Helically Finned Patents (Class 29/890.048)
  • Patent number: 11927404
    Abstract: Disclosed are a heat exchange tube, a processing method for same, and a heat exchanger having same. The heat exchange tube (10a, 10b, 10c, 10d, 10e) includes a body portion (11a, 11b, 11c, 11d, 11e) provided with a plurality of flow channels (111a, 111b, 111c, 111d, 111e) arranged in parallel and spaced apart with each other, the length direction of the flow channel (111a, 111b, 111c, 111d, 111e) being parallel to the length direction of the body portion (11a, 11b, 11c, 11d, 11e); at least one side of the body portion (11a, 11b, 11c, 11d, 11e) is provided with an extension portion (12a, 12b, 12c, 12d, 12e) along the width direction of the body portion (11a, 11b, 11c, 11d, 11e); and the extension portion (12a, 12b, 12c, 12d, 12e) and at least part of the body portion (11a, 11b, 11c, 11d, 11e) are formed by folding the same plate material.
    Type: Grant
    Filed: December 18, 2019
    Date of Patent: March 12, 2024
    Assignee: SANHUA (HANGZHOU) MICRO CHANNEL HEAT EXCHANGER CO., LTD.
    Inventors: Zhongyao Tong, Qiang Gao
  • Patent number: 11577292
    Abstract: Devices, systems, and methods are directed to formation of tubular structures, such as spirally formed structures, having spirally extending reinforcing material. In particular, tubular structures can be formed in a continuous process in which a first material is spiral formed along a first spiral and a second material is joined to the first material along a second spiral to reinforce the spirally formed first material. As compared to manual application of reinforcing material, such a continuous process can facilitate producing tubular structures at rates suitable for high-volume, commercial fabrication. Further, or instead, as compared to the use of circumferentially extending reinforcing material to support a spiral formed tube, reinforcing the spirally formed first material with a spiral of the second material may offer certain structural advantages, such as improved resistance to buckling.
    Type: Grant
    Filed: January 5, 2018
    Date of Patent: February 14, 2023
    Assignee: KEYSTONE TOWER SYSTEMS, INC.
    Inventor: Eric D. Smith
  • Patent number: 9644344
    Abstract: The present invention discloses an implement, in particular an excavator or a machine for material handling, with an element movable via at least one working drive, wherein at least one energy recovery cylinder is provided for energy recovery from the movement of the movable element, which includes a chamber filled with gas. In accordance with the invention, a device for adjusting the temperature of the energy recovery cylinder is provided.
    Type: Grant
    Filed: November 17, 2011
    Date of Patent: May 9, 2017
    Assignee: LIEBHERR-HYDRAULIKBAGGER GMBH
    Inventors: Hans-Peter Lavergne, Philipp Egenrieder, Dirk Asam, Jochen Fehse
  • Patent number: 9636733
    Abstract: Apparatus and method for forming a plurality of elongate members into a helical bundle. The apparatus has a plurality of bending die heads that are mounted in a circular array within a rigid housing. The bending die heads each have a pair of grooved rollers that engage the sides of the tubes to apply a bending force while allowing the tubes to move longitudinally through the bending die stock. The bending die heads can be rotated about their longitudinal axes to impart a helical twist to the tubes as they pass through the bending die stock. The apparatus also has a collet stock assembly, which consists of a collet that has a plurality of apertures equal to the number of tubes in the bundle to be formed. The collet stock is mounted to a housing that is secured to a carriage. The carriage is driven by motor and lead screw to move linearly along a track toward and away from the bending die stock while the collet is rotated at a predetermined speed to form a helical bundle.
    Type: Grant
    Filed: November 13, 2015
    Date of Patent: May 2, 2017
    Assignee: Neal Technologies IP Holdings, LLC
    Inventors: Kennieth Neal, Eugene Neal, Eric Wilderson, James Cunningham
  • Patent number: 9472931
    Abstract: Sealing ability with respect to a shield pipe is ensured. A wire harness is inserted in the inside of a shield pipe and a braid portion, and furthermore, a corrugated tube is disposed on the outer side of the braid portion. A sealing grommet is disposed to extend across a connecting portion between the shield pipe and the braid portion. A seal member made of rubber is pushed into an end portion of the shield pipe. A wire insertion hole in which a conductive wire of the wire harness is inserted penetrates the seal member, and a wire insertion path is formed in an outer circumferential surface of the seal member toward the wire insertion hole. Thus, the conductive wire can be inserted into the wire insertion hole from a radial direction.
