EP0188659A2 - Industrial furnace for the continuous heat treatment of articles - Google Patents

Industrial furnace for the continuous heat treatment of articles Download PDF

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Publication number
EP0188659A2
EP0188659A2 EP85111008A EP85111008A EP0188659A2 EP 0188659 A2 EP0188659 A2 EP 0188659A2 EP 85111008 A EP85111008 A EP 85111008A EP 85111008 A EP85111008 A EP 85111008A EP 0188659 A2 EP0188659 A2 EP 0188659A2
Authority
EP
European Patent Office
Prior art keywords
conveyor belt
heat
industrial furnace
heat transfer
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.)
Granted
Application number
EP85111008A
Other languages
German (de)
French (fr)
Other versions
EP0188659B1 (en
EP0188659A3 (en
Inventor
Reinhold Bayer
Gerhard Dreizler
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.)
Aichelin GmbH Germany
Original Assignee
Aichelin GmbH Germany
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 Aichelin GmbH Germany filed Critical Aichelin GmbH Germany
Priority to AT85111008T priority Critical patent/ATE58964T1/en
Publication of EP0188659A2 publication Critical patent/EP0188659A2/en
Publication of EP0188659A3 publication Critical patent/EP0188659A3/en
Application granted granted Critical
Publication of EP0188659B1 publication Critical patent/EP0188659B1/en
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
    • F27B9/14—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
    • F27B9/20—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 in a substantially straight path tunnel furnace
    • F27B9/24—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 in a substantially straight path tunnel furnace being carried by a conveyor
    • F27B9/243—Endless-strand conveyor
    • 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
    • F27B9/30—Details, accessories, or equipment peculiar to furnaces of these types
    • F27B9/38—Arrangements of devices for charging
    • 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
    • F27B9/20—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 in a substantially straight path tunnel furnace
    • F27B9/24—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 in a substantially straight path tunnel furnace being carried by a conveyor
    • F27B9/243—Endless-strand conveyor
    • F27B2009/2438—Endless-strand conveyor with means to transfer the heat from the outcoming band to the incoming band
    • 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
    • F27B9/30—Details, accessories, or equipment peculiar to furnaces of these types
    • F27B9/36—Arrangements of heating devices
    • F27B2009/3638—Heaters located above and under the track
    • 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
    • F27B9/068—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 radiant tubes, the tube being heated by a hot medium, e.g. hot gases
    • 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
    • F27D3/00—Charging; Discharging; Manipulation of charge
    • F27D3/12—Travelling or movable supports or containers for the charge
    • F27D2003/121—Band, belt or mesh
    • 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
    • F27D21/00—Arrangements of monitoring devices; Arrangements of safety devices
    • F27D2021/0007—Monitoring the pressure
    • 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
    • F27D21/00—Arrangements of monitoring devices; Arrangements of safety devices
    • F27D21/0014—Devices for monitoring temperature

