MX2010013776A - Método para fabricar un intercambiador de calor de tubo y aleta con diámetro reducido de tubo y aleta optimizada producida con el mismo. - Google Patents

Método para fabricar un intercambiador de calor de tubo y aleta con diámetro reducido de tubo y aleta optimizada producida con el mismo.

Info

Publication number
MX2010013776A
MX2010013776A MX2010013776A MX2010013776A MX2010013776A MX 2010013776 A MX2010013776 A MX 2010013776A MX 2010013776 A MX2010013776 A MX 2010013776A MX 2010013776 A MX2010013776 A MX 2010013776A MX 2010013776 A MX2010013776 A MX 2010013776A
Authority
MX
Mexico
Prior art keywords
fin
heat exchanger
fins
tube
optimized
Prior art date
Application number
MX2010013776A
Other languages
English (en)
Spanish (es)
Inventor
Pei Chen Pei
Tharp Russell
Original Assignee
Goodman Global Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Goodman Global Inc filed Critical Goodman Global Inc
Publication of MX2010013776A publication Critical patent/MX2010013776A/es

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28DHEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D1/00Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
    • F28D1/02Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
    • F28D1/04Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28FDETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00Tubular elements; Assemblies of tubular elements
    • F28F1/10Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F28F1/24Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely
    • F28F1/32Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely the means having portions engaging further tubular elements
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28DHEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D1/00Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
    • F28D1/02Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
    • F28D1/04Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits
    • F28D1/047Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits the conduits being bent, e.g. in a serpentine or zig-zag
    • F28D1/0475Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits the conduits being bent, e.g. in a serpentine or zig-zag the conduits having a single U-bend
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28FDETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00Tubular elements; Assemblies of tubular elements
    • F28F1/10Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28FDETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00Tubular elements; Assemblies of tubular elements
    • F28F1/10Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F28F1/14Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally
    • F28F1/22Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally the means having portions engaging further tubular elements
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28FDETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00Tubular elements; Assemblies of tubular elements
    • F28F1/10Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F28F1/24Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely
    • F28F1/32Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely the means having portions engaging further tubular elements
    • F28F1/325Fins with openings
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28FDETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F2215/00Fins
    • F28F2215/10Secondary fins, e.g. projections or recesses on main fins

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Geometry (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
MX2010013776A 2008-06-13 2009-06-15 Método para fabricar un intercambiador de calor de tubo y aleta con diámetro reducido de tubo y aleta optimizada producida con el mismo. MX2010013776A (es)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US6149808P 2008-06-13 2008-06-13
PCT/US2009/047396 WO2009152514A1 (fr) 2008-06-13 2009-06-15 Procédé de fabrication d’un tuyau et d’un échangeur de chaleur à ailette dont le diamètre de tuyau est réduit et ailette optimisée fabriquée à l’aide de ce procédé

Publications (1)

Publication Number Publication Date
MX2010013776A true MX2010013776A (es) 2011-03-29

Family

ID=41413702

Family Applications (1)

Application Number Title Priority Date Filing Date
MX2010013776A MX2010013776A (es) 2008-06-13 2009-06-15 Método para fabricar un intercambiador de calor de tubo y aleta con diámetro reducido de tubo y aleta optimizada producida con el mismo.

Country Status (7)

Country Link
US (1) US20090308585A1 (fr)
EP (1) EP2313728A1 (fr)
KR (1) KR20110033198A (fr)
CN (1) CN102216714A (fr)
CA (1) CA2727671A1 (fr)
MX (1) MX2010013776A (fr)
WO (1) WO2009152514A1 (fr)

