Abstract: A portable tube cutter and a method of cutting a boiler tube in a power generating station with the portable tube cutter is disclosed comprising electromagnetically clamping a portable tube cutter to a circumferential portion of a tube to be cut in a power generating station, the tube cutter having a frame formed with a clamping element adapted to fixedly, electromagnetically mount to a circumferential portion of the tube and having a power driven cutting element operable to cut the tube and movable upon the frame along an axis which intersects the longitudinal axis of the tube at an angle; and thereafter moving the power driven cutting element along the axis of movement and into engagement with the tube for cutting the tube.

Abstract: In an apparatus for rounding the edges of semiconductive wafers, the wafers are loaded onto two parallel counter rotating screws one having a right hand thread and the other having a left hand thread. The grooves of respective ones of said screw engage the edges of the semiconductive wafer to be rounded. The grooves of the respective screws are of rounded cross-section and an abrasive slurry is introduced into the grooves to facilitate abrading of the edges of the wafers. A pressure roller engages the edges of the wafers and forces the wafers into the grooves to further facilitate rounding of the edges. Due to the action of the screws, the wafers, as they are being rounded are caused to traverse the length of the screws to provide a continuous processing of the wafers.

Abstract: A method of and a device for working the sealing edge of a funnel portion for a cathode ray tube during a plurality of working phases. A number of funnel portions are simultaneously worked in successive working units. Each unit comprises a centering device for centering and bringing the funnel portion into a stationary working position. The funnel portions are simultaneously transported from one unit to another by a common transport device.

Abstract: The invention relates to a lamellar end grinding wheel in which abrasive flaps engage over one another in tile-like manner along the circumferential zones of a circular disc-shaped back plate and are advantageously fixed with the aid of fingers. The abrasive flaps are also anchored in the back plate in that thickened portions are provided along one or both sides of the rear edge region thereof. The anchoring means can also comprise the abrasive flaps having one or more slot-like recesses in the edge region thereof and through these can be passed fingers or finger portions.

Abstract: A housing construction comprising a first unit enclosing at least a kitchen, living/dining/bath and sleeping zones, a second unit enclosing at least a kitchen, storage, and laundry facilities with high heat, noise and or pollutant producing characteristics connected by or separated by a confluence of passageways lying between the first the first and second units to connect these units or alternatively to separate these units by forming sealed passageways between other parts of the housing construction to thus permit exchange of or exclusion of warm or cold air, restrict noise, direct or control traffic, and/or provide increased security as required to produce more security comfort and convenience for the occupants and house guests in the most economical and efficient manner.

Abstract: Apparatus for limiting the effect of vibrations between a building structure and its foundation is disposed between the foundation and the building structure. A plate is fixedly secured to a lower surface of the building structure. A hollow member having a rectangular cross-section is fixedly secured to the plate. An elastomeric bearing is disposed between and fixed to the hollow member and an upper surface of a foundation. A cable, anchored to the foundation, is centrally disposed within the elastomeric bearing and the hollow member, and has a stop attached to the free end thereof. The stop is disposed within the hollow member. The stop serves to limit horizontal and vertical movement of the elastomeric bearing. In a modified apparatus for limiting the effect of vibrations between the building structure and the foundation, an elastomeric material is disposed between the stop and the base of the hollow member to distribute a load applied by the stop through the deflection of the elastomeric material.

Abstract: A loading dock shelter of the pad type having L-shaped configuration, which, in normal operation provides a wrap-around type of engagement with the rear end of trucks backed into operative engagement with the loading dock shelter.

Abstract: The assembly of individual segments to obtain large-volume containers is facilitated by the edges of the individual segments being provided with projecting support members including cut-outs in which an aligning tool is insertable; an engaging element of said tool for aligning said one individual segment relative to the adjacent segment, which along the edge thereof is in contact with the edge of the first-mentioned individual segment, being brought into engagement with a surface of said adjacent individual segment so that the engaging element will ride or roll along the surface of said adjacent individual segment due to a pivoting or lever movement, the two edges being simultaneously brought to an aligned, coincident position.

