Abstract: Improved heat transfer surface for nucleate boiling is produced by metallizing a reticulated organic foam layer placed in contact with a tube or other heat transfer surface so as to form a reticulated metal surface layer which is integrally bonded to the heat transfer surface. The metallized foam layer is then at least partially pyrolyzed to form hollow metal strand portions. The boiling surface so produced is then modified to enhance its long term boiling stability by deforming the hollow strand portions to reduce their minimum internal diameter. In one manufacturing process, suitable small solid particles, which may or may not be permitted to remain in the finished product, are worked into the porous surface of the reticulated metal layer after which the layer is compacted so as to cause the particles to deform the hollow metal strand portions and thereby reduce their ability to carry liquid flow which could "flood out" vapor bubbles trapped in the tips of the hollow strands during a boiling operation.

Abstract: The invention is concerned with a heat transfer tube for use in boiling type heat exchangers, having an excellent heat transfer performance. More specifically, the invention relates to a surface condition of the heat transfer tube for improving the heat transfer performance and a method of producing the tube easily, especially a method for processing the surface condition efficiently and advantageously from an industrial point of view. The essential feature of the invention resides in a provision of a surface condition for promoting the boiling which consists of annular or spiral cavities extending along the tube surface in the circumferential direction of the latter, as well as narrow gaps extending along the cavities so as to allow the cavities to communicate the outside space. If necessary, spiral or annular fins may be provided on the tube surface, so as to improve the boiling performance at the outside of the tube.

Abstract: An air conditioning system in which a subcooling valve is located in the liquid line fitting upstream from the evaporator creating a pressure drop ahead of the capillary tube to effect liquid subcooling of refrigerant leaving the condenser, thereby resulting in higher cooling capacity and efficiency.

Abstract: A multi-tube evaporator for a cooler used in an automobile is provided with a columnar member tightly inserted in the evaporating tube at its inlet. A spiral groove is engraved on the surface of the columnar member. The spiral groove serves as a capillary through which refrigerant is expanded.

Abstract: An evaporator fabricated from a plurality of plates arranged in spaced parallel relation with one another within a housing or casing having inlet and outlet openings. The plates are arranged to define fluid passages for both water and refrigerant with the refrigerant passages having separators positioned therein. The housing is provided with partitions that cooperate with certain of said plates to define water passages which extend in a serpentine manner from the inlet to the outlet, with the inlet communicating with the greater number of water passages that gradually diminish in number from the inlet to the outlet.

Abstract: An improved portable refrigeration apparatus for selectively cooling or heating a limb of a patient or the like, and which includes at least one flexible pad adapted to be wrapped around a bodily limb and which incorporates flexible tubing serving as an evaporator. A separate auxiliary evaporator is positioned downstream of the pad in the cooling mode to insure that all of the refrigerant is evaporated before returning to the compressor. A temperature control system is provided for the pad which, in the cooling mode, includes a by-pass conduit which by-passes the pad, and a temperature controlled valve for selectively opening and closing the by-pass conduit, and so that the refrigerant will flow concurrently through the by-pass conduit and the pad when the valve is opened.

Abstract: The invention relates to finned heat transfer tubes and to a method for impoving the heat transfer properties in boiling liquids of such tubes by plating the tubes in an electroplating bath containing conductive particles such as graphite powder to produce a porous plated surface. The tips of the fins are covered before plating with a non-conductive coating to prevent plating of the tips. The non-conductive coating can be dissolved away or mechanically removed after plating.

Abstract: Apparatus and a method for securing capillary tubes and other small diameter components within a refrigeration machine. A capillary plug button having a retainer plate in which various small diameter components may be secured has extending therefrom a pair of fastening legs. The fastening legs are inserted through an opening within an internal wall of the refrigeration machine such that projections on the legs contact one side of the wall and the retainer plate contacts the opposite side of the wall thereby securing the plug button within the opening and securing the small diameter components within the retainer plate. The retainer plate has a slot connecting the edge of the plate to a plurality of apertures thereby allowing the plug button to be spread apart such that the components may be inserted into the apertures of the retainer plate.

Abstract: A heat transfer surface for nucleate boiling of liquids is formed on the outer surface of a heat exchanger tube. Helical ridges having two fins each encase the tube. A fin at each ridge is angled toward the adjacent fin on the adjacent ridge forming a gapped cavity therebetween. The method of making the tube includes rolling alternating deep grooves and shallow grooves in the outside surface of the tube and then flaring the fins to form the gapped cavity.

Abstract: A suction line/capillary tube assembly which provides improved heat exchange between the cool gaseous refrigerant conveyed by the suction line and the warm liquid refrigerant conveyed by the capillary tube in a refrigeration system. The assembly is generally characterized by the capillary tube being within and in direct thermal contact with the suction line wall along a substantial length thereof, which length is at least approximately two feet. In a first specific embodiment, the capillary tube is soldered to the inside of the suction line, as opposed to merely being loosely passed therethrough. In a second specific embodiment, an aluminum suction line is fabricated with an internal extruded channel defined between a pair of ridges extending from the interior surface of the suction line. A copper capillary tube is snugly positioned in the channel and preferably the ridges are deformed toward each other so as to substantially surround the capillary tube.

