Abstract: A flow conduit includes surface-enlarging members for cooling fluid in the flow conduit. The surface-enlarging members include cooling blades that extend outwards and downwards from the surface of the flow conduit.

Abstract: A heat exchanger assembly formed from primary structure comprising

Abstract: A heat exchanger, particularly an evaporator, has a number of ducts (19) for the flow of a cooling fluid which are connected in series, each duct (19) being produced as a pair of plates (13) including a concave region (3) limited by an edge (5) and provided with a number of studs forming dimples (9), the dimples being randomly distributed. The invention applies mainly to the air conditioning of motor vehicles.

Abstract: The invention relates to heat-exchanger tubes structured on both inner and outer sides with excellent heat-transfer characteristics, which have recesses on the outside and ribs with specific dimensions on the inside. The structuring tools utilized for the various method modifications are adjusted in such a manner that they are not only able to create aligned, continuous grooves and non-aligned, spaced apart recesses but also secondary structures. The heat-exchanger tubes provided preferably with smooth end sections and smooth intermediate sections are utilized in particular in shell and tube heat-exchangers.

Abstract: A folded tube and method of making the same for a heat exchanger includes a base, a top spaced from and opposing the base, a first side interposed between the base and the top along one side thereof, and a second side interposed between the base and the top along another side thereof. The folded tube includes at least one of the base and the top having at least one internal web having an initial web width and initial outside shoulder radius and being compressed to compress the at least one internal web to a final web width less than the initial web width and a final outside shoulder radius less than the initial outside shoulder radius and defining a plurality of fluid ports.

Abstract: Evaporator in a refrigerator, is disclosed, which has the refrigerant tube, cooling fins and the defrosting tube formed as one unit for simple structure and a better heat exchange efficiency, the evaporator including one pair of refrigerant tubes for flow of refrigerant therethrough, a defrosting tube disposed between the two refrigerant tubes, cooling fins formed as one unit with, and connecting the refrigerant tubes and the defrosting tube, turbulence forming means adapted to form a turbulence of air in a process of flowing around the evaporator for improving the heat exchange efficiency, internal heat conduction area enlarging means adapted to enlarge an internal area of the refrigerant tubes for improving the heat exchange efficiency, and external heat conduction area enlarging means adapted to enlarge an external area of the refrigerant tubes for improving the heat exchange efficiency.

Abstract: In boiling heat transfer tube, fins 2 are provided on an outer surface of the tube body 1 in a manner such that the fins 2 each extend in a peripheral direction of the tube and a direction inclined to the tube axis at a pitch P2 in the tube axial direction. Protrusions 4 and recesses 5 are alternately formed in a length direction of a fin, a protrusion coming after a recess or vice versa, by being pressed. Opening 6 widths at the top ends of the cavity 3 between an adjacent pair of fins 2 are narrowed by inward jutting-out of the fins at both recesses 5 and protrusions 4. A profile of each of the protrusions in section perpendicular to the tube axis assumes a trapezoid. An opening width (W) between protrusions in section including the tube axis is 0.13 mm<W ≦0.40 mm, an angle (&thgr;) formed between opposed side surfaces of each recess in section perpendicular to the tube axis is 55 degrees or less. A pitch (P1) of the recesses or the protrusions in section perpendicular to the tube axis is 0.

Abstract: A heat exchanger tube for a falling film evaporator has fins provided on the outer periphery of the tube body and extending in a direction transverse or in oblique to the axial direction of the tube. The fins have heights in a range of 0.2 to 0.8 mm. The fins are arranged in a density to have 905 to 1102 in number of fins per 1 m in the axial direction. Grooves formed in the tip end of the fins and extending substantially along the fins, the mutually opposing inner peripheral wall surface of the groove defining an angle within a range of 70° to 150°. Cut-outs formed in the tip end of the fins, the cut-outs being provided at a pitch in a range of 0.5 to 1.0 mm. With this construction, the heat exchanger tube for the falling film evaporator which exhibits a high refrigerant wetting and spreading ability as well as large surface area for providing remarkably improved heat transmission performance.