    Type: Grant
    Filed: October 15, 2015
    Date of Patent: October 18, 2016
    Assignee: SUMITOMO WIRING SYSTEMS, LTD.
    Inventor: Takamasa Maeda
  • Publication number: 20140366375
    Abstract: A heat exchanger tube with a tube axis and with a tube wall having a tube outside and a tube inside, axially parallel or helically encircling inner ribs, with a groove which lies in each case between adjacent inner ribs, being formed from the tube wall on the tube inside, the helix angle, measured with respect to the tube axis, of the inner ribs being smaller than or equal to 45°, the region of the inner ribs which is remote from the tube wall being deformed at regular intervals asymmetrically on one side essentially in the tube circumferential direction, the deformed material of the inner ribs forming protrusions above the groove, the protrusions extending in each case over a finite deformation zone along an inner rib, the markedness of the deformation changing continuously within the deformation zone.
    Type: Application
    Filed: August 27, 2014
    Publication date: December 18, 2014
    Inventors: Andreas Beutler, Jean El Hajal, Ronald Lutz
  • Patent number: 8732951
    Abstract: The invention relates to a method for manufacturing finned tubes made of metal, in particular heat exchanger tubes, where at least one continuous strip forming the fins is fed tangentially to a tubular body set into rotational motion, and wound onto it, the side of the strip facing the tubular body is connected to the tube surface by means of a welding device and using a filler material, and the strip to be wound is guided between guide discs just behind the welding area, said discs reaching close up to the tube surface and the welding point. To increase the service life of the guide discs, the guide discs are cooled, specifically with cooling water to which roughly 10% by volume of a welding release agent are added.
    Type: Grant
    Filed: July 2, 2009
    Date of Patent: May 27, 2014
    Inventor: Georg Bruendermann
  • Patent number: 8393079
    Abstract: A method of salvaging a scrap partially completed spine fin coil by initially placing the partially completed coil on a reel. Connecting an end of a straight tube that is helically wrapped with a spine fin strip to an end of the partially completed coil while said partially completed coil is on the reel, rotate the reel after completing the connection until the partially completed spine fin coil is complete.
    Type: Grant
    Filed: October 26, 2009
    Date of Patent: March 12, 2013
    Inventor: Mark Anthony Parmer
  • Publication number: 20120325443
    Abstract: Provided are a tube type heat exchanger and a method of the tube type heat exchanger capable of preventing spiral fins 12 from being deformed. In the tube type heat exchanger and the manufacturing method of the same according to the present invention, the plural spiral fins 12 are disposed in series in the axial direction so as to have edges of the spiral fins 12, 12 spaced apart from each other, and each holder 3 is disposed between the spiral fins 12, 12 and abuts to the outer circumference of the tube body 11.
    Type: Application
    Filed: March 11, 2010
    Publication date: December 27, 2012
    Applicant: Sumitomo Heavy Industries Process Equipment Co., Ltd.
    Inventors: Tetsuya Miyata, Yoshikazu Suwa
  • Publication number: 20120111551
    Abstract: A finned tube includes channels defined between adjacent fins on the tube body outer surface. Wings extend from side walls of the adjacent fins between the fin top and the fin base such that the wings form a barrier which splits the channel into an upper channel and a lower channel. A plurality of holes penetrate the barrier where the wings meet, so liquids and gases can pass into and out of the enclosed area defined by the lower channel. The wings can include alternating upper wings and lower wings, and there can be depressions formed in the fin top.
    Type: Application
    Filed: January 16, 2012
    Publication date: May 10, 2012
    Applicant: Wolverine Tube, Inc.
    Inventors: Jianying CAO, Zhong LUO, Jian WU, Yalin QIU
  • Patent number: 8091616
    Abstract: A heat transfer tube can comprise a tube body, and outer fins integrated with the tube body which are formed by allowing material on the tube body to extend along radial direction of the tube body and wind and extend around the tube outer surface in helical manner, wherein microscale channels are formed on at least one lateral surface of the outer fin.
