EP0189759B1 - Procédé et appareil de traitement thermique de pièces - Google Patents

Procédé et appareil de traitement thermique de pièces Download PDF

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Publication number
EP0189759B1
EP0189759B1 EP86100174A EP86100174A EP0189759B1 EP 0189759 B1 EP0189759 B1 EP 0189759B1 EP 86100174 A EP86100174 A EP 86100174A EP 86100174 A EP86100174 A EP 86100174A EP 0189759 B1 EP0189759 B1 EP 0189759B1
Authority
EP
European Patent Office
Prior art keywords
furnace
cooling
zone
cryogenic medium
workpieces
Prior art date
Legal status (The legal status 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 status listed.)
Expired
Application number
EP86100174A
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German (de)
English (en)
Other versions
EP0189759A1 (fr
Inventor
Georg Dipl.-Ing. Veranneman
Reinhard Dipl.-Ing. Strigl
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Linde GmbH
Original Assignee
Linde GmbH
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 Linde GmbH filed Critical Linde GmbH
Priority to AT86100174T priority Critical patent/ATE48443T1/de
Publication of EP0189759A1 publication Critical patent/EP0189759A1/fr
Application granted granted Critical
Publication of EP0189759B1 publication Critical patent/EP0189759B1/fr
Expired legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
    • C21D1/613—Gases; Liquefied or solidified normally gaseous material
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0062—Heat-treating apparatus with a cooling or quenching zone

