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Peco 4200 > A11 > Flashcards

A11 Flashcards

(100 cards)

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1
Q

What did Thomas Newcomen develop ?

A

Developed atmospheric pressure steam engine.

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2
Q

What was Thomas newcomens idea?

A

Power = difference between atmospheric pressure on one side of a piston, and a vacuum formed by condensing steam on the other.

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3
Q

What did James watt do/believe?

A

Improved Thomas newcomens engine. Boiler pressure acting against a vacuum = more power

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4
Q

What is a heating surface?

A

Part of a boiler which heat is transferred from combustion gas boiler water.

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5
Q

What is the fire side of a boiler ?

A

Products of combustion air, or heat transfer surface exposed to radiant heat.

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6
Q

What is the water side of a boiler?

A

Heat transfer surface covered with water, steam or both.

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7
Q

Older type boilers had?

A

Furnace outside of shell, being externally fired.

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8
Q

Richard trevithick made the first?

A

High presser design

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9
Q

The high pressure design has?

A

An internal furnace reducing heat loss, and a chimney/stack for improved combustion

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10
Q

Fire tube boilers increase?

A

The ratio between boiler heating surface, and water volume

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11
Q

Fire tube boilers support higher internal pressure because?

A

It has a stiffened boiler structure

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12
Q

What do water tube boilers have connected?

A

Drums and headers by water filled tubes to transfer heat within

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13
Q

Water tubes are called ____? And why (2)

A

Safe boiler because they have a small internal volume and, have small diameter pressure parts

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14
Q

Explosive potential for a boiler is?

A

The mass of saturated water in a shell

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15
Q

What is the purpose of bent tubes?

A

To increase surface area for more heat transfer, which produces more steam, and can replace super heaters, economizors and re heaters

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16
Q

What are the 3 main causes of boiler explosions ?

A
  1. Bad/inconsistent design 2.bad/inconsistent construction 3.bad operators
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17
Q

Hot oil can?

A

Achieve a very high temperature with out high pressure

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18
Q

Thermo flooding boilers are ?

A

Used to inject a large amount of heat into the ground to extract oil.

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19
Q

Once through boilers are?

A

Have no internal circulation, water enters at one end and comes out as steam, has no drums, and produces wet steam (85% dry + saturated)

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20
Q

Field erected boilers are

A

Built on site, and are the largest boilers

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21
Q

Packaged boilers

A

Are entirely factory built, and tested then transferred to site

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22
Q

A steam drum is

A

Where the water and steam get separated

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23
Q

Mud drums are

A

Where the debris and bad shit is collected

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24
Q

What are the 3 types of head and which is the most common and the best ?

A

Torispherical, ellepisodial(most common), and hemispherical(best one )

