Abstract: Oil return from the evaporator to the compressor of a refrigeration chiller is accomplished by routing the suction piping that communicates between the chiller's evaporator and compressor to a location physically below the lubricant-rich pool at the bottom of the evaporator shell and by connecting the lubricant-rich pool to the compressor suction piping at a location where the suction piping is disposed physically below the pool.

Abstract: Oil return from the evaporator to the compressor of refrigeration chiller is accomplished by routing the suction piping that communicates between the chiller's evaporator and compressor to a location physically below the lubricant-rich pool at the bottom of the evaporator shell and by connecting the lubricant-rich pool to the compressor suction piping at a location where the suction piping is disposed physically below the pool.

Abstract: Oil return from the evaporator to the compressor of a refrigeration chiller is accomplished by routing the suction piping that communicates between the chiller's evaporator and compressor to a location physically below the lubricant-rich pool at the bottom of the evaporator shell and by connecting the lubricant-rich pool to the compressor suction piping at a location where the suction piping is disposed physically below the pool.

Abstract: The existence of inverted start conditions in a refrigeration chiller is accurately identified by sensing the liquid level in the chiller evaporator. That liquid level is indicative of the location of the chiller's refrigerant charge at start-up. If the sensed liquid level is below a predetermined level, an inverted start condition is verified to exist. Failed starts and chiller system shutdowns are reduced or avoided as compared to systems in which less reliable indicators are used to identify the existence of inverted start conditions.

Abstract: A protection system for a compressor. The system comprises a compressor having a discharge and including at least one rotor and at least one bearing; a lubrication system including at least one oil recovery device for recovering oil from the compressor, and further including bearing conduit connecting the oil recovery device to the compressor bearing and including rotor conduit for connecting the oil recovery device to the compressor rotors; and an oil protection system. The oil protection system includes a compressor discharge temperature sensor located in the discharge for sensing the temperature of a lubricant/refrigerant mixture discharged by the compressor, a differential pressure sensor located in the bearing conduit for measuring a differential pressure in the bearing conduit, and an oil detector located in the rotor conduit for detecting the presence of oil in the rotor conduit.

Abstract: A refrigeration system employing a screw compressor and a falling film evaporator makes use of high-side pressure to drive lubricant, which escapes the compressor and collects as a lubricant-rich mixture of lubricant and refrigerant in the system evaporator, back to the compressor. The mixture is cyclically exposed to high-side pressure for a period of time which (i) varies in accordance with the difference between a sensed condenser-related pressure and a sensed evaporator-related pressure and (ii) is calculated to maintain a predetermined oil concentration in the lubricant-rich mixture in the evaporator so as to minimize the parasitic losses to system efficiency associated with the oil return process.

Abstract: A method of compressor over temperature protection. The method comprises the steps of monitoring the temperature of oil entering a compressor, determining an oil temperature differential between the entering and exiting oil temperatures, comparing the oil temperature differential to first and second predetermined limits, terminating compressor operation if the first limit is exceeded by the oil temperature differential, and terminating compressor operation if the second temperature limit is exceeded by the oil temperature differential for longer than a first time period.

Abstract: A method and apparatus for monitoring oil charge loss for use with a refrigeration system. The refrigeration system has a compressor for compressing a refrigerant gas, an oil/gas separator for separating compressed refrigerant from lubricating oil, a condenser for condensing the compressed refrigerant gas, an oil cooler for cooling oil separated from the refrigerant, the refrigerant and oil both having known and differing coefficients of heat transfer, and an injection system for injecting the cooled oil into the compressor.

Abstract: A condenser for an air conditioning or refrigeration system having first, second, third and fourth condenser coils arranged in a modified "W" arrangement.

Abstract: An oil separator for an air-cooled refrigeration system employing a screw compressor includes a U-shaped housing the bottom of which defines an oil sump and the upstanding leg portions of which are connected by flow splitting apparatus. The flow splitting apparatus divides and tangentially delivers portions of a mixture of compressed refrigerant gas received from the compressor, and in which oil is entrained, into the upper region of each leg portion. The tangential delivery of the mixture into the leg portions and the centrifugal force created thereby causes the entrained oil to be separated from the gas at two distinct locations in the separator. The separated oil drains along the inner walls of the leg portions of the separator to a common sump while the compressed refrigerant gas from which the oil has been separated exits each of the leg portions through open-ended conduits which extend into the leg portions.

Abstract: A liquid line service and process device for use in the liquid line of a refrigeration system comprising a housing respectively including an inlet, a filter core and an outlet forming a refrigerant flow path through the housing. The housing also includes an access port, means for connecting the access port to the refrigerant flow path, a moisture indicator in the refrigerant flow path, and means for controlling the flow of refrigerant in the flow path.