Abstract: A plate heat exchanger for accommodating a circulating refrigerant and heat transfer fluid. The plate heat exchanger includes a plurality of heat transfer plates and at least one electrode plate. The plurality of heat transfer plates are mounted in parallel relationship to each other defining alternating flow spaces for a refrigerant and a heat transfer fluid. The electrode plate is located in each refrigerant flow space and is spaced from the adjacent heat transfer plates. The electrode plate includes outer electrode surfaces on each side thereof to produce an electric field. The effect of the electric field is an increase in the heat transfer rate between the refrigerant and heat transfer fluid. The invention also includes a method of exchanging heat between a heat transfer fluid and a refrigerant in a plate heat exchanger.

Abstract: A system for calculating the degree of fouling in a heat exchanger having at least one longitudinal tube inside of a shell, the shell having a first heat exchange medium flowing inside the tube and a second heat exchange medium flowing across the outside surface of the tube. The apparatus includes a first temperature sensor, a device for determining the temperature of the tube at a first axial position of the tube, and a fouling detector. The first temperature sensor senses the temperature of the tube at a first axial position of the tube. The fouling detector calculates the degree of fouling in the tube based on the initial temperature difference between the temperature of the tube and the temperature of the first heat exchange medium in the tube at the first axial position, and a later temperature difference between the temperature of a surface of the tube and the temperature of the first heat exchange medium in the tube at the first axial position.

Abstract: A plate heat exchanger for accommodating a circulating refrigerant and heat transfer fluid. The plate heat exchanger includes a plurality of heat transfer plates and at least one electrode plate. The plurality of heat transfer plates are mounted in parallel relationship to each other defining alternating flow spaces for a refrigerant and a heat transfer fluid. The electrode plate is located in each refrigerant flow space and is spaced from the adjacent heat transfer plates. The electrode plate includes outer electrode surfaces on each side thereof to produce an electric field. The effect of the electric field is an increase in the heat transfer rate between the refrigerant and heat transfer fluid. The invention also includes a method of exchanging heat between a heat transfer fluid and a refrigerant in a plate heat exchanger.

Abstract: The condenser has a condenser shell with a reservoir portion, condenser tubes for cooling vapor flowing over the condenser tubes to condense the vapor to a liquid, and subcooler tubes in a subcooler compartment for cooling liquid within the reservoir portion. The condenser includes a drainage member for forming a void in the reservoir portion and having an upper surface inclined relative to a horizontal plane for directing the liquid from the condenser tubes toward the entrance to the subcooler compartment. The drainage member reduces the amount of liquid required in the reservoir for efficient subcooler and system operation by occupying space in the liquid reservoir that normally is occupied by liquid.

Abstract: Oil separator assembly for removing and collecting oil entrained in a gas includes a vessel having a cavity with a reservoir formed therein; an inlet pipe extending into the vessel; an inlet diffuser securely attached to the inlet pipe for initially separating the entrained oil from the refrigerant gas; and independent oil and gas outlet ports extending from the vessel for emitting the separated oil and ejecting the substantially oil-free refrigerant gas, respectively. The inlet diffuser includes a conical-shaped hollow member having an open base, a closed end, and a converging side wall extending from the open base to the closed end. Refrigerant gas and entrained oil, received through the open base, gradually impacts on the inner surface of the side wall in a manner sufficient to promote coalescence of the oil. The coalesced oil is directed across the inner surface of the side wall transversely away from the refrigerant gas.

Abstract: An oil recovery system for refrigeration apparatus of the type in which an oil lubricated screw compressor is oriented with a suction inlet in communication with an evaporated chamber positioned under the compressor so that under conditions of low capacity compressor operation, lubricating oil may fall from the compressor through the suction inlet thereof and into the evaporator. The recovery system takes advantage of an existing suction distribution tray in the upper region of the evaporator chamber of such systems, normally used to assure distribution of gaseous refrigerant to the suction inlet of the compressor, by removing oil dropping into the tray and returning it back to the compressor. An existing by-pass eductor loop for returning liquid refrigerant from the evaporator to the compressor is extended by a valve controlled branch to a second eductor for withdrawing the oil from the tray and returning it to the compressor.

Abstract: An improved condenser including a longitudinal extending baffle and a series of transversely extending baffle plates creating a desired flow path for vapor to be cooled which is introduced into a shell. The condenser is characterized by high efficiency performance resulting from improved heat transfer coefficients and better purging of non-condensable gases because of the novel baffle arrangement.

Abstract: A heat transfer surface for use in a flooded evaporator. In a preferred embodiment, a fibrous material is wrapped on the surface of a tubular heat exchange member so that the strands of material lie in spaced relation so as not to blanket the entire surface but rather to provide a good distribution of nucleation sites over the tube surface.