Compressors Flashcards
How many stages can you have on a single rotor
12
Type of casing used on small units with low-pressure ratios and small volumes
Sectional
Horizontally split casings are limited to less than this psi
1000 psi
Vertically split casings are used in high pressure applications of up to this psi
10000 psi
Compressor shaft speeds can exceed this many rpm
50000 rpm
The three basic impeller styles
Open, semi-closed, close
The most common seal used in dynamic compressors
Labyrinth
Seals used where there are low pressure requirements
Carbon ring (1/4 to 1/2 inch wide)
Two types of bearings used
Plain journal - for larger multi-stage compressors
Thrust - Usually tilting pad type
This refers to the rotor being supported by bearings at both ends
Beam
Axial compressors moves large volumes of gas in excess of this
500 000 CFM
Axial flow compressors are compromised of these three things
Rotor
Stator
Casing
What device can you use to examine the inside of s compressor without having to remove the cover
Borescope
What can you use to clean the blades while the compressor is still running
Crushed walnut shells
The range of stability in compressors are represented between these two points on a graph
Surge point and Stonewall point
This occurs when low flow causes flow reversal and compressed gas rushes back from the discharge to the inlet
Surge (causes pressure drop at the discharge)
This is the point along the compressor curve where maximum flow has been reached
Stonewall
Three ways to increase pressure in a sealed container
Reduce the Volume
Heat the Gas
Pack more gas into the confined space
The most accurate means of measuring a vacuum
Manometer
Most applications above 700psi use these types of compressors
Reciprocating
These compressors can run without oil
Labyrinth
Intercoolers reduce the average power requirements of a compressor by this much
15%
Pressure ratios are limited to this
5:1
Valves held together with a nut always have it facing this way
Away from the cylinder
