Abstract: A heat transfer assembly for a rotary regenerative air preheater has heat transfer plates which include means for spacing the plates apart to form flow passages and a plurality of rows of V-shaped ribs extending across the flow passages. Alternate rows of V-shaped ribs on each plate protrude outwardly from opposite surfaces of the plate. Several arrangements for aligning the ribs on one plate with the ribs on the adjacent plate are described as are alternate orientations of the adjacent rows of ribs on each plate. The relationship of the height of the ribs to the plate spacing is defined as is the relationship of the rib spacing to the rib height and the plate spacing to the length of the V-shaped rib sections.

Abstract: A heat transfer tube having an inner surface provided with a dense pattern of polyhedrons having crack-like cavities on at least two surfaces of a single polyhedron, forming three-dimensional crack-like cavities that enhance flow evaporation heat transfer. The tube is made by (a) forming in an inner surface for the tube a plurality of generally parallel first grooves, (b) forming in the inner surface and over the first grooves a plurality of generally parallel second fins extending at a first angle of between 0 and about 25 degrees relative to a longitudinal axis for the tube to thereby devolve the second angle fins into the pattern of cavities, and (c) forming in the second fins a pattern of generally parallel crosshatches extending cross-wise thereto.

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: There is disclosed a heat exchanger tube for conducting refigerant in a heat exchanger. The inner surface of the tube has a convex portion having a broad tip and a plurality of inner fins. The area of the tip of the convex portion is larger than that of the tip of the inner fins. The height of the convex portion can be set at more than that of the inner fin. A heat exchanger according to the invention has a plurality of plate fins, each having a hole therein. Heat exchanger tubes pass through the holes of the plate fins. A method of manufacturing a heat exchanger comprises the steps of stacking a plurality of plate fins, each having a hole, with a predetermined space therebetween. Heat exchanger tubes are inserted through the holes. Then, the tubes are expanded to engage the plate fins. A refrigerating circuit utilizing a heat exchanger is also described.

Abstract: Room temperature cure, antimicrobial coatings that demonstrate a balance of properties including low dissolution and good cohesion and adhesion are provided. Such coatings generally exhibit a greater zone of microbial inhibition, greater cohesion and a greater degree of adhesion to target surfaces when compared to high temperature cure, antimicrobial, hydrophilic coatings.

Abstract: A heat transfer tube (10) for use in an application, such as a shell and tube type air conditioning system condenser, in which a fluid flowing through the heat exchanger external to the tubes condenses by transfer of heat to a cooling fluid flowing through the tubes. The tube has at least one fin convolution (20) extending helically around its external surface (13). A pattern of notches (30) extends at an oblique angle (&agr;) across the fin convolutions at intervals about the circumference of the tube. There is a spike (22) between each pair of adjacent notches. The fin convolution, notches and spikes are formed in the tube by rolling the wall of the tube between a mandrel and, first, a gang of finning disks (63) and, second, a notching wheel (66). Because, during the manufacture of the tube, of the interaction of the rotating and advancing tube and the notching wheel, the angle (&bgr;) of inclination of the axis of the tip of the spike is oblique with respect to the notch angle.

Abstract: A heat exchange tube for air conditioning and refrigeration applications is internally enhanced with helically arranged fins. The fins are separated from adjacent fins by a trough. The heat transfer coefficient is increased by forming the fins with a height-to-trough width ratio, h:T, of from 1.3:1 to 2.5:1. A further gain in heat transfer coefficient is achieved by fins having a normalized height (fin height/tube inside diameter) of at least 0.02.

Abstract: Described is a heat exchanger comprising a nest of heat-exchange tubes held between two end plates, the heat exchanger being designed for connection downstream of a thermal-cracking installation. In order to reduce erosion of the base plate, the plate at the input end is coated on the side facing the oncoming gas with an erosion-resistant, fireproof coating of a chemically bound compound, leaving clear the apertures for the heat-exchange tubes.

Abstract: An improved air-to-air, heat-and-moisture exchanger is described which facilitates the simultaneous transfer of both heat and water vapor between two streams of air while greatly inhibiting the transfer of pollutant gases. A rigid encasement supports a stack of flat, thin-film composite membranes that are held in parallel, spaced-apart relation, thereby forming a box-shaped exchanger. The membranes are synthesized by interfacial polymerization, a process whereby a thin, non-porous film may be uniformly deposited onto a porous substrate material. The thin film is hydrophilic so as to provide high water vapor flux together with excellent selectivity against the transfer of other gases and vapors. The substrate provides mechanical support.