Abstract: An absorption chiller that uses an aqueous salt solution as an absorbent and water as a refrigerant, the absorption chiller including an evaporator that allows the water to trickle or flow downward onto the outer surface of a heat exchanger tube installed horizontally or approximately horizontally, an absorber that allows the aqueous salt solution to trickle or flow downward onto the outer surface of a heat exchanger tube installed horizontally or approximately horizontally, and a condenser that allows the water to be supplied onto the outer surface of a heat exchanger tube installed horizontally or approximately horizontally. At least one of the heat exchanger tubes is provided, on the inner surface thereof, with protruded threads formed in a spiral fashion. A plurality of rows of projections of a height of 0.2 to 0.4 mm with flat portions on the top is provided on the outer surface of the tube successively at a pitch of 0.4 to 0.8 mm between projections.

Abstract: The heat exchanger tube comprises a cylindrical, smooth walled outer tube (1) of steel into which a profiled insert (2) of aluminium is inserted. The profiled insert is constituted by two half shells (3,4) which engage in one another at their longitudinal edges with groove-shaped recesses (7) and rib-like projections (8). Both half shells (3,4) carry longitudinally extending ribs (5) on their internal surface which are so aligned that each half shell with its ribs constitutes a profile which is open on one side.

Abstract: A heat exchanger tube includes ribs formed in protrusion on an internal surface of the tube and extending spirally with a suitable distance between adjacent ribs, concavities formed on the external surface of the tube and extending spirally with a suitable distance between adjacent concavities, and a plurality of independent projections formed on the external surface of the tube and laid out spirally. The projections are formed with a recess on their top surfaces in such a way that a portion aligned with the ribs on the internal surface of the tube is lower than a portion aligned with an area between the ribs. Further, the concavities on the external surface of the tube and the ribs on the internal surface of the tube are formed at mutually aligned positions.

Abstract: A heat exchanger for a motor vehicle includes a fin/tube block with flat tubes which are provided on opposite sides with tube ends. The tube ends are widened such that transversely extending, mutually adjacent wall sections of the tube ends flatly adjoin one another and the tube ends of a row are aligned with one another. One flow box is placed on the tube ends on each side of the fin/tube block. Each of the flow boxes ends flush with corresponding longitudinally extending wall sections of the tube ends. The transversely extending, mutually adjacent wall sections of the tube ends adjoin one another in a form-locking manner.

Abstract: The invention relates to hydroaerodynamics and to thermal physics and concerns devices to control the boundary and near wall layers in the flows of continuos media such as gases, liquids, their two-phase or multicomponent mixtures and the like, moving along ducts under no pressure or under pressure.

Abstract: An ice rink installation having polymer plastic heat transfer piping imbedded in a substrate, such as concrete. The polymer plastic heat transfer piping extends throughout an ice rink and includes a tubular body having an exterior surface and an interior surface. The tubular body has a wall thickness of less than 8.5% of its inner diameter. In order for the tubular body to remain sufficiently robust with such thin walls, a plurality of vanes are positioned on either the exterior surface, the interior surface or on both surfaces.

Abstract: Heat transfer tubes have an exterior surface in contact with a refrigerant and an interior surface defining a path through which a liquid is conveyed in an axial direction of the tube. The exterior surface of the tube has a plurality of fins formed thereon; the interior surface of the tube has a plurality of ridges formed thereon. The fins have an average width v with respect to the axial direction of the tube and a pitch Q with respect to the axial direction of the tube. A channel is provided between adjacent fins, the channels having a channel bottom of length L with respect to the axial direction of the tube. The ridges have a ridge height (e) and a ridge base width (b). The tubes have a ratio of L/v in a range of from 1.22 to 3.40. L is greater than 45% of fin pitch Q, and is preferably between 45% and 75% of fin pitch Q. A ratio of (e.times.L)/b is in a range of from 0.0062 to 0.0165; a ratio of e/b is in a range of from 0.565 to 0.973.

