Adsorption dryers of the DPS series are designed for drying compressed air and nitrogen to pressure dew points of -25°C to -70°C (depending on the design) at operating pressures of 4 bar to 16 bar.
For drying the compressed air, i.e. “adsorption”, the compressed air flow is led through a vessel filled with desiccant. The desiccant extracts moisture from the compressed air and stores it in its structure until the desiccant is saturated with moisture. The saturated desiccant then has to be regenerated, i.e. the moisture stored in the structure has to be “removed” before the desiccant can be used for drying again.
Continuous operation of an adsorption dryer therefore requires two vessels that are operated alternately. One vessel is used for drying the compressed air (adsorption) and the other vessel for regenerating the desiccant. For the DPS series the change interval between adsorption and regeneration is 5 minutes at nominal conditions.
For the DPS series a certain quantity of dried compressed air is drawn off at the dryer outlet (approx. 15% of the nominal volume flow rate at nominal conditions). This amount of compressed air is expanded to atmospheric pressure and is led through the vessel to regenerate the desiccant. The dried, decompressed air is extremely moisture-subsaturated and thus extracts the moisture stored in the desiccant and discharges it to the atmosphere via a silencer (heatless regeneration).