WO1993021350A1 - Procede de fabrication d'un gaz protecteur ou reactionnel pour le traitement thermique de metaux - Google Patents
Procede de fabrication d'un gaz protecteur ou reactionnel pour le traitement thermique de metaux Download PDFInfo
- Publication number
- WO1993021350A1 WO1993021350A1 PCT/EP1993/000749 EP9300749W WO9321350A1 WO 1993021350 A1 WO1993021350 A1 WO 1993021350A1 EP 9300749 W EP9300749 W EP 9300749W WO 9321350 A1 WO9321350 A1 WO 9321350A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- oxygen
- nitrogen
- gas
- reactor
- vol
- Prior art date
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Classifications
-
- 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
- C21D1/76—Adjusting the composition of the atmosphere
- C21D1/763—Adjusting the composition of the atmosphere using a catalyst
Definitions
- the invention relates to a method for producing a protective or reaction gas for the heat treatment of metals.
- Heat treatments of metallic work pieces are carried out in the known heat treatment furnaces under a protective or reaction gas atmosphere.
- the gas atmosphere mainly consists of the inert gas component nitrogen with different proportions of hydrogen and carbon monoxide.
- Hydrogen is used to remove contaminants that have entered the furnace chamber, e.g. Binding oxygen to hydrogen, while CO is used to adjust the carbon level in the protective gas atmosphere, e.g.
- the inert gas component nitrogen is obtained and liquefied in very pure form in low-temperature air separation plants with an oxygen content ⁇ 10 vpm.
- the liquid nitrogen is stored in vacuum-insulated tanks at the consumer.
- the reactive gas components H 2 and CO are either also stored in the pressure vessel or generated on site by splitting methanol or by endothermic conversion of hydrocarbons with air. Mixing with cryogenic nitrogen creates a very pure protective gas atmosphere, ie low dew point and low CO 2 concentration with the desired composition.
- nitrogen can now also be obtained from the air by means of adsorbent or permeative processes. This nitrogen is produced by the pressure swing adsorption (PSA) or membrane process.
- PSA pressure swing adsorption
- Oxygen contents in the protective gas ⁇ 10 vpm are necessary for bright annealing of all metals.
- Non-cryogenically generated nitrogen must therefore be cleaned up.
- the oxygen reaction with hydrogen using a palladium or copper oxide catalyst is state of the art.
- Another option is to add natural gas or propane to the non-cryogenically generated nitrogen and introduce this mixture into the hot part of the heat treatment system. This leads to the formation of
- the C level is reduced not only by the oxygen content in the contaminated nitrogen of approx. 0.1 to 5 vol.% oxygen, but also by the water vapor that inevitably arises. This leads to a low carburization depth, which has to be compensated for by a longer carburization time.
- the existing oxygen post-purification processes or conversion processes are therefore either too complex or generate an inert gas which is unsuitable for most heat treatment processes.
- the invention is therefore based on the object of converting the oxygen in the contaminated nitrogen in such a way that a protective gas suitable for the heat treatment is produced.
- the invention is based on the surprising finding that the oxygen content required for the endothermic reaction can be reduced from approximately 15% by volume to 0.1% by volume.
- the necessary oxygen actuator varies depending on the desired shielding gas quality between 0.1 ⁇ ⁇ 0.3.
- an oxygen actuator of ⁇ ⁇ 0.25 residual methane is present due to a lack of oxygen.
- the methane content that may be required for the heat treatment can also be set by selecting the oxygen actuator. This lack of oxygen can also occur in a PPE system due to the process. Because when the throughput is reduced, the oxygen content is reduced at the same time. It is therefore not necessary to regulate the amount of methane.
- the oxygen is completely converted into the protective gas components desired for the heat treatment using the method described above.
- the composition of the protective gas is a function of the process temperature T, the oxygen concentration X in nitrogen and the oxygen actuator ⁇ .
- PSA-N 2 systems operate at residual oxygen levels in nitrogen of approx. 2 to 5 vol.% In an economical optimum.
- the shielding gas composition that arises corresponds to a high quality monogas, e.g. for the carbon neutral annealing of unalloyed and low-alloyed metals.
- the dew point increases to + 18 ° C and the CO 2 concentrations to 1.0% by volume.
- a protective gas is ideally suited for the heat treatment of non-ferrous metals.
- Higher CO and H 2 concentrations are achieved by increasing the oxygen concentration in nitrogen.
- the higher oxygen concentration in the N 2 can be adjusted depending on the process by increasing the throughput of the PSA or membrane system.
- the higher oxygen concentration upstream of the reactor can also be achieved by adding air to non-cryogenic nitrogen.
