問題一覧
1
What is turbine thrust?
A force created when moving steam strikes the blades in the turbine.
2
What is carryover?
When small amount of water carried with steam to the steam line
3
What is a creep?
Is the slow deformation of continuously stressed metal overtime, which could lead eventually to rupture
4
Spreader and chain grade stokers are type of?
overfeed stokers
5
Chemicals used to test water sample?
Reagents
6
Define flashpoint?
Is the temp in which vapor will flash when exposed to open flame
7
What is a rectifier?
Converts alternating current (AC) to direct current (DC)
8
What is a tandem and compound turbine?
Tandem turbine- in which both axles are joined together Compound turbine- in which has two separate axles
9
Y configuration 208V all phases what voltage is phase to ground?
120V
10
Define pour point.
Is the temp in which a vapor will flow as a liquid
11
What is a manual reset device?
Is a device that must be manually reset by the operator before the flame safeguard control will be able to restart the burner equipment.
12
______ Is the exertion of equal forces from opposite side of an object that pushes towards the middle.
Compression
13
Describe standing pilot?
Is lit always whether the burner is on or off
14
What is the range of specific gravity for fuel oils?
825 to 1.0 specific gravity on API is 10°F as equal to specific gravity of 1.0
15
Where does the greatest amount of energy loss in the steam cycle occur?
Condense Cycle
16
What is fixed blading?
A turbine blading that is fixed to casing, consist of nozzle shaped blades that direct steam flow through the turbine
17
Temp. of water leaving DA tank?
3 to 5 degrees of entering temp
18
What is demineralization?
Involves passing water through both cation and anion exchange materials. Hydrogen substitute cation while hydroxide replaces anion resulting in hydrogen and hydroxide in water.
19
How many BTUs/lb for #4 fuel oil?
18.840 BTU
20
What effect is soot in a boiler?
Soot is a great insulator on tubes and heating services. 1/16”= increased fuel consumption over 5%. 1/8”= increased fuel consumption over 9%
21
What is caustic embrittlement?
Is the cracking of boiler metal while it is still in service but not subjected to excessive pressure or temperature
22
What is specific gravity?
Is the weight of a given volume of a material divided by the weight of an equal volume of water when both are measured at the same temp
23
Where is induced draft located?
Between the breeching and the stack, as negative pressure is maintained on the furnace side to avoid leakage, and for flue gas to flow to the stack
24
What are pump slip?
Is the difference between the displacements of volume of reciprocating pump calculated at discharge volume to the actual discharge of the pump
25
Describe intermittent pilot?
Is lit when the burner is on and off when the burner is off
26
How are grades of fuel oil designated?
Grades of fuel oil are numbered No. 1 to No. 6
27
Fuel byproduct has the highest heating value?
Butane
28
What is proximate analysis of coal?
Is the percentage of moisture, volatiles, fixed carbon and ash
29
Boiler blow off pipe size in relation to vent size.
Min-Mar blow down valve= 3/4”-2 1/2” Safety valve= 1/2”-4 1/2” Blow down tank and vent= 2 1/2”-4”
30
What is the minimum clearance that an open type expansion tank from the highest element?
Minimum of 4 feet above the highest heating element
31
Types of blades that are in a turbine?
Stationary and rotating
32
What is a barometric meter?
Is a free, swinging, adjustable balanced damper used on small boilers to automatically limit the amount of air being pulled through the combustion chamber.
33
A sudden increase in chimney temp with no increase in firing rate indicates?
Broken baffle
34
What is the amount of access air for burning coal, gas, oil?
Coal= 50% Gas, oil, and pulverized coal= 10%-30%
35
What is control stage?
The first of a turbine, consisting of a nozzle block and a row of moving blading
36
Name the oil used for HFC refrigerant?
Polyester
37
What is control loop?
Is a collection of control devices necessary for automatic control of a process
38
Minimum clearance of a high-pressure boiler from the top of the boiler to the ceiling with the capacity over equals 5000 PPH, 1000 ft.² heating surface, more than 5 million BTU?
7 feet minimum clearance. Equals passage ways around all sides of boiler shall have an obstructed width of not less than 18 inches unless otherwise approved
39
What is flashback?
Is a condition where the flame travels upwind and into the burner assembly.
40
What is a process variable?
Is the condition of what is being controlled
41
Types of coal?
Anthracite-Hard coal, high fixed carbon content. 14,000 BTU heating value Bituminous-Soft coal, high volatile content. 15,000 BTU heating value
42
What is an output signal?
Is a signal leaving a device going to another device.
43
What is counter flow turbine?
To balance the blades
44
Centrifugal pump GPM and RPM?
HPx 33,000 2x3.14xRPM
45
What is banking a fire?
Is a process of slowing down the burning of coal or some other solid fuel
46
What type of pump that pumps back condensate water to the tank?
Condenser water pump
47
What is priming?
When large slugs of water enter the steam line
48
How do you increase feed water pressure on a steam turbine pump?