Abstract: A wedge anchorage for an axially elongated tension member, encased in and arranged to prestress a concrete structure, includes an anchor member with a conically widening surface where a wedge seats for securing the tension member in the tensioned state with a cap arranged to fit in locked engagement with the end of the anchor member through which the tension member extends out of the concrete structure. The cap has a cover wall extending transversely of the axial direction and spaced from the anchor member. An opening is provided in the cover wall through which the tension member extends out of the concrete structure. A spring or other biasing member is located within the cap for limiting axial displacement of the wedge when the tension member is stressed in tension. This arrangement avoids the formation of a recess in the surface of the concrete structure from which the tension member extends and the need for a filler member for sealing off the recess when the prestressing operation is completed.

Abstract: A fastener is disclosed for affixing void-forming members to underlying concrete slabs for use in composite slab construction. Each fastener comprises a stem having a cross limb with a barbed end for insertion into a foam member, a stabilizer bar transversely projecting from one side of the stem intermediate its ends, and bottom barbs. Upon insertion of the barbs of the cross limb into a foam member and projection of the bottom barbs of the stem into a concrete slab, the foam member is thus secured thereto. Several fasteners spaced around the periphery of the member are employed. The concrete slab with void-forming members installed is then overlaid with a poured concrete cap, thereby forming a unitary composite construction.

Abstract: The present invention provides a batten bar of plastic, corrosion-resistant, material which has thick side portions that resist curling, kinking, looping and distorting of that bar, even when the fasteners that are used to secure that bar and the underlying membrane to a roof are overdriven. That batten bar has a connecting or bridging portion between the thick side portions thereof; and the upper surface of that bridging portion is displaced below the upper surfaces of the thick side portions to form an elongated groove which is at least as deep as the head of a fastener which is used to secure that bar and the underlying membrane to a roof.

Abstract: A continuous concrete insert in the form of a channel shaped structural member having opposed side portions and a connected web portion. The web portion is formed with a plurality of pair of spaced apart slots arranged to frictionally retain an anchoring member in the form of a U-shaped staple or member. The intermediate portion of the staple is disposed contiguous to one side of the connected web portion and the opposed leg portions of the staple being projected through the pair of slots so as to extend to the other side of the web portion, and a fastener is provided for securing the structural member in place to a concrete form.

Abstract: A decorative beam assembly comprising a beam support bracket which is attached to a ceiling or wall and a hollow plastic channel shaped decorative beam, which snap-fittinglyengages the bracket by means of inwardly extending arms on the beam contacting flange surfaces on the bracket. The flexibility of the beam allows for easy installation, as well as removal and subsequent replacement, of the beam.

Abstract: A reinforced siding panel comprising, in combination, a metal sheet having interior and exterior surfaces and a contoured plastic sheet adhesively bonded to the interior surface of said metal sheet, wherein said plastic sheet includes a first regular pattern of protruding surfaces bonded to said interior surface of the metal sheet from said interior surface of the metal sheet. The plastic sheet provides greater rigidity to the panel while reducing the weight of the panel compared to a thicker metal sheet.

Abstract: The present invention provides a method and apparatus for attaching fitments to filled flexible containers. A series of interconnected filled flexible containers are conveyed between a pair of belt conveyors which limit lateral movement of the containers. A third conveyor urges fitments against the bottoms of the containers and the fitments are sealed to the containers.

Abstract: Packaging machines have to, on the one hand, achieve high levels of output but, on the other hand, take into account the sensitivity of the cigarettes to mechanical stresses. A two-track configuration of the packaging machine doubles the output at a given speed (number of strokes). By the special designing of a cigarette magazine (26) in conjunction with a group turret (28), it is accomplished that the formation of cigarette groups (21) and the insertion into the pockets (64) of the group turret (28) can be performed within adequately set stroke times at a high output of the packaging machine.

Abstract: Apparatus for packaging particulate product in bags for deposit into cartons of predetermined cross section and height.

Abstract: A coin wrapping mechanism for wrapping rolls of coins comprises a coin stacking system for forming a coin stack containing a predetermined number of coins; vertical and lateral supporting members for supporting the coin stack for rotation about its axis; a driven roll with a resilient surface for rotating the coin stack about its axis while pressing a wrapping material against the coin stack, the wrapping material having a coating of a pressure-sensitive, releasable adhesive on the side facing the coin stack so that the adhesive adheres to, and is wound around, the coin stack; and an ejector for removing the coin stack from the wrapping station after the desired length of wrapping material has been wound around the coins.