- FIG. 1 shows a heated reactor filled with the catalyst, which is arranged outside the heat treatment furnace.
- Fig. 2 is a filled with the catalyst heated reactor which is integrated in the heat treatment furnace.
- Reactor integrated in the heat treatment furnace and heated by it.
- the air becomes a pressure swing adsorption or
- the residual oxygen content in the nitrogen which is due to incomplete separation, is 0.1 to 5% by volume, depending on the throughput.
- Pressure swing adsorption systems 10 operate at residual oxygen levels in nitrogen of approximately 2 to 5% by volume in the economic optimum.
- the nitrogen contaminated with residual oxygen is fed via a gas supply 14 to a heat exchanger 11 and to the heated reactor 12 filled with the catalyst.
- the heat exchanger 11 is arranged in a suitable location in the heat treatment furnace 13 and serves to preheat the contaminated nitrogen in order to increase the throughput of the reactor 12.
- the reactor 12 is installed next to the heat treatment furnace 13 in FIG. 1.
- the reactor bed consisting of the catalyst with the active components nickel, platinum, palladium or rhodium is heated indirectly electrically (Q closed) or by a burner to the desired process temperature of 600 to 1,000 ° C. in a controlled manner.
- the hydrocarbon available for the endothermic conversion such as natural gas (methane) or propane, butane, town gas or heating oil, is mixed with the oxygen-contaminated nitrogen in the ratio necessary for the reaction before entering the reactor 12 and the gas mixture to the reactor 12 supplied.
- the endothermic catalytic conversion of the oxygen maintained by supplying energy by means of hydrocarbons, for example using methane theoretically takes place in the reactor 12 with the oxygen actuator of 0.1 ⁇ A. ⁇ 0.3 required for this reaction as follows:
- the maximum oxygen content in the protective gas is ⁇ 10 vpm.
- the dew point can be set between - 32 ⁇ TP ° C ⁇ + 18 and the carbon dioxide concentration (CO 2 ) between 0.001 ⁇ X CO 2 vol.% ⁇ 1.2, depending on the temperature and the oxygen actuator.
- CO 2 carbon dioxide concentration
- This lack of oxygen can also be adjusted in a pressure swing adsorption system by reducing the throughput, so that methane control is not absolutely necessary.
- Lower H 2 and CO concentrations are achieved through the lower oxygen contents in nitrogen with constant oxygen actuator ⁇ .
- Lower H 2 and CO concentrations in the protective gas are advantageously required for bright annealing.
- Higher H 2 and CO concentrations, as are required for carbonation-neutral annealing, are made possible by higher oxygen contents in nitrogen with a constant oxygen actuator and are achieved by additional admixture of air in the contaminated nitrogen.
- the reactor 12 filled with the catalyst is integrated in the heat treatment furnace 13.
- the reactor 12 is heated by a burner in a controlled manner to the desired process temperature of 600 to 1,000 ° C.
- FIG. 3 shows an embodiment in which one or more reactors 12, 12.1, 12.2, 12.3 are integrated in the heat treatment furnace 13. The heating is carried out exclusively by the heat treatment furnace 13 (furnace heating), the maximum process temperature in the reactor 12 'being predetermined by the furnace temperature.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Catalysts (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP93908854A EP0636189A1 (fr) | 1992-04-13 | 1993-03-27 | Procede de fabrication d'un gaz protecteur ou reactionnel pour le traitement thermique de metaux |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEP4212307.0 | 1992-04-13 | ||
DE19924212307 DE4212307C2 (de) | 1992-04-13 | 1992-04-13 | Verfahren zur Herstellung eines Schutz- oder Reaktionsgases für die Wärmebehandlung von Metallen |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1993021350A1 true WO1993021350A1 (fr) | 1993-10-28 |
Family
ID=6456692
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP1993/000749 WO1993021350A1 (fr) | 1992-04-13 | 1993-03-27 | Procede de fabrication d'un gaz protecteur ou reactionnel pour le traitement thermique de metaux |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0636189A1 (fr) |
DE (1) | DE4212307C2 (fr) |
