Abstract: Water contamination is purged from molecular sieve material used in oxygen concentrators by heating the molecular sieve material to a temperature in the range of approximately 450.degree. to 950.degree. F., and subjecting the molecular sieve material to a stream of dry sweep gas having a dew point in the range of approximately -80.degree. to -100.degree. F. In the preferred embodiment, the molecular sieve material is contained in a vessel and heated by means of a number of heating elements. In addition, a flow of dry sweep gas is produced by at least two drying chambers containing a desiccating material. A first valve assembly alternately cycles the sweep gas through the first drying chamber and then through said second drying chamber.

Abstract: An apparatus for continuously drying gas delivered from a compressor for compressing moisture laden gas in which oil is heated and discharged and separated from the gas includes a dryer having a moisture adsorbing condition and a regenerating condition and valves for selectively utilizing the heated oil from the compressor to control the moisture adsorbing and regenerating conditions of the dryer, and selectively admitting the separated gas delivered from the compressor to the dryer.

Abstract: An improved method and apparatus for regenerating desiccant in an adsorption dryer is disclosed. The method utilizes a two-phase regeneration, the first phase using the heat from the compressed gas supply to desorb a portion of the moisture from a regenerating desiccant chamber, with the second phase utilizing low pressure, dry product gas. The heat of compression/pressure swing combination offers reduced regeneration energy requirements with improved dewpoint performance.

Abstract: In some critical use, air-drying systems, 100% back-up capability is desired. The problem has been that an idle standby unit requires considerable time to reach full capability for dry air delivery. This invention bleeds enough dry air from the operating primary unit through parts of the idle back-up unit to maintain any dynamic conditions that are necessary to keep the standby unit ready for immediate use in the event of a failure of the primary unit.

Abstract: This invention makes possible the use of a very small pressure relief valve for protecting pressure gauges, thermometers, humidity indicators and other detectors from excessive pressure in an element in which the fluid is contained and of which the indicators must measure a characteristic. The pressure relief valve is located in an exhaust branch outlet from passages that connect the detector with the element in which the fluid is contained; and the relief valve has a housing with an inlet port of a cross-section much less than the cross-section of the passage from the element containing the fluid. This inlet port throttles the flow of fluid into the relief valve. By thus reducing the cross section of the inlet port, the relief valve can be as small and inexpensive as desired, commensurate with the flow required by the detector where the detector is of a nature requiring a flow of the fluid.