US3575398A - Apparatus for minimizing atmosphere upset in a furnace for heat treating articles - Google Patents

Apparatus for minimizing atmosphere upset in a furnace for heat treating articles Download PDF

Info

Publication number
US3575398A
US3575398A US775459A US3575398DA US3575398A US 3575398 A US3575398 A US 3575398A US 775459 A US775459 A US 775459A US 3575398D A US3575398D A US 3575398DA US 3575398 A US3575398 A US 3575398A
Authority
US
United States
Prior art keywords
atmosphere
opening
vestibule
furnace
chamber
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 - Lifetime
Application number
US775459A
Other languages
English (en)
Inventor
Joseph A Lincoln
Orville E Cullen
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.)
Grimes Aerospace Co
Original Assignee
Midland Ross Corp
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 Midland Ross Corp filed Critical Midland Ross Corp
Application granted granted Critical
Publication of US3575398A publication Critical patent/US3575398A/en
Anticipated expiration legal-status Critical
Assigned to FL AEROSPACE CORP. reassignment FL AEROSPACE CORP. CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). 9/11/86 AND 1/05/88, OHIO Assignors: MIDLAND - ROSS CORPORATION, CHANGED TO, MIDLAND-ROSS CORPORATION MERGING INTO, MRC MERGER CORP., CHANGED NAME TO
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D99/00—Subject matter not provided for in other groups of this subclass
    • F27D99/0073—Seals
    • F27D99/0075—Gas curtain seals
    • 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

