Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
• • 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
  • F27B9/16—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 circular or arcuate path
• • 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
  • C21D9/0037—Rotary furnaces with vertical axis; Furnaces with rotating floor
• • 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
  • F27B9/30—Details, accessories, or equipment peculiar to furnaces of these types
  • F27B9/39—Arrangements of devices for discharging
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/62—Quenching devices
  • C21D1/63—Quenching devices for bath quenching
• • 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
  • C21D9/0006—Details, accessories not peculiar to any of the following furnaces
  • C21D9/0018—Details, accessories not peculiar to any of the following furnaces for charging, discharging or manipulation of charge
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/0062—Heat-treating apparatus with a cooling or quenching zone
• • 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
  • F27B9/028—Multi-chamber type furnaces
• • 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
  • F27B9/04—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity adapted for treating the charge in vacuum or special atmosphere
  • F27B9/045—Furnaces with controlled atmosphere
• • 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
  • F27B9/40—Arrangements of controlling or monitoring devices
• • 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
  • F27D1/00—Casings; Linings; Walls; Roofs
  • F27D1/18—Door frames; Doors, lids, removable covers
  • F27D1/1858—Doors
  • F27D2001/1891—Doors for separating two chambers in the furnace
• • 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
  • F27D3/0024—Charging; Discharging; Manipulation of charge of metallic workpieces

