Figure 10-28.—HPAC, cross-sectional views.
Air from the first-stage separator is drawn into the
single-acting, second-stage cylinder on tile upward
stroke of the piston. As the piston travels downward, the
air is compressed and forced out the discharge valve.
The second-stage discharge air passes through the
second-stage intercooler into the second separator.
The third stage draws air from the second separator
and compresses it in the same manner as in the second
stage. Third-stage air enters a pulsation bottle before
passing through the third-interstage cooler. Pulsation
bottles are used after the third and fifth compression
stages to minimize the shock effect of inlet and
discharge pulses as well as pressure changes due to
condensate draining.
After passing through the third-interstage cooler
and moisture separator, the air is drawn into the
fourth-stage cylinder on the downstroke of the piston.
As the piston travels upward, the air is compressed and
10-30