Abstract: A heat exchanger that a tube member 2' has beads 21 protruded from the face of one plate toward the other plate, tube member 2' is held by block members 31, 31, a forming jig 40 is inserted between medium passages 24, 24 formed by the beads 21 to hold to press the beads 21 at an end 2a of the tube member 2' to mutually adhere the faces of the beads 21 on the outer face of the tube member 2', and recesses formed by the mutually contacted faces of the beads 21, 21 have a cross-sectional area of about 0.2 mm.sup.2 or below. And, a region where the recesses have a cross-sectional area of about 0.2 mm.sup.2 or below is within 10 mm outside header pipes 3, 4.

Abstract: To provide a heat transfer tube for an absorber in which the quantity of residence of an absorbing liquid on the surface of the tube staying in trough portions is large, and the staying absorbing liquid is thinly and widely spread on the surface of the tube to materially promote an absorbing performance. On an outer surface of a metal tube having an outer diameter of D, a group of N (N is a natural number) number of trough portions, wherein the length L1 in a longitudinal direction of the tube is 70 mm.ltoreq.L1.ltoreq.130 mm, and the depth H is 0.23 mm.ltoreq.H<0.5 mm, is formed on a circumference of a circle formed in section of the tube in the case of being cut perpendicular to a longitudinal direction of the tube so that the pitch P (=.pi. D/N) is set in the range of 6.2 to 8.

Abstract: Ceiling radiators for the heating or cooling of rooms, with a compact design preferably made of a powder-coated, X- or similar shaped, aluminum, extruded profile. The radiator is of light weight and has high resistance to deformation, and is available up to 12 meters in overall length, with a maximum circular diameter up to 350 mm. The radiator includes a heating pipe having four curved radiant surfaces integrally molded to the pipe, with attachment rails. The heating-pipe ends are equipped with internal screw threads for tube connections and pipe compensators. In one economical design, a directly-heated radiant pipe has twelve radiant surfaces arranged around it on six radiant plates, and includes four attachment rails. The invention produces a broad, all-round radiation on the surrounding room surfaces and furnishings, so that heat encirclement is produced with optimum comfort to people underneath it.

Abstract: A modular heat exchanger for a fluid flow is provided. The modular heat exchanger includes a plurality of modules formed from a heat transfer material. Each module has a generally rectangular cross section and a through bore extending longitudinally therethrough between parallel opposite faces. Each face includes a plurality of parallel fins extending fully across the face in a direction transverse to the longitudinal axis of the through bore. The fins have a generally saw tooth structure so as to increase the turbulence of the air flow through the heat exchanger.

Abstract: A heat exchanger used for a refrigerating cycle has a plurality of grooves formed in the inner surface of a pipe thereof in the flowing direction of a refrigerant. At least two types of grooves which differ in width are used. The pipe also has fins which are coated with a hydrophilic paint that is black in color. This design enables the heat exchanger to provide improved performance.

Abstract: An improved heat transfer tube for use in air conditioning chillers of the shell and tube type. The tube (10) achieves objectives of improved manufacturability, heat transfer performance and fluid flow characteristics by having external helical fins (12) with specified ranges of fin heights and fin density for a specified range of tube outer diameters.

Abstract: A ceramic recuperator (18) for a recuperator burner (1) is provided, in its heat exchanger region, with a plurality of radially inward- and outward-extending teeth. On the otherwise hollow-cylindrical recuperator (18), the teeth (19) are arranged in groups, e.g., in rings; the teeth of one ring are each offset from the teeth of an adjacent ring. Alternatively, it is possible to arrange the teeth on a single- or multi-start helical line. The recuperator can be produced economically by the slip-casting method.