WO (1) | WO1993021350A1 (fr) |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5441581A (en) * | 1994-06-06 | 1995-08-15 | Praxair Technology, Inc. | Process and apparatus for producing heat treatment atmospheres |
EP0778354A1 (fr) * | 1995-12-07 | 1997-06-11 | Linde Aktiengesellschaft | Procédé d'alimentation de gaz protecteur dans un four de traitement thermique et installation de traitement thermique |
EP0794263A1 (fr) * | 1996-03-07 | 1997-09-10 | Linde Aktiengesellschaft | Procédé pour la production d'une atmosphère protective pour four de traitement thermique et installation pour traitement thermique |
EP0802263A1 (fr) * | 1996-04-19 | 1997-10-22 | The Boc Group, Inc. | Formation d'atmosphères pour traitement thermique |
FR2747593A1 (fr) * | 1996-04-23 | 1997-10-24 | Air Liquide | Procede d'elaboration d'une atmosphere de traitement thermique et methode de regulation d'un tel procede |
FR2747594A1 (fr) * | 1996-04-23 | 1997-10-24 | Air Liquide | Procede et installation d'elaboration d'une atmosphere de traitement thermique |
WO1998023535A1 (fr) * | 1996-11-28 | 1998-06-04 | Messer Griesheim Gmbh | Procede et dispositif pour preparer un melange gazeux contenant du n2, du co et de l'h¿2? |
EP0866141A1 (fr) * | 1997-03-18 | 1998-09-23 | Praxair Technology, Inc. | Procédé pour la production d'atmosphères protectrices à bas point de rosée exempt d'oxygène, pour usage dans les traitements thermiques |
EP0931842A1 (fr) * | 1998-01-22 | 1999-07-28 | Praxair Technology, Inc. | Dispositif pour la production d'atmosphères pour traitement thermique |
US6007763A (en) * | 1996-04-23 | 1999-12-28 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Process and installation for preparing a heat treatment atmosphere |
WO2002033131A1 (fr) * | 2000-10-16 | 2002-04-25 | Linde Ag | Procede et dispositif pour produire un gaz de traitement contenant du co et de l'h2, pour traitement thermique |
US6531105B1 (en) | 1996-02-29 | 2003-03-11 | L'air Liquide-Societe Anonyme A'directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude | Process and apparatus for removing carbon monoxide from a gas stream |
US6884368B2 (en) | 2000-04-13 | 2005-04-26 | L'Air Liquide Sociétéanonyme a Directoire et Conseil de Surveillance pour l'Etude et l'Exploitation des Procedes Georges Claude | Process for the production of a mixture comprising hydrogen and CO |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19610722B4 (de) * | 1996-03-19 | 2006-07-13 | Air Liquide Deutschland Gmbh | Verfahren zum Herstellen von Schutz- oder Reaktionsgasen für die Wärmebehandlung von Metallen |
DE19651878C2 (de) * | 1996-12-13 | 2002-01-17 | Messer Griesheim Gmbh | Verfahren zum Herstellen eines Schutz- oder Reaktionsgases für die Wärmebehandlung von Metallen |
US6881242B2 (en) | 2003-01-13 | 2005-04-19 | Ati Properties, Inc. | Hydrogen reclamation apparatus and method |
US20070107818A1 (en) * | 2005-11-16 | 2007-05-17 | Bowe Donald J | Deoxygenation of furnaces with hydrogen-containing atmoshperes |
FR2915694B1 (fr) * | 2007-05-03 | 2009-06-05 | Air Liquide | Procede ameliore de brasage d'aluminium a pression atmospherique |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2822048A1 (de) * | 1978-05-20 | 1979-11-22 | Loi Ind Ofenanlagen | Anlage zur erzeugung von behandlungsgas |
EP0406047A1 (fr) * | 1989-06-30 | 1991-01-02 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Procédé de traitement thermique de metaux |
EP0482992A1 (fr) * | 1990-10-26 | 1992-04-29 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Procédé d'élaboration d'une atmosphère de traitement thermique |
-
1992
- 1992-04-13 DE DE19924212307 patent/DE4212307C2/de not_active Expired - Fee Related
-
1993
- 1993-03-27 EP EP93908854A patent/EP0636189A1/fr not_active Withdrawn
- 1993-03-27 WO PCT/EP1993/000749 patent/WO1993021350A1/fr not_active Application Discontinuation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2822048A1 (de) * | 1978-05-20 | 1979-11-22 | Loi Ind Ofenanlagen | Anlage zur erzeugung von behandlungsgas |
EP0406047A1 (fr) * | 1989-06-30 | 1991-01-02 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Procédé de traitement thermique de metaux |
EP0482992A1 (fr) * | 1990-10-26 | 1992-04-29 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Procédé d'élaboration d'une atmosphère de traitement thermique |