Definitions

  • This invention relates to the prevention of atmosphere upset and to the rapid recovery from such an upset which is caused by contaminating gases entering through the workpiece discharge opening of a controlled atmosphere furnace or hot chamber.
  • the discharge opening is protected by a flame screen directed across its outer face and by a jet stream curtain of gases directed outwardly across the opening. Atmosphere is constantly supplied to the furnace and, additionally, a restoring gas is supplied intermittently to the furnace.
  • a dynamic curtain or barrier formed by a high velocity wind stream of gases issuing from a slotted or apertured pipe located along at least one side of the discharge opening.
  • This wind or jet stream curtain of gases is turned on in response to the opening of the discharge door and is directed across the entire discharge opening and at least slightly outwardly with respect to the interior of the furnace or hot vestibule.
  • the curtain is directed outwardly at an angle which is sufficient to cause eduction of some atmosphere from the furnace and to prevent back eddying of barrier curtain gases into the interior of the furnace.
  • the jet stream curtain may impinge upon or brush over an opposite side of the discharge opening.
  • atmosphere is supplied continuously to the furnace or hot vestibule during operation.
  • a supplementary gas such as a restoring or enriching gas
  • a supplementary gas may be intermittently injected into the input atmosphere.
  • This gas tends to reduce the duration of any upset and if its injection is timed to begin at or near the commencement of an upset, it tends also to reduce the amount of the upset.
  • the dynamic barrier comprises a flame screen which is directed across the face of the discharge opening so as to ignite the combustibles that flow out of the opening.
  • the flame screen may be supplanted with a nonflammablc jet stream curtain in furnaces which do not contain readily combustible atmospheres.
  • FIG. I is a plan view in section showing an end portion of a controlled atmosphere furnace with a separate discharge vestibule embodying the jet stream barrier and supplementary gas surge means of this invention.
  • FIG. 2 is an enlarged clevational view of the discharge vestibule of FIG. I.
  • FIG. 3 is an elevational view of a rotary hearth furnace embodying the principles of this invention.
  • FIG. 4 is an enlarged front view of the discharge door assembly and door opening shown in FIGS. 1, 2, and 3 with parts broken away.
  • FIG. 5 is a fragmentary side elevational view in section of the discharge door assembly shown in FIGS. l4, with the discharge door in an open position and with the dynamic barrier in operation.
  • FIG. 6 is a fragmentary side elevational view in section of a discharge door assembly similar to that shown in FIGS. 1-4, but with the flame screen burner pipe directed upwardly and attached to the top of the vertically reciprocablc door.
  • FIG. 7 is a fragmentary side clevational view in section of a discharge door assembly similar to that shown in FIGS. 1-4, but with two flame screens directed across the discharge door opening from opposite sides.
  • FIG. 8 is a fragmentary side elevational view in section of a discharge door assembly similar to that shown in FIGS. I4, but with an additional jet stream curtain.
  • FIG. 9 is a fragmentary side elevational view in section of a discharge door assembly similar to that shown in FIGS. l4, but with a jet stream curtain directed upwardly and outwardly from the top of the open discharge door.
  • FIG. 10 is a fragmentary side elevational view in section of a discharge door assembly similar to that shown in FIGS. l-4,
  • FIGS. 1 and 3 show two types of heat treating atmosphere furnaces I0 and 20, respectively, embodying principles of this invention.
  • the furnace 10 is a tunnel type furnace having a hot vestibule 22 or holding chamber attached alongside the heat treating section 24 of the furnace adjacent its discharge end.
  • Radiant heating. means 25 and 27, such as fuel fired radiant tubes, are provided within the vestibule 22to maintain the temperature within the vestibule at the desired level, for
  • the relative internal size of the heat treating section 24 as compared to the vestibule 22 may be well in excess of 2 to l. ln one specific example of a continuous carburizing furnace, the volume of the vestibule was approximately 64 cubic feet and the volume of the heating section was about 30 times that of the vestibule. Vestibules or holding chambers having a volume of about 75 cubic feet or less are sufficiently small to permit a rapid recovery from an atmosphere upset.
  • the furnace 20 in FIG. 3 is a rotary hearth furnace having a heattreating chamber 30 with a volume less than 70 cubic feet which is heated by fuel fired radiant tubes 32. Although a separate hot vestibule or holding chamber could be provided, it is generally not needed because the chamber 30 is sufficiently small to permit rapid recovery from an atmosphere upset. On larger rotary hearth furnaces it is desirable to provide a discharge vestibule or hot chamber similar to that shown in FIG. 1.
