Abstract: A radiator (10) has tubes (14) and fins (15). The fins (15) have louvered sections (30) laterally aligned with a layer (20), and louvered sections (40), (42), and (46) misaligned from the layers. The louvered sections (40) and (42) are spaced from the louvered sections (30) to form a plain non-louvered section (44) therebetween.

Abstract: A large value of the radius R of the curved portion 110 of a corrugated fin 101 allows fillet portion 104 to have a large length along the length of the pipe 102 for decreasing the heat resistance between the pipe 102 and the fin 101, which makes the length of the louver portions 103 small. Contrary to this, a small value of the radius R of the curved portion 110 of a corrugated fin 101 allows louver portions 103 to have a large length, which is formed on the straight portion of the fin for increasing the heat transfer efficiency from the louver, which causes, however, the length of the fillet to be shortened. Best matching was obtained for decreasing the heat resistance and increasing the heat transfer efficiency when the radius of the curved portion is selected in a range between 0.14 mm to 0.37 mm.

Abstract: A flat tube heat exchanger includes headers (4) and a number of flat tubes (12) between the headers (4), the flat tubes (12) having flat sides (14) and short sides (50) that are rounded. The flat tubes (12) also have internal reinforcing ribs (42). The heat exchanger also includes zigzag fins disposed between the flat sides (14) of the flat tubes (12), the fins being soldered to the flat tubes. The longitudinal extent (1) of a rounded short side (50) of a flat tube (12) is greater than half the distance d between the flat sides (14) of the flat tube (12). Furthermore, the zigzag fins (16) are soldered to portions (58) of both rounded short sides (50) of the flat tube (12). In the process for producing the flat tube heat exchanger (12), the ends of the flat tubes (12) are inserted into slits (8) of a header (4) and are cut free from their reinforcement ribs (42). The ends of the flat tubes (12) are then expanded against the rims of the slits (8) in the header (4).

Abstract: A heat exchanger combines a lanced fin surface with a ruffled fin surface to create a lanced ruffled turbulizer. The lanced ruffled turbulizer combines the turbulence generated by lancing the heat transfer or turbulizer surface to the deflection forces on the fluid stream generated by a ruffled turbulizer to improve the thermal performance of the heat exchanger.

Abstract: A tube for heat exchangers is a flat tube which either comprises a pair of plane walls which are spaced a predetermined distance from one another, the plane walls respectively having lateral ends integrally connected to each other by a U-shaped bent portion, the plane walls further having other lateral ends which abut against and are tightly secured to one another, or alternatively, the flat tube comprises a pair of preformed plates having abutted and soldered portions at both lateral ends. The tube further comprises one or more curved lugs integral with and protruding inwardly from an inner surface of each plane wall, and the curve lugs respectively have innermost tops so that the innermost tops protruding from one plane wall bear against the inner surface of the other plane wall or against the innermost tops of the other curved lugs protruding from said other plane wall.

Abstract: A fin tube heat exchanger is used in an air conditioner or the like and comprised of a plurality of fin plates spaced at regular intervals in parallel with one another, a plurality of heat exchanger tubes arranged in at least one row and extending through the fin plates in a direction perpendicular to the direction in which the fin plates extend, a plurality of raised strips formed on each fin plate in a direction perpendicular to an air flow and raised out of their original plane, and at least one draining passage formed on each fin plate and extending along the center line of the row of the heat exchanger tubes. In this heat exchanger, air is allowed to flow between the fin plates whereas a fluid medium is allowed to pass in the heat exchanger tubes. Each raised strip has two leg portions inclined with respect to the direction of the air flow.

Abstract: A multi tube heat exchanger core in which each tube is made from a pair of substantially identical thin sheet metal plates interfitted in a face to face relationship. Each plate has a pair of enlarged protuberances projecting side by side from the upper side surfaces thereof to form tank portions which are adapted to receive the heat exchanger fluid after the plates are built up into a core. The paired plates forming the tubes are mechanically and accurately aligned at their lower side ends by interfitting locking arms and arm receiving slots. To precisely space the tubes from one another so that air centers can be readily installed therebetween, the lower ends of the plates are formed with tube spacing flanges bent perpendicular to the plane of the plate that interlock with one another by tabs and notches.

