EP0179050A2 - Four pour le traitement thermique de barres d'un métal léger - Google Patents

Four pour le traitement thermique de barres d'un métal léger Download PDF

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Publication number
EP0179050A2
EP0179050A2 EP85890257A EP85890257A EP0179050A2 EP 0179050 A2 EP0179050 A2 EP 0179050A2 EP 85890257 A EP85890257 A EP 85890257A EP 85890257 A EP85890257 A EP 85890257A EP 0179050 A2 EP0179050 A2 EP 0179050A2
Authority
EP
European Patent Office
Prior art keywords
furnace
conveying
bars
conveyor
vertical
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.)
Granted
Application number
EP85890257A
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German (de)
English (en)
Other versions
EP0179050B1 (fr
EP0179050A3 (en
Inventor
Günther Dipl.-Ing. Hertwich
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.)
HERTWICH GUNTHER DIPL ING
Original Assignee
HERTWICH GUNTHER DIPL ING
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 HERTWICH GUNTHER DIPL ING filed Critical HERTWICH GUNTHER DIPL ING
Publication of EP0179050A2 publication Critical patent/EP0179050A2/fr
Publication of EP0179050A3 publication Critical patent/EP0179050A3/de
Application granted granted Critical
Publication of EP0179050B1 publication Critical patent/EP0179050B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/02—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity of multiple-track type; of multiple-chamber type; Combinations of furnaces
    • F27B9/021—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity of multiple-track type; of multiple-chamber type; Combinations of furnaces having two or more parallel tracks
    • F27B9/022—With two tracks moving in opposite directions
    • 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
    • C21D9/005—Furnaces in which the charge is moving up or down
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/06—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity heated without contact between combustion gases and charge; electrically heated
    • F27B9/10—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity heated without contact between combustion gases and charge; electrically heated heated by hot air or gas
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
    • F27B9/142—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving along a vertical axis