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25
Two types of insulation
Fiber glass and mineral wool on the outside if boiler pressure vessel
26
Why do we use insulation?
To keep heat inside boiler, and to protect operators
27
What is refractory
A highly temperature resistant ceramic material
28
Tapered mandrel is
To expand tubes, fitted between 2 rollers
29
What are stays?
To support
30
11 things a boiler should
1.have large heating surface 2.boiler heating surface exposed to fire or hot gasses must b covered by water 3.must have a circulation of water 4.must b properly insulated 5. Steam space must be large enough for steam 6. Easy access for inspection 7. Built with high standards of workmanship 8. Should be an expensive and easy to maintain 9. Should be strong enough to withstand the pressure and temperature 10. Should allow expansion and contraction 11. Have approved fittings
31
Fire tubes have _____ pressure
External
32
Water tubes have ___ pressure
Internal
33
Water in tubes have _____ heat applied
External
34
Advantages of a water tube boiler (5)
They are more efficient, produces more steam, there is less water needed, better watercirculation, and superheated steam.
35
Disadvantages of a water tube boiler(3)
They need better quality water, more expensive, and are more complex to design
36
Furnaces are often lined with ____ to absorb more heat
Water tubes
37
Risers contain _____ and are ____ denser
Water and steam Are less denser
38
Downcomer’s only contain ____ and have a ____ density
Water Higher
39
What does a continuous blow down pipe do?
Continuously removes a small stream of boiler water to maintain, proper dissolved, solid levels to prevent foming from occurring.
40
What is the first stage of steam/water separation done by
Baffles
41
What does a dry pipe do
Further separates water from steam because of the turns in a pipe. Water is more dense than steam.
42
What do cydone separators do
They pair with baffles to separate steam by rapidly spinning. Dry steam leaves the top and water gets flung outside.
43
Scrubbers (chevron dryers) are
Use rapid change in direction to separate
44
Water walls do
Improve heat transfer, decrease heat loss, and reduce need for insulation
45
D type boiler
Has one steam drum, one furnace, and burner may be located in the front or side of the wall
46
A type
Has one steam drum and two small mud drums, and has bent tubes
47
O type
Has one steam drum one mud drum bent tubes and is used when space is limited
48
Packaged fire tube boilers can be
Power or heating boiler’s
49
Fire tube heads are also called
Tube sheets
50
Larger fire tube boilers have at least 1 _______ and also have ____ in tube sheets
Manhole Hand hole
51
Expanders on a fire tube boiler are used to
Flare/bell tube end
52
What does the contact between the tube and the tube sheet do?
Keeps the ends cool
53
What are the advantages of a fire tube boiler? (4)
1.have simple construction 2.have more water 3. Can tolerate shitty water 4. Cheaper to buy and maintain
54
Fire tubes are also called
Flues
55
Are fire tube boilers reinforced
No
56
What pass tube inlet is greater than the other?
2>3>4
57
Fire tube boilers are not produced in sizes bigger than
25000kw
58
Fire tube boilers have ____ heat in tubes
External
59
Fire tube boilers have ____ heat
Internal
60
Ftb horizontal return tubular boilers
Are expensive to construct and insufficient, because they have brick work
61
Ftb fire box boiler
Is an externally fired, two or three pass horizontal fire tube boiler and are similar to horizontal return tubular boilers
62
Ftb scotch boiler
Designed to maximize heat, transfer and increase efficiency by utilizing heat. This is suitable for high pressure and low pressure service.
63
A ____ is when the rear door is lined with refractory in a scotch boiler
Dry back boiler
64
A ___ is when the rear door is replaced with the water cooled surface to increase the heating surface
Wet back boiler
65
Why were multipass boilers developed
So the flu gas path could be length, and without the need for a longer boiler
66
Add to pass design is a
Dry back
67
A 3 and 4 pass design is a
Wet back
68
Single pass boilers
Have no central furnace tube instead each of the fire tubes is a small volume furnace. This creates more radiant heat transfer, resulting in boiler transfers heat very effectively. They have no internal baffles and no refractory.
69
As flue gas transfers heat it’s _____ decreases
Velocity
70
Vertical tubeless heater
Is a special two pass fire tube designed. It doesn’t have fire tubes but it has a central furnace tube. It is a high pressure steam boiler used in small industrial applications.
71
Water circulation is important because
Fire to boilers rely on circulation for natural convention
72
The grafted heat transfer is from
Radiant furnace heat
73
Poor water circulation can cause
Sludge
74
Lowest permissible water level for fire tube boiler design is __ above the upper most heating surface
25 mm
75
Tube sheets are
Flat heads
76
_____ and _____ strengthen furnace
Corrugations and reinforcing rings
77
AtvantGes of corrugated furnaces
They increase strength, have greater heat, transfer surface area, cause greater furnace, turbulence, help compensate for differential expansion
78
What are the 3 types of stays
Diagonal stay, through stay, stay bolt
79
Chemical feed pipe help
Prevent scale, formation, and corrosion
80
Setting means
Brick work
81
Sub critical steam generating units operate at pressures below
The critical pressure of water and steam
82
Radiant steam, generating unit
Does not have a boiler bank or a mudroom. The water is heated to evaporation in the water wall furnace tubes.
83
Fluidized bed combustion steam generators
Fuel is burned, suspended in mid air in a bed of inert material, like sand or gravel. Fuel is introduced to the bed with a variety of stoker mechanisms.
84
Advantages of fluidized bed, combustion steam generators (3)
Have high efficiency, can use a wide range of fuels, reduces nox, and sox
85
Bubbling bed is
When the combustion air passes through the bed like a large bubbles
86
Fluidized bed boilers have ____ conventional burners to preheat the inner bed material, so that combustion of the ____ begins as soon as it contacts the bed
Auxiliary Solid fuel
87
Auxiliary boilers and electric boilers can be used to
To keep standby steam generators warm so they can be brought online quickly and can also be used during periods of low process steam demand
88
Electric boilers may b used for
High-pressure or low-pressure applications in both steam in hot water service
89
Advantages of electric boilers
Are very compact, do not require furnace, vent, connectors, combustion air, equipment, or chimneys. No fuel storage space is required. Are installed or replaced quickly. Or highly efficient at 99%. Produce no pollution. Are silent. And don’t cause furnace explosions.
90
Disadvantages of electric boilers
Or more expensive. I have limited pressure to about 3100 KPA and operate at high voltages.
91
2 types of electric boilers
Electrode, immersion(resistance)
92
Electrode boiler
Uses water with dissolved solids to conduct electricity (never pure water), electrodes are submerged. Level of water determines steam rates. Higher the level of water, the more current than produces more steam. Doesn’t require cut off switches
93
Immersion (resistance)
Electricity flows through a heating element like a stove. The resistance to current flow causes the element to heat up and is submerged in water. Control steam rates by powering on and off. Require low water fuel cut off
94
Jet electrode boiler
Electrodes are mounted above the water level and to get current to flow, water will be sprayed onto the electrodes to increase current flow and the generation of steam
95
Industrial type water to boilers are seldom selected for
Low pressure heating
96
Flexible water tube heating boiler
Increases the heating surface and allows the tube to expand and contract without creating excessive stress, because turbulent in intensive scrubbing of gases around them
97
Coil tube heating boiler
Is actually a water tube boiler it has no drums or headers, and has one or more continuous coils of copper or steel tubing. If scale is present, water flow could become restricted, and tubes may overheat. These are very common in hot water supply or natural draft designs, and are popular in residential and commercial hot water heating systems
98
Why is copper used in heating systems
It resist corrosion and has better heat transfer
99
What is a aqua stat
It is a high water temperature cut off and a low-water cut off
100
What is pressuretrol
High pressure cut off in a low-water cut off

Peco 4200 (1 decks)

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