COMPRESSOROIL COALESCING
FILTER
CONTROL
LINE
CONTROL
PORT
TURBO
VALVE
(OPEN)
SUPPLY
PORT
SAFETY
VALVEEXHAUST
PURGE
VALVE
DESICCANT
BED
PURGE
ORIFICE
PURGE AIR
EXTENDED
PURGE
PORT
REAR
RESERVOIR
DELIVERY
CHECK
VALVE
FRONT
RESERVOIR
DELIVERY
PORT
FIGURE 4 - BENDIX® AD-9si™ AIR DRYER WITHOUT GOVERNOR—CHARGE CYCLE
The actual regeneration of the desiccant drying bed begins as dry air from the purge volume flows through the purge orifice into the desiccant bed. Pressurized air from the purge volume expands after passing through the purge orifice; its pressure lowers and its volume increases. The flow of dry air through the drying bed regenerates the desiccant material by removing any water vapor adhering to it. Approximately 40 seconds are required for the entire contents of the purge volume of a Bendix®
The delivery check valve assembly prevents air pressure in the brake system from returning to the air dryer during the purge cycle. After the purge cycle is complete, the air dryer is ready for the next charge cycle to begin.
6