Abstract: A pin-fin type heat exchanger comprising a plurality of wire-like heat conductive elements arranged in parallel and spaced from each other, and formed into a corrugated shape, and a method of manufacturing the same by making a corrugated sheet including the wire-like heat conductive elements and a temporary fixing material and removing the temporary fixing material after the heat conductive element is joined to a pipe through which fluid passes.

Abstract: An evaporator for an automotive air conditioner having a plurality of tubes therein arranged side by side so that spaces are provided for air centers mounted between the sidewalls of the tubes. Each tube is formed from a pair of interfacing plates having ribs indented in a predetermined pattern therein to form discrete fluid flow sections within each tube. The ribs are interconnected in such a manner that the sections effectively vary and tailor the flow of the heat exchanger fluid to reduce or substantially eliminate dry out areas in each tube thereby increasing heat exchanger tube and evaporator efficiency.

Abstract: A heat exchanger includes a pair of header pipes, a plurality of flat heat-transfer tubes parallel to each other, a plurality of radiation fins provided on the sides of the flat heat-transfer tubes, an additional flat heat-transfer tube disposed adjacent to the end flat heat-transfer tube, having a path cross-sectional area larger than those of the flat heat-transfer tubes and being connected to one of the header pipes and a joint unit, and an additional radiation fin provided on at least one side of the additional flat heat-transfer tube. The vacant space in the space for installation of the heat exchanger can be utilized as an additional heat exchange portion formed by the additional tube and fin; and the effectiveness of the heat exchanger can be efficiently increased even if the space for the installation is small or limited.

Abstract: Bi-directional fin stock, for use in heat exchangers of the fin and tube type, having louvers formed from the planar surface of the fin stock to project progressively farther into the airstream. This enables the fin stock to exchange heat with a broader airstream by translating the airflow substantially, permitting wider fin spacing.

Abstract: A heat exchanger having a plurality of flat and elongated tube passes operatively interconnected therein with inlet and outlet openings adjacent to one another so that refrigerant flowing therethrough can transfer the heat energy from a cross flow of air streaming between the tube passes. The tube passes have a divider rib offset so that the volume on the outlet or increased quantity side of each pass is greater than the volume on the inlet or low quantity vapor side. With a large volume available for vapor expansion, pressure drop is minimized and heat transfer performance is maximized in the heat exchanger.

Abstract: A heat exchanger core having a plurality of spaced fluid conducting tubes operatively connected in series at their upper ends by projecting tank portions. The tubes have flattened main body portions that extend downward from the tank portions to terminal ends having rows of integral spacing and locking links formed with snap fasteners for releasably locking onto one another to connect the lower end of the tubes to one another providing column strength thereby preventing damage to corrugated metal air centers disposed between adjacent tubes by compression forces exerted on the core. In addition to the spacing and locking links, this core features integral snap fasteners to lock the separate plates of each tube together in face to face relationship so that the entire core is mechanically connected and interlocked and is ready for permanent connection by brazing.

Abstract: A heat exchanger includes a plurality of integrally assembled heat exchanger cores each comprising a pair of header pipes, a plurality of flat heat transfer tubes and a plurality of fins. A heat medium flows from an inlet tube connected to one of the header pipes to an outlet tube connected to another one of the header pipes through the plurality of heat exchanger cores communicating with one another. The heat transfer area of the head exchanger can be increased without increasing the diameters of its header pipes, to thereby increase the total heat exchange ability of the heat exchanger.

