Virginia Chemicals Inc.

Ernest W Schumacher

Stephen E Evans

John P Clarke

Hisashi Ebisawa

A combined filter and filter-drier, for the suction side of refrigeration and air conditioning systems, comprises a dual filter system straddling a cylindrical plug of dessicant. Upstream of the dessicant, a rigidly built primary filter assembly comprises an inlet deflector and a stepped filter. Downstream of the dessicant, a secondary filter assembly comprises an outlet filter pad which is compressed by a coaxially disposed spring near the inlet of the filter/filter-drier. The inlet deflector is preferably triangular in shape and is disposed transversely to the inlet. The stepped filter comprises a deflector filter pad, which preferably has the same shape but a smaller size than the inlet deflector, and a filter pad which is round, preferably is twice as thick as the deflector filter pad, and has a smaller diameter than the inside diameter of the filter/filter-drier, whereby an annular space is provided for swirling flow of an incoming vaporous mixture which thereby enters the peripheries of the stepped filter. In consequence, particles are gradually deposited throughout the interiors of the deflector filter pad and inlet filter pad so that pressure build up across the filter/filter-drier is also gradual and provides a warning of impending need for replacement. A method for constructing the filter-drier is also disclosed.

Refrigerant suction line filter/filter-drier and method for the

An integral low-pressure accumulator/filter-drier for use in air conditioning and refrigeration systems between the evaporator and the compressor is described. This device is installed in upright position and includes a filter-drier and an accumulator which are separated by a bottom filter-drier retaining member which positions, in cooperation with a top filter-drier retaining member, an annular filter-drier assembly comprising a pair of thin cylindrical filter cartridges which straddle an annular dessicant bed which is itself straddled, at top and bottom, by a pair of annular filter pads. A pickup tube within the accumulator is sealably attached to an opening within the bottom retainer plate and extends coaxially within the inner filter cartridge, being biased against the top retainer plate by a spring assembly so that it is securely held and resistant to vibrations and rotation thereof. While the in-flowing mixture of refrigerant and oil is passing through the dessicant bed, the liquid separates from the vapor and flows downwardly into the plenum chamber of the accumulator. Porosity relationships within the filter-drier assembly direct a minor portion, such as 15%, of the vapor into the accumulator for picking up the liquid through a bottom orifice in the pickup tube.

Integral suction line accumulator/filter-drier

A replaceable float oil separator, for installation in large refrigeration systems of the vapor compression type using refrigerant-immiscible lubrication oils, comprises a compact float assembly that is disposed transversely to the axis of its vessel and a removal assembly on the side of the vessel through which the float assembly can be removed for repair or replacement. The float assembly is compact in its design because a counterweight supports up to 90%, preferably 60%, of the weight of the float ball, in accordance with an energy balance equation. The removal assembly includes a flange cover, an o-ring, and a flange which is attached to the cylindrical side of the vessel, near its bottom where temperature cycling is minimal, whereby the vessel is semi-hermetically sealed. The float assembly is entirely supported by its oil return line which is attached to and passes through the flange cover of the removal assembly. Because the oil return line is off-centeredly disposed in the flange cover, the float assembly can be replaced only in its correct operating position when the flange cover is bolted onto the flange.

Replaceable float oil separator

In a refrigerant system having a liquid trapping suction accumulator between the evaporator exit and the compressor entrance and a very short bore capillary as an expansion tube to replace the thermostatic expansion valve, a recirculating ejector is added to recirculate any liquid that may be trapped by the accumulator back into the evaporator inlet where it can be used to provide desired refrigerating effect without requiring additional work in the compressor. The expansion tube is positioned so that it functions as the primary nozzle of the ejector. Thus the high-pressure liquid refrigerant being expanded through the expansion tube becomes the prime mover that is needed to drive the liquid from the accumulator into the evaporator. Because the high-pressure liquid refrigerant must be expanded to the relatively lower evaporator pressure in any vapor cycle refrigeration system, the recirculating function is accomplished without using additional energy or penalizing system capacity. Additionally, a heat exchanger is provided to heat the liquid/vapor/oil mixture leaving the accumulator and to cool the high-pressure liquid feeding the ejector primary nozzle, thus thermodynamically compensating for the small amount of compressor work associated with liquid in the suction vapor by sub-cooling the high-pressure liquid en route to the evaporator.

Air-conditioning system having recirculating and flow-control means

A filter-drier that provides two-way or bi-directional flow for a heat pump or other refrigeration system is described. This filter-drier contains a spring-loaded check valve at each end of an adsorption space containing an adsorbent such as activated alumina, molecular sieve silica gel or combination thereof. Each check valve is surrounded by a filter pad and a flexible diaphragm. Reverse-discharge and separate-discharge embodiments are particularly described.

Two-way filter-drier for heat pump systems

A device is provided for monitoring and controlling the above-ambient pressure in a system by comparing a net pressure force, produced by the system pressure on a pair of diaphragms having unequal areas, with a net spring force produced by a pair of opposed springs which clamp together a valve member and a valve seat in a pressure-relief member. The valve seat is connected by a passage to a port which is connected to the system pressure. While thus clamped together, the valve member and the pressure-relief member travel together through most of the total stroke created by movement of the pair of diaphragms and activate a microswitch for admitting additional fluid to the system when the system pressure is insufficient. If the net pressure force is sufficiently greater than the net spring force because of excessive system pressure, a port is opened when the valve strikes a stop and the pressure-relief member continues to move. The device is suitable for systems at below-ambient pressures by reversing the inequality of the diaphragms.

Pressure control device for fluid systems

A thermostatic expansion valve for large-capacity refrigeration systems has a pressure-balanced valve pin and no means of communicating inlet pressures to the underside of the diaphragm. The valve pin has a coaxial bore, a pair of end faces, a pair of cylindrical portions fitting slideably in a feed bore leading to an outlet chamber, a reduced stem portion of small diameter between the pair of cylindrical portions, and a pair of shoulders connecting the reduced stem portion to the pair of cylindrical portions. The shoulders are exposed to the same pressure so that the valve pin is balanced.

Balanced single port thermostatic expansion valve

A combination liquid trapping suction accumulator and evaporator pressure regulator device used intermediate the compressor and evaporator in a vapor-compression refrigeration system as a protective device for the compressor. The device is characterized by the positioning of the evaporator pressure regulator chamber intermediate the inlet and outlet ports of the accumulator housing. Thus, evaporator pressure regulation is accomplished simultaneously with liquid accumulation in a compact and readily serviceable, unitary housing.

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Desoto, TX, United States of America

Ernest W Schumacher