Abstract: A compressed gas filter assembly having dual filter units each containing an adsorbent and alternating between filtering and regenerating cycles, the units alternately receiving compressed gas from a source for adsorbing a contaminant therefrom and having the adsorbent regenerated by reverse flow therethrough of filtered gas from the other unit and together providing an uninterrupted output of filtered gas from the assembly, and a regenerating line connecting filtered gas outlets of the units and having in each unit a restricted orifice centered on and directed toward a downstream end of a canister therein containing the adsorbent, each orifice alternately passing a metered flow of filtered gas under substantially constant pressure to the other unit and discharging filtered gas from the other unit as a substantially constant flow of gas at reduced pressure for regenerating and cooling the adsorbent in its unit.

Abstract: Assembly for filtering compressed gas having dual desiccant-containing filter units each equipped with pneumatically opened and closed inlet and outlet check valves and a pneumatically opened drain valve so connected to each other and a control valve for alternately receiving and exhausting actuating gas as to cause the inlet and outlet valves to close before opening and open after closing of the drain valve. Normally, one unit filters while the other is being regenerated in timed cycles under control of the control valve for maintaining an uninterrupted output of filtered gas, but a regulator valve in the actuating gas supply to the control valve prevents the units from cycling and forces both to filter when the pressure upstream or downstream of the assembly is below a predetermined level.

Abstract: Assembly for filtering compressed gas having a pair of desiccant type filter units each alternating between filtering and regenerating cycles and one filtering while the other is being regenerated and vice versa for maintaining an uninterrupted supply of filtered gas. The filter units are adjacently or remotely mountable and so valved and controlled as to prevent substantial loss of input compressed gas during shifting of filtering from one unit to the other. Filtered gas outlets of the units are connected to opposite ends of a cylindrical purge reservoir containing intermediate those ends a floating piston for diverting to and storing on one side of the piston for subsequent purging part of the output filtered gas from each unit during the unit's filtering cycle and at the same time applying substantially constant pressure for driving gas on the opposite side of the piston from the purge cylinder's opposite end for reverse flow regeneration of the desiccant in the other unit.