Abstract: The apparatus for spiral wrapping a load comprises a carriage which is mounted moveably in the vertical direction on a fixed base-mounted stand and to which two prestretch rollers each coupled with simultaneous rotation with a frictionally engageable wheel and a film supply roll are secured. The downstream prestretch roller and its associated frictionally engageable wheel are carried by a two-arm assembly moveable around a vertical axis and may be moved by moving the member in order to engage or to disengage the frictionally engageable gearing mechanism. A switching assembly which keeps the gearing mechanism disengaged at the beginning of the wrap and thereafter allows an engagement of the friction gearing mechanism until the end of the wrap comprises a base-supported, vertically displaceable and upwardly pretensioned cam member with an upper abutment surface and a lateral cam surface and a switching element coupled rotatably with one arm member of the two-arm member.

Abstract: Device for applying a closing strip, comprising: a housing provided with a channel; a feed for closing strip tape emerging into said channel; a rotor mounted for rotation on said housing and provided with blades projecting into said channel; and cutting means located downstream from said rotor for cutting off the formed closing strip from the closing strip tape, characterized by a member located between said rotor and cutting means and extending into said channel for forming the closing strip during the guiding of the closing strip tape thereover.Preferably said member is an edge positioned transversely on said channel, and forms a part of the housing. If the device comprises further a feed for tape form material emerging into said channel and a magazine therefor, said feed for tape form material and its magazine are, preferably accommodated in a separate cassette.

Abstract: A rotary lawnmower has an edger/trimmer including a freely rotatable disk disposed with a vacuum zone of the mower when in an edging position. In a retracted position, the edger is withdrawn fully inboard of the outer periphery of the mover housing such that no projections are left to interfere with close-in mowing. Guards are provided for the edging disk when in a stowed position, and in an edging position. An alternate embodiment provides for lifting the edger over obstruction when the edger is used on a riding mower. A trim position for trimming around foundations and the like is provided, together with methods of edging.

Abstract: A universal mower deck discharge boot is formed by rotational molding into two sections which telescope one over the other and each of which is formed with a blank forwardly or side facing wall portion, which wall portions together are adapted to be cut out and formed with an opening which closely conforms to the discharge chute of a mower deck. The forward section is otherwise generally closed at the sides and the top and the bottom and is formed with a curved forward wall to resist catching on obstructions, while the rear section is formed with a discharge spout adapted to receive a flexible conduit. The sections telescope one relative to the other to conform to the dimensions of a wide variety of mower deck discharge chutes.

Abstract: A harvesting apparatus for automatically removing fruit from its growth source comprising a harvesting hand mounted at a distal end of an articulated arm assembly, a video camera for picking up a fruit image, and a control unit for guiding the harvesting hand to the fruit in response to information provided by the video camera. The harvesting hand includes a vacuum pad for drawing and catching the fruit, and a calyx cutting device. The vacuum pad and cutting device are movable relative to each other between a first position in which the vacuum pad is disposed forwardly of the cutting device for approaching and drawing the fruit and a second position in which the cutting device is disposed forwardly of the vacuum pad for removing the fruit from its tree.

Abstract: A reinforcing structure for elastomeric articles, having 2-5 filaments. The filaments are arranged in parallel and have a common plane passing through them all. The wire has a diameter smaller than that of the filaments. The wire wraps the filaments together so that a relative position of the filaments with respect to each other and also bending rigidities in predetermined directions do not vary over a full length of the wrapped filament structure.

Abstract: An improved pneumatic spinning machine of the type which includes a draft device composed of a plurality of pairs of rollers, and an air injecting nozzle for producing whirling flows of air to act upon a bundle of fibers fed from the draft device. A front roller of the draft device has an annular air escaping groove formed on a circumference thereof.

Abstract: A device for the false twisting of synthetic threads is provided with a plurality of friction rotors, each constructed of a reusable central bore and an expendable composite ring that is form-fitted and force-fitted to said base so as to be conveniently removable therefrom for replacement when the friction coating along the outer edge of the ring has worn.

Abstract: An open-end spinning process in which the fiber sliver is separated into single fibers and in which the separated fiber material is brought by an air stream to a collecting surface from which it is drawn off while being twisted. According to the instant invention the fiber material is deposited on a collecting surface moving in the direction of thread draw-off, is then twisted and is continuously drawn off said collecting surface in form of a thread. The single fibers are fed upon the collecting surface in the direction of said collecting surface's movement, whereby an alignment of the fibers on the collecting surface takes place. The doubling process is separated from the spinning process as the fiber material is bundled and/or doubled on the collecting surface into a fiber sliver with the fiber mass required for the desired thread. The twisting process takes place independently of the collecting surface by means of a known twisting mechanism.