Families Citing this family (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070215330A1 (en) * 2006-03-20 2007-09-20 Ishikawajima-Harima Heavy Industries Co., Ltd. Heat exchanger
KR101520484B1 (ko) * 2008-07-04 2015-05-14 엘지전자 주식회사 열교환기
KR20120044847A (ko) * 2010-10-28 2012-05-08 삼성전자주식회사 열교환기 및 그 핀
KR20120044848A (ko) * 2010-10-28 2012-05-08 삼성전자주식회사 열교환기 및 그 마이크로채널튜브
JP5835907B2 (ja) * 2011-02-17 2015-12-24 三菱重工業株式会社 熱交換器
KR101936224B1 (ko) * 2012-04-26 2019-01-08 엘지전자 주식회사 열교환기
KR101882020B1 (ko) * 2012-08-01 2018-07-25 엘지전자 주식회사 열교환기
KR20140017835A (ko) * 2012-08-01 2014-02-12 엘지전자 주식회사 열교환기
CN103273295B (zh) * 2013-05-10 2015-05-13 丹佛斯微通道换热器(嘉兴)有限公司 换热器和换热器制造方法
CN103453793A (zh) * 2013-07-29 2013-12-18 姚福良 管翅一体式热传输单元及其热交换器
WO2016031032A1 (fr) * 2014-08-29 2016-03-03 日立アプライアンス株式会社 Échangeur de chaleur et climatiseur
US10209012B2 (en) * 2015-02-24 2019-02-19 Lgl France Heat exchanger with louvered fins
FR3038977B1 (fr) * 2015-07-17 2019-08-30 Valeo Systemes Thermiques Echangeur de chaleur a ailettes comprenant des persiennes ameliorees
CN106482568B (zh) * 2015-08-25 2019-03-12 丹佛斯微通道换热器(嘉兴)有限公司 用于换热器的换热管、换热器及其装配方法
USD800282S1 (en) * 2016-03-03 2017-10-17 Lennox Industries Inc. Heat exchanger fin
JP2017166757A (ja) * 2016-03-16 2017-09-21 三星電子株式会社Samsung Electronics Co.,Ltd. 熱交換器及び空気調和装置
US11774187B2 (en) * 2018-04-19 2023-10-03 Kyungdong Navien Co., Ltd. Heat transfer fin of fin-tube type heat exchanger
KR102137462B1 (ko) * 2018-06-20 2020-07-24 엘지전자 주식회사 공기조화기의 실외기
CN109737791B (zh) * 2018-12-29 2020-04-10 西安交通大学 一种梯形波纹与异形环管结构复合翅片
DE102019120862A1 (de) 2019-08-01 2021-02-04 Benteler Automobiltechnik Gmbh Verfahren zur Herstellung eines Plattenwärmetauschers sowie Plattenwärmetauscher
CN114623502B (zh) * 2020-12-11 2023-12-22 广东美的白色家电技术创新中心有限公司 空调室内机和空调器