Non-Patent Citations (2)
Title |
---|
METAL SCIENCE AND HEAT TREATMENT Bd. 30, Nr. 5/6, 1988, NEW YORK (US) Seiten 408 - 414 N.A. TITOV 'Carbon potential and composition of a neutral controlled atmosphere produced from methane and a nitrogen -oxygen mixture.' * |
METALS SCIENCE AND HEAT TREATMENT Bd. 20, Nr. 5/6, Juni 1978, NEW YORK (US) Seiten 377 - 381 V.B. SKALAKALSKII ET AL. 'Commercial nitrogen - the basis for a universal controlled atmosphere.' * |
Cited By (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5968457A (en) * | 1994-06-06 | 1999-10-19 | Praxair Technology, Inc. | Apparatus for producing heat treatment atmospheres |
EP0686701A1 (fr) | 1994-06-06 | 1995-12-13 | Praxair Technology, Inc. | Procédé et dispositif pour la production d'atmosphères pour traitement thermique |
US5441581A (en) * | 1994-06-06 | 1995-08-15 | Praxair Technology, Inc. | Process and apparatus for producing heat treatment atmospheres |
CN1047799C (zh) * | 1994-06-06 | 1999-12-29 | 普拉塞尔技术有限公司 | 一种吸热式生成一氧化碳和氢气氛的方法 |
EP0778354A1 (fr) * | 1995-12-07 | 1997-06-11 | Linde Aktiengesellschaft | Procédé d'alimentation de gaz protecteur dans un four de traitement thermique et installation de traitement thermique |
US6531105B1 (en) | 1996-02-29 | 2003-03-11 | L'air Liquide-Societe Anonyme A'directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude | Process and apparatus for removing carbon monoxide from a gas stream |
EP0794263A1 (fr) * | 1996-03-07 | 1997-09-10 | Linde Aktiengesellschaft | Procédé pour la production d'une atmosphère protective pour four de traitement thermique et installation pour traitement thermique |
EP0802263A1 (fr) * | 1996-04-19 | 1997-10-22 | The Boc Group, Inc. | Formation d'atmosphères pour traitement thermique |
FR2747593A1 (fr) * | 1996-04-23 | 1997-10-24 | Air Liquide | Procede d'elaboration d'une atmosphere de traitement thermique et methode de regulation d'un tel procede |
US5846340A (en) * | 1996-04-23 | 1998-12-08 | L'air Liquide, Societe Anonyme Pour Procedex Georges Claude | Process for preparing a heat treatment atmosphere and method for regulating said process |
EP0803580A1 (fr) * | 1996-04-23 | 1997-10-29 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Procédé et installation d'élaboration d'une atmosphère de traitement thermique |
US6007763A (en) * | 1996-04-23 | 1999-12-28 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Process and installation for preparing a heat treatment atmosphere |
EP0803581A1 (fr) * | 1996-04-23 | 1997-10-29 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Procédé d'élaboration d'une atmosphère de traitement thermique et méthode de régulation d'un tel procédé |
FR2747594A1 (fr) * | 1996-04-23 | 1997-10-24 | Air Liquide | Procede et installation d'elaboration d'une atmosphere de traitement thermique |
WO1998023535A1 (fr) * | 1996-11-28 | 1998-06-04 | Messer Griesheim Gmbh | Procede et dispositif pour preparer un melange gazeux contenant du n2, du co et de l'h¿2? |
EP0866141A1 (fr) * | 1997-03-18 | 1998-09-23 | Praxair Technology, Inc. | Procédé pour la production d'atmosphères protectrices à bas point de rosée exempt d'oxygène, pour usage dans les traitements thermiques |
US6051162A (en) * | 1997-03-18 | 2000-04-18 | Praxair Technology, Inc. | Process for the generation of a low dew-point, oxygen-free protective atmosphere for the performance of thermal treatments |
CN1117696C (zh) * | 1997-03-18 | 2003-08-13 | 普莱克斯技术有限公司 | 产生用于进行热处理的低露点无氧保护气氛的方法 |
EP0931842A1 (fr) * | 1998-01-22 | 1999-07-28 | Praxair Technology, Inc. | Dispositif pour la production d'atmosphères pour traitement thermique |
US6884368B2 (en) | 2000-04-13 | 2005-04-26 | L'Air Liquide Sociétéanonyme a Directoire et Conseil de Surveillance pour l'Etude et l'Exploitation des Procedes Georges Claude | Process for the production of a mixture comprising hydrogen and CO |
WO2002033131A1 (fr) * | 2000-10-16 | 2002-04-25 | Linde Ag | Procede et dispositif pour produire un gaz de traitement contenant du co et de l'h2, pour traitement thermique |
Also Published As
Publication number | Publication date |
---|---|
DE4212307A1 (de) | 1993-10-14 |
EP0636189A1 (fr) | 1995-02-01 |
DE4212307C2 (de) | 1994-07-28 |
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