Abstract: A heat recovery device is disclosed which is adapted for use in the drain conduit of standard shower installations having a hot water line, a cold water line, means for mixing water from both lines to deliver water at a suitable temperature to a shower head, and a drain conduit for disposing of waste water passing through the shower installation, the heat recovery device transferring heat from the waste water to cold water flowing to the cold water line. The heat recovery device has a first conduit connected into the drain conduit of the shower installation, and a second conduit connected into the cold water line leading into the shower installation and either wrapped around or inserted within the first conduit so that the second conduit is in operative heat transfer relationship with warm waste water passing through the first conduit, so that the incoming cold water is preheated by heat recovered from the waste water and transferred to the cold water.

Abstract: A heat exchanger system including an outer duct housing a powered fan at one end. A heat exchanger is positioned in line with the fan within the duct and includes two nested pipes. Each pipe includes radially outward fins and radially inward fins. The radially inward fins on the outer pipe and the radially outward fins on the inner pipe are interdigitated. Appropriately positioned radial dividers extend fully between the bodies of the two pipes to divide the space between pipes into segments. End caps placed on the ends of the pipes include baffles which appropriately divide annular manifolds defined between the pipes and between the ends of the fins and the end caps in order that four passes are possible through the length of the heat exchanger. The radial dividers may be asymmetrically positioned to accommodate changes in volume with condensation of the fluid passing between the inner and outer pipes.

Abstract: A plurality of protrusions 32 are formed in a longitudinal direction on the outer surface of a heat transmission pipe, a convex portion 33 and a concave portion 34 adjacent thereto of each of the protrusions 32 are each in the form of a curved surface, the curvature radius of the concave portion 34 is made larger than the curvature radius of the convex portion 33, and a groove 34A is formed in the bottom of the concave portion so that the absorption solution dropping onto the heat transmission pipe 31 flows from the concave portion 34 over the convex portion 33 to the next concave portion 34 smoothly, the shifting of the absorption solution in the concave portion 34 is carried out smoothly, and Marangoni convections generated in the convex portion 33 and the concave portion 34 interfere with each other.

Abstract: A heat exchanger for use in connection with engine cooling systems is disclosed herein. The heat exchanger is typically considered a heat exchanger and comprises a plurality of rows of tubes, a pair of headers secured to the ends of the tubes in a mechanical and brazed joint for providing improved vibration and torsional stress resistance and improved durability. More specifically, the tube include a plurality of dimples or tabulators arranged in opposed or non opposed relation agitate the fluid about the primary heat transfer axis to facilitate heat transfer from the hot fluid to the tube wall.

Abstract: Metallic tubes (10,10') for boiling have an outer surface (12) for contacting a refrigerant and an inner surface (14) for contacting a liquid heat transfer medium to be chilled. The outer surface (12) has a plurality of radially outwardly extending helical fins (18); the tube inner surface (14) has a plurality of helical ridges (16). The fins (18) of the outer surface are notched to provide nucleate boiling cavities having pores (30). The fins (18) and notches (N) are so spaced that the pores (30) have an average area less than 0.00009 square inches and a pore density of at least 2000 per square inch on the tube outer surface. The helical ridges (16) on the inner surface have a predetermined ridge height and pitch and are positioned at a predetermined helix angle, the inner surface having a severity factor .PHI. in the range of 0.006 to 0.008.

Abstract: A heat exchanger inner spiral-ribbed tube made of a hard metal such as stainless steel, titanium, or an iron-nickel alloy, and method of manufacture therefor for use in making a heat exchanger. The tube has an annular wall having an inner ribbed surface and an outer waved surface. The inner surface has a plurality of inner spiral ribs, each having a spiral angle. The spiral angle is about 18 degrees in the described embodiment. The tube-making method includes multiple steps in forming the outer waves and inner ribs simultaneously, progressively increasing the rib height while continuously pulling the tube in an axial direction.

Abstract: An elongated heat exchange tube and method of making same are disclosed wherein a pair of elongated generally right-angle metallic wall members are adapted for mirror image connection to form an outer tube wall of generally rectangular transverse cross-section. A plurality of internal generally planar heat transfer fins having 90.degree. weld flanges are secured to inner surfaces of the right-angle walls and define longitudinal flow passages through which heated combustion gases are passed to effect improved heat transfer to the outer peripheral wall of the heat transfer tube with enhanced heat convection to a medium in contact with the outer surface of the outer tube wall. A plurality of the heat exchange tubes may be mounted within a compact steam generator for highly efficient production of steam for a steam oven.