  • a door assembly 40 comprises a liner 42 fitted inside of the rectangular discharge door opening extending through a vertical wall of the furnace or hot vestibule.
  • the height of the opening is kept to a minimum, for example about l0" or less, to reduce the stack effect created by hot atmosphere gases seeking to escape through the opening into the colder ambient air.
  • the width of the opening is less critical and may be up to about four times the height without causing a severely detrimental effect.
  • the rectangular liner 42 may be a casting made of heat resistant metal and have a relatively wide bottom side or threshold 44 which extends inwardly beyond the vestibule wall.
  • a watercooled peripheral door frame 46 may be attached adjacent the outer edge of the liner 42.
  • the discharge opening is sealed by means of a vertically reciprocable sliding door 28 actuated by a hydraulic cylinder and piston means 48.
  • the dynamic barrier associated with the discharge door opening comprises at least two jet stream curtains 50 and 52 directed across the opening at an angle towards each other. This angle and the location of the jet pipes from which these jet stream curtains emanate are such that the curtains intersect each other in close proximity to the face of the door opening and cause at least a slight outflow of atmosphere from the furnace or vestibule 22.
  • the jet stream curtain 50 may be a high velocity curtain of flames which is directed substantially vertically across the face of the opening by means of a slotted or apertured burner pipe 54.
  • the burner pipe 54 may be located along top edge of the discharge opening or along top edge of the door 28.
  • a burner pipe 54 may he provided at both locations with theirjet streams directed towards each other at an angle at least slightly outward (see FIG. 7).
  • a nonflammable jet stream curtain may be substituted for one or both of the flame curtains 50 when a nonflammable atmosphere is used in the furnace.
  • the other jet stream curtain 52 may be a high velocity curtain of gases ofa type which is not adversely contaminating to the furnace atmosphere, such as an inert or nonoxidizing gas.
  • the jet stream curtain emanates from an apertured or slotted pressure pipe 56 rotatably affixed along the top inside edge of the discharge opening. It is directed outwardly and downwardly towards the front edge of the threshold 44 so as to impinge upon or brush over the outer surface portion of the threshold. An angle of incidence of about was found to produce good results when used in combination with the vertically directed flame curtain, as shown in FIGS. 2, 3, 4, 5, and 7.
  • the jet stream curtain 52 was also found to be effectual, in the combination, when it emanated from a pressure pipe 57 or 58 at the lower inner edge of the threshold 44 or along the top of the door 28, respectively, and was directed upwardly and outwardly (see FIGS. 9 and 10).
  • a PA inch pipe 56, 57, or 58 with a row of 37 020 MTD size holes spaced 1 inch apart provided a satisfactory jet stream curtain 52 when supplied with gas at the rate of 600 SCFH under a pressure equivalent to [3 inch of water column.
  • the jet stream curtains 50 and 52 may be turned on simultaneously in response to the opening of the discharge door 28 and may be turned off simultaneously by its closing switch 59 located adjacent the top of the furnace door 28 and associated with a solenoid valve means 61 (see FIG. 4) to control the flow of gases into jet curtain pipes 54 and 56.
  • the switch lever falls to its downwardly position as shown, closing the switch and energizing the valve means open, thus allowing gas to flow into pipes 54 and 56.
  • the door When the door is closed it forces the switch lever into its upward or open position, thereby deenergizing the valve means and shutting off the flow of gas to pipes 54 and 56.
  • atmosphere or an atmosphere carrier gas is injected into the furnace 20 or hot vestibule 22 through a pipe 60 at a rate which is sufficient to maintain a slightly positive pressure therewithin. This rate is normally about 5 to 10 times the volume of the furnace or vestibule per hour.
  • An intermittent supply or surge of restoring gas is injected by means of pipe 62 into the atmosphere in response to or in anticipation of an atmosphere upset. The duration and timing of this gas surge may be governed by a timer 64 and the movement of the discharge door 28 (see FIG. 2) so that the surge of restoring or enriching gas begins when the door is moved to its open position thereby causing the door limit switch lever, incorporated with the timer, to be depressed to its closed position, as shown in dashed lines in FIG. 2.
  • the timer 64 When the switch lever is in this position, the timer 64 is actuated and the solenoid valve 65 on the restoring gas supply pipe 62 is energized open.
  • the timer is preset to hold valve 65 open for a set period of time sufficient to insure recovery from any atmosphere upset that may occur within the furnace or furnace vestibule.