    Type: Grant
    Filed: July 10, 2008
    Date of Patent: January 10, 2012
    Assignee: Jiangsu Cuilong Precision Copper Tube Corporation
    Inventors: Minghua Lu, Chunming Zhang, Xing Luo, Haoping Zhou
  • Patent number: 7963035
    Abstract: A manufacturing method for a radiator and a structure thereof are disclosed. The manufacturing method for a radiator includes the following steps. A substrate and a plurality of cooling sheets are provided. The side wall of the substrate has a plurality of concave troughs. The cooling sheets are respectively plugged into the concave troughs. The two side walls of each of the concave troughs tightly contact the two opposing surfaces of the cooling sheet. Thereby, each of the cooling sheets is located at the side wall of the substrate, and the top portion and the bottom portion of the cooling sheet extend to outside of the top surface and the bottom surface of the substrate. By using the riveting technology to directly fasten the cooling sheets via the two side walls of the concave troughs, the present invention prevents the heat-conduction loss from being occurred.
    Type: Grant
    Filed: March 14, 2008
    Date of Patent: June 21, 2011
    Assignee: Neg Tyi Precision Co., Ltd.
    Inventor: Wen-Chen Wei
  • Publication number: 20110132590
    Abstract: A finned tube for heat transfer from one medium to a second medium, and the method of manufacture, is disclosed. A helical fin of the finned tube has an area of compressed fins positioned proximate an insertion section which has a metal tube exposed with the helical fin removed therefrom. The compressed fins are a portion of the helical fin which has been compressed so that the helical fin in the area of the compressed fins is more closely spaced than the remaining portion of the helical fin. A base portion of the helical fin in the area of the compressed fins is layered and compressed on itself and is compressed against the metal tube. The layers of the base portion are compressed together and to the metal tube of the finned tube, which causes the layers of the base portion to bind together and bind to the metal tube to prevent movement of the helical fin in the area of the compressed fins in a direction parallel to the longitudinal axis of the finned tube.
    Type: Application
    Filed: December 8, 2009
    Publication date: June 9, 2011
    Applicant: HARSCO CORPORATION
    Inventors: Jessie NUNES, Ramiro CAMARILLO, Allen JAMES, Tony MCPHAIL, Donnie BICKFORD, Art SANDERS, Ben COLE
  • Publication number: 20100270013
    Abstract: A turn-fin tube, a turn-fin type heat exchanger using the same, and an apparatus and method for manufacturing the same are provided. The turn-fin tube includes a tube in which a fluid flows, and a fin wound on an outer surface of the tube in a helical shape. The fin includes a base section wound on an outer surface in contact with the tube, and an extension section extending from the base section in an outward direction of the tube at a predetermined angle.
    Type: Application
    Filed: April 22, 2010
    Publication date: October 28, 2010
    Inventors: Dong Ha Lee, Jae Jung Park, Sung Jung Yun
  • Publication number: 20100193170
    Abstract: The invention relates to a heat exchanger tube with a tube axis and with a tube wall having a tube outside and a tube inside, axially parallel or helically encircling inner ribs, with a groove which lies in each case between adjacent inner ribs, being formed from the tube wall on the tube inside, the helix angle, measured with respect to the tube axis, of the inner ribs being smaller than or equal to 45°, the region of the inner ribs which is remote from the tube wall being deformed at regular intervals asymmetrically on one side essentially in the tube circumferential direction, the deformed material of the inner ribs forming protrusions above the groove, the protrusions extending in each case over a finite deformation zone along an inner rib, the markedness of the deformation changing continuously within the deformation zone, the deformation being marked to a greater extent in the middle of the deformation zone then at the margins, and cavities which assist the formation of bubbles being located between the
    Type: Application
    Filed: November 20, 2009
    Publication date: August 5, 2010
    Inventors: Andreas Beutler, Jean El Hajal, Ronald Lutz
  • Publication number: 20100101089
    Abstract: A method of salvaging a scrap partially completed spine fin coil by initially placing the partially completed coil on a reel. Connecting an end of a straight tube that is helically wrapped with a spine fin strip to an end of the partially completed coil while said partially completed coil is on the reel, rotate the reel after completing the connection until the partially completed spine fin coil is complete.
