Charge Cycle - BENDIX AD-9si Service Data

Compressor
Coalescing
Control
Control
Port
Turbo
Cut-Off
Valve
(open)
Supply
Port
Safety
Valve
Purge
Valve
Figure 2 – Bendix AD-9si
®

CHARGE CYCLE

(Refer to Figures 2 & 4)
When the compressor is running loaded (compressing air),
compressed air flows through the compressor discharge
line to the inlet (IN 1) port of the air dryer body. The
compressed air often includes contaminates such as oil,
oil vapor, water, and water vapor.
Traveling through the discharge line and into the air dryer,
the temperature of the compressed air falls, causing
some of the contaminants to condense and drop to the
bottom of the air dryer and purge valve assembly. These
contaminants are ready to be expelled at the next purge
cycle. The air then flows through the inlet tube and into
the desiccant cartridge, where it flows through an oil
separator – or coalescing filter if equipped with a Bendix
PuraGuard oil coalescing cartridge – which removes water
®
in liquid form, as well as liquid oil and solid contaminants.
4
Oil
Filter
Line
Exhaust
Exhaust
Air Dryer with a Governor — Charge Cycle
®
Desiccant
Bed
Purge
Orifice
Purge Air
Delivery
Governor
Air then flows into the desiccant drying bed and becomes
progressively more dry as water vapor adheres to the
desiccant material in a process known as adsorption.
Dry air exits the desiccant cartridge, through the outlet tube,
then flows to the delivery check valve. Some air exiting
the desiccant cartridge is diverted through the orifice into
the purge volume area. The delivery check valve opens,
supplying air to the two delivery ports. The purge reservoir
fills, storing air that will be used to regenerate the desiccant
during the purge cycle.
The air dryer will remain in the charge cycle until the air
brake system pressure builds to the governor cut-out
®
setting of approximately 130 psi.
Extended
Purge
Port
Reservoir
Check
Valve
Front
Reservoir
Delivery Port
Rear