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DE-102024132933-A1 - Vacuum furnace for the heat treatment of metallic workpieces

DE102024132933A1DE 102024132933 A1DE102024132933 A1DE 102024132933A1DE-102024132933-A1

Abstract

The invention relates to a vacuum chamber furnace for the heat treatment of metallic workpieces forming a batch, comprising a furnace housing (1), wherein the furnace housing (2) surrounds a heatable and evacuable treatment chamber (2) for receiving the batch. The treatment chamber (2) has closable cooling gas passages (6, 7) for introducing cooling gas into and exhausting the cooling gas from the treatment chamber (2). A heat exchanger (11) is surrounded by an enclosure (12) which has at least one closable inlet (13a, 13b) for introducing the cooling gas. According to the invention, the treatment chamber (2) and the housing (12) are connected to the heat exchanger (11) to form a block-shaped assembly (15), wherein the assembly (15) comprises at least one cooling gas channel (16a, 16b) which is configured to direct the cooling gas within the assembly (15) between the treatment chamber (2) and the heat exchanger (11), and wherein the assembly (15) is configured to be inserted into the oven housing (1) as a single piece during the construction of the vacuum oven.

Inventors

  • Torsten Requardt
  • Bennet Nagel

Assignees

  • IVA SCHMETZ GMBH

Dates

Publication Date
20260513
Application Date
20241111

Claims (14)

  1. Vacuum chamber furnace for the heat treatment of metallic workpieces forming a batch, comprising a furnace housing (1) with a horizontal main axis, wherein the furnace housing (2) surrounds a heatable and evacuable treatment chamber (2) for receiving the batch, wherein the treatment chamber (2) has at least one closable cooling gas passage opening (6) for introducing cooling gas into the treatment chamber (2) and at least one closable cooling gas passage opening (7) for venting the cooling gas from the treatment chamber (2), with min at least a heat exchanger (11) and a cooling gas fan (10) which is configured to circulate cooling gas through the treatment chamber (2) and the heat exchanger (11) during a cooling phase, characterized in that the heat exchanger (11) is surrounded by an enclosure (12) which has at least one closable inlet (13a, 13b) for introducing the cooling gas, that at least the treatment chamber (2) and the enclosure (12) are connected to the heat exchanger (11) to form a block-shaped assembly (15), that the assembly (15) comprises at least one cooling gas channel (16a, 16b) which is configured to direct the cooling gas within the assembly (15) between the treatment chamber (2) and the heat exchanger (11), and that the assembly (15) is configured to be inserted into the furnace housing (1) as a single piece during the construction of the vacuum furnace.
  2. vacuum chamber oven according to Claim 1 , characterized in that the heat exchanger (11) connects to the treatment chamber (2) in the direction of the main axis of the furnace housing (1), and that the cooling gas fan (10) can be connected to the heat exchanger (11) centrally on the suction side and to the cooling gas channel (16a, 16b) on the pressure side.
  3. vacuum chamber oven according to Claim 1 or 2 , characterized in that the assembly (15) comprises at least one heat exchanger flap (14a, 14b) by means of which the inlet (13a, 13b) in the housing (12) can be opened or closed, and that the heat exchanger flap (14a, 14b) is pivotably mounted and preferably pivotable into the cooling channel (16a, 16b) by means of an actuator (18a, 18b).
  4. Vacuum chamber furnace according to at least one of the preceding claims, characterized in that the housing (12) has two inlets (13a, 13b), that each inlet (13a, 13b) can be opened or closed with a heat exchanger flap (14a, 14b), that preferably an actuating element (18a, 18b) engages each heat exchanger flap (14a, 14b), which is preferably configured to open or close the heat exchanger flaps (14a, 14b) during the cooling phase alternately with reversing the flow direction of the cooling gas at predetermined intervals.
  5. Vacuum chamber furnace according to at least one of the preceding claims, characterized in that the assembly (15) has at least one treatment chamber flap (9a) with which the cooling gas passage opening (6) for introducing the cooling gas into the treatment chamber (2) can be opened or closed, and has at least one further treatment chamber flap (9b) with which the cooling gas passage opening (7) for venting the cooling gas from the treatment chamber (2) can be opened or closed, wherein each treatment chamber flap (9a, 9b) is pivotably mounted and preferably pivotable into the cooling channel (16a, 16b) by means of an actuating element (17a, 17b).
  6. vacuum chamber oven according to Claim 5 , characterized in that the actuators (17a, 17b) are configured to keep the treatment chamber valves (9a, 9b) open during the cooling phase.
  7. Vacuum chamber furnace according to at least one of the preceding claims, characterized in that the assembly (15) comprises a cooling gas channel (16a) for directing the cooling gas towards the treatment chamber (2) and a further cooling gas channel (16b) for directing the cooling gas from the treatment chamber (2) towards the heat exchanger.
  8. Vacuum chamber furnace according to at least one of the preceding claims, characterized in that the at least one cooling gas channel (16a, 16b) runs outside the treatment chamber (2) and the housing (12) in the direction of the longitudinal axis of the assembly (15).
  9. Vacuum chamber furnace according to at least one of the preceding claims, characterized in that each cooling gas channel (16a, 16b) has an outer wall (19a, 19b).
  10. vacuum chamber oven according to Claim 9 , characterized in that the treatment chamber flaps (9a, 9b) are arranged to form part of the outer wall (19a, 19b) of the at least one cooling gas channel (16a, 16b).
  11. vacuum oven after Claim 9 or 10 , characterized in that the heat exchanger flaps (14a, 14b) are arranged to form part of the outer wall (19a, 19b) of the at least one cooling gas channel (16a, 16b).
  12. Vacuum chamber furnace according to at least one of the preceding claims, characterized in that the housing (12) of the heat exchanger (11) and the cooling gas channel (16a, 16b) are made of sheet metal.
  13. Vacuum chamber furnace according to at least one of the preceding claims, characterized in that the assembly (15) has rollers for moving the assembly (15) in the furnace housing (1).
  14. Vacuum chamber furnace according to at least one of the preceding claims, characterized in that the furnace housing (1) contains stop points for the assembly (15).

