Abstract: A CO2 refrigeration system for an ice-playing surface comprises a transfer circuit, a CO2 refrigerant circuit and an independent condensation circuit. A transfer refrigerant circulates between a condensation heat exchanger and an evaporation heat exchanger. The CO2 circuit is in relation with the condensation heat exchanger to release heat from the CO2 refrigerant. The CO2 circuit comprises a CO2 condensation reservoir and an evaporation stage to receive the CO2 refrigerant from the condensation reservoir. The independent circuit is in relation with the refrigerant of the transfer circuit at the evaporation heat exchanger. The independent circuit comprises a magnetically operated compressor to compress a secondary refrigerant, a condensation stage and an evaporation stage in which the secondary refrigerant absorbs heat.

Abstract: A CO2 refrigeration system comprises a refrigeration circuit in which circulates CO2 refrigerant between a compression stage in which the CO2 refrigerant is compressed. A condensation stage is provided in which the CO2 refrigerant releases heat and is accumulated in a condensation reservoir. An evaporation stage is provided in which the CO2 refrigerant is expanded to a gaseous state to absorb heat from a fluid for refrigeration, with at least a portion of CO2 refrigerant exiting the evaporation stage being directed to a supra-compression circuit comprising a supra-compression stage in which the portion of CO2 refrigerant is compressed. A heat exchanger is provided by which the compressed CO2 refrigerant is in a heat-exchange relation with a secondary-refrigerant circuit, such that the compressed CO2 refrigerant releases heat to a secondary refrigerant used for heating purposes. Pressure-regulating means control a pressure of the compressed CO2 refrigerant being returned to the condensation stage.

Abstract: A defrost refrigeration system of the type having a main refrigeration circuit operating a refrigeration cycle. The defrost refrigeration system comprises a first line extending from the first compressor to the evaporator stage and is adapted to receive a portion of discharged low-pressure refrigerant from the first compressor. Valves are provided for stopping a suction of cooling refrigerant in an evaporator of the evaporator stage and for directing a flow of defrost refrigerant to release heat to defrost the evaporator. A second line is provided for directing the refrigerant having released heat to the expansion stage of the refrigeration cycle. A pressure reducing device is optionally positioned downstream of the condensing stage for adjusting a pressure of the refrigerant in the high-pressure liquid state mixing with the defrost refrigerant having released heat.

Abstract: A refrigeration system of the type having a compression stage, a condensation stage, an expansion stage and an evaporation stage, comprising a first evaporator group in the evaporation stage. The first evaporator group has two or more evaporators. A first valve is positioned upstream of the evaporators of the first evaporator group. The first valve is closeable to stop a supply of refrigerant to the evaporators of the first evaporator group simultaneously for a subsequent air defrost of the evaporators of the first evaporator group.

Abstract: A defrost refrigeration system having a main refrigeration system and comprising a first line extending from a compressing stage to an evaporator stage and adapted to receive refrigerant in high-pressure gas state from the compressing stage. A first pressure reducing device on the first line is provided for reducing a pressure of the refrigerant in the high-pressure gas state to a second low-pressure gas state. Valves are provided for stopping a flow of the refrigerant in a first low-pressure liquid state from a condensing stage to evaporators of the evaporator stage and directing a flow of the refrigerant in the second low-pressure gas state to release heat to defrost the evaporators and thereby changing phase at least partially to a second low-pressure liquid state. A second line is provided for directing the refrigerant having released heat to the compressing stage, the condensing stage or the evaporator stage.

Abstract: A defrost refrigeration system of the type having a main refrigeration circuit operating a refrigeration cycle. The defrost refrigeration system comprises a first line extending from the first compressor to the evaporator stage and is adapted to receive a portion of discharged low-pressure refrigerant from the first compressor. Valves are provided for stopping a suction of cooling refrigerant in an evaporator of the evaporator stage and for directing a flow of defrost refrigerant to release heat to defrost the evaporator. A second line is provided for directing the refrigerant having released heat to the expansion stage of the refrigeration cycle. A pressure reducing device is optionally positioned downstream of the condensing stage for adjusting a pressure of the refrigerant in the high-pressure liquid state mixing with the defrost refrigerant having released heat.