    Type: Application
    Filed: October 26, 2009
    Publication date: April 29, 2010
    Inventor: Mark Anthony Parmer
  • Patent number: 7451542
    Abstract: The invention relates to a heat-exchanger tube structured on both sides with excellent heat transfer characteristics utilizing both outer and also inner fins and secondary grooves intersecting the inner fins. Two spaced-apart rolling tools are provided in the utilized device in order to form the outer fins of two adjacent rolling tools; the inner structure is formed by two differently profiled mandrels. The first mandrel forms in a first forming area the inner fins. The second mandrel forms in a second forming area the inventive secondary grooves into the earlier created inner fins.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: November 18, 2008
    Assignee: Wieland-Werke AG
    Inventors: Karine Brand, Andreas Knoepfler, Andreas Beutler, Ronald Lutz
  • Patent number: 7267166
    Abstract: Grooved metal tubes, with a groove-bottom thickness Tf and outside diameter De, internally grooved with N helical ribs having an apex angle ?, height H, base width LN, and helix angle ?, two consecutive ribs being separated by a groove, generally flat-bottomed, having a width LR, with a pitch P equal to LR+LN, are characterized in that: a) the thickness Tf of the tube is such that Tf/De is equal to 0.023±0.005, Tf and De being expressed in mm, with De ranging between 4 and 14.5 mm; b) the ribs have a height H such that H/De is equal to 0.028±0.005, H and De being expressed in mm; c) the number N of ribs is such that N/De is equal to 2.1±0.4, and the corresponding pitch P is equal to p·Di/N, with Di equal to De?2·Tf, and De being expressed in mm; d) the base widths LN and LR are such that LN/LR is between 0.20 and 0.80; e) the apex angle ? ranges from 10° to 50°; and f) the helix angle ? ranges from 20° to 50°.
    Type: Grant
    Filed: May 25, 2004
    Date of Patent: September 11, 2007
    Assignee: Trefimetaux S.A.
    Inventors: Pascal Leterrible, Guy de Hollain, Nicolas Avanan
  • Patent number: 7254964
    Abstract: An improved heat transfer tube, an improved method of formation and an improved use of such a heat transfer tube is disclosed. The heat transfer tube includes an outer surface with a plurality of radially outwardly extending helical fins, the fins being grooved to define notches, a plurality of channels extending between adjacent fins, at least one nucleate boiling pore formed at the intersection of a notch and a channel. The fins are flattened or pushed down to form a primary nucleate boiling cavity within the at least one nucleate boiling pore; and the tips of the fins are further bent over or flattened to form a secondary nucleate boiling cavity within the at least one nucleate boiling pore. Also disclosed are improved refrigerant evaporator including at least one such boiling tube and a method of making such a boiling tube.
    Type: Grant
    Filed: June 10, 2005
    Date of Patent: August 14, 2007
    Assignee: Wolverine Tube, Inc.
    Inventors: Petur Thors, Tommy Tyler
  • Publication number: 20070051506
    Abstract: Provided is a turn fin condenser including a turn fin tube formed of a wrinkled strip having a predetermined width and spirally wound around a tube through which fluid flows, characterized in that the turn fin tube is primarily bent into a serpentine shape to be horizontally arranged and fixed by a horizontal fixing member, and secondarily bent in the longitudinal direction of the primarily bent serpentine shape.
    Type: Application
    Filed: August 21, 2006
    Publication date: March 8, 2007
    Inventors: Dong Ha Lee, Kwang Jeong
  • Publication number: 20060130329
    Abstract: A method for producing a heat exchanger in which the heat exchanger has a plurality of identically embodied guide baffles which form a helical guide for the composition and which are penetrated by heat exchanger tubes. For making through openings in the guide baffles for the heat exchanger tubes, a mounting device cooperates with a laser beam device. By making the through openings in the guide baffles that have already been provided with their final slope, the through openings can be adapted very precisely to the heat exchanger tubes. As a result, losses from overflow of the composition at the guide baffles are reduced, and the efficiency of the heat exchanger is increased.
    Type: Application
    Filed: December 21, 2005
    Publication date: June 22, 2006
    Inventor: Olaf Heinicke
  • Publication number: 20060112557
    Abstract: Disclosed is a tube made of a profile rolled metal product, in particular for use in heat exchangers, a rolled metal product and a method of producing the same. The tube includes a first wall and a second wall forming two opposing sides of the tube, and a plurality of reinforcing structures connecting the first and second walls and forming longitudinal passages between them. Each reinforcing structure is formed by a longitudinal ridge on the first wall projecting towards the second wall and a longitudinal ridge on the second wall protecting towards the first wall. The ridges are joined to each other at their sides.
