Test2 Flashcards
Provided at utility stations throughout the plant for operation of plant equipment and tools
service air
used in maintenance shops
shop air
service air that has been dried to a low dew point to prevent freezing of the equipment starter.
starting air
What does a plant air system consist of?
Compressor, Knockout drum, Air Dryers, Moisture analyzer, Nitrogen pipeline.
Compressor has what 2 types of systems?
Lube and oil, which cools and lubricates compressor. & Cooling water system, which cools the compressed air.
What does the knockout drum do?
remove moisture and oil
What does the air dryer do?
removes the remaining moisture, air must be very dry.
What does moisture analyzer do?
Measures air dew point. Dewpoint is kept around -40 to -70 degrees F
What is the purpose of the nitrogen
Maintains header pressure.
Available if there is a malfunction in air system**
how does instrument air differ from plant air
it is pressured and dried 105 psig
instrument air is used to
operate pneumatic instruments and controllers, drive equipment (pumps or drills), transport material (pneumatic conveying), purge equipment, and dry solids.
T or F
instrument air uses the same compressor as pant air
true
It is critical that what kind of air is always available?
Instrument air
Instrument air must be free of what?
and why
dust, particulates, moisture, hydrocarbons, and other contaminants.
because it will prevent damage to instruments.
What removes condensation?
O pots, air dryers, and water traps
Instrument air must be what
very dry
What is used as a backup in case dryer or compressor fails
nitrogen
Plant air operates around what psig
125 psig
Plant air can cause
injury to personnel or damage equipment. whipping hose, or flying debris
why cant nitrogen be used as a gas?
Because it displaces oxygen and can kill you easily
what is off gas?
off gas comes from the process (free) vs. natural gas which has supplements added to it.
What is natural gas?
chemicaaly known as methane (NOT PURE METHANE)
what are the 2 categories of natural gas?
Low Sulfur-Sweet natural gas, & High Sulfur-Sour Natural Gas
Tech Responsibility:
monitoring both pressure of the receiver and the flow leaving the receiver.
Monitor liquid levels in knockout and surge drums
Change line and vessel filters
Operate and monitor scrubbers
Test system for leaks
Saftey:
Highly Flammable (natural gas), serious safety issue,
Fuel for burners can come from
naturaal gas, oil, coal, or fuel gas.
Fuel gas is what?
Offgas and natural gas mixed together.
Fuel samples are usually collected in what?
Tedlar bag
Saftey: Fuel gas:
may contain H2S(Hydrogen Sulfide), is highly combustible.
safety feature is DB&B double block & bleed system.
steam generator
two sections ; the boiler and furnace.
fire tub boiler
fire or heat is applied to the inside of the tube while the water is circulated on the outside.
water tube boiler
water is inside the tube and fire on the outside
steam drum
Central piece of equipment
BFW enters
Gets steam from risers
mud drum
where impurities concentrate, blow down removes sediment
Blow down
Gets rid of suspended solids
SWELL
Steam demand instantly increases causing increase in steam drum level
Shrink
Steam demand instantly decreases, causing decrease in steam drum level
6 stages of water treatment
- Clarification
- Sedimentation
- Filtration
- Ion hardness
- Deaeration
- Adding one or more conditioning agents
What is added to boiler to maintain correct PH
Caustic
A steam distribution system is what kind of Loop
Closed loop
Steam that has had some heat energy removed
Condensate
Heat required is called
Latent heat
Type of heat that can be sensed and measured
Sensible heat
Bubbles in boiling water is a form of steam known as
Saturated steam
Steam exiting at a higher temperature than it’s saturation temperature is called
Super heated steam
High pressure
600+ psig
Medium pressure
200-600 psig
Low pressure
15-200 psig
Stations that have a valve and or injection of water or lower pressure steam
Letdown stations
Why do we have expansion loops
Because the allow for expansion and contraction of piping
Why do we recapture condensate?
It’s pure and you use less fuel converting it back to steam. It is also already treated. It’s the best economic choose for boiler feed water.
Economize
Like a preheater
Fire box
WHERE flame is
Burner
Can be on side walk or Floor
Tubes
Can be hanging many different ways
What kind of pressure is in firebox
Negative. .05 in of water. Don’t want stuff to flare out.
Saturated steam
Just recently boiled
Superheated steam
Had more energy added to it
What is used to catch condensate
Steam traps
What is used to get condensate out if it gets suck
Water hammer.
What puts film down on metal so that water can’t touch it
Passivator
What eats or reacts to make neutral
Scavenger