Definitions

  • the invention relates to an industrial furnace for heat treatment of workpieces running through according to the preamble of the main claim.
  • the working run of the conveyor belt runs essentially horizontally from the loading opening to the chute, where it is deflected downward by 90 ° in order to leave the furnace chamber.
  • a return channel for the empty run of the conveyor belt opens into it, which is therefore deflected again in the drop channel by 90 ° in order to run into the return channel.
  • the return duct extends below the actual furnace to approximately the level of the loading opening, where the return duct opens into a water siphon.
  • the empty run of the conveyor belt thus emerges largely gas-tight from the return channel and runs into the drive device for the conveyor belt, in which it is redirected upward, now in the direction of the loading opening. Between the drive device and the loading opening
  • the conveyor belt crosses a kind of table, in the area of which the workpieces are placed on the conveyor belt, which are then transported to the furnace chamber together with the working belt of the conveyor belt.
  • the conveyor belt Since the process temperature in the furnace is high, the conveyor belt usually consists of intertwined steel spirals and accordingly has a considerable heat capacity. In the area of the drop channel, a considerable amount of heat is therefore removed from the furnace chamber by the conveyor belt, which only contributes to the heating of the environment while passing through the return channel, but is otherwise lost to the treatment process. In any case, the conveyor belt has a temperature of less than 100 ° C when it emerges from the return duct. The conveyor belt is then optionally cooled further in the drive device before it, loaded with the workpieces, re-enters the furnace chamber through the loading opening.
  • the cooled working section of the conveyor belt must now be heated up again to the process temperature, which either leads to corresponding cooling of the process gases or makes additional heating devices necessary. In any case, the conveyor belt must again be supplied with the thermal energy that it lost when passing through the return channel.
  • the amount of heat for heating the conveyor belt can be greater than the amount of heat for Heating up the workpieces to be treated.
  • the object of the invention is therefore to provide an industrial furnace in which the conveyor belt dissipates less process heat.
  • the empty run inside the furnace chamber is returned to the loading opening, the temperature of the empty run remains at the process temperature.
  • the heat transfer device provided in the area of the loading opening between the empty run and the work run results in direct heat transfer from the empty run to the work run, the heat transfer taking place as it were in the countercurrent process. This achieves two things:
  • the empty run is cooled to temperatures which preclude damage to the drive devices, without the parts thereof coming into contact with the conveyor belt having to be made of heat-resistant material.
  • the heat released during cooling is immediately absorbed by the work strand and already transferred to the workpieces stacked on it. Without additional external energy supply, the temperature of the working area is raised significantly in the direction of the process temperature.
  • the heat energy conveyed out of the empty strand from the furnace chamber is transferred to the working strand with relatively small losses and is thus transported back into the furnace chamber.
  • a particularly favorable efficiency can be achieved if the heat transfer device is arranged essentially outside the furnace chamber.
  • a very effective and mechanically simple heat transfer device consists of a large number of cylindrical rollers made of heat-conducting material and extending over the width of the conveyor belt. These rollers are rotatably mounted at right angles to the direction of movement of the work strand, the work strand running over the heat-transferring rollers and thus reducing the heat from them. Underneath the heat-transferring rollers is the empty strand, which is held in contact with the peripheral surface of the heat-transferring rollers by means of pressure devices so that the empty strand can transfer its heat to the rollers.
  • the pressure device for the empty run can either be formed by an essentially flat slideway or a plurality of pressure rollers mounted axially parallel to the heat transfer rollers.
  • the former embodiment has the advantage of being somewhat easier to manufacture, while the second embodiment requires lower driving forces for the conveyor belt.
  • either the pressure rollers or the heat transfer rollers are each mounted in an associated sliding guide, so that a respective one Roll in the direction of the slideway or the heat transferring roller is guided longitudinally.
  • the heat loss through the conveyor belt can be further reduced if a prechamber connected to the furnace chamber via the loading opening is connected to the furnace chamber, through which the conveyor belt runs and in which at least the heat transfer device and possibly the drive device are located, the prechamber being a filling opening for entering the workpieces.
  • the prechamber Apart from the better thermal insulation, the prechamber largely prevents air from being carried into the furnace atmosphere and thus an impermissible change in its composition.
  • the empty run of the conveyor belt running out of the furnace chamber namely constantly transports the furnace atmosphere into the prechamber, which is flushed with the furnace atmosphere in this way. Any external air that may enter the workpieces can be flushed out of the entrained furnace gases via the filler opening.
  • the water siphon required in the prior art is therefore not required.
  • the filling opening is arranged above the conveyor belt and, viewed in the conveying direction, in front of the heat transfer device. This is because the entire length of the heat transfer device is used in this way to transfer heat from the empty run to the work run and the workpieces.
  • the feed opening which is particularly critical with regard to the loss of furnace gases, can be reduced in its clear width if a deflection device for the empty run is arranged within the furnace chamber in the vicinity of the feed opening and raises the empty run towards the underside of the working run.
  • an industrial furnace 1 is illustrated, or the like for the continuous heat treatment of workpieces, for example for carburizing, nitriding, carbonitriding. serves.
  • the industrial furnace 1 contains an elongated, heat-insulating-lined furnace chamber 2, through which heating pipes 3 lead from side wall to side wall, in which burners are used to heat the furnace atmosphere.
  • the furnace chamber 2 contains a loading opening 5, which is adjoined to the outside by a straight antechamber 6, which is tubular and is also heat-insulated.
  • the interior 7 of the prechamber 6, which is approximately rectangular in cross section, is aligned with the loading opening 5 and ends at a filling opening 8 opposite the loading opening 5.
  • the industrial furnace 1 contains an endless heat-resistant conveyor belt 12 which can be set in motion by means of a drive device 13 upstream of the prechamber 6.
  • the run of the conveyor belt 12 emerging from the drive device 13 forms the working run 14, which enters through the filling opening 8 into the interior 7 of the prechamber 6, runs there via a heat transfer device 15 described below and finally through the loading opening 5 into the interior of the furnace chamber 2 arrives.
  • the working device 13 which runs constantly horizontally from a drive 10 by a stove 10, which is shown in detail in FIG. 4 in cross section.
  • a deflection device 16 for the conveyor belt 12 is arranged in the interior of the furnace chamber 2, which is formed by a cylindrical roller which can freely rotate inside the furnace chamber 2; the width of the roll corresponds to the width of the conveyor belt used in each case 12.
  • the conveyor belt is deflected 12 above the lying inside the furnace chamber 2 opening of the chute 11 to about 180 0 back in the direction of the drive device 13; Objects brought in from the working section 14 fall into the chute 11 and thus leave the furnace chamber 2.
  • the section of the conveyor belt 12 now running back below the working section 14 and referred to as the empty section 17 runs through the interior of the furnace chamber 2 back to the loading opening 5, one in the vicinity of the loading opening 5 rotatably arranged roller 18 raises the empty sag 17 freely sagging inside the furnace chamber 2 near the underside of the working strand 15, so that the loading opening 5, through which the empty strand 17 emerges again from the furnace chamber 2, only a small one must have clear height.
  • the empty run 17 passes through the heat transfer device 15 located in the pre-chamber 6 before it exits the filling opening 8 from the interior 7 of the pre-chamber 6 and enters the drive device 13.
  • the drive device 13 essentially contains two axially parallel rotatable rollers 19 and 20, of which the roller 19 serves as a tensioning roller for the conveyor belt 12, while the roller 20 is to be set in slow revolutions by a geared motor 21 for the purpose of driving the conveyor belt 12.
  • the above-mentioned stove 10 arranged inside the furnace chamber 2 essentially consists, as shown in FIG. 4, of two parallel rails 25 and 26 running at a distance from one another, which in the exemplary embodiment shown are rigid on a total of four beams 27 running across the furnace chamber 2 are attached. 4, the bars 27 are loosely inserted in corresponding recesses 28 and 29 in the lining 31 of the furnace chamber 2.
  • angular rails 25 and 26 are intended to support the working strand 14 of the conveyor belt 12, their distance from one another corresponds to the width of the conveyor belt 12, which is provided with edge-side guide strips 32 and 33 in order to prevent the workpieces from falling off.
  • the heat transfer device 15 is explained below, which is located in the antechamber 6 between the working section 14 and the empty section 17 of the conveyor belt 12.
  • the heat The transfer device 15 serves to transfer the heat continuously conveyed out of the furnace chamber 2 with the empty strand 17 to the working strand entering the furnace chamber 2 from the pre-chamber 6, whereby two things are achieved:
  • the empty strand 17 is opened after exiting the furnace chamber 2 handy temperatures cooled so that no particularly heat-resistant devices are required on the part of the drive device 13.
  • the heat continuously conveyed out with the empty strand 17 is transferred to the working strand 14, which makes it possible to keep the heat loss from the furnace chamber 2 low.
  • the empty run 17 emerging from the loading opening 5 has the temperature of the furnace atmosphere of approximately 800 ° C.
  • the return strand of the mentioned 800 ° C to about 60 0 C is cooled down.
  • the thereby liberated heat is transferred to the working section provided with the workpieces 14, which, at the filling opening 8, a temperature of 40 0 C and is heated by the heat transfer device 15 in the charging opening 5 already at 600 C.
  • the heat transfer device 15 enables a significant improvement in the heat balance, because the heat emitted by the empty run 17 does not go uselessly into the environment, but can be used to heat the working run 14 and the workpieces.
  • the interior 7 of the prechamber 6 is delimited by a steel tube 41 with a rectangular cross section, which extends from the filling opening 8 to the outside of the end wall 4 of the furnace chamber 2 and the bottom 42, two parallel side walls 43, 44 and the ceiling 45 of the interior 7 forms.
  • the thermal insulation of the pre-chamber 6 is located outside the steel tube 41, the clear width of which corresponds to the width of the conveyor belt 12.
  • the heat transfer device 15 in the interior of the steel tube 41 is formed by a total of five rollers 46a to 46e, which are arranged parallel and at a distance from one another and each consist of a steel tube of corresponding width and are rotatable at right angles to the direction of movement of the conveyor belt 12.
  • the back of the working run 14 and the empty run 17 are held against these steel pipes 46a to 46e, so that a thermal contact or a thermal bridge between the two runs 14, 17 running in the opposite direction is created.
  • the empty run 17 runs over a flat and horizontally running slideway 47 fastened to the floor 42, the width of which is slightly smaller than the distance between the two guide strips 32 and 33 of the conveyor belt 12, as shown in FIG. 3.
  • the slideway 47 extends from the filling opening 8 to the loading opening 5, where it passes over an inclined ramp 48 which extends into the furnace chamber 2.
  • an inclined ramp 48 which extends into the furnace chamber 2.
  • the five heat transfer rollers 46a to 46e which can move freely in height.
  • the working strand 14 runs in the prechamber 6 with its rear side over the outer peripheral surface of the heat transfer rollers 46a to 46e and is held on the outer peripheral surface of the heat transfer rollers 46a to 46e due to gravity.
  • These heat transfer rollers 46a to 46e which are made of heat-conducting and heat-resistant material, have an outside diameter between 10 and 80 mm, but preferably a diameter between 10 and 50 mm and a center distance of about 100 mm from each other, which means that the conveyor belt 12 sags appreciably between two adjacent heat transfer rollers 46a to 46e is avoided.
  • each of the two side walls 43 and 44 contains a rectangular slot 49a to 49e, through which the heat transfer rollers 46a to 46e protrude at the end with a relatively large radial clearance, because their axial length is greater than the clear width of the distance between the two side walls 43 and 44.
  • an angled flange 51, 52 is attached outside of the interior 7 on each of the two side walls 43 and 44, which is only used as a contact surface for the each adjacent end of the heat transfer roller 46a to 46e is used.
  • a pivoting flap 54 is freely suspended above the filling opening 8, which slides along the work strand 14 and is folded up by the workpieces that move with the conveyor belt 12 into the prechamber 6. Furthermore, a flame curtain can be generated between the working section 14 and the empty section 17 with the help of burner nozzles 55, which further seals the interior of the furnace chamber 2 against the outside air. If outside air should nevertheless enter the prechamber, it is flushed out by the furnace atmosphere emerging from the prechamber 6 and its filling opening 8, which is particularly easy when the conveyor belt, as shown in FIG. 5, is particularly gas-permeable. There is then a constant slight flushing of the prechamber 6 with the furnace atmosphere, specifically over the entire cross section of the interior 7, which effectively prevents air ingress into the furnace chamber 2.
  • the conveyor belt 12 shown in perspective in FIG. 5 consists of a plurality of flattened wire spirals 56a to 56c running transversely to the longitudinal direction of the conveyor belt, two adjacent wire spirals 56a and 56b or 56b and 56c each using a common, likewise transverse round rod 57a to 57d are connected to each other.
  • Each of the plates 58a and 58d is placed on two adjacent round rods 57a to 57d, so that the scale-like superimposition of the plates 58a to 58d shown in FIG. 5 results in the longitudinal direction of the conveyor belt.
  • the round rods 57a to 57d are each bent in the same direction onto the adjacent round rod 57a to 57d and connected to it by a hook-shaped end.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Tunnel Furnaces (AREA)
  • Heat Treatments In General, Especially Conveying And Cooling (AREA)
  • General Induction Heating (AREA)
  • Heating, Cooling, Or Curing Plastics Or The Like In General (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
  • Muffle Furnaces And Rotary Kilns (AREA)
  • Furnace Charging Or Discharging (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
  • Heterocyclic Carbon Compounds Containing A Hetero Ring Having Oxygen Or Sulfur (AREA)
  • Crucibles And Fluidized-Bed Furnaces (AREA)

Abstract

The furnace (1) includes a furnace chamber (2) which at one end has a charging opening (5) and at the other end a chute (11). Between charging opening (5) and chute (11), there extends an endless conveyor belt (12) which, above the chute (11), is deflected in the direction of the charging opening (5). In order to avoid a constant heat loss through the empty section (17) of the conveyor belt (12) emerging from the furnace chamber, a heat transfer device (15) is provided in the region of the charging opening (5) between the cold working section (14) running in and the hot empty section (17) running out. <IMAGE>

Description

Die Erfindung geht aus von einem Industrieofen zur Wärmebehandlung durchlaufender Werkstücke gemäß dem Oberbegriff des Hauptanspruches.The invention relates to an industrial furnace for heat treatment of workpieces running through according to the preamble of the main claim.