Abstract: A heat exchanger is disclosed comprising a pair of laterally spaced fluid conducting tanks operatively interconnected by a plurality of elongated fluid conducting tubes having sector shaped cross sections and arcuately spaced from one another in a circular pattern to present parallel interfacing sides. A plurality of elongated corrugated fins or air centers each having convolutions of substantially constant height and width to have spaced lines of contact along the width and length of each of the sides of the tubes for maximizing heat transfer and so that the tubes will be optimally supported to provide increased resistance to pressure ballooning and burst. These air centers are standard corrugated rectilinear components that reduce complexity and cost of this circular heat exchanger. This heat exchanger can be arranged in a parallel relationship with a transverse automotive engine and a cooling fan operatively mounted within the heat exchanger can be directly driven by the engine.

Abstract: An evaporator for an automotive air conditioner having a plurality of tubes arranged side by side so that the tubes form spaces for air centers and channel heated air past the sidewalls of the tubes. Each tube has a divider rib to define liquid and vapor passages for the flow of refrigerant around the end the rib in a general U-shaped flow. The ribs have spaced bypass openings therein so that each rib is able to allow the leakage of liquid refrigerant across the rib from the liquid to the vapor side to eliminate dry out areas and thereby increase heat exchanger efficiency.

Abstract: A multiple serpentine tube heat exchanger having side-by-side arranged serpentine-shaped passageways each extending across the core and a mixing chamber connecting one such passageway to at least one other. The passageway constituting the back of the heat exchanger core has an enlarged internal surface area relative to the passageway constituting the face of the heat exchanger core. Microgrooving of the passageway can be used to further enhance heat transfer.

Abstract: An improved condenser for use in air conditioning or refrigeration systems. A pair of spaced headers have a plurality of tubes extending in hydraulic parallel between them and each tube defines a plurality of hydraulically parallel, fluid flow paths between the headers. Each of the fluid flow paths has a hydraulic diameter in the range of about 0.015 to about 0.04 inches. Preferably, each fluid flow path has an elongated crevice extending along its length to accumulate condensate and to assist in minimizing film thickness on heat exchange surfaces through the action of surface tension. Heat exchange surfaces may also be provided with microcracks or channels to enhance heat transfer.

Abstract: A laminated evaporator includes a plurality of heat exchanging elements and a plurality of corrugated fins disposed alternately and built up into layers. Each of the heat exchanging elements includes at least at its one end a pair of tubular portions and a plurality of spacers. The tubular portions of one heat exchanging element are fitted with the tubular portions of an adjacent heat exchanging element, and spacers of two adjacent heat exchanging elements are joined together to maintain a constant spacing between the adjacent heat exchanging elements.

Abstract: An evaporator for an automotive air conditioning refrigerant circuit is disclosed. The evaporator includes a plurality of flat pipes through which refrigerant flows, and corrugated metal sheets are disposed between the flat pipes. A plurality of linking members are hermetically fixed at both opening ends of the flat pipes and are also heremetically fixed to each other to facilitate communication between adjacent flat pipes.

Abstract: A highly efficient heat exchanger susceptible of a variety of uses is provided by a construction including first and second spaced, parallel headers 10, 12, 114 and 140 and a plurality of substantially identical serpentine conduits 18, 104 having at least three generally parallel runs 24, 105 and terminating in opposed ends 20, 22, 106, 108; 130, 132. The conduits 18, 104 are in generally spaced, side-by-side relation. One end 104 of each conduit 18, 104 extends to and is in fluid communication with the first header 10, 114, 140 and the other end of each conduit 18, 104 extends to and is in fluid communication with the second header 12. A plurality of serpentine fin sheets 30, 120 are located so as to extend between an associated pair of the conduits 18 in thermally conducive relation therewith.

Abstract: Louvered fins in fin and tube type heat exchangers extend across the spaces between adjacent tubes. Adjacent tubes are separated by a distance s and louvers in the fins extend between the tubes but stop short of the tubes to leave some plain fin area which defines a bypass channel of width b between each tube and adjacent louvers. The curve of heat transfer versus air side pressure drop increases as the ratio b/s decreases. An optimum value of b/s occurs at the knee of the curve and lower values of the ratio effect insignificant improvements in heat transfer.