Definitions

  • the invention relates to a method and an apparatus for the heat treatment of workpieces in a furnace with several chambers or zones, under which there is a cooling chamber or zone, in which the heat-treated workpieces are in direct heat exchange with a cooling fluid in the cooling chamber or zone harmless temperatures are cooled, the cooling fluid itself being cooled by indirect heat exchange with a liquid cryogas.
  • the goods When earthenware or ceramics are fired, their organic components are oxidized.
  • the goods are first heated from ambient temperature to temperatures between approx. 870 K and 1170 K, the carbon of the goods being oxidized by oxygen in the furnace.
  • the goods are then further heated in a burner zone.
  • the goods are then cooled in a cooling zone.
  • a heat treatment method with a vacuum chamber furnace in which metal is heated in a treatment chamber under vacuum and then a gaseous or liquid coolant is introduced into the treatment chamber for cooling in order to quench the metal and become one Cool temperature below - 80 ° C. It is also proposed to cool the gaseous coolant in indirect heat exchange outside the furnace with a liquid, cryogenic medium prior to introduction into the furnace, the vaporized cryogenic medium being discharged after being used as a cooling supplier.
  • the invention has for its object to provide a method of the type mentioned, in which on the one hand a cryogenic medium is used to cool workpieces and on the other hand the disadvantages of the direct injection of cryogenic liquefied cryogas into an oven system should be excluded and moreover - despite the Use of the cryogenic medium for cooling - a particularly good economy should exist.
  • a liquefied cryogenic medium is used, ie a medium that boils at low temperatures at ambient pressure, for example liquefied nitrogen. This cryogenic medium is brought into liquid form in indirect heat exchange with the fluid used to cool the heat-treated workpieces, the medium evaporating.
  • the indirect heat exchange between the liquefied cryogenic medium and the fluid advantageously takes place in the furnace area in which the workpieces are cooled by the fluid.
  • This furnace area can be, for example, the cooling section of a continuous furnace, the cooling pit of a pot furnace, the blast chiller of a vacuum or hood furnace or the oil bath of a hardening furnace.
  • the cooling fluid is either a gas or an oil.
  • the method according to the invention basically all of the heat required for the evaporation of the cryogenic medium is extracted from the fluid and thus from the workpieces to be cooled.
  • this fluid is cooled by indirect heat exchange with the cryogenic medium, which in turn then extracts the heat from the workpieces.
  • the method according to the invention prevents damage to furnace components due to hypothermia. Nevertheless, the fluid and therefore the workpieces are cooled intensely, since the cryogenic medium boils at a low temperature during indirect heat exchange and can absorb large amounts of heat.
  • the method according to the invention With the method according to the invention, it is thus possible in principle to extract all of the heat required for the evaporation of the liquefied cryogenic medium from the heat-treated workpieces. An additional air evaporator is not required. Because of the intensive cooling, the method according to the invention enables particularly rapid cooling. Contamination of the furnace atmosphere, which occurs when liquid cryogenic medium is directly sprayed in, does not take place in the method according to the invention.
  • the proposed method has e.g. B. in hardening furnaces the advantage that the commonly used water cooler for cooling the oil bath can be omitted. This measure eliminates the risk of explosion that occurs in the event of leaks due to water entering the hot oil.
  • a cryogenic medium is selected for cooling the fluid, which can be used in heat treatments after the evaporation in the heat exchange with the fluid.
  • the vaporized cryogenic medium is introduced into the glow chamber of a furnace, and a partial stream of the gas is also used in the cooling area. Since several furnaces are usually operated at the same time in a company for the heat treatment of workpieces, it has also proven to be expedient to lead the cryomedium evaporated during the indirect heat exchange into one of these furnaces.
  • the method according to the invention has particular advantages over conventional methods if an oven with locks is used and gas is to be supplied to it. If, in conventional processes, the amount of cryogenic medium intended for the locks had to be evaporated in the heat exchange with air, the process according to the invention also succeeded in using this amount first for intensive cooling of the workpieces.
  • liquid nitrogen or liquefied argon is used as the cryogenic medium.
  • gases are used, for example, in the heat treatment of metallic workpieces.
  • oxygen is advantageously used as the cryogenic medium.
  • Oxygen can be used, for example, in the heat treatment of workpieces made of clay or ceramic.
  • a device suitable for carrying out the method according to the invention is characterized in claim 4.
  • One or more heat exchangers with one or more channels are arranged within the cooling chamber or zone, the entrance of this channel or these channels being connected to a storage container for a cryogenic medium in liquid form and at the outlet of this channel or channels a line for forwarding the vaporized cryogenic medium into the same or an adjacent furnace. In this way, the entire liquefied cryogenic medium can be conducted through the heat exchanger (s).
  • two or more heat exchangers are arranged within the cooling chamber or zone in such a way that the annealing material is cooled uniformly from at least two sides.
  • distortion of heat-treated workpieces is avoided by better temperature distribution.
  • the outlet of the channel is connected to a line opening into the annealing zone of the furnace (or the channels).
  • the entire vaporized cryogenic medium can be directed into the glow chamber.
  • a gas injection device is connected to the channel outlet or to the channel outputs or to the channel outlet (the channel outputs) the line connecting the annealing zone is connected in the area of the cooling zone.
  • a heat exchanger is arranged within the oil bath in a variant of the device according to the invention.
  • the furnace shown schematically in FIGS. 1 and 2 is divided into three parts: the actual glow chamber 1 is connected to an inlet section 2 and subsequently a cooling zone 3.
  • the workpieces, not shown, pass through the furnace in the direction of the arrows 4.
  • a heat exchanger 5 with a channel for a liquid cryogenic medium is arranged in the region of the cooling zone.
  • a line 7 is connected to this channel and is connected to an insulated reservoir (not shown) for liquefied cryogenic medium, for example liquefied nitrogen.
  • a line 8 is connected which opens into the glow chamber 1.
  • An injection device 9, via which vaporized cryogenic medium can be introduced into the cooling zone, is only indicated schematically. This injection device 9 branches off from line 8 immediately after the exit of the heat exchanger channel.
  • the workpieces first pass through the inlet section 2, in which they are heated. In the annealing room they reach a maximum temperature, which has to be lowered again in the cooling section to a level at which the workpieces can no longer be oxidized.
  • the heat treatment including cooling of the workpieces, takes place in a protective gas atmosphere.
  • this is produced as follows: Liquid nitrogen is fed into line 7 from the storage container via a removal system (not shown). The liquid nitrogen flows through heat exchanger 5, which is exposed to the relatively high temperature prevailing in the furnace. The liquid nitrogen evaporates. The evaporated nitrogen leaves the heat exchanger 5 and flows via line 8 directly into the glow chamber 1.
  • part of the nitrogen can also be introduced directly into the cooling zone 3 via the injection device 9.
  • a protective gas atmosphere consisting of nitrogen prevails in the furnace and thus also within the cooling zone.
  • This nitrogen acts in the cooling zone 3 as a cooling fluid.
  • the workpieces are cooled in direct heat exchange with the nitrogen flowing in the cooling section.
  • the nitrogen is in turn cooled by indirect heat exchange with evaporating nitrogen via heat exchanger 5.
  • a further heat exchanger is indicated by dashed lines, which is also supplied with liquid nitrogen and is used to cool the workpieces.
  • the workpieces can be viewed from two sides, i.e. be cooled more evenly.
  • the heat exchangers 5 and 6 can, for example, be arranged such that heat exchanger 5 is above and heat exchanger 6 below the workpieces. This prevents warping of the workpieces due to uneven cooling. An even better temperature distribution can be achieved by arranging additional heat exchangers.
  • the furnace should have an entrance lock 12 and an exit lock 13.
  • a branch line 10 or a branch line 11 opens into the locks. Both branch lines 10, 11 are connected to the line 8 coming from the heat exchanger 5. Nitrogen for purging the lock chambers is removed in liquid form from the storage container, evaporated in heat exchanger 5 and passed into the respective locks 12, 13 via the branch lines 10, 11.
  • oil is used as the fluid.
  • Heat-treated, i.e. hardened workpieces are quenched in an oil bath 19.
  • a heat exchanger 5 is used to cool the oil bath and, as in the other exemplary embodiments, is connected via line 7 to a storage container for liquid nitrogen. When flowing through the heat exchanger 5, the nitrogen is evaporated and then passed via line 8 into the chamber furnace 18.
  • the method according to the invention allows particularly rapid cooling of heat-treated workpieces without the risk of damaging the furnace system.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatments In General, Especially Conveying And Cooling (AREA)
  • Furnace Details (AREA)
  • Tunnel Furnaces (AREA)
  • Heat Treatment Of Articles (AREA)