Abstract: An apparatus for heating a domestic water supply including a glass-lined storage tank for the domestic water supply and having a domestic water inlet port, a domestic water outlet port, and a heat-exchanging coil mounted therein. A heating tube is connected to the heat-exchanging coil to contain a recirculating fluid supply. The heat-exchanging coil within the glass-lined storage tank has a double-wall construction with a non-metallic outer wall in contact with a metallic inner wall. The double-wall prevents mixing of the domestic water supply with the recirculating fluid supply. The apparatus also includes a recirculating fluid heater positioned externally of the glass-lined storage tank to heat recirculating fluid to a temperature sufficient to heat the domestic water supply by heat transfer from the recirculating fluid in the heat-exchanging coil to the domestic water supply in the glass-lined storage tank.

Abstract: A brazing sheet which has an excellent corrosion resistance and cladding rolling property, and is formed from a four layer aluminum alloy cladding member, and a heat exchanger of aluminum alloy, in which the brazing sheet is used, are provided. The brazing sheet is suitable for use as a member in the fluid path of an aluminum heat exchange for a car, and particularly, as a core plate of a drawn cup type heat exchanger. In the brazing sheet, one side of a core member is cladded with an intermediate member less noble than a core member, and the other side of both the core member and the intermediate member are cladded with Al--Si--Mg type cladding member, wherein the core member is of an aluminum alloy containing 0.5 to 1.6% of Mn, 0.15 to 0.35% of Cu, 0.05 to 0.50% of Mg, 0.06 to 0.30% of Ti, and the remainder being Al and unavoidable impurities, and the intermediate member contains 0.5 to 1.2% of Mn and the remainder being aluminum and unavoidable impurities, and 0.05 to 1.

Abstract: A heat dissipator includes a heat-conductive substrate, a lid and a heat-conductive cover layer, and a coolant groove for passing a coolant therethrough is formed on a major surface of the substrate. The lid is positioned on the coolant groove to seal the same, and the cover layer covers the major surface of substrate and the lid. The lid may be received in a lid groove to be flush with the major surface of the substrate. The substrate, lid and cover layer are all made of diamond, and are joined together with substantially no other material therebetween. Thus, a high heat conductivity is achieved. The heat dissipator can be a heat dissipating substrate for an electronic component, or an optical transmission window.

Abstract: An arrangement for a heat exchange surface in a boiling application that retains particulate material between fins to provide nucleate boiling sites. The heat exchange surface most typically is part of a heat exchange tube and retains the particulate material by transversely extending the tops of the fins. The fins and extended tops form channels with a restricted opening at the top of the channel that prevents passage of the particulate material out of the channel. The surface may be formed on the inside or outside of tubes.

Abstract: A heat exchange unit for incorporation internally of a food or beverage container in such a manner that the external surface thereof is in contact with the food or beverage. A food grade coating is adhered to and completely covers the entire exterior surface of the heat exchange unit to preclude direct contact of the food or beverage with surface of the heat exchange unit.

Abstract: A sorption cooling exchanger module and a process for its use in sorption cooling processes is described. The apparatus, provides high efficiency sorption cooling operations by maintaining a characteristic diffusion distance between fin plates such that the sorption cooling process can be carried out with short cycle times which increase the efficiency of the sorption cooling process and increases the specific power. The apparatus comprises an adsorption zone comprising an adsorbent layer comprising a coating of adsorbent or comprising a paper layer containing a selective adsorbent. For sorption cooling processes, the heat transfer zone is disposed in tubes disposed normal to the fin plates. The apparatus provides an opportunity to provide an adsorber/generator module having a high fin plate density per unit length of tube without the characteristic diffusion distance becoming equal to the height of the fin from the tube resulting in an improvement in efficiency.

Abstract: A hydrophilic antimicrobial coating includes a porous ceramic-based coating and at least one biocide dispersed in the porous, hydrophilic ceramic-based coating. The coating can be an alumina coating, and the biocide can include silver oxide. A second biocide such as zinc oxide or copper oxide can also be dispersed in the porous, hydrophilic ceramic-based coating. The hydrophilic antimicrobial coating can be applied to a heat transfer surface of a heat exchanger.