Abstract: A transmission oil cooler has spaced elongated plates secured at the margins and ports at either end to define an oil flow channel. A center disposed between the plates for creating turbulence in the oil and enhancing heat transfer comprises a metal sheet folded to form generally planar fins in side-by-side relationship and the fins having louvers extending over most of their area. The center is disposed in the flow channel with the planes of the fins transverse to the oil flow or alternatively with the planes of the fins parallel to the oil flow.

Abstract: A plate type heat exchanger has a plurality of tube units and a plurality of corrugated fins. Each of the tube units is formed by a pair of plates, namely a pair of plates are connected to each other by a brazing material at a connecting portion at an outer periphery of the plate and a center rib at a center axis of the plate. The center rib has an enlarged portion at the top end thereof in order to gather the molten brazing material toward the enlarged portion. The brazing at the center rib is started from the enlarged portion. Therefore a brazing defect is prevented from occurring at the top end of the center rib. Since the tube unit is effectively connected by brazing, the tube unit of the present invention has enough anti-pressure strength.

Abstract: A cylindrically-shaped engine cooler for automobiles comprises a pair of water tanks or main coolant tubes, a plurality of water tubes connecting the water tanks or main coolant tubes, a plurality of cooling fins and at least one cooling fans. The cylindrical engine cooler is disposed in a vehicle so that the axis line of the cooler crosses the traveling line of a vehicle so that the air resistance against vehicle travel becomes small. The water tanks or main coolant tube can be used as the shroud for accommodating the cooling fan, when they are annularly shaped and disposed at the end of the cylindrically cooler. Two cooling fans disposed at the both ends of the cylindrically-shaped cooler may have different air-blowing capacity each other.

Abstract: The present invention is directed to an evaporator for an automotive air conditioning refrigeration circuit. The evaporator includes a serpentined tube through which refrigerant fluid flows, and a corrugated metal fin unit fixedly disposed between parallel planar portions of the serpentined tube. A plurality of louvers are formed through the parallel surfaces of the corrugated metal fin units. The side ends of the louvers terminate a predetermined distance away from the surfaces of the parallel planar portions of the tube. The distance is selected from a range of from over 0.5 mm to under 1.0 mm.

Abstract: A heat exchanger is disclosed, which comprises a plurality of heat-transfer elements (1) placed side by side each of which has more than one through-hole (3) and which are cyclically bent in a generally trapezoidal waveform in the direction of the flow of a fluid, the bends in one heat-transfer element (1) being out of phase with those in an adjacent heat-transfer element (1) by one-half cycle in such a manner that the main stream of said fluid will flow not through the holes in each of said heat-transfer elements (1) but through the passage formed by adjacent heat-transfer elements (1). This arrangement serves to provide improved heat-transfer characteristics.

Abstract: A stack type heat exchanger which comprises a plurality of tubular elements including a tank section at least at one end, the tubular elements being adapted to allow a heat exchange medium to pass through; a plurality of air paths interposed between one tubular element and the next, each of the air paths being provided with a fin member; wherein each tubular element comprises a pair of metal tray members jointed at their peripheries with an inner plate interposed therebetween; wherein each inner plate is provided with projections on its top surfaces and undersurface so that the flows of the medium are blocked by the projections so as to enlarge the effective area for heat transfer between the medium and the tubular element.

Abstract: In order to increase the heat exchange capacity and efficiency of a cooling fin for an automotive radiator, air conditioner heat exchanger, or the like, a plurality of small triangular or similar shaped projections which produce a texture similar to that of a vegetable grater, are arranged to project into the flow of a fluid medium which passes over the fin in a manner to split a part of the flow into spiralling flow patterns which curl along the surface of fin downstream of the projections and transfer heat from said surface to the fluid medium or vice versa.