Bei derartigen, aus der Praxis bekannten Industrie- öfen läuft das Arbeitstrum des Förderbandes im wesentlichen horizontal von der Beschickungsöffnung zum Fallschacht, wo es um 90° nach unten umgelenkt wird, um die Ofenkammer zu verlassen. Knapp oberhalb des unteren Endes des Fallschachtes mündet in diesen ein Rücklaufkanal für das Leertrum des Förderbandes, das deshalb im Fallkanal erneut um 90° abgelenkt wird, um in den Rücklaufkanal einzulaufen. Der Rücklaufkanal erstreckt sich unterhalb des eigentlichen Ofens bis etwa auf die Höhe der Beschickungsöffnung, wo der Rücklaufkanal in einen Wassersyphon einmündet. Das Leertrum des Förderbandes tritt so weitgehend gasdicht aus dem Rücklaufkanal aus und läuft in die Antriebseinrichtung für das Förderband ein, in der es erneut nach oben, nunmehr in Richtung auf die Beschickungsöffnung, umgelenkt wird. Zwischen der Antriebseinrichtung und der BeschickungsöffnungIn industrial ovens of this type, which are known from practice, the working run of the conveyor belt runs essentially horizontally from the loading opening to the chute, where it is deflected downward by 90 ° in order to leave the furnace chamber. Just above the lower end of the chute, a return channel for the empty run of the conveyor belt opens into it, which is therefore deflected again in the drop channel by 90 ° in order to run into the return channel. The return duct extends below the actual furnace to approximately the level of the loading opening, where the return duct opens into a water siphon. The empty run of the conveyor belt thus emerges largely gas-tight from the return channel and runs into the drive device for the conveyor belt, in which it is redirected upward, now in the direction of the loading opening. Between the drive device and the loading opening

überquert das Förderband eine Art Tisch, in dessen Bereich das Aufgeben der Werkstücke auf das Förderband erfolgt, die dann mitsamt dem Arbeitstrum des Förderbandes in die Ofenkammer geschafft werden.The conveyor belt crosses a kind of table, in the area of which the workpieces are placed on the conveyor belt, which are then transported to the furnace chamber together with the working belt of the conveyor belt.

Da die Prozeßtemperatur im Ofen hoch ist, besteht das Förderband üblicherweise aus miteinander verschlungenen Stahlspiralen und hat dementsprechend eine erhebliche Wärmekapazität. Im Bereich des Fallkanals wird deshalb von dem Förderband eine erhebliche Wärmemenge aus der Ofenkammer abgeführt, die während des Durchlaufens des Rückführungskanales lediglich zur Erwärmung der Umgebung beiträgt, aber im übrigen dem Behandlungsprozeß verloren geht. Beim Austreten aus dem Rücklaufkanal hat das Förderband jedenfalls eine Temperatur von unter 100°C. In der Antriebseinrichtung wird das Förderband dann gegebenenfalls noch weiter abgekühlt, ehe es mit den Werkstücken beladen durch die Beschickungsöffnung wieder in die Ofenkammer eintritt. Hinter der Beschickungsöffnung muß nun, abgesehen von den kalten Werkstücken, auch das ausgekühlte Arbeitstrum des Förderbandes wieder auf die Prozeßtemperatur aufgeheizt werden, was entweder zum entsprechenden Abkühlen der Prozeßgase führt oder zusätzliche Heizeinrichtungen erforderlich macht. In jedem Falle muß dem Förderband wieder die Wärmeenergie zugeführt werden, die es beim Durchlaufen des Rücklaufkanals verloren hat.Since the process temperature in the furnace is high, the conveyor belt usually consists of intertwined steel spirals and accordingly has a considerable heat capacity. In the area of the drop channel, a considerable amount of heat is therefore removed from the furnace chamber by the conveyor belt, which only contributes to the heating of the environment while passing through the return channel, but is otherwise lost to the treatment process. In any case, the conveyor belt has a temperature of less than 100 ° C when it emerges from the return duct. The conveyor belt is then optionally cooled further in the drive device before it, loaded with the workpieces, re-enters the furnace chamber through the loading opening. Behind the loading opening, apart from the cold workpieces, the cooled working section of the conveyor belt must now be heated up again to the process temperature, which either leads to corresponding cooling of the process gases or makes additional heating devices necessary. In any case, the conveyor belt must again be supplied with the thermal energy that it lost when passing through the return channel.

Gegebenenfalls kann sogar die Wärmemenge zum Aufheizen des Förderbandes größer sein als die Wärmemenge zum Aufheizen der zu behandelnden Werkstücke.If necessary, even the amount of heat for heating the conveyor belt can be greater than the amount of heat for Heating up the workpieces to be treated.

Aufgabe der Erfindung ist es deshalb, einen Industrieofen zu schaffen, bei dem das Förderband weniger Prozeßwärme abführt.The object of the invention is therefore to provide an industrial furnace in which the conveyor belt dissipates less process heat.

Diese Aufgabe wird erfindungsgemäß durch einen Industrieofen mit den Merkmalen des Hauptanspruches gelöst.This object is achieved by an industrial furnace with the features of the main claim.

Weil das Leertrum innerhalb der Ofenkammer zur Beschickungsöffnung zurückgeführt wird, bleibt die Temperatur des Leertrums auf der Prozeßtemperatur. Durch die im Bereich der Beschickungsöffnung vorgesehene Wärmeübertragungseinrichtung zwischen dem Leertrum und dem Arbeitstrum erfolgt eine unmittelbare Wärmeübergabe von dem Leertrum auf das Arbeitstrum, wobei die Wärmeübertragung gleichsam im Gegenstromverfahren erfolgt. Hierdurch wird zweierlei erreicht: Das Leertrum wird auf Temperaturen abgekühlt, die eine Beschädigung der Antriebseinrichtungen ausschließen, ohne daß deren mit dem Förderband in Berührung kommende Teile aus warmfestem Material gefertigt sein müssen. Die bei der Abkühlung freiwerdende Wärme wird unmittelbar vom Arbeitstrum aufgenommen und bereits auf die darauf geschichteten Werkstücke übergeben. Ohne zusätzliche äußere Energiezufuhr wird so die Temperatur des Arbeitstrums deutlich in Richtung auf die Prozeßtemperatur angehoben. Die vom Leertrum aus der Ofenkammer herausbeförderte Wärmeenergie wird mit verhältnismäßig geringen Verlusten auf das Arbeitstrum übertragen und damit wieder in die Ofenkammer zurücktransportiert.Because the empty run inside the furnace chamber is returned to the loading opening, the temperature of the empty run remains at the process temperature. The heat transfer device provided in the area of the loading opening between the empty run and the work run results in direct heat transfer from the empty run to the work run, the heat transfer taking place as it were in the countercurrent process. This achieves two things: The empty run is cooled to temperatures which preclude damage to the drive devices, without the parts thereof coming into contact with the conveyor belt having to be made of heat-resistant material. The heat released during cooling is immediately absorbed by the work strand and already transferred to the workpieces stacked on it. Without additional external energy supply, the temperature of the working area is raised significantly in the direction of the process temperature. The heat energy conveyed out of the empty strand from the furnace chamber is transferred to the working strand with relatively small losses and is thus transported back into the furnace chamber.

Ein besonders günstiger Wirkungsgrad läßt sich dabei erzielen, wenn die Wärmeübertragunsvorrichtung im wesentlichen außerhalb der Ofenkammer angeordnet ist.A particularly favorable efficiency can be achieved if the heat transfer device is arranged essentially outside the furnace chamber.

Eine sehr wirkungsvolle und mechanisch einfache Wärmeübertragungsvorrichtung besteht in einer Vielzahl von sich über die Breite des Förderbandes erstreckender zylinderförmiger Rollen aus wärmeleitendem Material. Diese Rollen sind rechtwinklig zur Bewegungsrichtung des Arbeitstrums drehbar gelagert, wobei das Arbeitstrum über die wärmeübertragenden Rollen hinwegläuft und so von diesen die Wärme abnimmt. Unterhalb der wärmeübertragenden Rollen zieht sich das Leertrum hin, das mittels Andruckeinrichtungen mit der Umfangsfläche der wärmeübertragenden Rollen in Berührung gehalten wird, damit das Leertrum seine Wärme auf die Rollen übertragen kann.A very effective and mechanically simple heat transfer device consists of a large number of cylindrical rollers made of heat-conducting material and extending over the width of the conveyor belt. These rollers are rotatably mounted at right angles to the direction of movement of the work strand, the work strand running over the heat-transferring rollers and thus reducing the heat from them. Underneath the heat-transferring rollers is the empty strand, which is held in contact with the peripheral surface of the heat-transferring rollers by means of pressure devices so that the empty strand can transfer its heat to the rollers.

Die Andruckeinrichtung für das Leertrum kann entweder von einer im wesentlichen ebenen Gleitbahn oder einer Vielzahl von zu den Wärmeübertragungsrollen achsparallel gelagerten Andruckrollen gebildet sein. Die erstgenannte Ausführungsform hat den Vorteil, etwas einfacher in der Herstellung zu sein, während das zweite Ausführungsbeispiel geringere Antriebskräfte für das Förderband erfordert. Je nach Ausführungsform sind entweder jeweils die Andruckrollen oder die wärmeübertragenden Rollen in einer zugehörigen Schiebeführung gelagert, damit eine jeweilige Rolle in Richtung auf die Gleitbahn bzw. die wärmeübertragende Rolle längsverschieblich geführt ist.The pressure device for the empty run can either be formed by an essentially flat slideway or a plurality of pressure rollers mounted axially parallel to the heat transfer rollers. The former embodiment has the advantage of being somewhat easier to manufacture, while the second embodiment requires lower driving forces for the conveyor belt. Depending on the embodiment, either the pressure rollers or the heat transfer rollers are each mounted in an associated sliding guide, so that a respective one Roll in the direction of the slideway or the heat transferring roller is guided longitudinally.