  • the restoring or enriching gas surge is controlled by an atmosphere sensing device 66 which operates a solenoid valve 67 in a restoring gas supply line 68 communicating with the atmosphere supply line 60.
  • a relay incorporated with the sensing device 66 energizes the solenoid valve 67 open and maintains it in this position until the sensing device senses that the atmosphere has been restored.
  • the gas flow may be controlled so as to begin prior to or at the beginning of an atmosphere upset and continue until recovery of the desired atmosphere is attained.
  • the flow rate of the restoring gas and the total amount required are dependent upon processing conditions, particularly the size of the furnace or vestibule and the extent of the atmosphere upset. Normally, this rate would be less than about one volume of the furnace or vestibule per hour.
  • methane was supplied at the rate of 45 SCFH from the time the discharge door was opened until 2 minutes after it was closed.
  • the restoring gas surge was used in combination with the dynamic barrier and a continuous supply of atmosphere which was supplied at the rate of 500 SCFH. Using this combination, the carbon content of the workpieces in the holding chamber was maintained even though the aforementioned typical cycle was repeated continuously.
  • a controlled atmosphere furnace comprising: walls defining a heat processing chamber having a discharge opening associated therewith, a jet stream curtain barrier means directed across said opening for producing an unbalanced outward component of force in said opening, said barrier including two jet stream curtains directed at an angle towards each other with at least one of said curtains being directed outwardly with respect to said opening, means for continuously supplying atmosphere to said chamber means for automatically supplying a surge of enriching gas to said chamber in response to a predetermined event and when said chamber is open to ambient atmosphere, said surge supply means having an inlet which is separate from said jet stream curtains.
  • one of said jet stream curtains is a curtain of nonoxidizing gas.
  • a controlled atmosphere furnace comprising: a heat processing chamber. a hot vestibule adjacent said processing chamber, an entry door means between said chamber and said hot vestibule for the admission of heat treated workpieces into said hot vestibule from said processing chamber, a discharge opening in said vestibule having a door for the removal of said workpieces from said hot vestibule, jet stream means for directing a barrier curtain of gases outwardly across the discharge door opening from within said hot vestibule and a flame curtain directed across the outside face of said opening whereby contaminating gases are prevented from entering said hot vestibule through said discharge door opening.
  • a furnace according to claim 5 further including means for actuating said barrier in response to the opening of said discharge door.
  • a furnace according to claim 5 further including means for supplying a quantity of atmosphere restoring gas to said hot vestibule intermittently in response to an atmosphere upset.
  • a furnace according to claim 8 further including means for initiating the flow of said atmosphere restoring gas in response to the opening of said discharge door and discontinuing said flow when the atmosphere in the vestibule is restored.
  • a furnace according to claim 9 further including means for constantly supplying an atmosphere carrier gas to said hot vestibule at a rate at least 5 times the rate at which the restoring gas is supplied to said vestibule.
  • a furnace according to claim 9 further including means for constantly supplying an atmosphere carrier gas to said hot vestibule at the rate of approximately 5 to l0 times the volume of the chamber per hour.
  • a controlled atmosphere furnace comprising: a heat processing chamber, a subsequent chamber adjacent said processing chamber, an entry door means between said chambers for the admission of heat treated workpieces into said subsequent chamber from said processing chamber, a discharge door means in said subsequent chamber for removing workpieces therefrom, jet stream means for directing a high velocity curtain barrier outwardly across the discharge door opening from within said subsequent chamber, means for intermittently supplying a restoring gas to said subsequent chamber in response to an atmosphere upset, means for directing a curtain of flame across the outside face of said opening whereby the upset of the furnace atmosphere caused by opening of the discharge door is minimized and the desired atmosphere is rapidly restored.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Furnace Details (AREA)
  • Heat Treatment Of Articles (AREA)
  • Tunnel Furnaces (AREA)
US775459A 1968-11-13 1968-11-13 Apparatus for minimizing atmosphere upset in a furnace for heat treating articles Expired - Lifetime US3575398A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US77545968A 1968-11-13 1968-11-13