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: In order to control the precipitation and formation of a deposition produced in an inner face portion of a heat transmitting tube for a boiler due to a boiler water and the formation of an oxide scale of a tube material due to overheated steam, there is provided a heat transmitting tube for a boiler provided with a porous sprayed coating. The porous sprayed coating is formed by using a metal.multidot.alloy having excellent high temperature oxidation resistance and corrosion resistance at high temperature as compared with a material of the heat transmitting tube onto an outer heat receiving surface for contacting a combustion gas, and optionally an oxide ceramic, and optionally an oxide cermet. Solid inorganic sintered fin particles are penetrated and filled in opening pores of the porous sprayed coating and form a heat shielding layer on the surface of the porous sprayed coating.

Abstract: A heat exchanger assembly includes at least one tube having an internal surface and an external surface, a composition cladding having at least lithium and magnesium applied to either one of the internal surface and external surface of the tube, and at least one component disposed adjacent the composition cladding, whereby the tube and component are joined together during a controlled atmosphere brazing process.

Abstract: There is provided heat exchange tube formed from a ductile metal strip which is formed into a generally circular configuration with the opposing longitudinal edges of the strip welded together. Both surfaces of the strip are enhanced. One surface of the tube is enhanced with protrusions in the shape of truncated cones. The ratio of the pitch between longitudinally aligned protrusions and transversely aligned protrusions maximizes the formation and maintenance of vortexes in a flowing fluid along the tube surface.

Abstract: The present invention relates to an Al alloy brazing sheet for use in vacuum brazing, which is applied to manufacture a heat exchanger having a tank portion and a refrigerant passage respectively formed by bonding press-formed brazing sheets together by means of vacuum brazing. The brazing sheet includes an Al alloy core material having a composition consisting of 0.5 to 2.0 mass % (hereinafter abbreviated simply as %) of Mn, 0.1 to 1.0% of Cu, 0.05 to 0.5% of Mg and 0 to 0.3%. of Ti, with the remainder being Al and inevitable impurities. An Al--Si--Mg alloy brazing filler metal or an alloy brazing filler metal prepared by further adding 0.05 to 1.0% of Sn to the Al--Si--Mg alloy brazing filler metal, is clad on both surfaces of the sheet to a thickness of 5 to 20% the total sheet thickness. An intermediate layer consisting of an Al alloy having a composition consisting of 0.5 to 2.0% of Mn, 0.05 to 0.5% of Mg and 0 to 0.

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: The invention discloses the manufacture of a metal tank comprising the following steps: coating a strip of sheet steel with a thermally adhesive polymer based layer, preparing segments provided with assembly zones from the blanks of the said coated sheet, assembling the said segments at the assembly zones, consolidating the assembly by cold mechanical assembling means and heating to activate bonding of the polymer layers in contact at the assembly zones. The invention is useful in particular for manufacturing fuel tanks and heat exchangers.

Abstract: A process for fabricating a low cost high efficiency liquid cold plate is described. The process uses a metal extrusion designed with internal fluid channels. A simple process for fabricating fluid inlet and outlet manifolds, creating turbulent flow inside the fluid channels, a method for capping the extrusion ends, and a method for improving the surface contact with heat generating components is described.

Abstract: A fluid heater includes a housing, a burner unit disposed in a bottom portion of the housing for burning combustible fuel, a combustion chamber disposed within the housing where the fuel is burned and a heat exchanger disposed substantially within the housing over the combustion chamber. The heat exchanger absorbs heat generated from burning the fuel and conducts the heat to a fluid to be heated. The heat exchanger includes a pair of spaced, parallel, stainless steel tubesheets with a plurality of tubes running therebetween and sealingly received within mating apertures in each of the tubesheets. A plastic front header and a plastic rear header are removably attached to the tubesheets distal to said tubes. The apertures in the tubesheets preferably have forged flanges for increasing the surface contact area with the heat exchanger tubes. The heat exchanger is corrosion resistant due to the combination of corrosion-resistant tubesheets, tubes and headers.