Abstract: A heat exchanger assembly of the side-entry cross-fin type includes first and second integral fin units, each comprising a single sheet of material provided with a plurality of aligned apertures, the sheet of material being folded in accordian-fashion such that the apertures define a plurality of notches arranged in rows which extend longitudinally of the fin unit. Two of the fin units are assembled together with a single length of heat exchange tube which threads the notches of the fin units, the tube extending over an oval-shaped helical path through the two fin units. In another embodiment, a single folded fin unit is provided with notches in fins on its upper and lower surface, a single length of tube being wrapped around the single fin unit threading the apertures therein, the tube extending in a generally oval-shaped helix path.

Abstract: A heat exchanger, particularly a coolant evaporator, is provided that has several flat pipes that are arranged parallel to one another and are each expanded at their ends with respect to a central part and are closed off by caps. The expanded ends are provided with connecting openings so that the heat exchange medium can flow to the adjacent pipe. At least one of the caps that are provided for closing off the pipe ends is equipped with a projection extending towards the inside of the pipe and closes off at least one of the connecting openings, so that the production of a heat exchanger of identically constructed flat pipes is simplified, in that by the insertion of correponding caps that either expose the connecting openings to the adjacent pipes or not, it is easy to control the flow of the heat exchange medium inside the flat pipes.

Abstract: A heat exchanger comprising fins and at least one heat transfer tube. An even number, not smaller than four, of louvers are severed and raised in an alternate and staggered manner with respect to a fin base line between the remaining adjacent fin base. Furthermore, the louvers raised on the same side with respect to the fin base line have heights defined by a line slanted at a constant angle in a stepped manner.

Abstract: A serpentine-type aluminum heat exchanger comprising a serpentine-anfractuous flat tube of an aluminum alloy and a plurality of corrugated fin units made of an aluminum alloy having a high aluminum content of 99 wt. % or more, and joined to the flat tube by brazing metal coating layers fixed onto flat surfaces of parallel portions of the serpentine-anfractuous flat tube. The heat exchanger is produced by preparing the serpentine-anfractuous flat tube of an aluminum alloy, the corrugated fin units and foil plates of an aluminum alloy brazing filler metal, disposing the fin units in spaces between adjacent ones of parallel portions of the serpentine-anfractuous flat tube with foil plates being interposed between respective fin units and opposite parallel portions of the flat tube, and heating the flat tube, the fin units and foil plates in the assembled relation to the brazing temperature.

Abstract: A generally corrugated fin of a finned tube heat exchanger is formed to have a plurality of cylindrical collars that fit closely around tubes containing a first fluid, for good thermally conductive contact therewith. The collars are arrayed in rows along the corrugations and, within each local fin region between adjacent collars, cuts are provided parallel to and between adjacent crests and troughs, with a portion of each crest locally inverted to form a local trough and each trough inverted to form a local crest between successive cuts. A second fluid flowing outside the tubes between adjacent fins is thereby enabled to form numerous short boundary layers and to flow from one side of each fin to the other, thereby promoting turbulence and flow-mixing that enhance heat transfer between the two fluids.

Abstract: The invention relates to an oil cooler, especially for cooling the transmission oil of a motor vehicle, which includes a guide channel for the oil to be cooled extending in a region where it is subjected to a cross-flow of a cooling medium. The oil guide channel is constructed with two walls of folded, curved sheet metal, between which walls the oil is guided. The folded sheet metal cooler construction offers an improved heat exchange capacity as compared to previously used double pipe or double tube coolers. In especially advantageous embodiments of the invention, the oil is restrictively guided through the folded sheet metal cooler body so that a long path or passage for the flow-through of the oil results, whereby the heat exchange capacity is yet further increased.

Abstract: A plate-type heat exchanger comprises a stack of flat fluid flow tubes each composed of a pair of confronting core plates joined to each other and defining a fluid flow pass therebetween, each of the core plates having an inlet hole for introducing a fluid into the fluid flow pass and an outlet hole for discharging the fluid from the fluid flow pass. Each core plate has a plurality of ribs on an inner wall surface thereof, the ribs on one of the pair of plates being held in contact with the confronting ribs on the other core plate. The ribs are present in the fluid flow pass between the joined core plates in every direction along the inner wall surface of each of the core plates. The fluid flow pass does not have any fluid passage free of ribs. Therefore, the heat exchanger has improved heat transfer efficiency, and the fluid flow tube is mechanically strong or highly resistant to pressure.

