CMPR 6001 - Air Compression (Chp 27) Flashcards
Which of the following types of air compressors requires internal lubrication?
A) Rotary lobe B) None of the above C) Axial D) Centrifugal E) Rotary screw
B) None of the above
Compressor lubrication oil provides:
- Corrosion resistance
- Sealing around pistons, vanes, etc
- Heat removal
- Wear prevention
A) 1, 2, 4 B) 2, 4 C) 1, 2, 3, 4 D) 1, 3, 4 E) 2, 3, 4
C) 1, 2, 3, 4
The compressor that would favour volume over pressure would be the:
A) Sliding vane B) Rotary lobe C) Axial D) Screw E) Centrifugal
E) Centrifugal
Which of the following is not a true advantage of sliding vane compressors over reciprocating compressors?
A) They produce a steadier flow of air
B) They require less power when staring up
C) Their initial cost is less
D) They do not require inlet or discharge valves
E) They are more efficient
E) They are more efficient
Compressor internal lubrication applies lubrication to:
A) Crankshaft bearings B) Pistons and cylinder walls C) Rotor shaft bearings D) Connecting rod bearings E) Crossheads
B) Pistons and cylinder walls
An advantage of dynamic compressors is that they do not require:
A) Inlet baffles B) Internal lubrication C) External lubrication D) Maintenance E) Air receivers
B) Internal lubrication
To reduce air temperature between stages, we would use:
A) An intercooler B) An aftercooler C) A chiller D) A convertor E) A receiver
A) An intercooler
In a centrifugal compressor, the kinetic energy is converted to potential energy in the:
A) Intercooler B) Volute only C) Compressor cavity D) Volute, diffuser or both E) Diffuser only
D) Volute, diffuser or both
A constant speed compressor is controlled by a/an:
A) Fluid coupling B) Unloader C) VFD (Variable Frequency Drive) D) Variac (variable autotransformer) E) Variable speed coupling
B) Unloader
A reciprocating compressor unloader:
A) Throttles discharge B) Uses variable inlet vanes C) Uses a wastegate D) Throttles suction E) Holds intake valves open
E) Holds intake valves open