Publications (1)

Publication Number Publication Date
US3575398A true US3575398A (en) 1971-04-20

Family

ID=25104496

Family Applications (1)

Application Number Title Priority Date Filing Date
US775459A Expired - Lifetime US3575398A (en) 1968-11-13 1968-11-13 Apparatus for minimizing atmosphere upset in a furnace for heat treating articles

Country Status (5)

Country Link
US (1) US3575398A (enrdf_load_stackoverflow)
JP (1) JPS4814523B1 (enrdf_load_stackoverflow)
CA (1) CA918418A (enrdf_load_stackoverflow)
GB (1) GB1286986A (enrdf_load_stackoverflow)
SE (1) SE360111B (enrdf_load_stackoverflow)

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3994210A (en) * 1975-11-24 1976-11-30 Powlesland Engineering Limited Jet fume control systems
US4551091A (en) * 1983-05-04 1985-11-05 Air Products And Chemicals, Inc. Method for reducing the volume of atmosphere needed to inhibit ingress of ambient oxygen into the furnace chamber of a continuous heat treatment furnace
FR2607233A1 (fr) * 1986-11-26 1988-05-27 Ipsen Ind Int Gmbh Procede et agencement de conformation d'un front de flammes sur une ouverture de chargement de four de traitement thermique
FR2612619A1 (fr) * 1987-03-17 1988-09-23 Air Liquide Procede pour limiter les entrees d'air dans un four et four pour la mise en oeuvre de ce procede
US4823680A (en) * 1987-12-07 1989-04-25 Union Carbide Corporation Wide laminar fluid doors
FR2627849A1 (fr) * 1988-02-26 1989-09-01 Vieillard Guy Dispositif d'obturation permettant la mise en place d'un appareil de mesure ou d'intervention dans une enceinte a atmosphere chaude et sous pression
US4894009A (en) * 1987-12-22 1990-01-16 Carl Kramer Apparatus for contactless sealing of an opening against emerging or entering gas
US4898319A (en) * 1987-12-04 1990-02-06 Bruce T. Williams Ambient air exclusion system for brazing ovens
EP0332926A3 (en) * 1988-03-15 1990-02-28 NUOVA MATRIX S.r.l. Continuous furnace for sintering pressed metal powders
US4940376A (en) * 1988-10-12 1990-07-10 Mph Industries, Inc. Scrap loader for molten metal furnace
US5125556A (en) * 1990-09-17 1992-06-30 Electrovert Ltd. Inerted IR soldering system
US5230460A (en) * 1990-06-13 1993-07-27 Electrovert Ltd. High volume convection preheater for wave soldering
EP0587518A1 (fr) * 1992-09-11 1994-03-16 UNIMETAL Société Française des Aciers Longs Porte de décrassage d'un four électrique à arc
US5306209A (en) * 1992-05-04 1994-04-26 Lang Fred D Contaminant shield for viewing ports
EP0778453A1 (en) * 1995-11-27 1997-06-11 The Boc Group, Inc. Furnace with an inert gas flowed toward the inlet and/or outlet sections
US5655563A (en) * 1994-12-19 1997-08-12 Ecolab Inc. Dispensing apparatus with line pressure diverter
US5965048A (en) * 1998-11-20 1999-10-12 General Electric Company Heated chamber including an open wall with a gas curtain
US20020195056A1 (en) * 2000-05-12 2002-12-26 Gurtej Sandhu Versatile atomic layer deposition apparatus
US20100183992A1 (en) * 2007-06-21 2010-07-22 Fives Stein Device for limiting the exhausting of combustion flue gases at the inlet of a furnace for reheating steel products
WO2011029565A1 (de) * 2009-09-10 2011-03-17 Ald Vacuum Technologies Gmbh Verfahren und vorrichtung zum härten von werkstücken, sowie nach dem verfahren gehärtete werkstücke
CN102032795A (zh) * 2010-11-29 2011-04-27 苏州中门子科技有限公司 热处理炉用气幕式供气装置
US20160102914A1 (en) * 2012-07-30 2016-04-14 General Electric Company Modular heat treatment system
US10196730B2 (en) 2009-09-10 2019-02-05 Ald Vacuum Technologies Gmbh Method and device for hardening workpieces, and workpieces hardened according to the method

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5448942U (enrdf_load_stackoverflow) * 1977-09-12 1979-04-05
DE3827267A1 (de) * 1988-08-31 1990-03-08 Herbert Koch Begasungseinrichtung fuer waermebehandlungsanlagen mit schutz- oder reaktionsgasbetrieb

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US549235A (en) * 1895-11-05 Friedrich ernst gatcke
US1357790A (en) * 1919-10-04 1920-11-02 Marx Richard Furnace
US1851831A (en) * 1931-02-06 1932-03-29 Carl I Hayes Atmospheric control for heat treating furnaces
US3039407A (en) * 1957-08-01 1962-06-19 Foster Wheeler Corp Closure means for pressurized furnaces
US3142272A (en) * 1960-07-20 1964-07-28 Foster Wheeler Corp Safety closure means for pressurized furnaces
US3270655A (en) * 1964-03-25 1966-09-06 Howard P Guirl Air curtain door seal
US3356541A (en) * 1965-08-20 1967-12-05 Midland Ross Corp Carburizing method and apparatus
US3387600A (en) * 1966-04-13 1968-06-11 Berj A. Terzian Oven with automatic air curtain means