Der Wärmeverlust durch das Förderband kann weiter verringert werden, wenn an die Ofenkammer eine mit dieser über die Beschickungsöffnung in Verbindung stehende Vorkammer angeschlossen ist, durch die das Förderband verläuft und in der sich zumindest die Wärmeübertragungseinrichtung und gegebenenfalls die Antriebseinrichtung befindet, wobei die Vorkammer eine Einfüllöffnung zum Eingeben der Werkstücke aufweist.The heat loss through the conveyor belt can be further reduced if a prechamber connected to the furnace chamber via the loading opening is connected to the furnace chamber, through which the conveyor belt runs and in which at least the heat transfer device and possibly the drive device are located, the prechamber being a filling opening for entering the workpieces.

Abgesehen von der besseren Wärmeisolation verhindert die Vorkammer weitgehend ein Einschleppen von Luft in die Ofenatmosphäre und damit eine unzulässige Änderung von deren Zusammensetzung. Das aus der Ofenkammer auslaufende Leertrum des Förderbandes transportiert nämlich ständig Ofenatmosphäre in die Vorkammer, die auf diese Weise mit Ofenatmosphäre gespült wird. Mit den Werkstücken eventuell eintretende Fremdluft kann auf diese Weise von den mitgerissenen Ofengasen über die Einfüllöffnung herausgespült werden. Der beim Stand der Technik erforderliche Wassersyphon wird deshalb nicht benötigt.Apart from the better thermal insulation, the prechamber largely prevents air from being carried into the furnace atmosphere and thus an impermissible change in its composition. The empty run of the conveyor belt running out of the furnace chamber namely constantly transports the furnace atmosphere into the prechamber, which is flushed with the furnace atmosphere in this way. Any external air that may enter the workpieces can be flushed out of the entrained furnace gases via the filler opening. The water siphon required in the prior art is therefore not required.

Weil obendrein Arbeitstrum und Leertrum durch die Beschickungsöffnung laufen, ist auch der Verlust an Ofenatmosphäre insgesamt geringer als beim Stand der Technik.Because the working run and empty run also run through the loading opening, the loss of furnace atmosphere is also less overall than in the prior art.

Besonders vorteilhaft ist es, wenn die Einfüllöffnung oberhalb des Transportbandes und,in Förderrichtung gesehen, vor der Wärmeübertragungseinrichtung angeordnet ist. Es wird nämlich auf diese Weise die .gesamte Länge der Wärmeübertragungseinrichtung ausgenutzt, um Wärme vom Leertrum auf das Arbeitstrum und die Werkstücke zu übertragen.It is particularly advantageous if the filling opening is arranged above the conveyor belt and, viewed in the conveying direction, in front of the heat transfer device. This is because the entire length of the heat transfer device is used in this way to transfer heat from the empty run to the work run and the workpieces.

Die hinsichtlich des Verlustes von Ofengasen besonders kritische Beschickungsöffnung kann in ihrer lichten Weite verringert werden, wenn innerhalb der Ofenkammer in der Nähe der Beschickungsöffnung eine Umlenkeinrichtung für das Leertrum angeordnet ist, die das Leertrum in Richtung auf die Unterseite des Arbeitstrums anhebt.The feed opening, which is particularly critical with regard to the loss of furnace gases, can be reduced in its clear width if a deflection device for the empty run is arranged within the furnace chamber in the vicinity of the feed opening and raises the empty run towards the underside of the working run.

In der Zeichnung ist ein Ausführungsbeispiel des Gegenstandes der Erfindung dargestellt. Es zeigen:

  • Fig. 1 einen Industrieofen gemäß der Erfindung in einem Längsschnitt,
  • Fig. 2 die Vorkammer des Industrieofens nach Fig. 1, ebenfalls im Längsschnitt, jedoch in vergrößertem Maßstab und ohne das durchlaufende Förderband,
  • Fig. 3 die Vorkammer des Industrieofens nach Fig. 1, geschnitten entlang der Linie III-III nach Fig. 1,
  • Fig. 4 die Ofenkammer des Industrieofens nach Fig. 1, geschnitten entlang der Linie IV-IV in einem Ausschnitt und
  • Fig. 5 das Förderband des Industrieofens nach Fig. 1 in einer perspektivischen Ausschnittsdarstellung.
In the drawing, an embodiment of the object of the invention is shown. Show it:
  • 1 shows an industrial furnace according to the invention in a longitudinal section,
  • 2 the prechamber of the industrial furnace according to FIG. 1, also in longitudinal section, but on an enlarged scale and without the conveyor belt running through,
  • Fig. 3, the prechamber of the industrial furnace of FIG. 1, cut along the line III-III according to Fi g. 1,
  • Fig. 4 shows the furnace chamber of the industrial furnace of FIG. 1, cut along the line IV-IV in a section and
  • Fig. 5 shows the conveyor belt of the industrial furnace according to Fig. 1 in a perspective detail.

In Fig. 1 ist ein Industrieofen 1 veranschaulicht, der zum kontinuierlichen Warmbehandeln von Werkstücken, beispielsweise zum Aufkohlen, Nitrieren, Karbonitrieren od.dgl. dient. Der Industrieofen 1 enthält eine längliche wärmeisolierend ausgekleidete Ofenkammer 2, durch die von Seitenwand zu Seitenwand Heizrohre 3 führen, in denen Brenner zum Aufheizen der Ofenatmosphäre stecken. Die Ofenkammer 2 enthält an einer Stirnseite 4 eine Beschickungsöffnung 5, an die sich nach außen eine gerade verlaufende Vorkammer 6 anschließt, die rohrförmig ausgebildet und ebenfalls wärmeisoliert ist. Der im Querschnitt etwa rechteckige Innenraum 7 der Vorkammer 6 fluchtet mit der Beschickungsöffnung 5 und endet an einer der Beschickungsöffnung 5 gegenüberliegenden Einfüllöffnung 8.In Fig. 1, an industrial furnace 1 is illustrated, or the like for the continuous heat treatment of workpieces, for example for carburizing, nitriding, carbonitriding. serves. The industrial furnace 1 contains an elongated, heat-insulating-lined furnace chamber 2, through which heating pipes 3 lead from side wall to side wall, in which burners are used to heat the furnace atmosphere. On one end face 4, the furnace chamber 2 contains a loading opening 5, which is adjoined to the outside by a straight antechamber 6, which is tubular and is also heat-insulated. The interior 7 of the prechamber 6, which is approximately rectangular in cross section, is aligned with the loading opening 5 and ends at a filling opening 8 opposite the loading opening 5.

An dem der Stirnwand 4 gegenüberliegenden Ende der Ofenkammer 2 befindet sich in deren Boden 9 ein Fallschacht 11, durch den die durch die Ofenkammer 2 gewanderten Werkstücke den Industrieofen 1 verlassen.At the end of the furnace chamber 2 opposite the end wall 4 there is a chute 11 in the bottom 9 thereof, through which the workpieces which have moved through the furnace chamber 2 leave the industrial furnace 1.