Abstract: An absorption type refrigerating machine comprising an evaporator, an absorber, a regenerator, and a condenser, all connected by piping to form a refrigerating cycle. The evaporator, condenser or absorber includes a plurality of heat transmission pipes accommodated therein and arranged generally in a horizontal direction. Each pipe has at least one continuity of protrusion on the inner surface thereof extending in an axial direction of the pipe in a spiral fashion and at least one continuity of groove corresponding to the continuity of protrusion formed on the outer surface of the pipe.

Abstract: A heat transfer tube for use in a refrigeration evaporator. This tube includes an outer surface with axially spaced bent fins which form and enclose annular tunnels. The bent fins have top edge portions which have peripherally spaced sets of notches of different sizes on the same fin convolution and refill gaps for fluid flow to the tunnels for heat transfer through the annular wall. The concept of placing different pore sizes next to each other on the same fin allows a more efficient use of the tube's surface area for evaporative heat transfer.

Abstract: A heat transfer tube for an absorber, including a plurality of crest portions and trough portions extending in parallel to each other in an axial direction of the tube and arranged alternately in a circumferential direction of the tube. The ratio d/P of a depth d of each of the trough portions to a pitch P of the crest portions defined as P=.pi.D/n is set in the range of 0.1 to 0.4; the depth d is set in the range of 1.50 to 2.00 mm; the ratio R.sub.2 /d is set in the range of 2.5 to 6.0; the ratio R.sub.1 /R.sub.2 is set larger than 1, where n represents a positive integer, R.sub.1 represents a radius of curvature of an outer top surface of each crest portion, R.sub.2 represents a radius of curvature of an outer bottom surface of each trough portion, and D represents a diameter of a circumscribed circle of the crest portions.

Abstract: Heat exchanger has a first surface on which a first fluid flows and a second surface on which a second fluid flows, at least one of the first and second surfaces has at least two projections and a bottom therebetween, and an imaginary line on the bottom along a shortest distance between the projections adjacent to each other is prevented from extending along an imaginary face substantially parallel to a main flow direction of one of the first and second fluids which flows over the bottom.

Abstract: One heat transfer tube for an absorption refrigerating machine of the present invention has a plurality of grooves formed on the circumferential surface of a tube at uniformly angular intervals to extend continuously or discontinuously in the length direction of the tube, wherein the width and/or depth of each groove gently varies in the length direction of the groove, and the height of each ridge between the mutually adjacent grooves gently varies from the axial tube center in the length direction of the ridge. Another heat transfer tube of the present invention has a large number of concave portions formed in rows on the circumferential surface of the tube at predetermined angular intervals and each having a gently down-grade surface extending in the tube length direction to gradually get closer to the axial tube center and a gently up-grade surface extending continuously from the down-grade surface in the tube length direction to gradually become more distant from the axial tube center.

Abstract: A heat exchanger of the multi-flow type is provided with baffle members which are adapted to impart a zigzagging flow to the heat-exchange fluid in motion inside a flat tube and define, in conjunction with the inner wall of the flat tube, a flow path of a cross-sectional area having an equivalent diameter in the range of 0.4 to 1.5 mm. This heat exchanger excels in heat exchange ability and in facility of manufacture and assemblage.

Abstract: A refrigeration and heating system in which an absorber (97), condenser (100) and recuperator are placed (107) in a single module (270) and are provided with tube-in-tube or tube-in-cylinder construction with fluted inner tubes. A general purpose, divided-flow, tube-in-cylinder, heat transfer device (400) is used to reduce the pressure drop in the circulating fluid.