Abstract: A motor vehicle tube and fin heat exchanger is disclosed comprising a plurality of tubes arranged in spaced side-by-side relationship and a plurality of louvered fins arranged in spaced side-by-side relationship and between and in heat transfer relationship with adjacent ones of the tubes. The fins preferably have a thickness and stacked density such as to constitute not more than 12% nor less than 2.5% of the space between the adjacent tubes, a total louvered area not more than 60% nor less the 40% of the total fin area, and a linear fin edge projection density of not more than 1.2 mm.sup.-1 nor less than 0.68 mm.sup.-1.

Abstract: An improved fin configuration is provided for use in central air conditioning unit heat exchangers in which heat transfer takes place between a first fluid, typically a refrigerant, flowing inside a nested plurality of tubes and a second fluid, typically air, flowing between the tubes and through a plurality of heat conducting fins attached to and arrayed between the tubes. Lanced pairs of streamwise adjacent bridge-like formations, one out each side of a generally corrugated fin surface, provide numerous leading edges to generate a plurality of reforming velocity and heat transfer boundary layers which leads to an increase in flow turbulence for enhanced heat transfer between the fins and the second fluid. By strategic location of a pair of such formations between tubes, with the upstream one of the pair at a positive angle of attack to the flow, air flow is directed through the fin to mix with flow on the other side of the fin and hence the heat transfer rate is improved.

Abstract: In a corrugated fin unit assembled to a serpentine-anfractuous refrigerant pipe in a serpentine-type heat exchanger, each of generally parallel fin plate portions of the fin unit has a group of louvers parallel to the fin plate portion in the windward region and another group of louvers inclined downwardly in the leeward region, to thereby reduce air flow resistance of each fin unit without substantial reduction of heat exchange rate of the heat exchanger.

Abstract: A tube and fin heat exchanger is disclosed comprising a pair of tanks, a plurality of tubes of non-circular cross section connected at their ends to tanks, and a plurality of corrugated fin strips each arranged between and extending along the length of adjacent ones of the tubes. Each of the fin strips has a constant corrugation spacing extending along an intermediate and almost the entire length of the tubes and a smaller corrugation spacing extending the remainder of the length of the tubes to their ends so as to provide increased resistance to ballooning of the tubes at their ends by internal pressure.

Abstract: A heat exchanger having corrugated fins interposed between adjacent folds of a liquid tube, which corrugated fins severally contain in each of the holds thereof a louver having louver blades alternately projected from the base line of fin and having at least part of said louver blades so arranged that the states of inclination thereof relative to said base line of fin vary alternately.

Abstract: A serpentine type heat exchanger for use in, for example, an evaporator or condenser in an automobile air conditioner comprises a flat tube provided with a plurality of refrigerant passages therein and bent to form a serpentine tortuous cross section. Corrugated fin units which are folded into wavy form are attached to adjacent parallel portions of the flat tube. The serpentine tortuous flat tube consists of a plurality of parallel portions spaced apart from each other in the longitudinal direction of the tube and a plurality of connecting portions each connecting with two of the adjacent parallel portions. Each connecting portion consists of a plurality of arc shaped segments and at least one central connecting segment. Therefore, the height of the heat exchanger is reduced without reducing the heat exchanging area.

Abstract: A heat exchanger comprising a tube for guiding heat-exchange fluid and a fin affixed to the outer side of said tube and adapted to guide air for exchanging heat with said heat-exchange fluid, said fin having an opening formed in the web thereof and a multiplicity of louvers formed astraddle said opening substantially perpendicularly to the direction of the flow of said air as staggered across said opening, said louvers each comprising a louver body separated by a fixed distance from said web of said fin and two legs connecting the opposite ends of said louver body to said web of said fin.

