written 6.0 years ago by | modified 6.0 years ago by |
Marks: 5M, 6M
Year: Dec2014, Dec2015, Dec2013, May2014
Difficulty: Medium
written 6.0 years ago by | modified 6.0 years ago by |
Marks: 5M, 6M
Year: Dec2014, Dec2015, Dec2013, May2014
Difficulty: Medium
written 6.0 years ago by |
Compressors are classified as:
Positive displacement
Reciprocating compressor:
The motor windings are cooled by incoming suction vapors.
These have advantage of no leakage, less noise and compactness.
These are classified again as hermetically sealed, semi sealed and open-type
Rotary compressor:
In rolling piston type, roller is mounted on eccentric shaft with single blade.
In rotating vane type with four vanes the rotor is concentric with the shaft.
Screw compressor
The machine consists of two helically grooved rotors which rotate in a housing.
Centrifugal Compressor
This compressor increases pressure of low pressure vapor refrigerant to high pressure by centrifugal force.
It generally consists of an inlet casing, impeller, diffuser and a volute casing.
It is used for refrigerants that require large displacement and low condensing pressure such as R-11 and R-113