Family Cites Families (67)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1002382B (it) * 1973-12-27 1976-05-20 Gaiardelli Giuseppe Pulitore pneumatico in partcicolare per fusi e consimili di macchine tessili
US3902551A (en) * 1974-03-01 1975-09-02 Carrier Corp Heat exchange assembly and fin member therefor
US3979042A (en) * 1975-01-16 1976-09-07 Raytheon Company Vacuum brazing of nickel to aluminum
US4063317A (en) * 1975-11-13 1977-12-20 Michael Santore Hydro-pneumatic pipe, tube and drain cleaner
US4137928A (en) * 1977-09-09 1979-02-06 Naylor Industries, Inc. Apparatus for cleaning the interior of tubes
US4225362A (en) * 1979-01-18 1980-09-30 Richard R. Paseman Method for cleaning the interior of tubes
US4776391A (en) * 1979-10-04 1988-10-11 Heat Exchanger Industries, Inc. Heat exchanger method and apparatus
US4669530A (en) * 1982-08-10 1987-06-02 Heat Exchanger Industries, Inc. Heat exchanger method and apparatus
US4577380A (en) * 1979-10-04 1986-03-25 Heat Exchanger Industries, Inc. Method of manufacturing heat exchangers
US4526112A (en) * 1982-08-10 1985-07-02 Heat Exchanger Industries, Inc. Heat exchanger method and apparatus
AU571845B2 (en) * 1983-08-19 1988-04-28 Barry Bros. Specialised Services Pty Ltd Pig, launcher and catcher for tube or pipe cleaning
JPS6015064A (ja) * 1983-07-06 1985-01-25 Hitachi Ltd 熱交換器
US4785516A (en) * 1986-01-30 1988-11-22 Gilbertson Richard G Method of inserting tubes into heat exchangers and apparatus therefor
US4730667A (en) * 1986-06-04 1988-03-15 Alex Chevion Liquid to solids heat exchanger
US4723599A (en) * 1987-03-06 1988-02-09 Lennox Industries, Inc. Lanced fin heat exchanger
US4771536A (en) * 1987-03-30 1988-09-20 Crown Unlimited Machine, Inc. Expansion rod mounting structure
US4780955A (en) * 1987-05-20 1988-11-01 Crown Unlimited Machine, Inc. Apparatus for making a tube and fin heat exchanger
US4839950A (en) * 1987-05-20 1989-06-20 Crown Unlimited Machine, Incorporated Method for making a tube and fin heat exchanger
US4831844A (en) * 1988-05-26 1989-05-23 General Motors Corporation Condenser with improved flow path
JPH07109353B2 (ja) * 1989-02-01 1995-11-22 松下電器産業株式会社 フィン付熱交換器
CH681636A5 (fr) * 1989-05-30 1993-04-30 Agm Ag Mueller
US4980966A (en) * 1990-04-27 1991-01-01 Burr Oak Tool & Gauge Company Rod holder for the assembly of heat exchangers
WO1991017843A1 (fr) * 1990-05-18 1991-11-28 Graham Hubert Smith Dispositif de nettoyage de tubes
US5003691A (en) * 1990-07-06 1991-04-02 Burr Oak Tool & Gauge Company Mechanical tube expander with hairpin bend support
US5111876A (en) * 1991-10-31 1992-05-12 Carrier Corporation Heat exchanger plate fin
US5220722A (en) * 1991-12-09 1993-06-22 Burr Oak Tool & Gauge Company Quick height change adjustment for tube expander
US5233853A (en) * 1992-01-03 1993-08-10 Burr Oak Tool & Gauge Company Stretch straightening hairpin bender
IT1264434B1 (it) * 1992-06-12 1996-09-23 Burr Oak Tool & Gauge Espansore meccanico per tubi, con controllo su quattro assi
US5442826A (en) * 1992-07-24 1995-08-22 Matsui Manufacturing Co., Ltd. Apparatus for cleaning the inside of a pipe
US5360060A (en) * 1992-12-08 1994-11-01 Hitachi, Ltd. Fin-tube type heat exchanger
CA2087518C (fr) * 1993-01-18 1995-11-21 Serge Gamache Systeme de martelage pour chaudiere a tube
US5588345A (en) * 1993-11-22 1996-12-31 Burr Oak Tool & Gauge Company Fin sheet control apparatus for press
US5379624A (en) * 1993-11-22 1995-01-10 Burr Oak Tool & Gauge Company Slaved tube length control for hairpin bender
US5410800A (en) * 1994-03-14 1995-05-02 Carrier Corporation Tube expander with rod support apparatus
KR0128678B1 (ko) * 1994-07-21 1998-04-04 김광호 공기조화기의 열교환기
US5632080A (en) * 1994-07-26 1997-05-27 Burr Oak Tool & Gauge Company, Inc. Tube cutter/bender to lacer transfer station
KR960031954A (ko) * 1995-02-20 1996-09-17 구자홍 열교환기의 핀
US5806173A (en) * 1995-07-28 1998-09-15 Hidaka Seiki Kabushiki Kaisha Tube expander
IT1283800B1 (it) * 1995-09-01 1998-04-30 Burr Oak Tool & Gauge Dispositivo di taglio stazionario e spostabile in modo graduato
KR100202061B1 (ko) * 1995-12-28 1999-06-15 전주범 공기조화기용 열교환핀구조
US5771962A (en) * 1996-04-03 1998-06-30 Ford Motor Company Manufacture of heat exchanger assembly by cab brazing
CN1125309C (zh) * 1996-10-02 2003-10-22 松下电器产业株式会社 翅片式热交换器
KR100220724B1 (ko) * 1996-12-30 1999-09-15 윤종용 공기조화기의 열교환기
US5983994A (en) * 1997-10-30 1999-11-16 Electric Power Research Institute, Inc. Method and apparatus for on-line cleaning of and improvement of heat transfer in a heat exchanger tube
JP3038179B2 (ja) * 1998-04-08 2000-05-08 日高精機株式会社 熱交換器用フィン及びその製造方法
US5901596A (en) * 1998-04-17 1999-05-11 Burr Oak Tool And Gauge Company, Inc. Tube bender loader and unloader
US6158074A (en) * 1999-03-15 2000-12-12 Castille; Alan J. Pipe cleaning machine
KR100347944B1 (ko) * 1999-06-03 2002-08-09 엘지전자주식회사 공기조화기용 증발기의 핀
US6397923B1 (en) * 1999-07-29 2002-06-04 Amsted Industries Incorporated Pipe core clean out system
KR20010026725A (ko) * 1999-09-08 2001-04-06 윤종용 열교환기의 리턴벤드 자동 삽입기
US6553601B1 (en) * 1999-09-21 2003-04-29 Michael R. Major Pipe and cleaning device
US6176006B1 (en) * 1999-09-21 2001-01-23 Burr Oak Tool And Gauge Company, Inc. Rod lock and unlock mechanism for a mechanical tube expander
JP2001194084A (ja) * 1999-12-15 2001-07-17 Lg Electronics Inc フィン・チューブ型の熱交換器
IT1318156B1 (it) * 2000-02-29 2003-07-23 Sanyo Electric C Ltd Scambiatore di calore
US6354126B1 (en) * 2000-04-25 2002-03-12 Burr Oak Tool And Gauge Company Tube straightener and drive therefor
US6512205B1 (en) * 2000-05-16 2003-01-28 Visteon Global Technologies, Inc. Gettering system for brazing heat exchangers in CAB furnace
KR100347894B1 (ko) * 2000-07-06 2002-08-09 엘지전자주식회사 세경관형 열교환기
US6681839B1 (en) * 2001-02-23 2004-01-27 Brent A. Balzer Heat exchanger exchange-tube cleaning lance positioning system
US7178534B2 (en) * 2001-03-16 2007-02-20 Aquadynamics, Inc. High pressure tube cleaning apparatus
CA2391077A1 (fr) * 2001-06-28 2002-12-28 York International Corporation Ailette a plaque en v sureleve pour echangeur thermique et methode de fabrication connexe
US6644079B2 (en) * 2001-12-21 2003-11-11 Burr Oak Tool And Gauge Company, Inc. Hairpin bender with leg length measurement and adjustment feature
DE10216787B4 (de) * 2002-04-15 2008-01-03 Illinois Tool Works Inc., Glenview Rohrendenbearbeitungsmaschine
US6936112B2 (en) * 2002-11-26 2005-08-30 Refined Technologies, Inc. Heat exchanger cleaning process
US6800025B2 (en) * 2002-12-04 2004-10-05 Deere & Co. Combine air system for cleanout
US20070151716A1 (en) * 2005-12-30 2007-07-05 Lg Electronics Inc. Heat exchanger and fin of the same
USD566824S1 (en) * 2006-03-20 2008-04-15 Ishikawajima-Harima Heavy Industries Co., Ltd. Plate fin for a heat exchanger
US7464670B2 (en) * 2006-07-26 2008-12-16 Framatome Anp, Inc. System for cleaning, inspection and tooling delivery in the secondary side of a steam generator

