Vane compressor Flashcards
(44 cards)
What is pressure ratio?
Ratio of the absolute incoming air pressure to the absolute
compressor discharge pressure.
What is the casing?
Metal outside structure that holds all the components in place.
What is a stator?
Stationary inner metal cylinder that the vanes contact and slide
across as they turn within the unit. Machined as a separate unit and
contains inlet & outlet ports, oil relief valves and oil release valves..
What is a rotor?
Only rotating part in a vane compressor.
What is the purpose of the bearing carriers?
Locate the rotor in the correct position
What are vanes?
Metal or composite sliding parts that fit into rotating block slots
What purpose do the bearings serve?
Support and position the rotor in the off centre position within
the stator ring so no metal to metal contact takes place.
What types of valves are found on vane compressors?
Min. pressure valve, check valves, unloader valves, servo
valves, oil relief, oil return, oil release, safety relief and vacuum
What is the purpose of the minimum pressure valve and where
is it found?
Allows the wet sliding vane compressor to build enough
pressure to get oil lubrication system working 1st before sending any
air out into they system. Located at compressor discharge.
What is the purpose of the check valve and where is it found?
Prevent back flow of compressed air into the compressor on
shutdown. Located at discharge. On wet vane it is located in the
minimum pressure valve assembly, plus another in the unloader
valve to prevent compressor air and oil mixture from discharging
though the inlet on shutdown.
What is the purpose of the unloader valve and where is it
found?
Regulates incoming air and matches it to the system
requirements. Found after the inlet are filter but before the rotor.
What is the purpose of the servo valve and where is it found?
When opened, allows oil pressure to reach the unloader valve
and move it to the closed position. Found in the oil reservoir just
before the unloader valve.
What is the purpose of the oil relief valve and where is it found?
Allows trapped oil an escape route to prevent hydraulic lock.
Found on Stator near the compressor discharge.
What is the purpose of the oil return valve and where is it
found?
Allows separated oil, but not air, to be fed back into the
compressor intake.
What is the purpose of the oil release valve and where is it
found?
Allows oil to drain back into the reservoir to prevent hydraulic
lock. Found on bottom of the stator.
What is the purpose of the safety relief valve and where is it
found?
Prevents over pressure of the casing and to unload the
compressor for ease of starting. Found on the casing between the
rotor and minimum pressure valve.
What is the purpose of vacuum valve and where is it found?
Used to break the vacuum that causes blade instability, found
near the compressor intake.
What are internal valve ports and where are they found?
Allow air into the inlet or out of the outlet chamber at the correct
time during the cycle. Cast into the stator ring at specific locations.
Roughly how often should you change vane compressor oil and
grease?
10,000 hours and grease every 6 months
What is a common problem with the servo/unloader valve
modulation control?
Valves get stuck and blow relief valve.
In a sliding vane compressor, explain the position of the rotor,
which enables it to compress air.
Set in the stator off centre.
What type of compressor requires the vanes be made from a
special material with a low coefficient of friction such as teflon or
graphite?
Dry Vane
What type of compressor is flooded with oil all the time that it is
running?
Wet vane.
How do vane compressor systems often eliminate the need for
an air receiver?
By using an inlet throttling system