Abstract: A heat exchange system for an engine having cooling passages and a heat exchanger. The heat exchanger has a shell side flow of coolant from the cooling system and air flowing through tubes which extend across the shell and are open at both ends to outwardly of the shell. The tubes may have fins on the outer and/or inner surfaces. The tubes may be formed with one of the tube sheets, with the other tube sheet defining rectangular sidewalls and including holes through which the tubes penetrate and are sealed. An inlet and an outlet are diametrically opposed with flow therebetween being regulated through baffling.

Abstract: A flat-type refrigerant tube for use in an heat exchanger which has a plurality of refrigerant passage chambers formed in a flat aluminum plate having a first end and a second end, the chambers extending from the one end to the opposite end in parallel with first another and arranged in a plane parallel to the flat outer surface of the flat tube, each of the chambers having a rectangular cross-section with four corners which is determined by a first pair of opposite sides with a dimension of A and a second pair of opposite sides with a dimension of B perpendicular to the first pair of opposite sides. Each of the four corners is formed with a curvature R determined by the following formula: 0.2 mm.ltoreq.R.ltoreq.D/2, where D equals A when A.ltoreq.B but equals B when B<A. Each of the chambers can be provided with at least one of elongated ribs longitudinally extending on the inner surface thereof.

Abstract: A heat transfer assembly 11 is disclosed for transferring heat from a heat generating electronic device 15 or computer chip to ambient air. The heat transfer assembly 11 is comprised of a heat pipe 20 mounted perpendicular to a heat generating electronic device 15. The heat transfer assembly 11 is designed to provide a mechanically solid support for the bonding of the various heat transfer assembly components and to use circumferentially mounted fins 23 to increase the efficiency of heat transfer away from the electronic devices 15. The heat transfer assembly can function effectively when mounted in any direction. Thermocouples 42 are used to monitor the temperature and efficiency of the heat generating electronic device 15 such that corrective action can be initiated if the device begins to overheat.

Abstract: A method of making an automotive heat exchanger comprises the steps of assembling a heat exchanger core having a plurality of interleaved tube and fins disposed between a pair of endsheets and expanding the diameter of the tubes a predetermined distance by forcing an expansion tool therethrough. The tubes of the heat exchanger include a plurality of internal projections of predetermined height and the expansion process decreases the height of the projections by less than 25% of its original height. A heat exchanger formed in accordance with this method is also disclosed.

Abstract: The heat exchanger includes a plurality of heat transfer tubes 1, 1 . . . arranged in parallel, and a multiplicity of mesh-form fins 2, 2 . . . arranged parallel to axes of the tubes and joined to the heat transfer tubes 1, 1 . . . . Each of the heat transfer tubes 1 consists of a pair of tube component members 4, 4 of a half cylindrical configuration having, at their respective circumferential ends, joining flanges 4a, 4b extending along the axis of the tube. The opposed joining flanges 4a, 4b of the tube component members 4, 4 are joined together by being pressed against the fins 2, 2 from outer side thereof. This provides for improvement in operating efficiency in the process of assembling heat transfer tubes and mesh-form fins together.

Abstract: An improved heat exchanger for exchanging heat between the ambient and a refrigerant that may be in a liquid or vapor phase. The same includes a pair of spaced headers with one of the headers having a refrigerant inlet and the other of the headers having a refrigerant outlet. A heat exchanger tube extends between the headers and is in fluid communication with each of the headers. The tube defines a plurality of hydraulically parallel refrigerant flow paths between the headers and each of the refrigerant flow paths has a hydraulic diameter in the range of about 0.015 to about 0.07 inches.

Abstract: The heat exchange structure comprises a series of tubes arranged in a circular pattern extending between upper and lower manifolds. Water flows from the upper manifold through these tubes to the lower manifold. Annular fins are stacked on these tubes. A larger tube is arranged concentric with each of the smaller diameter water-carrying tubes and hot gaseous products of combustion flow through these larger tubes in counterflow to the water flow through the water tubes. The fins have through-holes allowing the hot gases to pass through the stacks of fins. The combustion chamber is located centrally just above the lower manifold. Ambient air is introduced via perforations in the side wall of the casing near the upper manifold and flows downwardly past the heat exchange structure for recuperative effect before reaching the combustion chamber.