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US549235A (en) * 1895-11-05 Friedrich ernst gatcke
US1357790A (en) * 1919-10-04 1920-11-02 Marx Richard Furnace
US1851831A (en) * 1931-02-06 1932-03-29 Carl I Hayes Atmospheric control for heat treating furnaces
US3039407A (en) * 1957-08-01 1962-06-19 Foster Wheeler Corp Closure means for pressurized furnaces
US3142272A (en) * 1960-07-20 1964-07-28 Foster Wheeler Corp Safety closure means for pressurized furnaces
US3270655A (en) * 1964-03-25 1966-09-06 Howard P Guirl Air curtain door seal
US3356541A (en) * 1965-08-20 1967-12-05 Midland Ross Corp Carburizing method and apparatus
US3387600A (en) * 1966-04-13 1968-06-11 Berj A. Terzian Oven with automatic air curtain means

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3994210A (en) * 1975-11-24 1976-11-30 Powlesland Engineering Limited Jet fume control systems
US4551091A (en) * 1983-05-04 1985-11-05 Air Products And Chemicals, Inc. Method for reducing the volume of atmosphere needed to inhibit ingress of ambient oxygen into the furnace chamber of a continuous heat treatment furnace
FR2607233A1 (fr) * 1986-11-26 1988-05-27 Ipsen Ind Int Gmbh Procede et agencement de conformation d'un front de flammes sur une ouverture de chargement de four de traitement thermique
FR2612619A1 (fr) * 1987-03-17 1988-09-23 Air Liquide Procede pour limiter les entrees d'air dans un four et four pour la mise en oeuvre de ce procede
US4898319A (en) * 1987-12-04 1990-02-06 Bruce T. Williams Ambient air exclusion system for brazing ovens
US4823680A (en) * 1987-12-07 1989-04-25 Union Carbide Corporation Wide laminar fluid doors
US4894009A (en) * 1987-12-22 1990-01-16 Carl Kramer Apparatus for contactless sealing of an opening against emerging or entering gas
FR2627849A1 (fr) * 1988-02-26 1989-09-01 Vieillard Guy Dispositif d'obturation permettant la mise en place d'un appareil de mesure ou d'intervention dans une enceinte a atmosphere chaude et sous pression
EP0332926A3 (en) * 1988-03-15 1990-02-28 NUOVA MATRIX S.r.l. Continuous furnace for sintering pressed metal powders
US4940376A (en) * 1988-10-12 1990-07-10 Mph Industries, Inc. Scrap loader for molten metal furnace
US5230460A (en) * 1990-06-13 1993-07-27 Electrovert Ltd. High volume convection preheater for wave soldering
US5125556A (en) * 1990-09-17 1992-06-30 Electrovert Ltd. Inerted IR soldering system
US5306209A (en) * 1992-05-04 1994-04-26 Lang Fred D Contaminant shield for viewing ports
FR2695715A1 (fr) * 1992-09-11 1994-03-18 Unimetall Sa Porte de décrassage d'un four électrique à arc.
EP0587518A1 (fr) * 1992-09-11 1994-03-16 UNIMETAL Société Française des Aciers Longs Porte de décrassage d'un four électrique à arc
US5655563A (en) * 1994-12-19 1997-08-12 Ecolab Inc. Dispensing apparatus with line pressure diverter
EP0778453A1 (en) * 1995-11-27 1997-06-11 The Boc Group, Inc. Furnace with an inert gas flowed toward the inlet and/or outlet sections
US5965048A (en) * 1998-11-20 1999-10-12 General Electric Company Heated chamber including an open wall with a gas curtain
SG85151A1 (en) * 1998-11-20 2001-12-19 Gen Electric Atmosphere controlled workpiece heating chamber
US20020195056A1 (en) * 2000-05-12 2002-12-26 Gurtej Sandhu Versatile atomic layer deposition apparatus
US20100183992A1 (en) * 2007-06-21 2010-07-22 Fives Stein Device for limiting the exhausting of combustion flue gases at the inlet of a furnace for reheating steel products
WO2011029565A1 (de) * 2009-09-10 2011-03-17 Ald Vacuum Technologies Gmbh Verfahren und vorrichtung zum härten von werkstücken, sowie nach dem verfahren gehärtete werkstücke
CN102625859A (zh) * 2009-09-10 2012-08-01 Ald真空技术有限公司 用于对工件进行淬火的方法和装置以及根据该方法被淬火的工件
CN102625859B (zh) * 2009-09-10 2015-11-25 Ald真空技术有限公司 用于对工件进行硬化的方法和装置以及根据该方法被硬化的工件
US9518318B2 (en) 2009-09-10 2016-12-13 Ald Vacuum Technologies Gmbh Method and device for hardening work pieces and workpieces hardened according to said method
US10196730B2 (en) 2009-09-10 2019-02-05 Ald Vacuum Technologies Gmbh Method and device for hardening workpieces, and workpieces hardened according to the method
CN102032795A (zh) * 2010-11-29 2011-04-27 苏州中门子科技有限公司 热处理炉用气幕式供气装置
US20160102914A1 (en) * 2012-07-30 2016-04-14 General Electric Company Modular heat treatment system
US9528764B2 (en) * 2012-07-30 2016-12-27 General Electric Company Modular heat treatment system