Abstract: A sealing device for a modulating valve of the type having a valve body defining a flow passage, an inlet and outlets, a valve displaceable in the flow passage, and an actuator having an actuator rod rotatably coupled to the valve for displacing the valve in the flow passage. The sealing device comprises a body surrounding the actuator rod. A connector is adapted to secure the body of the sealing device to the valve body. Seals are provided between the body of the sealing device and the actuator rod arid between the body of the sealing device and the valve body, to prevent fluid flow therebetween. The body of the sealing device and the seals are adapted to conceal and contain fluid leaks, whereby no fluid is lost due to a leaking modulating valve.

Abstract: A defrost refrigeration system having a main refrigeration system and comprising a first line extending from a compressing stage to an evaporator stage and adapted to receive refrigerant in high-pressure gas state from the compressing stage. A first pressure reducing device on the first line is provided for reducing a pressure of the refrigerant in the high-pressure gas state to a second low-pressure gas state. Valves are provided for stopping a flow of the refrigerant in a first low-pressure liquid state from a condensing stage to evaporators of the evaporator stage and directing a flow of the refrigerant in the second low-pressure gas state to release heat to defrost the evaporators and thereby changing phase at least partially to a second low-pressure liquid state. A second line is provided for directing the refrigerant having released heat to the compressing stage, the condensing stage or the evaporator stage.

Abstract: A refrigeration system having a main refrigeration circuit having a condensing stage, wherein a first refrigerant in a high pressure gas state is condensed at least partially to a liquid state. The condensing stage has a pair of stand-alone condensing stage closed loops in heat exchange relation with the main refrigeration circuit. The stand-alone condensing stage closed loops are parallel one to another and each comprise a second refrigerant circulating between at least a heat absorption stage, wherein the second refrigerant absorbs heat from the first refrigerant in the main refrigeration circuit so as to condense the first refrigerant to the liquid state, and a heat release stage, wherein the second refrigerant releases the absorbed heat. The condensing stage has modulating valves for selectively and quantitatively modulating the temperature of said first refrigerant and compressor head pressure.

Abstract: A high-speed evaporator defrost system is described. It comprises a defrost conduit circuit having valves for directing hot high pressure refrigerant gas from a discharge line of a compressor and through a refrigeration coil of an evaporator of a refrigeration system during a defrost cycle thereof, and back to a suction header of the compressor through a reservoir of the refrigeration system to remove any liquid refrigerant contained in the refrigerant gas prior to returning to the suction header. The reservoir has an internal pressure which is generally at the same pressure as that of a suction header of the compressor thereby creating a pressure differential across the refrigeration coil sufficient to accelerate the hot high pressure refrigerant gas in the discharge line through the refrigeration coil of the evaporator to quickly defrost the refrigeration coil. The reservoir is repressurized after the defrost cycle for using the reservoir in a refrigeration cycle.

Abstract: A stand-alone refrigeration enclosure is comprised of a sealed housing having a solid floor, a roof and sidewalls. Air conditioning equipment is provided in the housing to maintain an internal predetermined temperature range in the housing during seasonal periods. Refrigeration, electrical and auxiliary equipment is disposed in the housing and accessible for maintenance from outside the housing through access doors. Surveillance and monitoring equipment is also provided in the housing for remote visual access and control of the equipment. The housing is also provided with a shielding enclosure to shield a working person from inclement weather conditions when working on the equipment from outside the enclosure through access doors.

Abstract: A refrigeration system having a main refrigeration circuit having a condensing stage, wherein a first refrigerant in a high pressure gas state is condensed at least partially to a liquid state. The condensing stage has a pair of stand-alone condensing stage closed loops in heat exchange relation with the main refrigeration circuit. The stand-alone condensing stage closed loops are is in parallel one to another with a condenser of the condensing stage and each comprise comprises a second refrigerant circulating between at least a heat absorption stage, wherein the second refrigerant absorbs heat from the first refrigerant in the main refrigeration circuit so as to condense the first refrigerant to the liquid state, and a heat release stage, wherein the second refrigerant releases the absorbed heat. The condensing stage has modulating valves for selectively and quantitatively modulating the temperature of said first refrigerant and compressor head pressure.