DE3740948A1 - Device for heating bars or the like - Google Patents

Abstract

Heating of bars for further processing (rolling mill, forge), in which the inductive heating is subdivided into a zone of heating to the further-processing temperature (rolling temperature, forging temperature) and a second zone for maintaining the further-processing temperature constant. In the case of long workpieces, the coil interior cools down too much, since the bars are conveyed rapidly out of the holding zone, whereas it takes a certain length of time until the space is filled by the advancing bars. The lowering of the temperature after the transporting of a workpiece out of the holding zone in the coil interior is avoided by the fact that the coils in the holding zone include intermediate pipes made of electrically conductive material, the internal dimensions of which are greater than the external dimensions of the bars or the like. <IMAGE>

Description

The invention relates to heating Stan gene or the like for further processing (rolling factory, forge or the like), the heating with constant feed to a zone for heating the further processing temperature (rolling temperature, Forging temperature) and a zone for keeping constant the processing temperature is divided, and the bars from the warming zone, for example, quickly subtracted from.

In inductive heating systems, several coils are in the heating zone arranged one behind the other. That too warming goods, e.g. Rods, billets or the like, is taken from a magazine and through the coils transported. This can be done using transport rollers that are between are arranged between the individual coils or by means of so-called pinch rollers, which the rods on Detect the beginning of the inductive heating zone and  simultaneously with those already in the coils Transport bars further. After the warming zone comes the warming zone, in the gas-heated or elec trisch-resistance heated warmers provided are to the workpieces at the processing temperature to keep. The workpieces become from this warming zone ke deducted for further processing. The removal line speed is sometimes much higher than the normal transport speed in the warming Zone.

The gas-heated or electrically heated warmer However, they have significant disadvantages because they are large Require space and the start-up times of such systems are very large. In addition, with electrically heated Warmers keep the thermal load on the heating elements te and the transport elements considerably, with gas-heated The warming elements become the transport elements and the Environment heavily polluted.

The object of the invention is to create a device fen that can be built more compact and their start-up time can be significantly reduced. The Repa maturity time in the event of accidents and the thermal pollution of the environment.

This is achieved according to the invention in that the Muffle in the warming zone made of electrically conductive Material (e.g. steel, silicon carbide and protective gas atmosphere graphite) surround the rods and the muffles are covered with thermal insulation.

The power supply to the muffle is advantageous via air or water-cooled rings, which are connected by means of Fe are pressed against the muffles at the end.

A schematic embodiment of the invention is shown in Fig. 1, while Fig. 2 shows an arrangement for heating rod-shaped material, in which the invention can be used.

In a known heating system, as shown in FIG. 2, the workpieces to be heated, for example billets 3, are brought from the magazine 1 into the loading position 2 . Here they are captured by the pinch rollers 6 and transported into the first of the coils 9 of the inductive heating zone 7 . Between each coil 9 , a transport or guide roller 4 is provided, which ensures the further transport of the rods. At the end of the inductive heating zone, the processing temperature is reached and the bars are transported to the electrical resistance-heated heating zone 8 with the muffles 11 . At the end of the warming zone 8 , pinch rollers 10 are provided, for example, which are provided for the rapid removal of the workpieces and transport to the roll stand 5 . After removal of such workpieces, the muffles 11 are empty, but the temperature in these muffles does not drop, as in an inductively heated holding zone. A decrease in the temperature has a negative effect on the storage heat of the coil lining in the case of inductively heated warming zones.

Fig. 1 is now an electrically-resistance heated muffle according to the invention. The workpiece 11 , for example a long rod or a billet, is transported by the trans roller 12 through the muffle 13 and at the end of the muffle by the transport roller 16 (pinch roller). The muffle 13 consists of a tube made of electrically conductive material. It can be steel or silicon carbide. If a protective gas atmosphere is used, a muffle made of graphite is also possible.

To the outside, the muffle 13 is surrounded by thermal insulation 14 in order to avoid unnecessary heat losses. The electrical connections 16 are air-cooled or water-cooled and are arranged on the end faces of the muffle in the form of contact rings 17 . The contact rings 17 are pressed in a manner not shown by means of springs against the end face of the muffle. By means of clamping bolts 18 or the like, the muffle 13 is held together with the contacts 17 .

If the workpiece 11 has been withdrawn from the holding zone 8 for further processing, heat is still generated in the muffle 13 , so that no drop in temperature can occur.

Claims (3)

1. Device for heating rods or the like for further processing (e.g. rolling mill, forge or the like), the heating with constant feed into a zone for heating to the processing temperature (rolling temperature, forging temperature) and a zone for keeping the temperature constant Further processing temperature is subdivided, and the rods are quickly withdrawn from the holding zone, for example, characterized in that electrically conductive muffles ( 11 , 13 ) in the holding zone ( 8 ) made of electrically conductive material (e.g. steel, silicon carbide and graphite with a protective gas atmosphere) the rods ( 11 ) ben ben and the muffles are clad with thermal insulation ( 14 ). 2. Device for heating according to claim 1, characterized in that the power supply ( 16 ) to the muffles through which current flows via air- or water-cooled rings ( 17 ) which are pressed against each other by means of springs on the end faces of the muffles. 3. Device for heating according to claim 1, there characterized in that several muffle electrically are connected in parallel and / or in series.