Definitions

  • the invention relates to a furnace for the heat treatment of light metal bars, consisting of a furnace chamber through which hot gas flows, in which a step conveyor is provided between the goods inlet and a goods outlet for the individual bars lying transversely to the conveying direction.
  • extruded round bars which must be subjected to a heat treatment known as homogenization annealing in order to compensate for casting heterogeneities that occur during continuous casting.
  • the treatment temperature for the most commonly used alloys is around 560 - 580 ° C. After this homogenization temperature has been reached, the bars must be kept at this temperature in order to ensure the time required for the diffusion processes.
  • the walking beam conveyor must receive a corresponding number of bars for a desired throughput so that the individual bars not only brought to the homogenization temperature within the continuous furnace, but can also be kept at this temperature for a predetermined time, which is generally several hours.
  • the comparatively large number of ingot receptacles requires a large furnace length, which in turn means a large furnace space pulls, so that there is an unfavorable ratio of the furnace output to the furnace volume. Since the bars of the walking beam conveyor are mainly subjected to bending due to the bars on them, these bars must be supported accordingly.
  • the subjected to a heat treatment billet must be reheated prior to extrusion to achieve a certain ductility, whereby the required heating temperatures about 50 to 100 * C below the treatment temperature for the homogenization.
  • This heating of the bars before the extrusion generally takes place in separate furnaces, which entails an additional expenditure of energy. It is therefore obvious that the homogenization glu hen the ingot immediately before pressing in order to save the subsequent warming up to the pressing temperature.
  • the merging of the homogenization annealing and the warming up for the pressing process in a common continuous furnace generally fails because of the large space requirement of such a furnace, because the space available is limited, particularly in existing extrusion plants.
  • the invention is therefore based on the object to avoid these deficiencies and to improve a furnace for the heat treatment of light metal ingots of the type described above in such a way that the space required for the continuous furnace is substantially reduced so that the individual ingots while maintaining an advantageous efficiency of the heat treatment required in each case can be subjected and that the step conveyor between the product inlet and the product outlet of the furnace does not require expensive covering of through openings in the furnace housing.
  • the invention achieves the stated object in that the step conveyor is arranged in a shaft-like furnace space and in a manner known per se from at least two vertical conveying lines arranged next to one another and connected to one another by a transfer line is set and that at least between the conveyor line adjoining the material inlet and the immediately adjacent conveyor line a vertical partition dividing the shaft-like furnace space is provided.
  • the floor space required for the furnace is first significantly reduced compared to the conventional continuous furnaces with horizontal walking beam conveyors.
  • the height of the furnace space compared to the required conveying length is at least halved by lining up at least two opposing conveying sections, so that a particularly favorable ratio between the furnace output and the furnace volume is achieved.
  • the hot gas flow regardless of whether it runs counter to or in the conveying direction, is guided in a thermally advantageous manner in a vertical direction through the furnace space, which results in a particularly uniform heating of the individual bars. Since the supports for the bars in vertical step conveyors run in the conveying direction and are therefore only moved axially during a conveying movement, the penetrations of these supports through the furnace housing can be carried out in a simple manner in a heat-insulating manner.
  • the vertical partition between the opposing conveying sections of the vertical step conveyor advantageously separates the furnace space into two vertical flow paths. These flow paths on both sides of the dividing wall can be connected to one another to form a hot gas circuit if the ingots passing through the furnace are to be brought to the pressing temperature after homogenization annealing. If rapid warming up and then maintaining the treatment temperature reached is desired, then a flow path in the region of the furnace inlet becomes available Closing conveyor line used for a hot gas guide, in which the hot gas temperature is above the treatment temperature of the ingot, while the flow path on the opposite side of the partition only requires a hot gas flow that covers the heat losses that occur. Particularly advantageous ratios are achieved if the partition wall is designed to be heat-insulating in order to rule out mutual temperature effects between the two flow paths.
  • the hot gas flow required to cover the heat losses in the region of the conveyor line or conveyor lines adjoining the inlet-side conveyor line can be branched off in a simple manner from the hot gas flow in the region of the inlet-side conveyor line.
  • the dividing wall can preferably have throughflow openings in a wall region which is opposite the transition between the conveying sections separated by the dividing wall in the vertical direction and can be closed by control flaps.
  • the secondary circuit of the hot gas flow for keeping the bars brought to the treatment temperature warm can be controlled according to the respective requirements via the position of the control flaps.
  • the conveying lines in the longitudinal direction of the bars can have vertically arranged, rotatably mounted, vertical shafts, which support arms for the bars at a uniform axial distance, some of the shafts being axially immovable and the other shafts around a dimension corresponding to at least the axial distance of the support arms from one another is held axially displaceably.
  • the axially displaceable shafts have to be raised or lowered by one conveying step so that the bars can be swiveled back into the working position after the support arms swiveled out of the bar path into the working position Support arms of the immovable shafts can be put down.
  • the support arms of the raisable and lowerable shafts are then returned to their starting position after being pivoted out of the bar path in order to be ready for a new conveying step. Since the shafts for the support arms only require support in the axial direction due to their vertical arrangement and the shafts perform at most one axial displacement movement in addition to a rotary adjustment, the Durdh Adjust of this shaft through the furnace housing can be effectively heat-insulating in a simple manner, which prevents additional heat losses .
  • these furnaces can be assigned directly to the press systems, so that the bars can be pressed after the homogenization annealing without additional heating.
  • these ovens can also be used with advantage as separate heating ovens or as homogenizing ovens.
  • subsequent cooling of the ingots emerging from the furnace must be ensured. This cooling can be carried out in a particularly simple manner in connection with ovens in which an odd number of conveying sections is provided, a further vertical conveying section following the conveying section assigned to the product outlet in a cooling shaft outside the furnace chamber.