Claims (9)

1. Procédé de traitement thermique de pièces dans un four comportant plusieurs chambres ou zones parmi lesquelles se trouve une chambre ou zone de refroidissement, dans lequel, les pièces traitées thermiquement sont refroidies à des températures non nuisibles pour elles dans la chambre ou zone de refroidissement en échange de chaleur direct avec un fluide réfrigérant, le fluide réfrigérant étant à son tour refroidi par échange de chaleur indirect avec un gaz cryogénique à l'état liquide, caractérisé en ce que l'échange de chaleur indirect entre le fluide réfrigérant et le fluide cryogénique est réalisé dans la chambre ou zone de refroidissement ellemême et en ce que le fluide cryogénique ainsi évaporé est introduit dans le même four de traitement thermique ou dans un four voisin, pour servir de gaz de protection et/ou gaz de balayage et/ou de fluide réfrigérant.
2. Procédé selon la revendication 1, caractérisé en ce qu'on utilise comme fluide cryogénique liquide de l'azote liquide ou de l'argon liquide.
3. Procédé selon la revendication 1, caractérisé en ce qu'on utilise comme fluide cryogénique liquide de l'oxygène liquide.
4. Dispositif pour la mise en oeuvre du procédé selon l'une des revendications 1 à 3, constitué d'un four de traitement thermique comportant plusieurs chambres ou zones, parmi lesquelles se trouve une chambre ou zone de refroidissement, caractérisé en ce qu'un ou plusieurs échangeurs de chaleur à un ou plusieurs canaux sont disposés à l'intérieur de la chambre ou zone de refroidissement (3), l'entrée de ce canal ou de ces canaux étant reliée à un réservoir de fluide cryogénique liquide, et en ce qu'une conduite (8) pour la poursuite du transport du fluide cryogénique évaporé dans le même four ou dans un four voisin se raccorde à la sortie du canal ou des canaux.
5. Dispositif selon la revendication 4, caractérisé en ce qu'à l'intérieur de la chambre ou zone de refroidissement (3) sont disposés deux ou plusieurs échangeurs de chaleur (5, 6) de manière à ce que les articles chauffés au rouge soient refroidis de façon régulière d'au moins deux côtés.
6. Dispositif selon l'une des revendications 4 ou 5 caractérisé en ce que la sortie du canal ou des canaux du ou des échangeurs de chaleur est reliée à une conduite (8) débouchant dans la chambre rayonnante.
7. Dispositif selon l'une des revendications 4 à 6, caractérisé en ce que, dans la région de la zone de refroidissement, un dispositif de pulvérisation de gaz (9) est relié à au moins une sortie de canal ou à ladite conduite (8).
8. Dispositif selon l'une des revendications 4 à 7 caractérisé en ce que la conduite (8) reliée à la sortie du canal ou aux sorties de canaux des échangeurs de chaleur (5, 6) débouche par une conduite de branchement (10, 11) dans des écluses (12, 13) disposées à l'entrée et à la sortie du four.
9. Dispositif selon l'une des revendications 4 à 8 comportant un bain d'huile comme dispositif de refroidissement, caractérisé en ce que l'échangeur de chaleur pour l'évaporation du fluide cryogénique liquide est disposé dans le bain d'huile.
EP86100174A 1985-01-17 1986-01-08 Procédé et appareil de traitement thermique de pièces Expired EP0189759B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86100174T ATE48443T1 (de) 1985-01-17 1986-01-08 Verfahren und vorrichtung zur waermebehandlung von werkstuecken.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3501463 1985-01-17
DE19853501463 DE3501463A1 (de) 1985-01-17 1985-01-17 Verfahren und vorrichtung zur waermebehandlung von werkstuecken

