BENDIX SD-08-2414 manual Operation, General, Charge Cycle Refer to Figure

OIL

SEPARATOR

PURGE

ORIFICE

CONTROL

PORT

PURGE

CONTROL

LINE

SUPPLY

PORT

GOVERNOR	ENGINE
COMPRESSOR			TURBO		PURGE
	TURBO	CUT-OFF VALVE		EXHAUST	VALVE

Note 1:

The Bendix® AD-IP®air dryer and reservoir system purge piston has a purge control channel drain. This allows any condensation in this area to flow past a diaphragm in the top of the purge piston and out through a channel in the middle of the central bolt of the purge assembly to be drained. During the purge cycle this drain is closed.

DESICCANT

BED

PURGE

VOLUME

DELIVERY

CHECK VALVE

DISCHARGE

PORT

FIGURE 2 - BENDIX® AD-IP®INTEGRAL PURGE AIR DRYER CHARGE CYCLE

OPERATION

GENERAL

Note: Unless otherwise stated in this manual, the Bendix® AD-IP®air dryer refers to both the standard and Bendix® AD-IP®PuraGuard® oil coalescing air dryer. The AD-IP air dryer alternates between two operational modes or “cycles” during operation: the Charge Cycle and the Purge Cycle. The following description of operation is separated into these “cycles” of operation.

CHARGE CYCLE (Refer to Figure 2)

When the compressor is loaded (compressing air) compressed air — along with oil, oil vapor, water and water vapor — flows through the compressor discharge line to the supply port of the air dryer body.

As air travels through the end cover assembly, its direction of flow changes several times, reducing the temperature, causing contaminants to condense and drop to the bottom or sump of the air dryer end cover.

After exiting the end cover, the air flows into the desiccant

cartridge. Once in the desiccant cartridge the air first flows through an oil separator, located between the outer and inner shells of the cartridge. The separator removes water in liquid form as well as liquid oil and solid contaminants.

Air, along with the remaining water vapor, is further cooled as it exits the oil separator and continues to flow upward between the outer and inner shells. Upon reaching the top of the cartridge the air reverses its direction of flow and enters the desiccant drying bed. Air flowing down through the column of desiccant becomes progressively drier as water vapor adheres to the desiccant material in a process known as “ADSORPTION.” The desiccant cartridge using the adsorption process typically removes most of the water vapor from the pressurized air.

Dry air exits the bottom of the desiccant cartridge and flows through the center of the bolt used to secure the cartridge to the end cover. Air flows down the center of the desiccant cartridge bolt, through a cross drilled passage and exits the air dryer delivery port through the delivery check valve.

4