  • the warm ingots discharged from the furnace also pass through the cooling shaft in the vertical direction, which not only ensures a small space requirement for the cooling device, but also results in advantageous flow conditions for the cooling air, the sensible waste heat of which, for example, for space heating or the like. can be exploited. Due to the odd number of conveying sections in the furnace chamber, the conveying section in the cooling shaft results in an even total number of conveying sections, so that a uniform conveying level outside the furnace area can be maintained. Whether the bars are initially down or up are promoted, is irrelevant to the function of the furnace and generally depends on the local conditions.
  • a standing furnace housing 1 and 2 consists essentially of a standing furnace housing 1, which encloses a shaft-like furnace chamber 2.
  • a step conveyor for bars 3 lying transversely to the conveying direction is provided between an oven inlet (not shown in more detail for reasons of clarity) and an oven outlet, said step conveyor consisting of two vertical conveyor lines 4a and 4b lined up next to one another.
  • These conveying lines 4a and 4b each have vertical shafts 5a and 5b lined up in the longitudinal direction of the bars 3, which are rotatably mounted in the furnace housing 1 and carry support arms 6 for the bars 3 at a uniform, axial distance.
  • the shafts 5a are only rotatably adjustable in the housing 1 of the furnace, the shafts 5b are additionally displaceably guided in the axial direction, so that the bars 3 are in each case one support step to the next higher or lower one via the support arms 6 of the shafts 5b Support arm 6 can be raised or lowered. In order to be able to move the bars past the support arms 6 of the immovable shafts 5a when lifting or lowering, these support arms with the shafts 5a must be swung out of the bar path.
  • the raised or lowered bars are then placed on the pivoted-back support arms of the immovable shafts 5a, the support arms 6 of the displaceable shafts 5b having to be swung out of the bar path before these shafts are returned to the starting position in order to be able to be moved past the bars.
  • the bars 3 which are fed to the step conveyor or driven away from the step conveyor via longitudinal roller drives 7 and 8 through the furnace inlet or through the furnace outlet, can be lifted step by step or be lowered.
  • shafts 5a and 5b serve with the shafts non-rotatably connected, arranged outside the furnace housing adjusting arms 9, which are connected to each other via control rods 10 and are driven by an actuator, not shown, for example a cylinder drive, which on the one hand on the furnace housing and on the other hand to the Control rods is articulated.
  • the axial conveying movement of the shafts 5b takes place with the aid of spindle drives 11, which are connected to each other by a common drive shaft 12 for each conveying path.
  • a transfer line 13 which, according to the exemplary embodiment, consists of drain wedges connected to the shafts 5a, on which the bars placed roll to the subsequent, oppositely moving conveyor line.
  • partition 14 which divides the furnace chamber 2 into two flow paths and which has passage openings in the wall region opposite the transfer line 13 in the vertical direction gen 15 form, which can be covered with the help of control flaps 16.
  • fans 17 are provided which are driven by drives 18 outside the furnace chamber 2 and are arranged in the region of a flow shaft 19 provided inside the furnace housing 1, which is separated from the furnace chamber 2 by a wall 20. With the aid of the blower 17, air can thus be drawn in from the furnace chamber 2 and pressed into the furnace chamber 2 again in the circuit through the flow shaft 19. Since an electrical heating register 21 is provided in the flow shaft 19, the air pressed through the heating register 21 is heated to a corresponding temperature.
  • the bars 3 introduced into the furnace chamber 2 via the roller inlet 7 via the material inlet of the furnace are gradually conveyed upwards by the conveying path 4a and heated to a desired treatment temperature by the hot air which is conducted in opposite directions through the furnace chamber.
  • the downward conveying section 4b is thermally insulated from the upward conveying section 4a by the partition 14, heating in the area of the conveying section 4a can be carried out with hot gas which has been overheated compared to the desired treatment temperature, which allows rapid heating.
  • An overheating of the bars is not to be feared because after reaching the treatment temperature, the bars are taken over by the conveyor section 4b, which is located in a secondary circuit of the hot gas flow.
  • the flow conditions in this secondary circuit can be adjusted via the control flaps 16, only the temperature reached having to be maintained by covering the heat losses accordingly. If the temperature of the bars 3 is measured at the end of the conveyor section 4a, the desired end temperature can be set precisely via the temperature of the hot gases.
  • burners 22 are used for this purpose, which achieve a comparatively high efficiency with the aid of a recuperator.
  • the furnace according to FIG. 4 has no separation shaft for the hot gas generation which is separated from the furnace space 2. Rather, the shaft-like furnace chamber 2 is divided by the partition 14 between the two conveyor sections 4a and 4b into two vertical flow paths connected to form a circuit, through which the hot gas is guided. A burner 23 is used to generate this hot gas, which opens into the furnace area in the floor area and expels the combustion gases at high speed for hot gas circulation. Since the conveyor sections 4a and 4b are not thermally insulated from one another in accordance with this design variant, such a furnace is preferably used only for heating the ingots to a desired temperature, for example to the pressing temperature. Nevertheless, all advantages with regard to the simple design of the conveyor lines and with regard to the small space requirement and the high efficiency are retained.
  • the step conveyor in the furnace chamber 2 does not have two, but three vertical conveyor sections 4a, 4b and 4c.
  • the ingots 3 introduced into the furnace chamber 2 via the roller table 7 are gradually raised over the conveyor section 4a and heated in countercurrent by a hot gas flow, which is sucked in with the aid of the fan 17 and separated by a wall 20 from the furnace chamber 2 by the electric heating register 21 Flow shaft 19 is pressed in order to be guided downward again from the flow shaft 19 between the partition wall 14 and the wall 20.
  • the bars 3 heated up in the area of the conveyor line 4a in a comparatively short period of time are transferred to the conveyor line 4b after reaching the desired final temperature, which is provided together with the conveyor line 4c in the furnace space 2 divided by the partition wall 14, in which the temperature reached Ingots should be retained to ensure the diffusion processes necessary to compensate for casting heterogeneities.
  • the ingots are transferred via the closable furnace outlet 24 to a further conveyor section 25, which is provided outside the furnace housing 1 in a cooling shaft 26 and has the same structure as the other conveyor sections.
  • a cooling shaft 26 In this cooling shaft 26, the bars 3 are cooled in countercurrent, the heated cooling air being sucked off with the aid of fans 27.
  • the sensible waste heat of this cooling air can be used for heating purposes, for example.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Combustion & Propulsion (AREA)
  • Tunnel Furnaces (AREA)
  • Heat Treatments In General, Especially Conveying And Cooling (AREA)
EP85890257A 1984-10-19 1985-10-14 Four pour le traitement thermique de barres d'un métal léger Expired - Lifetime EP0179050B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT0333584A AT382396B (de) 1984-10-19 1984-10-19 Ofen zur waermebehandlung von leichtmetallbarren
AT3335/84 1984-10-19

