HSO 2024 to HSO 2035 Installation, Operation and Maintenance Manual
Issue 1.2 : 03/10
Publication 2-119
Page 17 of 94
3.
C
OMPRESSION
4.
D
ISCHARGE
Fig 1 (continued) Compression Process
3.4.2.
Compression
As the main rotor turns, the volume of gas trapped within the flute is
reduced as the length of the flute shortens and compression occurs.
3.4.3.
Discharge
As the star rotor tooth approaches the end of a flute, the pressure of the
trapped vapour reaches a maximum value occurring when the leading
edge of the flute begins to overlap the triangular shaped discharge port.
Compression immediately ceases as the gas is delivered into the
discharge manifold. The star rotor tooth continues to scavenge the flute
until the flute volume is reduced to zero. This compression process is
repeated for each flute/star tooth in turn.
While the compression process described above is occurring in the upper
half of the compressor, there is an identical process taking place
simultaneously in the lower half using star B, thus each main rotor flute is
used twice per rotor revolution (one by one tooth in each star). The
compression process may be likened to an assembly of six double-acting
cylinders (the main rotor flutes) in which the star rotor teeth move as
pistons (always in the same direction).
a
b
c
a
b
a
b
c
a
b
B
A
B
A