Abstract: A heat transfer tube with a cross-grooved inner surface used in refrigerators, air conditioners or the like and a manufacturing method thereof are disclosed. The heat transfer tube is formed in such a manner that the helix angle .alpha. of a primary spiral groove to the longitudinal axis of the tube is in the range of 10.degree. to 40.degree., the intersecting angle .beta. of a secondary groove to the primary spiral groove is in the range of 75.degree. to 105.degree., the ratio H/Hf of a height H of the secondary groove to a height Hf of the primary spiral groove is in the range of 0.5 to 1.0, the slope angle .gamma..sub.1 of an upstream slant face is in the range of 90.degree. to 105.degree. to the direction of the primary spiral groove, the slope angle .gamma..sub.2 of a downstream slant face is in the range of 30.degree. to 60.degree.

Abstract: In a heat transfer tube for a zeotropic refrigerant mixture, the inner surface of the tube in which the zeotropic refrigerant mixture flows is formed with grooves having cross portions where the grooves intersect with each other, or the inner surface of the tube is formed with a plurality of independent projections. Thus, concentration boundary layers generated in the zeotropic refrigerant mixture are stirred to reduce the thickness of the concentration boundary layers, thereby decreasing the diffusion resistance and promoting the stirring effect. Consequently, there can be provided a heat transfer tube for a zeotropic refrigerant mixture which exhibits a high heat transfer performance, and a heat exchanger of a cross-fin tube type, a refrigerator and an air conditioner which include such heat transfer tubes.

Abstract: A plurality of tubes (3) for flowing a heat transfer tedium, a plurality of fins (4), and tanks (1) connected to the tubes (3) is provisionally assembled. Each of the tubes (3) comprises a pair of formed plates (3a, 3b) coupled to each other. Each of the formed plates (3a, 3b) has a peripheral portion (20) and a plurality of protrusions (14) formed on an inside thereof and having through-holes in top ends thereof. The outer surface of the provisional assembly is coated with a noncorrosive flux (40) in an amount rate of 3 g/m.sup.2 or more on the base of the total area of the outer surfaces and inner surfaces of the tanks, fins and tubes. Then, the provisional assembly is subjected to a brazing treatment. The noncorrosive flux (40) is melted and flows to penetrate into the inside of the tubes (3) through the through-holes (45, 18a) to bond the paired formed plates to each other.

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: A heat exchanger (10) assembly with a first header (12), a second header (14), a plurality of seamed or folded type heat exchanger tubes (18) extending between the two headers (12, 14), and a plurality of heat exchanger fins (16). Each of the plurality of fins (16) has between 0.01% and 0.9% magnesium to improve the braze between the header (12, 14) and tube joint and the tube seam to inner surface joint (140). Additionally, the headers (12, 14) have a cladded inner surface with between about 0% to about 12.6% silicon to improve the braze at the tube-to-header joint.

Abstract: A groove configuration, formed on an inside wall of a heat exchanger tube, has a cross-sectional area varying in the longitudinal direction of the heat exchanger tube. An increased rate of the cross-sectional area is differentiated from a decreased rate of the cross-sectional area by changing the height or top width of a protruding portion, or the depth or bottom width of a recessed portion.

Abstract: The present invention relates to dielectric materials which may be used in the manufacture of, e.g., low profile heaters. Such dielectric materials comprise at least about 50% of a glass composition having about 35-50% SiO.sub.2, about 30-40% of an alkaline earth metal oxide selected from the group consisting of CaO, MgO, and SrO, about 13--22% Al.sub.2 O.sub.3, and about 0-10% B.sub.2 O.sub.3, the percentages being weight percentages based on the weight of the total glass composition. Certain dielectric compositions of the disclosure have a linear thermal expansion coefficient in the range of about 6.0 to 9.0 ppm/.degree. C.

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: In an inner surface-grooved heat transfer tube, a plurality of fins is formed on the inner surface thereof along a line forming a first predetermined angle with respect to the longitudinal axis of the tube, a plurality of notches is defined on the fins along a line forming a second predetermined angle with respect to the longitudinal axis, and the depth Hf' of the notches is specified to be 20% or more and below 40% (0.2.ltoreq.Hf'/Hf<0.4) with respect to the height Hf of the fins, to provide an inner surface-grooved heat transfer tube which can suppress pressure loss of a refrigerant, and by which improvements in performance of condensation and evaporation are intended. In addition no increase of power consumption is required for the pump.