Zum Transport der Werkstücke von der Einfüllöffnung 8 durch die Vorkammer 6 und die Ofenkammer 2 bis hin zum Fallschacht 11 enthält der Industrieofen 1 ein endloses hitzebeständiges Förderband 12, das mittels einer der Vorkammer 6 vorgelagerten Antriebseinrichtung 13 in Bewegung zu setzen ist. Das oben aus der Antriebseinrichtung 13 austretende Trum des Förderbandes 12 bildet das Arbeitstrum 14, das durch die Einfüllöffnung 8 in den Innenraum 7 der Vorkammer 6 eintritt, dort über eine weiter unten beschriebene Wärmeübertragungseinrichtung 15 läuft und schließlich durch die Beschickungsöffnung 5 in den Innenraum der Ofenkammer 2 einläuft. Innerhalb der Ofenkammer 2 ist das von der Antriebseinrichtung 13 ausgehend ständig horizontal verlaufende Arbeitstrum von einem Herd 10 unterstützt, der in Fig. 4 im einzelnen im Querschnitt gezeigt ist. An dem dem Fallschacht 11 benachbarten Ende des Herdes 10 ist im Inneren der Ofenkammer 2 eine Umlenkeinrichtung 16 für das Förderband12 angeordnet, die von einer im Inneren der Ofenkammer 2 frei drehbaren zylindrischen Rolle gebildet ist; die Breite der Rolle entspricht der Breite des jeweils verwendeten Förderbandes 12. Auf diese Weise wird das Förderband 12 oberhalb der im Inneren der Ofenkammer 2 liegenden Öffnung des Fallschachtes 11 um etwa 1800 zurück in Richtung auf die Antriebseinrichtung 13 umgelenkt; vom Arbeitstrum 14 herangeschaffte Gegenstände fallen hier in den Fallschacht 11 und verlassen so die Ofenkammer 2. Der nunmehr unterhalb des Arbeitstrums 14 zurücklaufende und als Leertrum 17 bezeichnete Abschnitt des Förderbandes 12 läuft durch das Innere der Ofenkammer 2 zurück zu der Beschickungsöffnung 5, wobei eine in der Nähe der Beschickungsöffnung 5 drehbar angeordnete Rolle 18 das im Inneren der Ofenkammer 2 frei durchhängende Leertrum 17 in die Nähe der Unterseite des Arbeitstrums 15 anhebt, so daß die Beschickungsöffnung 5, durch die das Leertrum 17 wieder aus der Ofenkammer 2 austritt, nur eine geringe lichte Höhe aufzuweisen braucht. Von der Beschickungsöffnung 5 herkommend durchläuft das Leertrum 17 die in der Vorkammer 6 befindliche Wärmeübertragungseinrichtung 15, ehe es an der Einfüllöffnung 8 aus dem Innenraum 7 der Vorkammer 6 aus- und in die Antriebseinrichtung 13 eintritt.To transport the workpieces from the filling opening 8 through the prechamber 6 and the furnace chamber 2 to the chute 11, the industrial furnace 1 contains an endless heat-resistant conveyor belt 12 which can be set in motion by means of a drive device 13 upstream of the prechamber 6. The run of the conveyor belt 12 emerging from the drive device 13 forms the working run 14, which enters through the filling opening 8 into the interior 7 of the prechamber 6, runs there via a heat transfer device 15 described below and finally through the loading opening 5 into the interior of the furnace chamber 2 arrives. Within the Oven chamber 2 is supported by the working device 13, which runs constantly horizontally from a drive 10 by a stove 10, which is shown in detail in FIG. 4 in cross section. At the end of the hearth 10 adjacent to the chute 11, a deflection device 16 for the conveyor belt 12 is arranged in the interior of the furnace chamber 2, which is formed by a cylindrical roller which can freely rotate inside the furnace chamber 2; the width of the roll corresponds to the width of the conveyor belt used in each case 12. In this way, the conveyor belt is deflected 12 above the lying inside the furnace chamber 2 opening of the chute 11 to about 180 0 back in the direction of the drive device 13; Objects brought in from the working section 14 fall into the chute 11 and thus leave the furnace chamber 2. The section of the conveyor belt 12 now running back below the working section 14 and referred to as the empty section 17 runs through the interior of the furnace chamber 2 back to the loading opening 5, one in the vicinity of the loading opening 5 rotatably arranged roller 18 raises the empty sag 17 freely sagging inside the furnace chamber 2 near the underside of the working strand 15, so that the loading opening 5, through which the empty strand 17 emerges again from the furnace chamber 2, only a small one must have clear height. Coming from the loading opening 5, the empty run 17 passes through the heat transfer device 15 located in the pre-chamber 6 before it exits the filling opening 8 from the interior 7 of the pre-chamber 6 and enters the drive device 13.

Die Antriebseinrichtung 13 enthält im wesentlichen zwei achsparallel gelagerte drehbare Rollen 19 und 20, von denen die Rolle 19 als Spannrolle für das Förderband 12 dient, während die Rolle 20 von einem Getriebemotor 21 zum Zweck des Antriebs des Förderbandes 12 in langsame Umdrehungen zu versetzen ist.The drive device 13 essentially contains two axially parallel rotatable rollers 19 and 20, of which the roller 19 serves as a tensioning roller for the conveyor belt 12, while the roller 20 is to be set in slow revolutions by a geared motor 21 for the purpose of driving the conveyor belt 12.

Der Vollständigkeit halber sei noch erwähnt, daß unterhalb der Decke der Ofenkammer 2 sich ein motorisch angetriebener Lüfterflügel 22 zum Umwälzen der Ofenatmosphäre befindet, die in ihrer Zusammensetzung und Temperatur mittels einer Partialdrucksonde 23 und eines Thermometers 24 überwacht wird.For the sake of completeness, it should also be mentioned that below the ceiling of the furnace chamber 2 there is a motor-driven fan blade 22 for circulating the furnace atmosphere, the composition and temperature of which are monitored by means of a partial pressure probe 23 and a thermometer 24.

Der oben genannte, innerhalb der Ofenkammer 2 angeordnete Herd 10 besteht im wesentlichen, wie Fig. 4 zeigt, aus zwei parallelen, im Abstand zueinander verlaufenden Schienen 25 und 26, die im gezeigten Ausführungsbeispiel auf insgesamt vier quer durch die Ofenkammer 2 verlaufenden Balken 27 starr befestigt sind. Die Balken 27 stecken, wie sich ebenfalls aus Fig. 4 ergibt, lose in entsprechenden Ausnehmungen 28 und 29 in der Ausmauerung 31 der Ofenkammer 2.The above-mentioned stove 10 arranged inside the furnace chamber 2 essentially consists, as shown in FIG. 4, of two parallel rails 25 and 26 running at a distance from one another, which in the exemplary embodiment shown are rigid on a total of four beams 27 running across the furnace chamber 2 are attached. 4, the bars 27 are loosely inserted in corresponding recesses 28 and 29 in the lining 31 of the furnace chamber 2.

Da die winkelförmigen Schienen 25 und 26 das Arbeitstrum 14 des Förderbandes 12 unterstützen sollen, entspricht ihr Abstand voneinander der Breite des Förderbandes 12, das, um ein Herunterfallen der Werkstücke zu verhindern, mit randseitigen Führungsleisten 32 und 33 versehen ist.Since the angular rails 25 and 26 are intended to support the working strand 14 of the conveyor belt 12, their distance from one another corresponds to the width of the conveyor belt 12, which is provided with edge-side guide strips 32 and 33 in order to prevent the workpieces from falling off.

Anhand der Fig. 2 und 3 ist im folgenden die Wärmeübertragungseinrichtung 15 erläutert, die sich in der Vorkammer 6 zwischen dem Arbeitstrum 14 und dem Leertrum 17 des Förderbandes 12 befindet. Die Wärmeübertragungseinrichtung 15 dient dazu, die mit dem Leertrum 17 aus der Ofenkammer 2 ständig herausbeförderte Wärme auf das von der Vorkammer 6 in die Ofenkammer 2 einlaufende Arbeitstrum zu übertragen, womit zwei Dinge erreicht werden: Das Leertrum 17 wird nach dem Austreten aus der Ofenkammer 2 auf handliche Temperaturen abgekühlt, so daß seitens der Antriebseinrichtung 13 keine besonders warmfesten Einrichtungen erforderlich sind. Andererseits wird die ständig mit dem Leertrum 17 herausgeförderte Wärme auf das Arbeitstrum 14 übertragen, was den Wärmeverlust aus der Ofenkammer 2 gering zu halten ermöglicht.2 and 3, the heat transfer device 15 is explained below, which is located in the antechamber 6 between the working section 14 and the empty section 17 of the conveyor belt 12. The heat The transfer device 15 serves to transfer the heat continuously conveyed out of the furnace chamber 2 with the empty strand 17 to the working strand entering the furnace chamber 2 from the pre-chamber 6, whereby two things are achieved: The empty strand 17 is opened after exiting the furnace chamber 2 handy temperatures cooled so that no particularly heat-resistant devices are required on the part of the drive device 13. On the other hand, the heat continuously conveyed out with the empty strand 17 is transferred to the working strand 14, which makes it possible to keep the heat loss from the furnace chamber 2 low.

So konnten bei einem praktisch ausgeführten Industrieofen folgende Temperaturen an dem Förderband gemessen werden: Das aus der Beschickungsöffnung 5 austretende Leertrum 17 weist die Temperatur der Ofenatmosphäre ca. 8000 C auf. Am Ende der Wärmeübertragungseinrichtung 15, d.h. in der Nähe der Einfüllöffnung 8, ist das Leertrum von den erwähnten 800° C auf ca. 600 C heruntergekühlt. Die dabei frei gewordene Wärme ist auf das mit den Werkstücken versehene Arbeitstrum 14 übertragen, das an der Einfüllöffnung 8 eine Temperatur von 400 C aufweist und durch die Wärmeübertragungseinrichtung 15 bei der Beschickungsöffnung 5 bereits auf 600 C aufgeheizt ist.For example, the following temperatures could be measured on the conveyor belt in a practically designed industrial furnace: The empty run 17 emerging from the loading opening 5 has the temperature of the furnace atmosphere of approximately 800 ° C. At the end of the heat transfer device 15, ie near the filling opening 8, the return strand of the mentioned 800 ° C to about 60 0 C is cooled down. The thereby liberated heat is transferred to the working section provided with the workpieces 14, which, at the filling opening 8, a temperature of 40 0 C and is heated by the heat transfer device 15 in the charging opening 5 already at 600 C.

