DE9316514U1 - Multi-purpose chamber furnace - Google Patents

Description

The invention relates to a multi-purpose chamber furnace for the heat treatment of metallic workpieces, with a charge chamber arranged in a furnace housing and a heating chamber which can be connected to the charge chamber via at least two gas passage openings, with a heating device arranged in the heating chamber, and with a circulation device for a treatment gas.

Such multi-purpose chamber furnaces are known per se. A heating chamber is usually formed in a furnace housing, in which a heating gas is heated by means of a heating device. Furthermore, a charge chamber is usually formed in the furnace housing, in which the charge to be treated is arranged. This charge chamber is also referred to as a heating chamber. Normally, the treatment gas is extracted from the charge chamber and blown into the heating chamber, where the gas is heated again by means of the heating device, in order to then re-enter the charge chamber at another opening, in order to be guided past the charge to be treated due to the extraction from the charge chamber.

A disadvantage of the previously known device is that the treatment gas is fed into different inlet points due to the design of the charge chamber and the gas flow conditions.

places in the batch room can have different temperatures. This results in undesirable different local batch temperatures.

A major reason for this is the non-uniformity of the flow velocity of the circulating gas flow in the heating chamber, the non-uniform impact on the heating surfaces in the heating chamber and the unmixed entry of the gas flow into the charge chamber.

Based on this, the invention is based on the object of improving a multi-purpose chamber furnace in such a way that the disadvantages mentioned are eliminated and the charge to be treated is exposed to a gas of the same temperature at all locations.

As a technical solution to this problem, a generic multi-purpose chamber furnace is further developed in that the circulation device has a suction device with which the treatment gas can be sucked from the heating chamber into the charge chamber.

The design according to the invention reverses the flow direction in the atmosphere circulation. When entering the charge chamber, the gas sucked in from the heating chamber is mixed so that gas enters the charge chamber that has essentially the same temperature at all locations. Furthermore, no undesirable thermal streaks can form in the heating chamber, so that the charge chamber is heated essentially the same at all locations. Due to the uniform treatment gas temperature, the desired temperature can be easily recorded and regulated, regardless of the type of furnace loading and the flow formation in the charge chamber. Furthermore, complex

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Finally, leaks or false air entering the heating room can no longer affect the temperature of the gas hitting the charge, so that local temperature inequalities are completely avoided.

According to an advantageous embodiment of the invention, the circulation device comprises a circulation impeller which is driven by a motor. This circulation impeller is advantageously arranged in the charge chamber in the region of a gas passage opening for gas intake.

It is advantageous to arrange guide devices in the gas flow path. These are advantageously formed in the charge chamber in the area of the charge chamber walls.

Further advantages and features of the invention emerge from the following description of an embodiment based on the attached figure. It shows

Fig. 1 a section through a multi-purpose chamber furnace

according to the invention.

The multi-purpose chamber furnace 1 shown in Fig. 1 comprises a heating chamber 2 which is delimited by the furnace wall. Heating devices 3 are arranged in the heating chamber 2. These can be heating pipes arranged in the heating chamber in a manner known per se. Furthermore, a charge chamber 4 is arranged in the heating chamber 2, which in the embodiment shown is set up on a frame in a manner known per se. A charge 5 is shown set up in the charge chamber. The so-called guide muffle 6 is arranged in the upper area of the charge chamber. Gas passage openings are formed on the top and bottom of the charge chamber 4. In the area of the

A circulating impeller 9 is arranged in the upper gas passage opening 7 and is driven by a thermally insulated motor 10. Guide devices 11 are formed in the area of the walls in the charge chamber.

In contrast to previously known devices, the gas heated in the heating chamber is sucked in by the circulating impeller 9 in the area of the guide muffle 6, mixed and pressed into the charge chamber 4, as shown by the arrows indicating the flow paths. Due to the inevitable mixing, the gas has a uniform temperature and flows around the charge 5. The gas then leaves the charge chamber through the lower gas passage opening 8, hits the heating devices 3, is heated, rises upwards, is sucked in again by the circulating impeller 9 and pressed into the charge chamber 4.

With the design of a multi-purpose chamber furnace according to the invention, the disadvantages in the prior art caused by different temperatures of the treatment gas can be avoided. The invention can also be used in multi-purpose chamber furnaces that have a different structure than that shown. For example, the charge chamber does not have to be surrounded by the heating chamber. A conducting muffle does not have to be arranged either.

List of reference symbols

1 chamber furnace

2 Boiler room

3 Heating device

4 Batch room

5 batches

6 Conductive muffle

7 upper gas passage opening

8 lower gas passage opening

9 Circulating impeller

engine

Guidance device

Claims (5)

Expectations 1. Multi-purpose chamber furnace for the heat treatment of metal workpieces, with a charge chamber arranged in a furnace housing and a heating chamber which can be connected to the charge chamber via at least two gas passage openings, with a heating device arranged in the heating chamber, and with a circulation device for a treatment gas, characterized,
that the circulation device has a suction device (9) with which the treatment gas can be sucked from the heating chamber (2) into the charge chamber (4). 2. Multi-purpose chamber furnace according to claim 1, characterized in that the circulation device is a circulation impeller (9) which is driven by a motor (10). 3. Multi-purpose chamber furnace according to one of the preceding claims, characterized in that the circulating impeller (9) is arranged in the charge chamber in the region of a gas passage opening (7). 4. Multi-purpose chamber furnace according to one of the preceding claims, characterized in that guide devices (11) are arranged in the flow path of the treatment gas. 5. Multi-purpose chamber furnace according to claim 4, characterized in that the guide devices (11) are arranged in the charge chamber (4). R/RS/mg