Abstract: An apparatus for displacing a line of track chain is disclosed which is employable for the purpose of disassembling, assembling, or reassembling the chain. A guide table for guiding movement of the chain is adapted to tilt only in the upward direction together with a pair of rails which are raised or lowered by actuating a first cylinder. A trolley moves forward and backward in the space as defined by both the rails by actuating a second cylinder while it is guided along the rails. The trolley is provided with an engagement rod which extends upwardly therefrom through a slot on the guide table to come in engagement to a bushing in the chain.

Abstract: For flight safety reasons in gas turbine aeroengines it is desireable that in the event of malfunction of an electronic control system--such as a fuel control system--caused, for example, by overheating due to fire, the control system should protect the engine and the aircraft against the consequences of such a malfunction. In the present invention this is achieved by arranging that the control system is provided with a failsafe unit which monitors the condition of the control system and puts the engine into a failsafe control mode if a control system condition signal generated by the failsafe unit varies beyond a predetermined limit. Thus, to ensure safety under overheating conditions, the control system condition signal is representative of the temperature experienced by the fuel control system and the failsafe control mode is a speed-limiting control mode.

Abstract: The cooling air for the nozzle of an augmentor of a gas turbine engine is maintained uniformly around the circumference to assure the prevention of hot streaks that would be occasioned by the liner "sagging". A separate end piece having judiciously located gaps for directing air over the nozzles, flaps and seals attached to the end of the augmentor duct maintains concentricity during augmentor operation, and affords support to the liner of the duct.

Abstract: The assembly comprises an elongated float member which floats on the surface of a body of water having waves moving therealong. A support arm freely pivotally connects to the float member for maintaining the float member parallel to the surface of the water. The support arm member is effective to maintain the float member with its longest dimension disposed in a direction parallel to the length of the waves moving along the surface of the body of water. A transmission assembly is responsive to the support arm member as the float member moves up and down with the movement of the waves to produce a rotational movement in a transmission shaft from which energy may be derived. Various features directed to the specific configuration of the float member, support arm member, transmission mechanism including the structure of a transmission shaft and a clutch mechanism are also disclosed.

Abstract: An apparatus which generates electrical power from a combination of gravity forces and the inherent buoyancy of a hollow body immersed in a fluid is disclosed. The apparatus includes a long chain having a plurality of hollow buoyant elements attached thereto. The chain extends around a pair of sprockets and the buoyant elements are immersed in a fluid along the portion of the chain moving against gravity and the buoyant elements pass through an airspace along the portion of the chain moving with gravity. The combination of buoyancy and gravitational forces cause movement of the chain to thereby rotate the sprocket gears which are used to drive an electrical power generator. Also disclosed is a housing including a hatch assembly for the apparatus and a valve unit and an insulator for use with the apparatus.

Abstract: A system for converting DC electrical solar generated energy to AC electrical energy. A DC motor is driven by electricity obtained from DC electrical energy producing solar panels. The DC motor drives an air compressor which in turn provides, via Archimedes' principle, a constant flow of air to a submerged cross-flow turbine. The turbine is rotated by the rising air bubbles through the water. An AC generator is connected to the shaft of the turbine. The output of the AC generator is then fed to the consumers or homeowners electrical supply lines.

Abstract: The master cylinder (10) comprises a housing (12) having a longitudinal bore (14), an end (24) enclosed by a bearing member (18) which retains a sleeve member (20) within the bore (14), a reservoir (70) mounted on the housing (12) and a pair of pistons (30, 40) slidably received within the bore (14), one piston (30) extending through the end (24) of the sleeve member (20). The one piston (30) has a reduced diameter end (32) which provides seating for a fast fill valving mechanism (110). The fast fill valving mechanism (110) comprises a fast fill seal (120) having a flexible arm (122) engaging an interior surface of the sleeve member (20) and the sleeve member (20) having longitudinal grooves (22) adjacent the arm (122), a fast fill spring member (140) trapped between the fast fill seal (120) and a land member (130), the land member (130) having pockets (132) covered by the fast fill spring member (140) and the pockets (132) communicating with passages (133) in the land member (130).