Abstract: A heat exchanger tube for effecting a heat exchange between a fluid inside the heat exchanger tube and another fluid flowing outside the heat exchanger tube, which is provided with a first kind of spiral grooves and a second kind of spiral grooves, each being formed on an outer surface of the heat exchanger tube. The twisting direction of the first kind of spiral grooves in relative to the axis of the heat exchanger tube is the same as that of the second kind of spiral grooves but differs in helix angle from each other with helix angles of the first kind of spiral grooves and the second kind of spiral grooves falling within the range of 3.degree. to 80.degree. in relative to the axis of the heat exchanger tube.

Abstract: In order to improve the anticorrosion properties of a flat plate or an intake/outlet passage plate provided at an outermost end in the direction of lamination in a laminated heat exchanger, a sacrificial layer, whose electrical potential is lower than the electrical potential of the core material, is provided at the outer surface of the flat plate or the intake/outlet passage plate located at the outermost end of the laminated heat exchanger in the direction of lamination. The above arrangement prevents corrosion of the core material through sacrificial corrosion of the sacrificial layer.

Abstract: A heat transfer tube having an internal surface that enhances the heat transfer performance of and also improves the workability of the tube and a method of manufacturing such a tube. The internal surface has a plurality of ribs that extend at an angle to the longitudinal axis of the tube. A pattern of parallel notches, extending at an angle to the ribs, extend through the ribs and into the main inner surface of the tube wall. The tube can be made by rolling embossing the pattern of ribs and notches on to one side of a flat metal strip, then roll forming the strip into a tubular shape with the embossed pattern on the interior of the tubular shape and the edges of the strip forming a longitudinal seam, then joining, preferably by welding, the edges along the longitudinal seam to form a tube. In a preferred embodiment, the notches in the inner surface extend into the weld zone of the tube.

Abstract: A product and a method for manufacturing the product include a metallic basic body with at least one longitudinal duct disposed therein and with a number of transverse ducts branching off from the longitudinal duct. A covering layer lies on the outside of the basic body. The covering layer serves as a protective or adhesive layer. An enrichment layer covers walls of the longitudinal duct and of the transverse ducts and parts of the covering layer. A ceramic heat-insulating layer can also be provided on the outside.

Abstract: An absorption refrigerator uses water as a refrigerant and a halogen compound as an absorption solution, and is characterized in that an oxide film of thickness of 0.02-5.0 .mu.m is formed on a surface of at least one of a heat exchanger and a high temperature regenerator. And a production method of the absorption refrigerator is characterized by oxidizing a surface of at least one of a heat exchanger and a high temperature regenerator at a temperature of 200-800.degree. C., and adjusting a heating temperature and a heating retaining time so that a value of parameter (P), obtained according to P=T (5+log t) is 3.5-6.0.times.10.sup.3, wherein T represents heating temperature (.degree.K), and t heating retaining time (minute).

Abstract: The present invention discloses a method a method of making a material for thermal cores and the material so made. In particular, the present invention disclose a method including the steps of applying thermally conductive particles over at least a portion of a fiber layer, providing another fiber layer upon the fiber layer, and repeating the above steps as desired. In another aspect of the present invention is disclosed a method of making a thermally conductive material including applying thermally conductive particles upon at least a portion of a fiber prepreg layer, providing another fiber prepreg layer upon the fiber layer, repeating the above steps as desired, and bonding the fiber prepreg layers, including the thermally conductive particles, together. The material in accordance with the present invention includes a plurality of layers made of thermally conductive fibers bonded by a resin, and a plurality of interposed layers of resin having a high concentration of high conductivity particles therein.

Abstract: A heat exchange tube useful as a reactor tube for producing ethylene and highly improved in heat transfer efficiency has fins formed on the inner surface of wall of the tube in one or a plurality of regions or all regions arranged from an inlet end of the tube to an outlet end thereof axially of the tube. The fins are positioned in a direction intersecting the axis of the tube and have a suitable pitch. The fins are formed by a projection helically extending on the tube wall inner surface around the axis or are each in the form of an annular projection circumferentially extending on the inner surface in a direction intersecting the axis at right angles therewith. The pitch of the fins, the angle of intersection of the fins with the axis and the height of the fins are suitably determined in conformity with the inside diameter of the tube.