Ersichtlicherweise ermöglicht die Wärmeübertragungseinrichtung 15 eine deutliche Verbesserung der Wärmebilanz, weil die von dem Leertrum 17 abgegebene Wärme nicht nutzlos in die Umgebung geht, sondern zum Aufheizen des Arbeitstrums 14 und der Werkstücke verwendet werden kann.Obviously, the heat transfer device 15 enables a significant improvement in the heat balance, because the heat emitted by the empty run 17 does not go uselessly into the environment, but can be used to heat the working run 14 and the workpieces.

Bei dem gezeigten Ausführungsbeispiel ist der Innenraum 7 der Vorkammer 6 von einem im Querschnitt rechteckigen Stahlrohr 41 begrenzt, das von der Einfüllöffnung 8 bis zur Außenseite der Stirnwand 4 der Ofenkammer 2 reicht und den Boden 42,zwei parallel im Abstand verlaufende Seitenwände 43, 44 sowie die Decke 45 des Innenraumes 7 bildet. Die Wärmeisolierung der Vorkammer 6 befindet sich außerhalb des Stahlrohrs 41, dessen lichte Breite der Breite des Förderbandes 12 entspricht.In the embodiment shown, the interior 7 of the prechamber 6 is delimited by a steel tube 41 with a rectangular cross section, which extends from the filling opening 8 to the outside of the end wall 4 of the furnace chamber 2 and the bottom 42, two parallel side walls 43, 44 and the ceiling 45 of the interior 7 forms. The thermal insulation of the pre-chamber 6 is located outside the steel tube 41, the clear width of which corresponds to the width of the conveyor belt 12.

Die Wärmeübertragungseinrichtung 15 im Inneren des Stahlrohrs 41 wird von insgesamt fünf parallel im Abstand zueinander angeordneten Rollen 46a bis 46e gebildet, die jeweils aus einem Stahlrohr entsprechender Breite bestehen und rechtwinklig zur Bewegunqsrichtung des Transportbandes 12 drehbar sind. An diesen Stahlrohren 46a bis 46e ist jeweils die Rückseite des Arbeitstrums 14 und des Leertrums 17 anliegend gehalten, so daß ein Wärmekontakt oder eine Wärmebrücke zwischen den beiden in entgegengesetzter Richtung laufenden Trums 14, 17 entsteht. Das Leertrum 17 läuft hierzu über eine auf dem Boden 42 befestigte ebene und horizontal verlaufende Gleitbahn 47, deren Breite geringfügig kleiner ist als der Abstand der beiden Führungsleisten 32 und 33 des Förderbandes 12, wie dies Fig. 3 zeigt. Hierdurch wird eine flächige Unterstützung des Leertrums 17, und zwar auf der die Werkstücke aufnehmenden Fläche des Förderbandes 12 erreicht und verhindert, daß das Förderband 12 mit seinen Führungsleisten 32, 33 auf der Gleitbahn 47 aufsteht und damit hohlliegen würde. Die Gleitbahn 47 reicht von der Einfüllöffnung 8 bis zu der Beschickungsöffnung 5, wo sie in eine schräge Rampe 48 überaeht, die bis in die Ofenkammer 2 hineinreicht. Auf der nach oben gekehrten Rückseite des von der Gleitbahn 47 unterstützten Leertrums 17 liegen die fünf Wärmeübertragungsrollen 46a bis 46e auf, die sich in der Höhe frei bewegen können. Das Arbeitstrum 14 läuft in der Vorkammer 6 mit seiner Rückseite über die Außenumfangsfläche der wärmeübertragenden Rollen 46a bis 46e und wird aufgrund der Schwerkraft an der Außenumfangsfläche der wärmeübertragenden Rollen 46a bis 46e gehalten. Diese aus wärmeleitendem und warmfestem Material bestehenden Wärmeübertragungsrollen 46a bis 46e haben einen Außendurchmesser zwischen 10 und 80 mm, vorzugsweise jedoch einen Durchmesser zwischen 10 und 50 mm und einen Mittenabstand voneinander von etwa 100 mm, womit ein nennenswertes Durchhängen des Förderbandes 12 zwischen jeweils zwei benachbarten Wärmeübertragungsrollen 46a bis 46e vermieden ist.The heat transfer device 15 in the interior of the steel tube 41 is formed by a total of five rollers 46a to 46e, which are arranged parallel and at a distance from one another and each consist of a steel tube of corresponding width and are rotatable at right angles to the direction of movement of the conveyor belt 12. The back of the working run 14 and the empty run 17 are held against these steel pipes 46a to 46e, so that a thermal contact or a thermal bridge between the two runs 14, 17 running in the opposite direction is created. For this purpose, the empty run 17 runs over a flat and horizontally running slideway 47 fastened to the floor 42, the width of which is slightly smaller than the distance between the two guide strips 32 and 33 of the conveyor belt 12, as shown in FIG. 3. This results in a flat support of the empty run 17, namely on the workpiece-receiving surface of the conveyor belt 12, and prevents the conveyor belt 12 with its guide strips 32, 33 from standing on the slideway 47 and thus lying hollow. The slideway 47 extends from the filling opening 8 to the loading opening 5, where it passes over an inclined ramp 48 which extends into the furnace chamber 2. On the upward-facing rear side of the slide 47 under supported empty runs 17 are the five heat transfer rollers 46a to 46e, which can move freely in height. The working strand 14 runs in the prechamber 6 with its rear side over the outer peripheral surface of the heat transfer rollers 46a to 46e and is held on the outer peripheral surface of the heat transfer rollers 46a to 46e due to gravity. These heat transfer rollers 46a to 46e, which are made of heat-conducting and heat-resistant material, have an outside diameter between 10 and 80 mm, but preferably a diameter between 10 and 50 mm and a center distance of about 100 mm from each other, which means that the conveyor belt 12 sags appreciably between two adjacent heat transfer rollers 46a to 46e is avoided.

Für jede der Wärmeübertragungsrollen 46a bis 46e enthält jede der beiden Seitenwände 43 und 44 einen rechteckigen Schlitz 49a bis 49e, durch die die wärmeübertragenden Rollen 46a bis 46e endseitig mit verhältnismäßig großem Radialspiel hindurchragen, denn deren axiale Länge ist größer als die lichte Weite des Abstandes zwischen den beiden Seitenwänden 43 und 44. Um ein allmähliches Herauswandern der wärmeübertragenden Rollen 46a bis 46e in axialer Richtung zu vermeiden, ist außerhalb des Innenraumes 7 an jeder der beiden Seitenwände 43 und 44 ein abgewinkelter Flansch 51, 52 befestigt, der lediglich als Anlauffläche für die jeweils benachbarte Stirnseite der wärmeübertragenden Rolle 46a bis 46e dient.For each of the heat transfer rollers 46a to 46e, each of the two side walls 43 and 44 contains a rectangular slot 49a to 49e, through which the heat transfer rollers 46a to 46e protrude at the end with a relatively large radial clearance, because their axial length is greater than the clear width of the distance between the two side walls 43 and 44. To avoid a gradual migration of the heat transfer rollers 46a to 46e in the axial direction, an angled flange 51, 52 is attached outside of the interior 7 on each of the two side walls 43 and 44, which is only used as a contact surface for the each adjacent end of the heat transfer roller 46a to 46e is used.

Wenn, wie nachstehend noch erläutert, die Führungsleisten 32 und 33 des Förderbandes 12 über dessen Rückseite hinausstehen, ist es erforderlich, die wärmeübertragenden Rollen 46a bis 46e in der in Fig. 3 gezeigten Weise endseitig abzusetzen, um zu vermeiden, daß das Förderband mit seinen Leisten 32, 33 auf den wärmeübertragenden Rollen 46a bis 46e aufstehen, wodurch die Rückseite des Förderbandes 12 hohlliegen würde.Wenn für die wärmeübertragenden Rollen 46, wie gezeigt, zylindrische Rohre verwendet werden, genügt es, in diese zylindrischen Rohre endseitig zylindrische Rohre 53 mit entsprechend geringerem Durchmesser einzustecken und zu befestigen.If, as will be explained below, the guide strips 32 and 33 of the conveyor belt 12 protrude beyond the rear side, it is necessary to heat the transferring rollers 46a to 46e in the end settle manner shown in Fig. 3, in order to avoid that the conveyor belt with its strips 32, stand 33 on the heat transferring rollers 46a to 46e, whereby the back of the conveyor belt 12 hohllie g en würde.Wenn for the heat-transferring rollers 46, as shown, cylindrical tubes are used, it is sufficient to insert and fasten cylindrical tubes 53 with a correspondingly smaller diameter at the end of these cylindrical tubes.