    Type: Application
    Filed: October 4, 2005
    Publication date: June 1, 2006
    Applicant: Corus Aluminium Walzprodukte GmbH
    Inventors: Achim Buerger, Adrianus Jacobus Wittebrood, Nicole Cornelia Maria Agatha Smits
  • Publication number: 20060026835
    Abstract: Heat exchanger fins and a method for fabricating fins particularly suitable for the head of Stirling engine. The fins have a frusto-conical contour and surround and are brazed to the heater head at axially spaced positions. The inner edges of the fins are rolled to provide a flange for engaging and being joined to the head and have axially aligned, radial slots cut into the outer edge to provide channels for the passage of the products of heater combustion. The fins can be formed of annular rings or from a ribbon bent into a helix.
    Type: Application
    Filed: August 3, 2004
    Publication date: February 9, 2006
    Inventor: James Wood
  • Publication number: 20050241150
    Abstract: The invention relates to a heat-exchanger tube structured on both sides with excellent heat transfer characteristics utilizing both outer and also inner fins and secondary grooves intersecting the inner fins. Two spaced-apart rolling tools are provided in the utilized device in order to form the outer fins of two adjacent rolling tools; the inner structure is formed by two differently profiled mandrels. The first mandrel forms in a first forming area the inner fins. The second mandrel forms in a second forming area the inventive secondary grooves into the earlier created inner fins.
    Type: Application
    Filed: April 19, 2005
    Publication date: November 3, 2005
    Inventors: Karine Brand, Andreas Knoepfler, Andreas Beutler, Ronald Lutz
  • Patent number: 6840074
    Abstract: A cylindrical pipe which is excellent in heat transfer characteristic and has no accumulation of liquid, wherein a flat-shaped portion (2) along the pipe axis (L) is formed inside the cylindrical pipe (1) formed in corrugated shape. As a method for manufacturing said pipe, the present invention provides a pipe manufacturing method, wherein a thin-wall blank cylindrical pipe (P) is fed in increments of a prescribed distance, while being rotated at a definite speed, a roller die (85) being pressed against the outer periphery of the cylindrical pipe, the roller die being advanced and retracted in accordance with the feed of the cylindrical pipe, for forming a spiral corrugation such that the groove depth thereof is gradually increased, starting from the flat portion of the cylindrical pipe, and reaches a maximum in the portion opposed to the flat one.
    Type: Grant
    Filed: March 11, 2003
    Date of Patent: January 11, 2005
    Inventors: Tojo Kamino, Masaji Nukuto
  • Patent number: 6789317
    Abstract: A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at least one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.
    Type: Grant
    Filed: June 17, 2003
    Date of Patent: September 14, 2004
    Assignee: Bechtel BWXT Idaho, LLC
    Inventors: Monohar S. Sohal, James E. O'Brien
  • Patent number: 6715202
    Abstract: An apparatus and method of forming serpentine heat exchanger coils from spine fin tubing involves applying spine fins to a tube while simultaneously forming the tube into a serpentine shape. The bending and fin wrapping occurs while a feed roll continues paying out the tube without interruption. Multiple bends can be made simultaneously.
    Type: Grant
    Filed: November 2, 2001
    Date of Patent: April 6, 2004
    Assignee: American Standard International Inc.
    Inventor: Danny D. Beaver
  • Publication number: 20040049917
    Abstract: An internal grooved tube according to the present invention comprises a large number of fine spiral grooves on the inside surface in parallel arrangement, wherein the grooves are formed to assure that the ratio of a groove width in the tube axial direction to a groove height is in the range of 1 to 2. A lead angle &thgr; of the grooves to the tube axis is preferably limited to 26 to 35 degrees. A method of manufacturing an internal grooved tube according to the present invention comprises the steps of inserting a grooved plug into a blank tube rotatably, and then pressing the blank tube against the outside surface of the grooved tube with several balls revolving both around the circumference of the blank tube and on its axis in a location of the grooved plug inserted, while drawing out the blank tube longitudinally in one direction, wherein the number of balls is limited to 2 to 3.
    Type: Application
    Filed: August 4, 2003
    Publication date: March 18, 2004
    Inventors: Koji Yamamoto, Tetsuya Sumitomo, Yasutoshi Mori, Toshiaki Hashizume
  • Patent number: 6601299
    Abstract: A method of forming an extended surface heat transfer fin by differentially rolling a metal strip having a wedge-shaped profile. The method includes linearly stretching the thicker edge of the metal strip to a greater degree than the thinner edge.
