Instrument Air Generation

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Instrument air generation is a process to generate instrument air for control air. Instrument air is used to operate pneumatic instruments. The only difference between making instrument air and plant air is that instrument air is passed through an adsorber filled with alumina gel, but moisture air is passed through a filter only after the compressor and not through an adsorber. Instrument air is moisture free air


A bank of compressors c1, c2 … c-n takes the atmospheric air and compresses to a pressure of approx 10 kg/cm2.

Wet Air Receiver

Compressed air from compressor bank goes to a wet air receiver.

Air Filter

After wet air receiver , Wet air goes to Air filter. Here all the dust and other suspended particles gets filtered.


After filtering air in air filter, filtered air goes to Adsorber units, where all the moisture gets separated out.

Air Receiver

From adsorber unit Dry air goes to Dry Air Receiver. After this receiver the pressure of the air gets controlled at approx 7.0 kg/cm2 through a control valve.

After the control valve the instrument air goes to different users.

Adsorber Saturation & Change Over

After certain time of service Adsorber gets saturated with moisture. Then the second unit comes in-line for service.


The wet adsorber gets dried-up by using hot air coming from air blower via heater element. These service and regeneration cycles goes one-by-one with a fixed time period automatically. This scheme is shown as follows-air comp

Instrument Air Generation

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