Definitions

• the invention relates to a system for heat treatment of workpieces, with a cyclically rotating rotary hearth furnace, which has an outer and an inner wall that delimit an oven space that is divided by means of vertically movable doors into a heating zone and at least one treatment zone, the outer wall in the heating zone has a closable opening for loading or unloading, with a transport device for transporting the workpieces into or out of the rotary hearth furnace and a quenching device.
• Such a system is known from DE C1 34 27 716. It is a system for hardening individual parts with a rotary hearth furnace and a hardening press.
• the rotary hearth furnace has a lock-like loading or unloading zone which is formed by means of vertically movable doors arranged on both sides next to the loading and unloading opening. After opening the furnace door, the workpieces can be removed individually from this loading or unloading zone using a loading and unloading robot and transferred to the hardening press.
• the cycle time ie the time between loading and unloading a workpiece in or out of the rotary hearth furnace is relatively long in the known system, since one only opening is used for both loading and unloading. Therefore, there is also a need to minimize the cycle time.
• the invention is therefore based on the object of creating a system of the type mentioned which can be used universally and whose cycle time is short.
• the rotary hearth furnace has two closable openings, both of which are used for loading and unloading or one for loading only and the other for unloading only.
• a lock is in front of the second opening.
• a quench bath is directly connected to the rotary hearth furnace by means of this lock.
• the system according to the invention can be used universally. In addition, the cycle time can be minimized and the hourly throughput of workpieces increased.
• the two openings are arranged next to one another with a small circumferential distance, the circumferential distance between the first and the second opening preferably being essentially 45 °. Depending on the space available in individual cases, the circumferential distance can also be up to 90 °.
• the first opening is preceded by a lock for loading, so that the first opening is used exclusively for loading.
• the second opening will only be used for unloading.
• the first opening is arranged vertically above the furnace space.
• the first opening is preceded by a loading lock in the vertical direction, which is designed as an elevator lock known per se, with a transport device for the horizontal transport of the workpieces. So that the loading opening can be relatively tight or immediate be arranged next to the removal opening. This has the advantage that the furnace space available for the heat treatment can be optimally used.
• both the lock and any loading lock which may be present are gas-tight.
• the locks have at least one lock door that is essentially perpendicular to the opening in the outer wall.
• the lock door is therefore in a side wall of the lock.
• the quenching bath which is connected to the rotary hearth furnace by means of the lock, is accordingly arranged on a side wall of the lock.
• a second quenching device is preferably connected to the rotary hearth furnace by means of the lock.
• This can be a gas quenching chamber or another quenching bath. This increases the flexibility of the system considerably, since the workpieces can be quenched at different temperatures.
• the two quenching devices are arranged on the opposite side walls of the lock.
• a transport device in the form of an impact device is preferably assigned to at least one opening.
• the batch is transported in a simple manner into the removal lock by means of the pusher device and from there is transferred into the quenching bath adjoining the removal lock.
• an impact device can also be used here.
• the workpieces, which are packed in batches in baskets or similar containers, are transported into the lock by means of the pusher and from there transferred to the rotary hearth furnace.
• One of the vertically movable doors is located between the first opening and the second opening, so that a zone is separated between loading and unloading.
• At least one additional vertically movable door for changing the length of the heating and / or treatment zone.
• the additional door can be used for zone separation if necessary. All doors can be controlled individually and can therefore be moved individually.
• the invention also provides a rotary hearth furnace for the heat treatment of workpieces, with a cyclically rotatable rotary hearth, with an outer and an inner wall which delimit an oven space which is divided into vertically movable doors in a heating zone and at least one treatment zone, with a closable loading and discharge opening, which is arranged in the outer wall, adjacent to the heating zone.
• the rotary hearth furnace is characterized in that a second closable loading and unloading opening is arranged in the outer wall, adjacent to the heating zone and at a distance from the first loading and unloading opening, and in that the rotary hearth can be rotated in both directions.
• the rotary hearth furnace according to the invention offers the choice between two loading and unloading options.
• Both loading and unloading openings can be used for both loading and unloading. Both loading and unloading openings are located adjacent to the heating zone, so that when each opening is loaded, it is ensured that the workpieces, after they have been introduced into the furnace chamber, reach the heating zone directly. It is only necessary to change the direction of rotation of the lathe accordingly. This significantly improves the functionality of the rotary hearth furnace.
• the heating zone preferably extends between the first and the second loading and unloading opening over a range of essentially 90 °.
• At least two treatment zones are provided, each of which adjoins the heating zone and which can be set differently with regard to the treatment temperature and treatment atmosphere.
• the lock is accordingly preferably gas-tight.
• doors are provided on both sides immediately next to the first loading and unloading opening, so that a loading and unloading zone is formed which can be heated.
• the invention also provides a system with a rotary hearth furnace according to the invention, with a transport device for transporting the workpieces into or out of the rotary hearth furnace and a quenching device, characterized in that a lock is arranged in front of the second loading and unloading opening, that a second quenching device is provided, which is designed as a quench bath and which is connected to the second opening of the rotary hearth furnace by means of the lock.
• This system can be used particularly universally, since a quenching device is provided at each opening. Each opening is used for both loading and unloading. Depending on which of the two openings the workpieces get into the furnace, the direction of rotation of the rotary hearth furnace is changed so that the workpieces first reach the heating zone.
• Figure 1 is a schematic plan view of a first embodiment of a plant for heat treatment.
• Fig. 2 is a schematic plan view of a second embodiment of a plant for heat treatment.
• the system for hardening workpieces according to FIG. 1 has a rotary hearth furnace 1 which is cyclically rotatable only in one direction, namely in the clockwise direction.
• the furnace space is divided into a heating zone 6 and three treatment zones 7, 8, 9, namely a first and a second diffusion / carbonization zone 7, 9, and a carbonation zone 8.
• the doors 5a-5d can be raised vertically in a manner not shown.
• the workpieces are located on batch carriers 10 in the form of grates.
• a first closable opening 11 in the outer wall which is preceded by a gas-tight lock 12 for loading.
• the opening 10 between the furnace chamber and the lock 12 can be opened or closed in a known manner by means of an oven door.
• the lock 12 has a lock door 13, which is essentially runs at right angles to the opening 10 and which is alternately opened or closed for loading.
• the batch carriers 10 with the workpieces are in a pre-oxidation furnace 14.
• the batch carriers 10 are inserted from the lock 12 into the furnace chamber by means of a first impact device 15.
• the batch carriers 10 first arrive in the heating zone 6 and from the heating zone 6 into the treatment zones 7, 8 and 9 as a result of the rotation of the rotary hearth.
• the treatment zones are diffusion / carbonization zones in which the treatment temperatures and the treatment atmosphere differ are adjustable.
• the treatment atmosphere or a neutral gas, for example nitrogen, can be located in the lock 12 and the loading lock.
• a second closable opening 16 In the outer wall 2 there is a second closable opening 16, which is preceded by a gas-tight lock 17 for unloading. There is a circumferential distance of approximately 45 ° between the two openings 11 and 16.
• a first quench bath 18 and a second quench bath 19, in which different temperatures prevail, are coupled to the lock 17 via lock doors (not shown in more detail) which run essentially at right angles to the opening 16.
• the unloading of the individual batch carriers 10 with the workpieces at the end of the last treatment zone takes place by means of a second pushing device 20.
• the unloading like the loading, is carried out in cycles.
• the batch carrier 10, which has arrived at the end of the last treatment zone is transported and quenched after opening the second opening 16 by means of the pushing device 20 into the lock 17 and from there optionally into one of the two quenching baths 18, 19.
• the second opening 16 is closed again after each removal process.
• a vertically movable door 5d is located between the first opening 11 and the second opening 16, so that the loading and unloading take place in different zones, namely the heating zone 7 and the last treatment zone 9. Modifications are possible within the scope of the invention without further notice.
• the circumferential distance between the two openings can deviate from 45 °.
• the circumferential distance should be as small as possible, but can be up to 90 ° for reasons of space.
• the second quenching device can be designed as a gas quenching chamber. Additional doors could be used to change the length of the heating zone and / or treatment zone.
• FIG. 2 shows a rotary hearth furnace 21, which is used for heat treatment in the context of a method for hardening workpieces 22, and has a rotary hearth 23 which is cyclically rotatable in both directions.
• the furnace space is divided by means of doors 26a-26e into a heating zone 27 and three treatment zones 28 to 30, namely a first and a second diffusion / carburizing zone 28, 30 and a carburizing zone 29.
• the doors 26a-26d can be lifted vertically in a manner not shown.
• first opening 31 for loading and unloading, to which doors 26a-26e are connected on both sides, so that a loading and unloading zone 32 is formed.
• a furnace door 33 closes the first opening 31.
• the loading is carried out in cycles.
• the workpieces 22 on the rotary hearth 23 are guided through the treatment zones 28, 29 and 30.
• the treatment temperature and the treatment atmosphere can be set differently in the diffusion / carbonization zones 28, 30.
• the first diffusion / carbonization zone 28 is set up in such a way that the zone functions as a carbonation zone.
• the workpieces that have arrived in the loading and unloading zone 32 are individually removed after opening the furnace door 33 and quenched in a hardening machine 35. Of course, the oven door 33 is closed again after each removal process.
• a second closable opening 36 for loading and unloading is arranged in the outer wall 24 at a distance from the first opening 31 for loading and unloading.
• the heating zone 27 extends over a range of approximately 90 °, which can be closed by a door 26b immediately behind the second opening 36 for loading and unloading.
• the two openings 31, 36 are therefore each adjacent to the heating zone 27.
• the direction of rotation of the rotary hearth is selected depending on which of the two loading and unloading openings 31, 36 is loaded. In any case, the workpieces enter the heating zone after loading.
• a lock 37 with a cooling bath 38 in the form of an oil bath connects to the second opening 36 for loading and unloading.
• the workpieces 22, which are located on batch carriers in a known manner, are introduced into the furnace chamber in the second loading and unloading opening 36 and are transported clockwise through the furnace chamber on the rotary hearth 23.
• the second diffusion / carburizing zone 30 is set up as a carburizing zone and the first diffusion / carburizing zone 28 as a diffusion zone.
• the heating zone 27 can thus extend over a larger area of the furnace space.