Abstract: An internal combustion engine exhaust energy recovery apparatus including a turbine housing retaining a recovery turbine disc and defining a recovery inlet, a recovery exhaust port for discharging exhaust gases, a turbine chamber enclosing the turbine disc, and a convoluted recovery passage extending between the inlet and a periphery of the turbine disc. Disposed in the housing is a partition that separates the convoluted passage into first and second passages each providing communication between the inlet and the periphery of the turbine disc. A recovery valve is disposed in the first passage and is operable to control the flow of exhaust gases received at the inlet from a supercharger.

Abstract: Improved apparatus and method in which brine of the geothermal and geopressured types is directed into one or more flash-crystallizer-separator units from a geothermal well. Such brine is separated into a gaseous fraction, a liquid fraction and a solids fraction. The gaseous fraction is used to provide useful work, such as driving a turbine, while the liquid and solids fractions are treated to remove the mineral values therefrom. The liquid fraction, following the mineral recovery therefrom, is directed back into the earth through an injection well. An important aspect of the invention is the injection of chemicals into one or more of the process vessels of the apparatus of the present invention. This causes additional mineral growth, such as the growth of heavy metal sulfide, in the brine. This is achieved by injecting sulfide ions into the brine, preferably in the form of sodium sulfide. The resulting brine slurry formed in the vessels can be sent to a thickener and then to a filter press for dewatering.

Abstract: The purpose of a thermal induction machine is to put thermal resources and thermal uses (Q.sub.o, Q.sub.1, Q'.sub.1, Q.sub.2) into relation, so as to valorize the energy of the resources, the device operating in very similar fashion to reversibility with a binary working fluid used in diphasic form. It includes a first direct assembly of heat transfer elements inserted serially on the liquid and working fluid vapor flows. The first assembly consists of a first diphasic contact column (Kd) operating at an initial pressure value. It also includes a second assembly of heat transfer elements. The second assembly is reverse to the first and containing the same number of elements and notably a second diphasic contact column (Kg), the second column working at a second pressure value lower than the first value, adventitious flows (m.sub.o, m'.sub.o, m.sub.1, m'.sub.1) being established between the two assemblies on the terminals of the homologous elements.

Abstract: A combustion chamber is defined by a wall having a closed end into which liquid fuel and oxidant are introduced and an open end through which exhaust gases flow. A baffle at the open end causes exhaust gas to flow adjacent the wall. Injector devices direct liquid fuel radially inwardly of the chamber between the closed and open ends. Unburnt fuel attached to the wall cools the walls and passes to the open end before being entrained by the exhaust gas flow through the baffle.

Abstract: A cryogenic storage vessel and method for a high value cryogenic liquid wherein a second cryogenic liquid is utilized as a refrigerant. The refrigerant cryogenic liquid is caused to pass between a large reservoir and a small accumulator by differential pressure caused by heat leak into the vessel whereby the refrigeration of the cryogenic liquid is more efficiently employed for cooling.

Abstract: A cryopump is regenerated by means of an ejector pump which draws gas from the cryopump as the pump is warmed. The ejector is actuated by an inert gas. The same inert gas may also be used to purge the pump during evacuation.

Abstract: A cryopump with quicker adsorption of non-condensible gases is disclosed. The second stage cryopanel of this cryopump is comprised of an array of discs spaced along an axis perpendicular to the frontal cryopanel, and in close thermal contact with the second stage heat sink. Each disc of the array is bent toward the frontal cryopanel at the outer edge of the disc and is flat radially inward from the bend. Each disc is coated with adsorbent material on the surface away from the frontal cryopanel radially inward from the bend in the disc.

Abstract: A chemical heat pump utilizing a hydrating agent as the working fluid is disclosed. The clathrate formation reaction of a hydrating agent such as flon 31 or 22 is used as one of the two equilibrium reactions of the working fluid so that heat can be pumped up across a temperature difference greater than that between the two heat sources. The heat pump comprises four container means in which reactions take place so that the regeneration process can be effected simultaneously with the heating or refrigerating process in which the temperature of the thermal medium to be utilized, e.g., water, is raised or lowered. The working fluid flows either in continuous one-directional circulation through the four container means, or in alternate directions therebetween. In addition to the two heat sources at two different temperatures, such as waste heat and open air, the heat pump further comprises gas pipes which allow the free movement of the working fluid between the connected container means.