Um ein Einströmen von Außenluft in die Ofenkammer 2 weitgehend zu vermeiden, ist oberhalb der Einfüllöffnung 8 eine Schwenkklappe 54 frei pendelnd aufgehängt, die auf dem Arbeitstrum 14 entlanggleitet und von den sich mit dem Förderband 12 in die Vorkammer 6 bewegenden Werkstücken hochgeklappt wird. Weiterhin kann zwischen dem Arbeitstrum 14 und dem Leertrum 17 noch mit Hilfe von Brennerdüsen 55 ein Flammvorhang erzeugt werden, der den Innenraum der Ofenkammer 2 weiter gegen die Außenluft abdichtet. Falls dennoch Außenluft in die Vorkammer eindringen sollte, wird sie von aus der Vorkammer 6 und deren Einfüllöffnung 8 austretende Ofenatmosphäre mit herausgespült, was insbesondere dann besonders leicht vonstatten geht, wenn das Förderband, wie in Fig. 5 gezeigt, besonders gasdurchlässig ausgebildet ist. Es erfolgt dann eine ständige geringfügie Spülung der Vorkammer 6 mit Ofenatmosphäre, und zwar über den gesamten Querschnitt des Innenraums 7, was wirksam Lufteinbrüche in die Ofenkammer 2 verhindert.In order to largely prevent outside air from flowing into the furnace chamber 2, a pivoting flap 54 is freely suspended above the filling opening 8, which slides along the work strand 14 and is folded up by the workpieces that move with the conveyor belt 12 into the prechamber 6. Furthermore, a flame curtain can be generated between the working section 14 and the empty section 17 with the help of burner nozzles 55, which further seals the interior of the furnace chamber 2 against the outside air. If outside air should nevertheless enter the prechamber, it is flushed out by the furnace atmosphere emerging from the prechamber 6 and its filling opening 8, which is particularly easy when the conveyor belt, as shown in FIG. 5, is particularly gas-permeable. There is then a constant slight flushing of the prechamber 6 with the furnace atmosphere, specifically over the entire cross section of the interior 7, which effectively prevents air ingress into the furnace chamber 2.

Das ausschnittsweise in Fig. 5 perspektivisch gezeigte Förderband 12 besteht aus einer Vielzahl von zur Förderbandlängsrichtung quer verlaufenden abgeplatteten Drahtspiralen 56a bis 56c, wobei jeweils zwei benachbarte Drahtspiralen 56a und 56b bzw. 56b und 56c mittels einer ihnen jeweils gemeinsamen, ebenfalls quer verlaufenden Rundstange 57a bis 57d miteinander verbunden sind. An jedem Ende der Drahtspiralen 56a bis 56c steckt auf jeder der Rundstangen 57a bis 57d je zwei Platten 58a bis 58d, die die beiden Führungsleisten 32 und 33 bilden. Dabei steckt jede der Platten 58a und 58d auf jeweils zwei einander benachbarten Rundstangen 57a bis 57d, so daß sich das in Fig. 5 ersichtliche schuppenartige Ubereinanderliegen der Platten 58a bis 58d in Transportbandlängsrichtung ergibt.The conveyor belt 12 shown in perspective in FIG. 5 consists of a plurality of flattened wire spirals 56a to 56c running transversely to the longitudinal direction of the conveyor belt, two adjacent wire spirals 56a and 56b or 56b and 56c each using a common, likewise transverse round rod 57a to 57d are connected to each other. At each end of the wire spirals 56a to 56c there are two plates 58a to 58d on each of the round rods 57a to 57d, which form the two guide strips 32 and 33. Each of the plates 58a and 58d is placed on two adjacent round rods 57a to 57d, so that the scale-like superimposition of the plates 58a to 58d shown in FIG. 5 results in the longitudinal direction of the conveyor belt.

Außerhalb der Platten 58a bis 58d sind die Rundstangen 57a bis 57d jeweils in gleicher Richtung auf die benachbarte Rundstange 57a bis 57d abgebogen und mit dieser durch ein hakenförmiges Ende verbunden.Outside the plates 58a to 58d, the round rods 57a to 57d are each bent in the same direction onto the adjacent round rod 57a to 57d and connected to it by a hook-shaped end.

Falls die durch die Gleitbahn 47 hervorgerufenen Reibungskräfte zu groß sind, ist es auch möglich, anstelle der durchgehenden Gleitbahn 47 unterhalb jeder der wärmeübertragenden Rollen 46a bis 46e weitere Rollen drehbar zu lagern, so daß zwischen dem Förderband 12 und den Teilen in der Vorkammer 6, die mit dem Förderband 12 in Berührung kommen, lediglich Abwälzbewegungen auftreten.If the frictional forces caused by the slideway 47 are too great, it is also possible, instead of the continuous slideway 47, to rotatably mount further rollers underneath each of the heat-transferring rollers 46a to 46e, so that between the conveyor belt 12 and the parts in the antechamber 6, that come into contact with the conveyor belt 12, only rolling movements occur.

Claims (13)

