Adsorption dryers regenerating without heat input, i.e. cold, are known as Heatless Dryers and are based on the principle of Pressure Swing Adsorption (PSA), thus permitting desorption to take place without an external heat supply. The principle of heatless regeneration uses a current of dry air typically 8-18%, expanded to atmospheric pressure and purged through the adsorbent bed to bring about regeneration. The strong undersaturation of the purge flow and the heat of adsorption arising through the adsorption process are utilised to bring about desorption.
