# US 7,231,783 B2 · Oil control system for a refrigeration system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,231,783 B2 - Document ID: US7231783B2 - Status: Granted - Kind: B2 - Application number: 11/211,310 - Filed: 2005-08-25 - Published: 2006-03-02 - Granted: 2007-06-19 - Earliest claimed: 2004-08-27 - Assignees: Zero Zone, Inc. - Inventors: Steve L. Esslinger; Erik B. Haffner - Web page: https://patentgrep.com/patent/US7231783B2 ## CPC - F25B 31/004: {oil recirculating arrangements} - F25B 2400/075: with parallel compressors - F25B 2400/22: Refrigeration systems for supermarkets - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract A refrigeration system includes a compressor having a compressor housing and operable to compress a flow of refrigerant. A pump is operable to provide a flow of oil to the compressor. A portion of the oil mixes with the flow of refrigerant and the remainder of the oil flows into the compressor housing. A valve is movable between an open position and a closed position. When in the closed position, the valve is operable to inhibit the addition of oil above a predetermined level within the housing. ## Claims ### Claim 1 A refrigeration system comprising: a compressor having a compressor housing an operable to compress a flow of refrigerant; a pump operable to provide a flow of oil to the compressor, a portion of the oil mixing with the flow of refrigerant and the remainder of the oil flowing into the compressor housing; a valve movable between an open position and a closed position, when in the closed position, the valve being operable to inhibit the addition of oil above a predetermined level within the housing; a suction header in fluid communication with the compressor and operable to provide the flow of refrigerant to the compressor; and a dip pocket providing a fluid communication path between the suction header and the oil pump that bypasses the compressor. ### Claim 2 (depends on 1) The refrigeration system of claim 1, wherein the pump draws oil from the compressor housing. ### Claim 3 (depends on 1) The refrigeration system of claim 1, wherein the valve includes a float operable to close the valve when the oil exceeds the predetermined level. ### Claim 4 (depends on 1) The refrigeration system of claim 1, further comprising a drain port positioned to continuously drain oil from the compressor housing when the oil level is above a second predetermined level. ### Claim 5 (depends on 1) The refrigeration system of claim 1, further comprising an oil filter, wherein th pump draws oil from the compressor continuously and directs the oil through the oil filter to provide oil filtration. ### Claim 6 A refrigeration system comprising: a plurality of compressors operable to compress a flow of refrigerant, each compressor including a housing and receiving a flow of oil; a plurality valves, each in fluid communication with one of the compressors and defining a float space, each valve operable to inhibit the addition of oil above a first predetermined level within the float space; a pump in fluid communication with each of the valves and operable to pump oil out of each of the float spaces; a plurality of drain ports, each drain port in fluid communication with one of the float spaces and operable to continuously drain oil from the float space when the oil level exceeds a second predetermined level within the float space; a suction header in fluid communication with each of the plurality of compressors and operable to provide the flow of refrigerant to the compressor; and a dip pocket providing a fluid communication path between the suction header and the oil pump that bypasses the plurality of compressors. ### Claim 7 (depends on 6) The refrigeration system of claim 6, wherein each valve includes a float operabler to close the valve when the oil level in the associated float space exceeds the first predetermined level. ### Claim 8 (depends on 6) The refrigeration system of claim 6, wherein the second predetermined level is below the first predetermined level. ### Claim 9 (depends on 6) The refrigeration system of claim 6, further comprising an oil filter, wherein the pump draws oil from the plurality of float spaces continuously and directs the oil through the oil filter to provide oil filtration. ### Claim 10 A refrigeration system comprising: a pump operable to receive a flow oil and deliver a flow of oil to an oil header; a plurality of compressors, each compressor including a housing and operable to draw refrigerant from a suction header and to draw oil from the oil header, the compressor discharging a high-pressure flow of an oil-refrigerant mixture; an oil separator receiving the flow of the oil-refrigerant mixture and operable to separate the flow into an oil flow stream and a refrigerant flow stream; the refrigerant flow stream flowing to an evaporator to cool a space; the flow of oil flowing to an oil reservoir for delivery to the oil header; a plurality of valves including a float space, each valve associated with one of the compressors and operable to inhibit a flow of oil into the float space when an oil level within the float space exceeds a first predetermined level; a suction header in fluid communication with each of the plurality of compressors and operable to provide the flow of refrigerant to the compressor; and a dip pocket providing a fluid communication path between the suction header and the oil pump that bypasses the plurality of compressors. ### Claim 11 (depends on 10) The refrigeration system of claim 10, wherein each valve includes a float operable to close the valve when the oil level in the associated float space exceeds the first predetermined level. ### Claim 12 (depends on 10) The refrigeration system of claim 10, further comprising a plurality of drain ports, each associated with a valve and positioned to continuously drain oil from the float space when the oil is above a second predetermined level. ### Claim 13 (depends on 10) The refrigeration system of claim 10, further comprising an oil filter, wherein the pump draws oil from the float spaces continuously and directs the oil through the oil filter to provide oil filtration.