Publications (2)

Publication Number Publication Date
EP0189759A1 EP0189759A1 (fr) 1986-08-06
EP0189759B1 true EP0189759B1 (fr) 1989-12-06

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EP86100174A Expired EP0189759B1 (fr) 1985-01-17 1986-01-08 Procédé et appareil de traitement thermique de pièces

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EP (1) EP0189759B1 (fr)
AT (1) ATE48443T1 (fr)
DE (2) DE3501463A1 (fr)
ZA (1) ZA86322B (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2227570B1 (fr) 2007-11-29 2017-01-25 Benteler Automobiltechnik GmbH Procédé de fabrication d'une pièce façonnée comprenant au moins deux zones structurelles à ductilité différente

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4422588C2 (de) * 1994-06-28 1999-09-23 Ald Vacuum Techn Gmbh Verfahren zum Abschrecken von Werkstücken durch Gase und Wärmebehandlungsanlage zur Durchführung des Verfahrens
DE19820083A1 (de) * 1998-05-06 1999-11-11 Ald Vacuum Techn Gmbh Verfahren zum Abschrecken von Werkstücken und Wärmebehandlungsanlage zur Durchführung des Verfahrens
EP3282023A1 (fr) 2016-08-11 2018-02-14 Linde Aktiengesellschaft Dispositif de refroidissement et procede de refroidissement des elements en continu

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1154134B (de) * 1960-08-04 1963-09-12 Iaofuia Ofenbau Union Ges Mit Vorrichtung zum Kuehlen erwaermten, insbesondere metallischen Gutes innerhalb eines Industrieofens
DE1227930B (de) * 1965-06-30 1966-11-03 Mannesmann Ag Widerstandsbeheizter Ofen zum Gluehen von metallischen Werkstuecken und Verfahren zum Betrieb desselben
GB1452062A (en) * 1972-10-10 1976-10-06 Boc International Ltd Metal treatment
GB2082634B (en) * 1980-08-13 1984-04-18 Boc Ltd Heat treatment method
DE3234863C2 (de) * 1982-09-21 1986-04-10 Messer Griesheim Gmbh, 6000 Frankfurt Verfahren und Vorrichtung zum Blankglühen von metallischen Werkstücken mit Stickstoff als Schutzgas

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2227570B1 (fr) 2007-11-29 2017-01-25 Benteler Automobiltechnik GmbH Procédé de fabrication d'une pièce façonnée comprenant au moins deux zones structurelles à ductilité différente

Also Published As

Publication number Publication date
DE3667300D1 (de) 1990-01-11
EP0189759A1 (fr) 1986-08-06
ZA86322B (en) 1986-08-27
DE3501463A1 (de) 1986-07-17
ATE48443T1 (de) 1989-12-15

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