    Type: Grant
    Filed: October 19, 2001
    Date of Patent: August 5, 2003
    Assignee: IBC Corporation
    Inventor: Allan Stikeleather
  • Publication number: 20030106599
    Abstract: The invention relates to a method for producing gilled metal pipes (1). According to said method, at least one continuous, gill-forming strip (4) is applied to a rotating pipe body (2) at a tangent and unwound onto the pipe body in an approximately helical line. The side of the strip facing towards the pipe body (2) is connected to the pipe surface by means of a welding device (8), using an additional material. The welding process is optimised and the finishing quality increased by moulding a web that is bent at right angles to the strip that forms the gills before said strip is unwound onto the pipe body (2). The strip is preferably bent into a U-shape and the web, which runs between the two limbs of the U-shape, is guided flatly on the pipe body.
    Type: Application
    Filed: October 18, 2002
    Publication date: June 12, 2003
    Inventor: Georg Brudermann
  • Patent number: 6443040
    Abstract: A device for manufacturing a screw (2) comprises a cylindrical support (3) having a horizontal axis (x-13 x)and being rotatable there about. A straight bar (7) is wound spirally about the support (3). The bar (7) is constrained to a guide (8) and can perform movements in a parallel direction to the axis (x—x) of the support (3) on command of a translator provided with an endless screw (14). The process for manufacturing the screw comprises controlling axial movement of the guide (8) in a predetermined rapport with the rotation of the support (3). The invention is particularly applicable in the manufacture of a screw for a screw conveyor.
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: September 3, 2002
    Assignee: WAM S.p.A.
    Inventor: Vainer Marchesini
  • Patent number: 6439301
    Abstract: The invention relates to a heat exchanger, which includes a pipe, heat conductive fins having an elongate cross-section, and a coating of silver applied to the outer surface of the fins and the outer surface of the pipe adjacent to the fins. The fins of the heat exchanger, are a metal wire helically wound around the pipe, are connected to the pipe solely by the coating of silver.
    Type: Grant
    Filed: May 1, 1997
    Date of Patent: August 27, 2002
    Assignee: Rafael-Armament Development Authority Ltd.
    Inventor: Ben-Zion Maytal
  • Publication number: 20020104216
    Abstract: A method of forming an extended surface heat transfer fin by differentially rolling a metal strip having a wedge-shaped profile. The method includes linearly stretching the thicker edge of the metal strip to a greater degree than the thinner edge.
    Type: Application
    Filed: October 19, 2001
    Publication date: August 8, 2002
    Inventor: Allan Stikeleather
  • Publication number: 20020033035
    Abstract: A machine may produce a tube having textured internal and external surfaces in a single operation. Inner and outer knurling tools may form the textured surfaces. The texturing of the internal and external surfaces may be helical patterns of ribs and grooves. The height of the ribs formed in the internal and external surfaces may be less than about 35 mils. The angles of the patterns relative to a longitudinal axis of the tube may be less than about 45°. The angle of the helical pattern allows textured tubes to be used as heat exchanger elements wherein flow is directed substantially coaxial to the longitudinal axes of the tubes. The helical pattern formed in the external surface may be oriented in a right hand or left hand helical orientation. Similarly, the helical pattern formed in the internal surface may be oriented in a right hand or left hand orientation.
    Type: Application
    Filed: July 10, 2001
    Publication date: March 21, 2002
    Inventor: L. Robert Zifferer
  • Patent number: 6336501
    Abstract: A tube having a grooved inner surface capable of achieving high condensing performance and high evaporating performance even in a region of a small flow rate of a refrigerant and preferable as a heat exchanger tube for a condenser as well as an evaporator and its fabrication method, wherein spiral groove fabricating zones 1 formed with spiral grooves are arranged at an inner surface of a metal or an alloy tube and intersecting groove fabricating zones 2 formed with intersecting groove groups intersected with pluralities of grooves are arranged at the inner surface of the metal or the alloy tube at regions different from each other, singles or pluralities of the spiral groove fabricating zones 1 and the intersecting groove fabricating zones 2 are alternately arranged in a tube circumferential direction of the metal or the alloy tube, when a fabrication width of the spiral groove fabricating zone 1 in the tube circumferential direction is designated by W1 and a fabrication width of the intersecting groove fabri
    Type: Grant
    Filed: December 21, 1999
    Date of Patent: January 8, 2002
    Assignee: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Mamoru Ishikawa, Kiyonori Ozeki, Nobuaki Hinago, Chikara Saeki