Abstract: The invention relates to a method of operating a heat pump system in an absorption heat pump mode and/or boiler heating mode. According to this method, a solution of a refrigerant in a solvent is heated in a boiler, the evaporated refrigerant is delivered either directly to an absorber through a condenser, a throttle and an evaporator when the system is operated in the heat pump mode, or directly to an absorber when the system is in the boiler heating mode. The refrigerant is combined with the solvent that is drawn, low in refrigerant, from the boiler. The rich solution thus obtained is redirected to the boiler. To shut down the system, the heating of the boiler is turned off.

Abstract: A first air conditioner is generally applied to a vehicle including a windshield and a passenger compartment having a front segment and a rear segment. The windshield faces the front segment of the passenger compartment. Air is injected into the front segment of the passenger compartment via a first duct. Air is injected into the rear segment of the passenger compartment via a second duct. A humidifier acts on the air injected into the rear segment of the passenger compartment via the second duct. In a second air conditioner, a humidifier can be selectively activated and deactivated. A temperature control arrangement responsive to activation and deactivation of the humidifier compensates for fluctuations in the temperature of air resulting from changes between activated and deactivated states of the humidifier.

Abstract: The refrigeration system includes a refrigerant reservoir, a condenser bypass valve of the gas pressure diaphragm type and a diaphragm-type hot gas bypass valve for supplying hot gaseous refrigerant directly from the compressor or refrigerant receiver to the evaporator, bypassing the expansion valve. The bypass valves may be hermetically housed in the refrigerant reservor. The system is useful in a refrigerated gas separation apparatus such as a refrigerated dryer for compressed air, which includes a conditioner in the form of a shell and tube heat exchanger which cools incoming hot moist compressed air and warms outgoing cold dry air. The cooled moist gas is refrigerated by contact with a refrigeration system evaporator, in the form of a finned baffled coil, and the condensed moisture is removed in a moisture separator including a central conical baffle and peripheral longitudinal hooked scraper bars or baffles defining channels for collecting moisture and directing the liquid to a sump.

Abstract: A pressure control override apparatus for overriding a conventional pressure control starting switch on a refrigeration system is provided. The apparatus includes a power supply that receives power only when the valve in the liquid line of the refrigeration system is open. The apparatus also includes a temperature sensor for sensing the ambient temperature in the area of the compressor and condenser. The apparatus further includes a circuit to start the compressor that is separate from the normal pressure control starting switch when the apparatus is energized and the ambient temperature sensed by the temperature sensor is lower than a preselected temperature.

Abstract: A refrigerator temperature control system is disclosed in which the compressor for compressing a refrigerant is driven selectively at either a normal lower rotation speed or a higher rotational speed and the higher rotational speed is applied only when any of the freezer compartment temperature and the fresh food compartment temperature is not reduced below a predetermined temperature level for at least a predetermined time interval.

Abstract: A heating and cooling system with a single compressor and first and second compressor reversing valves for connecting a refrigerant fluid to more than one heat exchanger in a system. Said second compressor reversing valve permits the compressor to function as the primary compressor for different operating modes. A reversible heat pump means is operably connected to a plurality of heat exchange devices in indirect heat exchange with external thermal storage media common to the home such as room airspace, domestic hot water and pool or spa. Combinations of heating and cooling of the various external thermal storage media are realized by arranging valving and conduit means using appropriate control and switching apparatus.

Abstract: Disclosed is a method of and apparatus for heating and cooling. The method and apparatus employ a thermodynamic moat across which heat energy conductance can be entirely prohibited. The moat comprises a heat source for a heat pump. The heat pump can be contained within the thermal protection of the moat. Thus its energy of operation may be added to, rather than lost from, the system. Structures for absorbing solar irradiation are disclosed, as are means to contain these structures within the protection of the moat, thereby to overcome grave deficiencies of solar collectors used in cold climates. A method of and apparatus for utilizing the solar absorber structures for summer cooling are also disclosed.

Abstract: A compact refrigeration heat exchanger comprising coiled tubing wrapped around a cylindrical chamber having input and output ports for preheating the evaporatior output to superheat liquid refrigerant prior to the compressor inlet by passing hot gas from the compressor output back through the coil while low pressure refrigerant flows through the chamber. The heat exchanger enables a refrigeration system to be defrosted without liquid refrigerant flood back to the compressor. Any liquid remaining accumulates in the heat exchanger due to the different lengths of the tubing in the heat exchanger.