Abstract: A cooling device is provided for use in an engine comprising, a first cooling circuit which is filled with first cooling water; a second cooling circuit which includes second cooling water and air; a water jacket of the engine disposed in the first cooling circuit; a heat exchanger including a radiating portion and a cooling portion, the radiating portion being disposed in the first cooling circuit while the cooling portion being disposed in the second cooling circuit; a first pump which is disposed in the first cooling circuit; a condenser which is disposed in the second cooling circuit; and a second pump which is disposed in the second cooling circuit.

Abstract: A refrigeration and heating system has been made in which improved efficiencies are obtained by placing helical concentric coils of at least two generators (80 and 81) and recuperators (86 and 95) on a common axis (232) with a heating unit (84) at the center and allowing the hot combustion gases (245) to circulate in serpentine fashion through separate concentric chambers containing the coils. Further efficiencies are obtained by placing an absorber (97), condenser (100) and recuperator (107) in a single module (270) and by using tube-in-tube or tube-in-cylinder construction with fluted inner tubes. A general purpose, divided-flow, tube-in-cylinder, heat-transfer device (400) is used to reduce the pressure drop in the circulating fluid.

Abstract: Cooling device of a magnetron for a microwave oven, which includes a plurality of radiation fins disposed between an outer periphery of an anode cylinder and an inner surface of a yoke serving as a frame for radiating heat of a high temperature produced during osicillating operation of the magnetron for generating an electromagnetic wave. The temperature of the fins disposed centrally in substantially the same as the temperature of the fins disposed at both ends of the anode cylinder. This is accomplished by, the fins disposed centrally on the outer peripherey being arranged at a diffeent distance from the distance between the fins disposed on both ends of the anode cylinder or by the fins disposed centrally being made of different materials from the materials of the end.

Abstract: A vapor recovery system for a fuel filling installation in which the recovered air-vapor mixture is pumped to the submerged end of a discharge pipe. The discharge pipe is connected to a closed tube which extends along the bottom of an underground fuel tank. The closed tube has a porosity that generates very small bubbles from the air-vapor mixture that flows through the fuel within the tank. A vent pipe for the underground tank separates air from the air-vapor mixture through decreasing density separation by means of a large cross-section for the vent pipe and by providing baffles in the pipe interior.

Abstract: A heat exchanger having a core comprising a conduit, a plurality of heat conducting elements extending transversely through the conduit and having portions projecting outwardly on each side of the conduit, a plurality of fins spaced along the length of said portions, and a housing enclosing said conduits and heat conducting elements, means for directing a medium to be heated or cooled through said conduit, and means for inducing a flow of heat exchanging medium through said housing and over said heat conducting elements and fins.

Abstract: The improved split resistant tubular heat transfer member of the present invention is directed to an elongated tube having a substantially circular transverse cross-section. The elongated tube hereof has an outer surface and an inner surface, and further has an outer diameter, a defined wall thickness, and an inner diameter. The tube inner surface has disposed therein a plurality of spiral grooves, defining and separating a corresponding plurality of spirally disposed fins extending from the inner diameter of the tube. The respective spirally disposed fins have an inverted substantially V-shape and have further an apex angle of approximately 28.degree.. In some such preferred embodiments the spiral grooves have a ratio of the cross-sectional area thereof to the depth thereof of approximately 0.01475 inches.

Abstract: The heat transfer tube of the present invention is provided in an inner surface thereof with a plurality of main grooves and a plurality of narrow grooves. The main grooves have rectangular shaped cross sections, parallel to one another, and extend at an angle to the longitudinal direction of the heat transfer tube. The narrow grooves are formed parallel to one another, extend independently of the main grooves. Each of the narrow grooves has a bottom face and a pair of side faces, the side faces are inclined closely toward the bottom face, and each of the side faces and a part of the bottom face form sharp cuts.