Abstract: Disclosed is a heat transfer tube with grooves in an inner surface thereof, which is excellent in both evaporation performance and condensation performance. In the heat transfer tube with grooves in an inner surface thereof according to the present invention, groove processing regions 1 having a width W1 and groove processing regions 2 having a width W2 are alternately arranged in the inner surface thereof, and a linear groove region 3 having a width W3 extending in a longitudinal direction of the tube is arranged between the groove processing region 1 and the groove processing region 2. The width W1 is larger than the width W2. A group of grooves within the groove processing region 1 are helically formed at a torsional angle .theta.1 with respect to a longitudinal direction of the tube, and a group of grooves within the groove processing region 2 are at a torsional angle .theta.2 different from .theta.

Abstract: This invention relates to water-based hydrophilic coatings suitable for giving hydrophilicity primarily to the surface of aluminum and to a process for manufacturing precoated fin materials for heat exchangers with use of said coatings. The coatings are composed of colloidal silica with a dispersed particle diameter of 5 to 100 nm, water-soluble polymers containing at least carboxylic acid polymers, anionic surfactants and water; the colloidal silica and the water-soluble polymers are present at a weight ratio of 30:70 to 70:30 on a solid basis in a combined content of 4 to 20% by weight, the content of carboxyl group in the carboxylic acid polymers contained in the water-soluble polymers is 20 to 63% by weight, the anionic surfactants are alkali salts of sulfosuccinic acid monoalkyl esters with alkyl groups containing 1 to 18 carbon atoms and present in an amount of 5 to 20% by weight of the combined solid content of the colloidal silica and the water-soluble polymers, and the pH is 1 to 5 as a whole.

Abstract: The present invention is a brazing composition for brazing a tube made of aluminum or aluminum alloy and a fin made of aluminum or aluminum alloy when manufacturing a heat exchanger such as evaporators, condensers, radiators, etc., comprising a powder of Al--Si--Zn alloy and binder, wherein the content of Zn in the powder of Al--Si--Zn alloy is in a range of 10 to 55 wt %.

Abstract: The present invention is an aluminum assembly comprising at least two components brazed to each other. The assembly comprises: at least a first aluminum based component having a coating of a zinc-antimony alloy having at least 1.0 wt. % antimony applied to a region of a surface of the component which is to be joined to a second aluminum based component; and at least one second aluminum based component disposed adjacent to the coating; whereby the at least first aluminum based component and the at least second aluminum based component are joined together during a controlled atmosphere brazing (CAB) process.

Abstract: Micro-conduit with enhanced wetting characteristics for use in providing a blood heat exchanger apparatus with improved heat exchange capability. The micro-conduit comprises a plurality of elongated fibers, which may be made of a hydrophobic material such as polypropylene or polyethylene. Each fiber is open at two opposing ends, and has an inner surface between the open ends. The inner surface is coated with a wetting agent, such as phosphatidyl choline or another ampiphilic material with a hydrophilic end and a hydrophobic end. The fibers may have a shape and size that without presence of the wetting agent, would otherwise substantially impair free passage of water. The micro-conduit may be provided as a heat exchanger micro-conduit wrapping material, wherein micro-conduit fibers are attached to a thin flexible interconnect, such as woven netting, to maintain the fibers at predetermined spacings in substantially parallel alignment with each other.

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: A heat exchanger includes one or more parts composed of a braze clad aluminum alloy having a composition defined essentially by the formula: Al 1.1% Mn 1.1% Mg 0.15 Cu and being brazed to other aluminum parts. The heat exchanger exhibits usable strength at operating temperatures ranging up to 232.degree. C. ?450.degree. F!, and is especially suited for use in the charge air cooler of a diesel engine.

Abstract: A heater includes an aluminum die cast body defining an enclosure and an adaptor block. A heating element within the enclosure activates, under control of an associated heat sensing device, a heating element within the enclosure to transfer heat energy into the adaptor block. The adaptor block, including features specific to a given mechanical device, e.g., pneumatic valve or pump, transfers the heat energy into the mechanical device to avoid a frozen condition resulting from, for example, sudden expansion of air when passing through the device.