Compressed air coming from the Receiver containing solid, liquid & vapour contaminants enters the Dryer through the Pre-filter (where solid & liquid contaminants are removed). It then passes through Oil Removal Filter and enters into Adsorption Tower A1 through a 3-way valve (CV-1) where it gets dried and then passes out of the Dryer through the After-filter. A part of this dry air passes through Tower A2 through the Purge Control Valve, where it picks up the moisture from the adsorbent thereby regenerating it and making it ready for the adsorption cycle. The purge air exhausts out of the Dryer through Purge Exhaust Valve (CV-2) of Tower A2.

After a fixed time, the functions of Towers A1 & A2 have to be reversed but doing this when the towers are at unequal pressures (Tower A1 is at line pressure & Tower A2 is at atmospheric pressure) will result in : adsorbent being subject to pressure shock and also starvation of air at outlet till Tower A2 attains line pressure in Tower A2. To avoid this, CV-2 is closed before the change-over and pressure in Tower A2 slowly rises to line pressure. The change-over is then effected by operating CV-1 and opening Purge Exhaust Valve CV-3 of Tower A1. The Adsorption Towers are now fully reversed, with Tower A2 under adsorption and Tower A1 under regeneration. At the end of this cycle, the tower functions will again be reversed. This cyclic operation is done through a Sequence Timer and the Dryer runs automatically.

Compressed air coming from the Receiver containing solid, liquid & vapour contaminants enters the Dryer through the Pre-filter (where solid & liquid contaminants are removed). It then passes through Oil Removal Filter and enters into Adsorption Tower A1 through a 3-way valve (CV-1) where it gets dried and then passes out of the Dryer through the After-filter. A part of this dry air passes through Tower A2 through the Purge Control Valve, where it picks up the moisture from the adsorbent thereby regenerating it and making it ready for the adsorption cycle. The purge air exhausts out of the Dryer through Purge Exhaust Valve (CV-2) of Tower A2.

After a fixed time, the functions of Towers A1 & A2 have to be reversed but doing this when the towers are at unequal pressures (Tower A1 is at line pressure & Tower A2 is at atmospheric pressure) will result in : adsorbent being subject to pressure shock and also starvation of air at outlet till Tower A2 attains line pressure in Tower A2. To avoid this, CV-2 is closed before the change-over and pressure in Tower A2 slowly rises to line pressure. The change-over is then effected by operating CV-1 and opening Purge Exhaust Valve CV-3 of Tower A1. The Adsorption Towers are now fully reversed, with Tower A2 under adsorption and Tower A1 under regeneration. At the end of this cycle, the tower functions will again be reversed. This cyclic operation is done through a Sequence Timer and the Dryer runs automatically.