B) mechanical
C) pneumatic
D) hydro
C) pneumatic
- The _____ system involves the use of solids handling equipment, sucks scraper, conveyors, bucket elevators, and conveyor belts.
A) ash
B) mechanical
C) pneumatic
D) hydro
B) mechanical
- 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
- In the _____ scrubbing system, a solution of lime/limestone slurry contacts the sulphur dioxide laden flue gas.
A) dry
B) wet
C) liquid
D) adsorption
B) wet
- 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