1. Industrieofen zur Wärmebehandlung durchlaufender Werkstücke, mit einer einenends eine Beschickungsöffnung und andernends einen Fallkanal aufweisenden Ofenkammer , mit einem endlosen Förderband, von dem zumindest sein die Werkstücke aufnehmendes Arbeitstrum die Ofenkammer von der Beschickungsöffnung bis zu dem Fallschacht durchzieht, sowie mit einer Antriebseinrichtung für das Förderband, das im Bereich des Fallschachtes entgegen der Transportrichtung der Werkstücke umgelenkt wird, wobei das Arbeitstrum durch die Beschickungsöffnung in die Ofenkammer eintritt und die auf dem Förderband herangebrachten Werkstücke durch den Fallschacht die Ofenkammer verlassen, und mit einer außerhalb der Ofenkammer angeordneten und der Beschickungsöffnung benachbarten zweiten Umlenkeinrichtung für das Förderband, dadurch gekennzeichnet, daß das Leertrum (17) des Förderbandes (12) durch die Ofenkammer (2) zurücklaufend geführt ist und durch die Beschickungsöffnung (5) aus der Ofenkammer (2) austritt, und daß an dem der Beschickungsöffnung (5) benachbarten Ende des Förderbandes (12) zwischen dem Leertrum (17) und dem Arbeitstrum (14) eine Wärmeübertragungseinrichtung (15) vorgesehen ist.1.Industrial furnace for heat treatment of workpieces running through, with an oven chamber having a loading opening on one end and a drop channel on the other, with an endless conveyor belt, of which at least his work piece receiving the workpieces runs through the furnace chamber from the loading opening to the chute, and with a drive device for this Conveyor belt, which is deflected in the area of the chute against the direction of transport of the workpieces, the work strand entering the furnace chamber through the loading opening and the workpieces brought up on the conveyor belt leaving the furnace chamber through the chute, and with one located outside the furnace chamber and adjacent to the loading opening second deflection device for the conveyor belt, characterized in that the empty run (17) of the conveyor belt (12) is guided back through the furnace chamber (2) and exits the furnace chamber (2) through the loading opening (5), u nd that at the loading opening (5) adjacent end of the conveyor belt (12) between the empty run (17) and the work strand (14) is provided with a heat transfer device (15). 2. Industrieofen nach Anspruch 1, dadurch gekennzeichnet, daß sich die Wärmeübertragungsvorrichtung (15) im wesentlichen außerhalb der Ofenkammer (2) befindet.2. Industrial furnace according to claim 1, characterized in that the heat transfer device (15) is located essentially outside the furnace chamber (2). 3. Industrieofen nach Anspruch 1, dadurch gekennzeichnet, daß die Wärmeübertragungsvorrichtung (15) von einer Vielzahl von sich über die Breite des Förderbandes (12) erstreckenden zylinderförmigen oder zylindrischen Rollen (46a ... 46e) aus wärmeleitendem, hitzbeständigem Material gebildet ist, die rechtwinklig zur Bewegungsrichtung des Arbeitstrums (14) drehbar gelagert sind und über die das Arbeitstrum (14) anliegend hinwegläuft, und daß das Leertrum (17) mittels Andruckeinrichtungen (47) mit der Umfangsfläche der wärmeübertragenden Rollen (46a ... 46e) in Berührung gehalten ist.3. Industrial furnace according to claim 1, characterized in that the heat transfer device (15) of a plurality of across the width of the conveyor belt (12) extending cylindrical or cylindrical rollers (46a ... 46e) is formed of heat-conducting, heat-resistant material, which are rotatably mounted at right angles to the direction of movement of the working section (14) and over which the working section (14) runs, and that the empty section (17) is held in contact with the peripheral surface of the heat-transferring rollers (46a ... 46e) by means of pressure devices (47) is. 4. Industrieofen nach Anspruch 3, dadurch gekennzeichnet, daß die Andruckeinrichtung von einer im wesentlichen ebenen Gleitbahn (47) gebildet ist, auf der das Leertrum (17) englanggleitet und die das Leertrum (17) unterstützen, und daß jede der wärmeübertragenden Rollen (46a ... 46e) rechtwinklig zu der durch die Gleitbahn (47) gebildeten Fläche frei beweglich ist.4. Industrial furnace according to claim 3, characterized in that the pressure device is formed by a substantially flat slideway (47) on which the empty run (17) glides in and support the empty run (17), and in that each of the heat-transferring rollers (46a ... 46e) is freely movable at right angles to the surface formed by the slideway (47). 5. Industrieofen nach Anspruch 3, dadurch gekennzeichnet, daß die Andruckeinrichtung von zu den wärmeübertragenden Rollen (46a ... 46e) achsparallel gelagerten Andruckrollen gebildet ist, und daß für die Lagerung entweder jeder Andruckrolle (46a ... 46e) oder jeder der wärmeübertragenden Rollen eine Schiebeführung vorgesehen ist, in denen jede Rolle in Richtung auf die andere Rolle vertikal längsverschieblich geführt ist.5. Industrial furnace according to claim 3, characterized in that the pressure device of the heat-transferring rollers (46a ... 46e) is formed axially parallel pressure rollers, and that for the storage of either each pressure roller (46a ... 46e) or each of the heat transfer rollers a sliding guide is provided, in which each roller is guided vertically longitudinally in the direction of the other roller. 6. Industrieofen nach Anspruch 1, dadurch gekennzeichnet, daß an die Ofenkammer eine mit dieser über die Beschickungsöffnung (5) in Verbindung stehende Vorkammer (6) angeschlossen ist, durch die das Förderband (12) verläuft und in der sich zumindest ein Teil der Wärmeübertragungseinrichtung (15) befindet, und daß die Vorkammer (6) eine Einfüllöffnung (8) zum Eingeben der Werkstücke aufweist.6. Industrial furnace according to claim 1, characterized in that to the furnace chamber with this via the loading opening (5) in connection pre-chamber (6) is connected, through which the conveyor belt (12) runs and in which at least part of the heat transfer device (15), and that the pre-chamber (6) has a filling opening (8) for entering the workpieces. 7. Industrieofen nach Anspruch 6, dadurch gekennzeich- .net, daß sich die Einfüllöffnung (8) oberhalb des Transportbandes und in Förderrichtung gesehen vor der Wärmeübertragungseinrichtung (15) befindet.7. Industrial furnace according to claim 6, characterized gekennzeich- .net that the filling opening (8) above the conveyor belt and seen in the conveying direction is in front of the heat transfer device (15). 8. Industrieofen nach Anspruch 8, dadurch gekennzeichnet, daß innerhalb der Ofenkammer (2) in der Nähe der Beschickungsöffnung (5) eine weitere Umlenkeinrichtung (18) für das Leertrum (17) angeordnet ist, durch die das Leertrum (17) an die Unterseite des Arbeitstrums (14) heranführbar ist.8. Industrial furnace according to claim 8, characterized in that within the furnace chamber (2) in the vicinity of the loading opening (5) a further deflection device (18) for the empty run (17) is arranged, through which the empty run (17) to the underside of the working strand (14) can be brought up. 9. Industrieofen nach Anspruch 3, dadurch gekennzeichnet, daß die wärmeübertragenden Rollen (46a ... 46e) zylindrische Rohiesind, deren Durchmesser zwischen 10 mm und 80 mm, vorzugsweise zwischen 10 mm und 50 mm beträgt.9. An industrial furnace according to claim 3, characterized in that the heat transferring rollers (46a ... 46e) are cylindrical Rohi e are of a diameter between 10 mm and 80 mm, preferably between 10 mm and 50 mm is. 10. Industrieofen nach Anspruch 1, dadurch gekennzeichnet, daß parallel zur Bewegungsrichtung des Transportbandes (12) gesehen die Länge der Wärmeübertragungseinrichtung (15) zwischen 0,5 m und 2 m beträgt.10. Industrial furnace according to claim 1, characterized in that seen parallel to the direction of movement of the conveyor belt (12), the length of the heat transfer device (15) is between 0.5 m and 2 m. 11. Industrieofen nach Anspruch 3, dadurch gekennzeichnet, daß als Wärmeübertragungseinrichtung (15) wenigstens fünf äquidistant angeordnete Rollen (46a ... 46e) vorgesehen sind.11. Industrial furnace according to claim 3, characterized in that at least five equidistantly arranged rollers (46a ... 46e) are provided as the heat transfer device (15). 12. Industrieofen nach Anspruch 1, dadurch gekennzeichnet, daß das Förderband (12) gasdurchlässig ist.12. Industrial furnace according to claim 1, characterized in that the conveyor belt (12) is gas permeable. 13. Industrieofen nach Anspruch 12, dadurch gekennzeichnet, daß das Förderband (12) von einer Vielzahl von parallel nebeneinander angeordneten Spiralen (56a ... 56c) besteht, von denen je zwei benachbarte, mittels eines durch sie hindurchverlaufenden Stabes (57a ... 57c) miteinander verbunden sind.13. Industrial furnace according to claim 12, characterized in that the conveyor belt (12) consists of a plurality of spirals (56a ... 56c) arranged parallel to one another, two of which are adjacent, by means of a rod (57a ...) extending through them. 57c) are connected to one another.
EP85111008A 1984-11-27 1985-08-31 Industrial furnace for the continuous heat treatment of articles Expired - Lifetime EP0188659B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85111008T ATE58964T1 (en) 1984-11-27 1985-08-31 INDUSTRIAL FURNACE FOR HEAT TREATMENT OF CONTINUOUS WORKPIECES.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3443112A DE3443112C1 (en) 1984-11-27 1984-11-27 Industrial furnace for heat treatment of continuous workpieces
DE3443112 1984-11-27

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EP0188659A2 true EP0188659A2 (en) 1986-07-30
EP0188659A3 EP0188659A3 (en) 1987-12-02
EP0188659B1 EP0188659B1 (en) 1990-12-05

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EP85111008A Expired - Lifetime EP0188659B1 (en) 1984-11-27 1985-08-31 Industrial furnace for the continuous heat treatment of articles

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EP (1) EP0188659B1 (en)
AT (1) ATE58964T1 (en)
CS (1) CS261231B2 (en)
DE (2) DE3443112C1 (en)
DK (1) DK160656C (en)
NO (1) NO165045C (en)
PL (1) PL146609B1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100186940A1 (en) * 2007-07-12 2010-07-29 Jean Marc Raick Method, Device and System for the Heat Treatment of a Moving Metal Strip
CN105858279A (en) * 2015-01-22 2016-08-17 夏佩文 Movable high-temperature material distributing machine

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1828036A (en) * 1928-06-25 1931-10-20 Frank A Fahrenwald Process of heat treating
US2319301A (en) * 1942-08-17 1943-05-18 Associated Spring Corp Contact strip annealing furnace
FR1482719A (en) * 1966-06-09 1967-05-26 Four Electr Delemont Sa Du Furnace for continuous heat treatment of metal parts
DE1483513A1 (en) * 1965-08-11 1969-02-13 Elektro Ind Ofenbau Veb Continuous furnace with belt conveyor, especially for operation at high temperatures and protective gas atmospheres

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1828036A (en) * 1928-06-25 1931-10-20 Frank A Fahrenwald Process of heat treating
US2319301A (en) * 1942-08-17 1943-05-18 Associated Spring Corp Contact strip annealing furnace
DE1483513A1 (en) * 1965-08-11 1969-02-13 Elektro Ind Ofenbau Veb Continuous furnace with belt conveyor, especially for operation at high temperatures and protective gas atmospheres
FR1482719A (en) * 1966-06-09 1967-05-26 Four Electr Delemont Sa Du Furnace for continuous heat treatment of metal parts

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100186940A1 (en) * 2007-07-12 2010-07-29 Jean Marc Raick Method, Device and System for the Heat Treatment of a Moving Metal Strip
CN105858279A (en) * 2015-01-22 2016-08-17 夏佩文 Movable high-temperature material distributing machine

Also Published As

Publication number Publication date
NO165045B (en) 1990-09-03
NO853857L (en) 1986-05-28
CS261231B2 (en) 1989-01-12
DK543085D0 (en) 1985-11-22
DK160656C (en) 1991-09-02
PL146609B1 (en) 1989-02-28
EP0188659B1 (en) 1990-12-05
DE3580840D1 (en) 1991-01-17
EP0188659A3 (en) 1987-12-02
DE3443112C1 (en) 1986-08-07
CS849185A2 (en) 1988-05-16
DK543085A (en) 1986-05-28
NO165045C (en) 1990-12-12
PL256206A1 (en) 1986-09-23
ATE58964T1 (en) 1990-12-15
DK160656B (en) 1991-04-02

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