Also Published As

Publication number Publication date
CA918418A (en) 1973-01-09
JPS4814523B1 (enrdf_load_stackoverflow) 1973-05-08
GB1286986A (en) 1972-08-31
SE360111B (enrdf_load_stackoverflow) 1973-09-17

Similar Documents

Publication Publication Date Title
US3575398A (en) Apparatus for minimizing atmosphere upset in a furnace for heat treating articles
KR930007148B1 (ko) 열 처리장치
US3020032A (en) Vacuum furnace
ES484978A1 (es) Un horno industrial
US2254900A (en) Door seal for furnaces with protective atmosphere
US3111400A (en) Method of and apparatus for removing and burning or chemical uttlization of convertergases, particularly during the fining process of crude-iron with oxygen
US2804855A (en) Furnace door construction
JP3017303B2 (ja) 熱処理装置
US3582055A (en) Furnace plants for heat treatment of workpieces under protective gas atmospheres
US2141192A (en) Apparatus for annealing
US3623714A (en) Method of and apparatus for operating a furnace
US1898674A (en) Annealing art
KR930010200A (ko) 철계금속의 열처리 방법 및 그 열처리 장치
SU405958A1 (ru) В П ТБ;°'П'^" Q-'.mnroTf-1 •...',:',,4 u..i.Mii«s ii
GB910741A (en) Improvements relating to batch-type controlled-atmosphere heat-treatment furnaces
JPS5763641A (en) Controller for pressure in gas-water cooling furnace in continuous annealing furnace
CN214193367U (zh) 一种具备烟气处理功能的罩式回火炉
US2307522A (en) Bright-finish metal-treating furnace
CN2498168Y (zh) 一种具有前后稳压排气装置的网带式连续渗碳炉
CA1103569A (en) Preheat and cleaning system
SU1476281A1 (ru) Установка дл химико-термической обработки изделий
US1507665A (en) Method of furnace operation
SU1618982A1 (ru) Электропечь дл термообработки изделий
ES440667A1 (es) Un aparato para el recocido en proceso continuo de una bandade acero.
GB2197938A (en) Creation of flame fronts at charging openings of heat-treatment furnaces

Legal Events

Date Code Title Description
AS Assignment

Owner name: FL AEROSPACE CORP.

Free format text: CHANGE OF NAME;ASSIGNORS:MIDLAND-ROSS CORPORATION MERGING INTO;MRC MERGER CORP., CHANGED NAME TO;MIDLAND - ROSS CORPORATION, CHANGED TO;REEL/FRAME:005240/0352

Effective date: 19880926