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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)
• Tunnel Furnaces (AREA)
• Heat Treatments In General, Especially Conveying And Cooling (AREA)
• Muffle Furnaces And Rotary Kilns (AREA)
• Plural Heterocyclic Compounds (AREA)
• Treatments Of Macromolecular Shaped Articles (AREA)

Applications Claiming Priority (5)

Publications (2)

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ID=28042866

Family Applications (1)

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• 2003
  • 2003-03-10 DE DE10310739A patent/DE10310739A1/de not_active Withdrawn
  • 2003-03-11 WO PCT/EP2003/002461 patent/WO2003081156A1/fr active IP Right Grant
  • 2003-03-11 AU AU2003219035A patent/AU2003219035A1/en not_active Abandoned
  • 2003-03-11 DE DE50307651T patent/DE50307651D1/de not_active Expired - Lifetime
  • 2003-03-11 EP EP03714799A patent/EP1488181B1/fr not_active Expired - Lifetime
  • 2003-03-11 KR KR1020047015527A patent/KR100964994B1/ko not_active IP Right Cessation
  • 2003-03-11 CN CNB038058766A patent/CN100434545C/zh not_active Expired - Fee Related
  • 2003-03-11 US US10/508,735 patent/US7588719B2/en not_active Expired - Fee Related
  • 2003-03-11 AT AT03714799T patent/ATE366903T1/de not_active IP Right Cessation

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