Abstract: A method of flow stabilizing for maintaining parallel channel flow through a multiple tube vaporizer wherein different mass flow rates may occur in the flow of the liquid to be vaporized through the different tubes. The stabilizer includes a plurality of inlet tubes in thermally isolated relationship to the vaporizer and having inner ends extending into the entrance end portions of the vaporizer heat exchanger tubes so as to discharge the incoming liquid to be vaporized inwardly of the entrance end of the exchanger tubes. A flow passage is provided for conducting vaporized liquids from the supply chamber into the heat exchanger tube entrance end portions to prevent choking of the system.

Abstract: Apparatus for and a method of operating a high performance shell and tube type heat exchanger utilizing tubes having integral internal fins. A specific tube circuit configuration is selected to limit the temperature drop of the refrigerant within the tube to a preselected range as the refrigerant flows through the circuit.

Abstract: An evaporator comprising a tube plate having a number of through holes to which the upper ends of a plurality of U-tubes are fixed, a first cover plate secured to the tube plate and having a plurality of through holes aligned to some through holes of the tube plate, a second cover plate secured to the first cover plate and defining in cooperation therewith passages for introducing and distributing refrigerant, and an expansion valve assembly installed through the first and second cover plates and having a constriction formed therein. The first cover plate defines connecting passages and a collecting passage for the refrigerant in cooperation with the tube plate.

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.

Abstract: A method is provided for customizing the heat transfer from the walls of an electronic unit such as a semi-conductor chip or wafer by determining the required heat transfer characteristics of the units; drilling holes of a predetermined size and location in the walls of the unit with a high energy beam in accordance with the required heat transfer characteristics of the unit; immersing the unit in a suitable dielectric coolant so that nucleate boiling will start at approximately the desired wall temperature to obtain the required heat transfer from the unit, thereby providing a uniform wall temperature.A further aspect of the invention is the inclusion of a heater means located at or near the bottom of the heat transfer wall so that bubble generation can be started thereat, which bubbles wash the liquid from the downstream drilled holes or natural nucleation sites, thereby starting nucleate boiling when the required temperature is reached.

Abstract: A multiple stage expansion valve for use in an air conditioning system for an automotive vehicle including multiple stage flow control orifices located between a refrigerant condenser and a refrigerant evaporator, the high pressure side of the refrigerant gas compressor being in fluid communication with the inlet side of the condenser, the low pressure side of the compressor being connected to the outlet side of the evaporator through a suction throttling valve device, said expansion device comprising multiple stage orifice valves defined in part by a movable piston that responds to the pressure differential across the expansion device to establish optimum refrigerant flow through the air conditioning system during operation at high load, for establishing a relatively high fluid flow restriction during operation at low and moderate loads, and for establishing a moderate fluid flow restriction during operation at high loads and low compressor speeds.

Abstract: An expansion device for use in a reversible vapor compression refrigeration cycle for producing, upon demand, either heating or cooling. Two devices are mounted in opposed relationship in a supply line carrying refrigerant between a first heat exchanger and a second heat exchanger. Each expansion device includes a body having a flow passage therein opening into an expanded chamber. A free-floating piston is slidably mounted in the chamber and is moved to a first position when refrigerant is passed through the line in a first direction and to a second position when the direction of flow is reversed. A centrally located metering port passes through the piston while fluted channels are formed in its outer periphery. When in the first position, the fluted channels are closed against one side wall of the chamber and refrigerant is throttled through the metering port from the high pressure exchanger (condenser) into the low pressure exchanger (evaporator).

Abstract: A plate and fin heat exchanger in the form of a refrigerant evaporator. The heat exchanger comprises a plate and fin structure providing alternately channels for the flow of refrigerant and spaces for the flow of air. An apertured inlet manifold is in communication with the refrigerant flow channels. A refrigerant distribution tube is inserted into the inlet manifold through the aperture in the latter. The distribution tube is provided with a series of orifices formed in the tube wall in register with the refrigerant flow channels.The improvement comprises a construction and arrangement in which the orifices are directed toward the air inlet side of the heat exchanger. Preferably, the orifices are directed to the air inlet side of the heat exchanger at an acute angle to a horizontal plane, the angularity being on the order of 0.degree. to 15.degree. relative to the horizontal plane and below the latter.

Abstract: An automatic expansion valve for controlling refrigerant flow from a condenser to an evaporator in which the valve includes an apertured deflectable disc which defines the refrigerant expanson orifice with other structure within the valve, and with the flow passage arrangement in the valve body being such as to subject the upstream face of the disc to the pressure of the liquid refrigerant, and the downstream face of the disc to the pressure of the expanded vaporous refrigerant so that the disc deflects in accordance with the differential pressure on the opposite faces and accordingly effects changes in the effective opening of the expansion orifice.

Abstract: An automatic expansion valve for controlling refrigerant flow from a condenser to an evaporator in which the valve includes a deflectable member which defines a refrigerant expansion orifice with other structure within the valve, and with the flow passage arrangement in the valve body being such as to subject at least part of the opposite faces of the deflectable member to the different pressures resulting from refrigerant flow through the expansion orifice so that changes in the deflection of the deflectable member are in accordance with differential pressure across the orifice and accordingly effects changes in the effective opening of the expansion orifice.

Abstract: A boiling surface layer is formed on a thermally conductive wall comprising a plurality of ridges separated by grooves provided at microscopic density, with outer sections of the ridges partly deformed into adjacent grooves to provide sub-surface cavities with restricted openings to the outer surface and sub-surface, openings between some of the cavities.