Abstract: A solid state system for controlling a compressor or pump which is driven by a motor, the compressor being loaded or unloaded manually or automatically and proportionally to maintain a selected suction-pressure setpoint and to maintain the load on the drive motor within a motor-current setpoint limit, the system having start-up and shut-down sequences which have timed stages including a delay to permit the building up of oil pressure prior to loading of the compressor and including the automatic loading and unloading of the compressor incident to start-up and shut-down. The control includes monitoring of temperatures and pressures associated with the system and automatic shut-down in response to malfunctions internal to the system, and includes automatic shut-down in response to external malfunctions as selectable options, and further includes separate malfunction indicators with a circuit for providing their operability.

Abstract: Heat is recovered in a medium at higher than normal condensing temperature of a refrigeration system by using two cascade connected refrigeration systems and heating the medium in isolated stages by refrigerant subcooling and refrigerant condensing stages of the higher temperature system.

Abstract: A tube shell ice-maker has a false bottom compartment in which trapped refrigerant gas is present to prevent ice formation around the bottom during ice-making and from which during defrosting hot gaseous refrigerant flows upwardly into the refrigerant within the tubes, the liquid remaining within the tubes, whereby delay in initiating further ice-making is minimized.

Abstract: A solid state system for controlling a compressor or pump which is driven by a motor, the compressor being loaded or unloaded manually or automatically and proportionally to maintain a selected suction-pressure setpoint and to maintain the load on the drive motor within a motor-current setpoint limit, the system having start-up and shut-down sequences which have timed stages including a delay to permit the building up of oil pressure prior to loading of the compressor and including the automatic loading and unloading of the compressor incident to start-up and shut-down. The control includes monitoring of temperatures and pressures associated with the system and automatic shut-down in response to malfunctions internal to the system, and includes automatic shutdown in response to external malfunctions as selectable options, and further includes separate malfunction indicators with a circuit for providing their operability.

Abstract: A single casing valve is especially adapted for the inlet of a rotary screw type compressor, the valve having provision for both a manual and an automatic shut-off, the latter responsive to discharge pressure for closing the inlet, and having a strainer in the suction line which is downstream from the valve seat in order that the strainer may be changed with the compressor isolated from the inlet source.

Abstract: A two-stage refrigeration system has a gas-liquid intercooler which subcools liquid refrigerant passing from the feed tank to the evaporators. The feed tank is maintained at the desired pressure adequate for supplying the evaporators and receives return liquid from a separating system which is pressurized from the receiver. In a modification the system may be operated as a single stage or as a compound system.

Abstract: Liquid ammonia at a temperature of approximately -28.degree. F has its temperature raised to a level more suitable for transporting it, e.g. 40.degree. F, by passing it in heat exchange relation with higher temperature ammonia vapor which results from passing a liquid, such as water, from a waste heat source, in heat exchange relation with the ammonia, the vapor then condensing and the condensate returning to the heat exchange relation with the water, controls being provided to avoid inadvertent freezing of the water.

Abstract: A rotary compressor apparatus having a housing with a rotor eccentrically mounted therein and such rotor includes a plurality of sliding vanes which define constantly changing compression pockets as the rotor is rotated. The apparatus includes a plurality of ports which may be opened to permit full unloading when starting the compressor and which may be selectively closed to control the quantity of gaseous matter being compressed. The apparatus also includes a high pressure oil injector at each end of the rotor for sealing such ends to prevent loss of compression.

Abstract: A refrigerant delivery and separation apparatus and a process for delivering refrigerant at evaporator temperature to an evaporator at a predetermined pressure which is less than the pressure at the receiver, and simultaneously separating refrigerant liquid and vapor which is discharged from the evaporator. The apparatus includes a pair of tanks connected by time operated control members to conventional refrigeration equipment so that one tank is pumping liquid refrigerant to an evaporator at a predetermined pressure while the other tank is separating liquid and vapor refrigerant substantially at evaporator pressure.

Abstract: Rotary apparatus for compressing and discharging fluid within a container. The apparatus includes an oscillating rotor or cam-like projection of substantially constant thickness in the plane of the longitudinal axis of the housing which cooperates with a sliding partition to define multiple compartments into which fluid is introduced during a portion of the rotation of the rotor or projection and is compressed during another portion of rotation of the rotor or projection.

Abstract: A screw compressor apparatus in which the rotors have equal pitch circle diameters, and addendum and dedendum of equal radius.