Also Published As

Publication number Publication date
US20090308585A1 (en) 2009-12-17
KR20110033198A (ko) 2011-03-30
CA2727671A1 (fr) 2009-12-17
EP2313728A1 (fr) 2011-04-27
WO2009152514A1 (fr) 2009-12-17
CN102216714A (zh) 2011-10-12

Similar Documents

Publication Publication Date Title
MX2010013776A (es) Método para fabricar un intercambiador de calor de tubo y aleta con diámetro reducido de tubo y aleta optimizada producida con el mismo.
EP2447659A3 (fr) Échangeur de chaleur et ailette correspondante
MX2010013774A (es) Método y sistema para fabricar un intercambiador de calor de tubo y aleta con diámetro reducido de tubo y un producto producido por los mismos.
WO2012018536A3 (fr) Echangeur de chaleur à ailettes et tubes en aluminium
WO2008105760A3 (fr) Évaporateur à tube plat multicanaux avec évacuation de condensat améliorée
EP2369285A3 (fr) Échangeur de chaleur
MY138112A (en) Stacking-type, multi-flow, heat exchangers and methods for manufacturing such heat exchangers
TR201909098T4 (tr) Isı eşanjörü.
EP1462753A3 (fr) Faisceau d'échangeur de chaleur
EP2236971A3 (fr) Ailette pour échangeur thermique et échangeur thermique utilisant l'ailette
WO2010008960A3 (fr) Echangeur de chaleur à micro-canaux à plusieurs circuits intégrés
MY144548A (en) Fin-and-tube heat exchanger and return bend tube thereof
WO2011005986A3 (fr) Echangeur thermique multicanaux doté d'un espacement d'ailette différent
EP1498683A3 (fr) Echangeur de chaleur multipasses à tubes parallèles
EP2447660A3 (fr) Échangeur de chaleur et son tuyau à microcanaux
MY197027A (en) Heat exchanger and refrigeration device using same
WO2012119660A3 (fr) Élément rapporté générateur de turbulences pour tubes plats d'échange de chaleur, tube plat pour un échangeur de chaleur pourvu d'un élément rapporté de ce type, échangeur de chaleur pourvu de tubes plats de ce type, et procédé et dispositif de fabrication d'un tube plat de ce type
EP1610080A3 (fr) Echangeurs de chaleur à empilage à passages multiples et leur procédé de fabrication
WO2010019401A3 (fr) Ailette d'échangeur de chaleur comprenant des persiennes
WO2009028901A3 (fr) Échangeur de chaleur et climatiseur équipé de celui-ci et procédé de fabrication
WO2009057623A1 (fr) Echangeur de chaleur
SE0800716L (sv) Ändplåt och värmeväxlare innefattande en sådan
ATE430298T1 (de) Wärmetauscher
JP2019526775A (ja) 熱交換器、熱交換器モジュールおよび空調システム
EP1857763A3 (fr) Boite de distribution pour échangeur thermique haute pression

Legal Events

Date Code Title Description
FA Abandonment or withdrawal