Abstract: A heat exchanger includes a plurality of hollow panels arranged in a stack with fins interspersed therebetween and each having a fluid passageway therein and an upper header and a lower header at opposite sides of the fluid passageway. An end plate is applied to at least one end of the stack and formed with an inlet opening and an outlet opening in nearby positions which communicate to a fluid circulation path defined in the stack by the fluid passageways and the upper and lower headers of the hollow panels. An inlet and outer manifold block is mounted on the end plate for fluidly communicating the inlet opening of the end plate to an inlet conduit and the outlet opening to an outlet conduit.

Abstract: An evaporator comprising a plurality of heat transfer fins arranged mutually parallelly relative to the direction of air current and a multiplicity of louver boards formed by cuts inserted in substrates of said heat transfer fins perpendicularly to the direction of air current and sloped to prescribed angles from said substrates so as to be divided into a plurality of louver groups by the direction of sloping, which evaporator has the louver at the downstream zone of the fins in the direction of air current sloped so that the flow of the water condensate by gravity directs to the direction of an interior of the evaporator.

Abstract: A heat exchange unit suitable for combination with a propeller fan comprises at least one pipe for coolant having porous passages for coolant inside thereof, said pipe being either spirally wound or one of a plurality of substantially circular pipes which are coaxially arranged. An inlet header are and an outlet header respectively connected to the inlet or the outlet of the pipe for coolant. At least one corrugated fin is interposed in a space formed between the adjacent pipes or portions of the spirally wound pipe. The heat exchanger is provided with a space at the central portion, and a fan motor is positioned in the central space of the heat exchanger. A propeller fan is fitted to the rotary shaft of the fan motor to feed air to the heat exchanger.

Abstract: A fin element for a heat exchanger has alternate fins A and B in parallel planes in a longitudinal central zone 10. Edge zones 12 are bent at obtuse included angles with respect to the parallel planes. The fin element is formed from a metallic strip of material by pressing the fins A and B in opposite directions and allowing the overall width of the strip to reduce so that the finished element has a constant thickness.

Abstract: A heat exchanger fin according to the invention has a multiplicity of fins arranged substantially in parallel with the direction of air flow and at least one heat transfer tube to which said fins are connected in a heat conducting relation. A multiplicity of louvers inclined by a small angle to the direction of air flow are formed in said fins.According to this construction, it is possible that the air as a whole can flow substantially straight across the heat exchanger and can strongly collide with all louvers, thereby to ensure a reduced flow resistance encountered by the air flow, as well as improved heat transfer performance of the heat exchanger.

Abstract: A fin assembly for heat exchangers used in air conditioners or the like. The fin assembly is formed from a thin plate material which is bent and wound to have a plurality of alternating turns each of which constitutes a fin. The fin is provided with a multiplicity of louvers cut-out and raised from the major plane thereof. The fins are inclined at an angle .theta. which is 30.degree. or smaller to the direction of flow of the gas entering the fin assembly, while the louvers are inclined at an angle .gamma. which is 20.degree. or smaller to the direction of flow of the gas entering the fin assembly in the direction opposite to the direction of inclination of the fin plates.

Abstract: A corrugated core structure for a heat exchanger in the form of a corrugated plate, walls 2 of corrugations 1 defining passages 3 for the flow of a heat-transfer agent to pass therethrough. The walls 2 are provided with pairs of extending along the length thereof projections 4 and recesses 5 successively separated by smooth wall portions 6 to effect successive throttling of the heat-transfer agent flow. Each smooth wall portion 6 is of a length essentially below five values of the hydraulic diameter of the smooth portion 6 of the passage 3. The inner curvature radius of the vertex of the corrugation 1 is essentially below a difference between one fourth of the pitch of the corrugations 1 and half the wall thickness thereof, the projections 4 and recesses 5 on the walls 2 of the corrugations 1 having a length capable to ensure an intensified heat transfer process.