Description

The invention relates to a vacuum chamber furnace for the heat treatment of metallic workpieces forming a batch, comprising a furnace housing with a horizontal main axis, wherein the furnace housing surrounds a heatable and evacuable treatment chamber for receiving the batch, wherein the treatment chamber has at least one closable cooling gas passage opening for introducing the cooling gas into the treatment chamber and at least one closable cooling gas passage opening for venting the cooling gas from the treatment chamber, comprising at least one heat exchanger and a cooling gas fan, which is arranged to circulate cooling gas through the treatment chamber and the heat exchanger during a cooling phase. The furnace housing of vacuum chamber furnaces is typically hollow and cylindrical. It can be double-walled and water-cooled. The furnace housing is usually mounted horizontally on a furnace frame and surrounds a treatment chamber, which can be heated and evacuated. The treatment chamber is generally rectangular. Both the furnace housing and the treatment chamber have a loading opening at each end, which can be opened or closed by means of doors. Heat treatment refers to processes used to treat workpieces or metallic components. The workpieces are heated in a controlled manner and then cooled or quenched to alter their material properties. Common heat treatments include annealing, tempering, and hardening. The heat treatment of metal workpieces or components generally requires rapid cooling after heating, i.e., quenching or quenching. The batch is quenched using a cooling gas, particularly nitrogen or argon, which is introduced into the treatment chamber through at least one cooling gas inlet in a wall of the chamber and discharged from the treatment chamber through at least one further cooling gas inlet. The cooling gas is circulated between the treatment chamber and the heat exchanger by a cooling gas fan or blower to cool the batch. After passing through the treatment chamber, the cooling gas is cooled again. The cooling gas fan is connected to a cooling gas source. After cooling the batch of workpieces, the cooling gas is directed from the treatment chamber to the heat exchanger through at least one cooling gas passage opening. It is known in practice that the cooling gas flows through the space between the furnace housing and the treatment chamber, so that baffles are located inside the furnace housing to guide the cooling gas. The cooling gas passages can be closed by means of closing elements. These closing elements are closed during the heating phase and open during the cooling or quenching phase. The closing elements are generally designed to abut the inner wall of the furnace housing. Because the furnace housing is round and the treatment chamber is rectangular, parts of the treatment chamber, especially the sealing elements that extend towards the housing and abut the inside of the furnace housing, must be adapted to the round inner wall of the furnace housing during assembly. This adaptation work is time-consuming, and the manufacturing costs for the vacuum chamber furnace are correspondingly high. It is known from practice that the furnace housing directly surrounds the heat exchanger, so the inner surface of the furnace housing must be designed accordingly to guide the cooling gas in the area of the heat exchanger, which is complex from a manufacturing perspective. The invention is therefore based on the objective of further developing a vacuum chamber furnace of the type mentioned above in such a way as to reduce the manufacturing effort. The problem underlying the invention is solved with a vacuum chamber furnace having the features of claim 1. According to the invention, the heat exchanger is surrounded by an enclosure which has at least one closable inlet for introducing the cooling gas, wherein at least the treatment chamber and the enclosure are connected to the heat exchanger to form a block-shaped assembly, wherein the assembly comprises at least one cooling gas channel which is configured to guide the cooling gas within the assembly between the treatment chamber and the heat exchanger, and wherein the assembly is configured to be inserted into the oven housing as a single piece or in its entirety during the construction of the vacuum furnace. The housing and the cooling gas duct form a closed flow path for the cooling gas between the treatment chamber and the heat exchanger within the assembly. This allows the block-shaped assembly to be completed and assembled outside the furnace housing. The assembly can include any additional components required for the cooling function. The assembled assembly can be easily inserted into the furnace housing and connected to the cooling gas fan. Complex modifications to components for guiding the cooling gas inside the furnace housing are avoided. Consequently, the manufacturing effort for the furnace housing is significantly reduced. The heat exchang