By throttling on the Leslie feed water pressure regulator
49
What is API?
American Petroleum Institute- is used for the measurement of density for petroleum products or the petroleum scale
50
What is ion exchange?
It has an ion exchange material, usually in the form of small beds of crystal change in calcium and magnesium into sodium ions
51
Super critical boiler operates at?
3206 PSIA, 705 degrees- steam and water has the same density
52
How many safety controls that shut down a boiler during unsafe condition?
1. press limit or temp switches 2. low water fuel cut off 3. flame safeguard 4. auto ignition control 5. oil and gas fuel shut off control 6. air and fuel press control 7. feed water regulating control
53
Purpose of orifice plate in operation of a boiler?
Balance heat transfer
54
What is analog signal?
Is a continuous signal of a continuous process
55
What is excess air?
Is the amount of air added to the combustion process over and above that which is theoretically necessary.
56
What is set point?
Is the desired point in which a variable is controlled or maintained
57
Drop in substitute for our R-22?
R417A
58
What is ultimate analysis of coal?
Is the percentage of moisture, volatiles, fixed carbon, ash, sulfur and hydrogen
59
What is a shrouded ring?
1 metal attach to the outer edge of a turbine’s moving blading to dampen blade vibration.
60
What is acro name MATT mean?
Mixture, atomization, time, temperature
61
What is ramp rate?
The rate at which turbine metal temperature can be increased each hour during start up or decreased each hour during shutdown
62
Define particulate?
Is a fine ash particle from a burner that ultimately settle back to the earth.
63
What three element feed water regulator senses?
Steam flow, feed water flow, water level
64
What are combustibles in the reuse?
Are unburned or partly burned pieces of coal in the ash coming off the grates.
65
Define Ringlemann chart
Is a comparison chart used to measure opacity
66
______ Is the plasticity biome material under tension loading.
Ductility
67
What is a digital signal?
Is a one time instantaneous signal.
68
Why would air be admitted over the fire?
It creates turbulence in the flue gases above the top of the fuel bed to help complete combustion
69
What is predictive maintenance?
Monitoring critical equipment parameter, and then comparing the result with the past records or readings
70
What is peening?
The process in which shrouding is attached to a row of moving blading by hammering tenons on the blades through holes in the shrouding to rivet the blading
71
What is the specific gravity of #4 oil?
0.966
72
What is the percentage of air a confined space should have before entry?
19.5%
73
What is the purpose of the flame scanner?
It senses pilot and main flame signal of flame safeguard to stop firing sequence if either of the two won’t come on
74
Y Configuration 480V all phases what voltage is phase to ground?
277V
75
What causes bulge in tubes?
Is caused by overheating of the shell plate and it affects the entire thickness of the plate
76
What is a condensing turbine?
Is a turbine that allows condensate to be reclaimed for use in the system
77
What is a tandem and compound turbine?
Tandem turbine- in which both axles are joined together Compound turbine- in which has two separate axles
78
What tore or flame control senses visible light?
Cadium sulfide photo cell – rectifying photo tube
79
After Steam leaves the turbine re-heater, it is routed to the:
Intermediate pressure turbine
80
What is chief chemical compound and temporary hard water?
Calcium bicarbonate
81
What type of flame detector senses infrared radiation?
Lead sulfide cell
82
Steam station safety valve, reducing valve is 3 inch diameter inlet pressure 25 PSI.
RVC= 1/3”x7200x7.39= 17,736
83
What is breakdown maintenance?
Is when equipment is allowed to operate till it fails before being replaced
84
What is labrinyth?
A component of the gland seal system made of groove and ridges that form a tortuous path to restrict the flow of fluid such as air or steam
85
What is an AC gear oil pump?
An electrically powered oil pump in the turbine lubricating system that serves as a back-up to the auxiliary pump
86
Describe the operation of safety shut off valve ?
Open- admits fuel to the gas burner. Closed – stop gas flow to the burner.
87
______ Is the exertion of equal forces from opposite side of an object that pushes towards the middle.
Compression
88
What is a confined space?
Is a space that has limited or restricted means for entry and exit.
89
A water seal is used to stop what on a turbine?
Leakage of air
90
What is an input signal?
Is a signal going to a device
91
Why do you extract steam from a turbine?
To use for heating domestic water
92
How do you control the speed of a turbine?
By control valve
93
What is bridged wall?
Is a firebrick wall built across the furnace to support the rear end of grates
94
What position position does a super heater drain during warm-up and operation?
Warm up= open Operation= closed
95
What supply the turbine lubricating oil during operation?
Main oil pump
96
What is Pyrometer?
Is an instrument that measures above temp. range of a thermometer.
97
What is a clinker?
Is a mass coal and ash that are fused together during burning
98
What controls the starting and stopping of a hot water boiler?
Aqua-Stat
99
What causes bagging and bulging of boiler shell in tubes?
Do primarily of overheating, a plate or tube
100
Fly ash and soot are removed from the boiler by a?
Electrostatic precipitators