Publications (3)

Publication Number Publication Date
EP0179050A2 true EP0179050A2 (fr) 1986-04-23
EP0179050A3 EP0179050A3 (en) 1988-08-10
EP0179050B1 EP0179050B1 (fr) 1991-04-24

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ID=3548966

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Application Number Title Priority Date Filing Date
EP85890257A Expired - Lifetime EP0179050B1 (fr) 1984-10-19 1985-10-14 Four pour le traitement thermique de barres d'un métal léger

Country Status (4)

Country Link
US (1) US4664359A (fr)
EP (1) EP0179050B1 (fr)
AT (1) AT382396B (fr)
DE (1) DE3582646D1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0703423A1 (fr) * 1994-06-23 1996-03-27 General Signal Corporation Ascenseur pas à pas pour transporter verticalement des pièces dans un four
EP0716152A1 (fr) * 1994-12-08 1996-06-12 Schmitz + Apelt LOI Industrieofenanlagen GmbH Procédé de traitement thermique de pièces

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5997286A (en) * 1997-09-11 1999-12-07 Ford Motor Company Thermal treating apparatus and process
US6210156B1 (en) * 1999-07-26 2001-04-03 General Motors Corporation Heat treatment material handling unit
DE10032251A1 (de) 2000-07-03 2002-01-17 Voith Paper Patent Gmbh Maschine sowie Verfahren zur Herstellung einer Faserstoffbahn
US7226630B2 (en) * 2002-11-26 2007-06-05 Kraft Foods Holdings, Inc. Edible moisture barrier for food and method of use products
DE10339526B4 (de) * 2003-08-21 2006-04-06 Strikowestofen Gmbh Vorwärmeinrichtung für in einem Schmelzofen zu schmelzende Masseln
US7365287B1 (en) * 2006-11-29 2008-04-29 Ellis Frederick G Vertical electrically heated oven for baking coated parts
EP2139628B1 (fr) * 2007-03-29 2013-02-27 Consolidated Engineering Company, Inc. Système de traitement thermique vertical
US8789459B2 (en) * 2008-12-05 2014-07-29 Terry Tae-Il Chung Food heating device

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR823437A (fr) * 1936-10-01 1938-01-20 Fourment & Laduree Four continu pour traitements thermiques
US2620918A (en) * 1947-11-28 1952-12-09 Fallon John Conveyer mechanism
DE752031C (de) * 1939-12-14 1953-05-18 Aeg Foerdereinrichtung fuer Paternosteroefen
DE2148562A1 (fr) * 1971-09-29 1972-05-31

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2711309A (en) * 1950-05-17 1955-06-21 Sclas Corp Heat treating apparatus
US2793027A (en) * 1956-01-19 1957-05-21 Metal Rolling And Tube Company Heat-treatment of metal articles
JPS5433246A (en) * 1977-08-18 1979-03-10 Nippon Aviotronics Kk Method and apparatus for resistance welding
US4398700A (en) * 1982-09-29 1983-08-16 Midland-Ross Corporation Annealing furnace with an improved cooling section

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR823437A (fr) * 1936-10-01 1938-01-20 Fourment & Laduree Four continu pour traitements thermiques
DE752031C (de) * 1939-12-14 1953-05-18 Aeg Foerdereinrichtung fuer Paternosteroefen
US2620918A (en) * 1947-11-28 1952-12-09 Fallon John Conveyer mechanism
DE2148562A1 (fr) * 1971-09-29 1972-05-31

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0703423A1 (fr) * 1994-06-23 1996-03-27 General Signal Corporation Ascenseur pas à pas pour transporter verticalement des pièces dans un four
EP0716152A1 (fr) * 1994-12-08 1996-06-12 Schmitz + Apelt LOI Industrieofenanlagen GmbH Procédé de traitement thermique de pièces

Also Published As

Publication number Publication date
ATA333584A (de) 1986-07-15
US4664359A (en) 1987-05-12
EP0179050B1 (fr) 1991-04-24
EP0179050A3 (en) 1988-08-10
DE3582646D1 (de) 1991-05-29
AT382396B (de) 1987-02-25

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