DE1095420B - Induction coil arrangement for heating or melting electrically conductive materials - Google Patents

Description

GERMAN

The fastening of the induction coil prepares, in particular in large furnaces, difficulties. On the one hand cause the very strong magnetic fields a considerable stress on the coil itself and its holder, on the other hand, the coil arrangement should also insensitive to moisture, e.g. B. condensation, its penetration give rise to electrical Can be rollover. Furthermore, the coil should be easily accessible and exchangeable in the event of repairs be.

It is known to either fix the coil to the furnace body or to fix it to the possibly existing ones To connect magnetic yokes. In the case of smaller coils, it is known to convert them into cement-like substances, e.g. B. in foam concrete, or to cast in synthetic resins. Such smaller coils are used in forge heating systems also known with metallic end plates not connected to the coil. This was the case with large coils Method unsatisfactory because the potting is insufficient to fix the coil. Also a furnace coil assembly is known in which the coil is the supporting framework for the construction of the furnace wall. These Construction, which still assigns the task of mechanically stiffening the structure of the furnace to the coil disadvantageous. The coil, which is subject to high electrical loads, should be relieved of mechanical loads.

Around. the coils of induction heating systems, especially those of large smelting furnaces to give such stability that they are even with the considerable mechanical and thermal stresses, especially alternating stresses, to a stable one Component of the system is proposed according to the invention, the upper and the lower turn of the Coil to connect each with a preferably slotted end ring and these two rings by means of insulating To brace bolts against each other and this component then preferably with a suitable filler shed.

The invention therefore relates to an induction coil arrangement for heating or melting electrically conductive mass, which is characterized in that the upper and the lower coil winding each with one the power supply to the coil serving end ring of approximately the same diameter as the diameter of the encapsulated Coil corresponds, is firmly and electrically conductively connected by soldering, welding or riveting and that this both end rings mechanically against each other by means of insulating bolts or by fastening in the filler be braced that the coil after filling the space between the two end rings with Foam concrete, molten cement or a pourable mixture of plastics with resins is cast in such a way that that it is stable in itself and results in a rigid, compact body.

Induction coil assembly

for heating or melting

electrically conductive masses

Applicant:

General Electric Company,
Berlin-Grunewald, Hohenzollerndamm 150, and Deutsche Edelstahlwerke

Corporation,
,,. Krefeld, Oberschlesienstr. 16

Dr.-Ing. Borut Marincek, Küsnach, Zurich (Switzerland),
has been named as the inventor

Compared to the known designs, the coil according to the invention has the advantage that the upper and the lower coil turn are mechanically absolutely firm. Especially at the end faces of the coils the inclined relatively thin layer of lightweight concrete to cracking, and there were the associated disturbances. According to According to the invention, the coil has now become a stable component together with the concrete mass.

Often when using the coil arrangement according to the invention on the laminated, U-shaped yokes, as far as these were used for mechanical support, can be omitted. Even with high thermal shock loads this coil retains its position. There are no cracks in the coil liner, and the service life the linings or the furnace lining is considerably increased. This is particularly important for large systems significant economic advantage. The compact coil arrangement can also be used here in the event of a fault can be easily replaced, with the coil being protected against damage during installation or removal. One reliable isolation from the high voltages, around 3 kV, is achieved.

The manufacture of the coil arrangement according to the invention is economical because the mold is simple and no more lids are needed. There is also the special definition of the cable and water connections dispensable in the coil arrangement according to the invention.

The slotted end rings, which are not closed by metal, may be made of thin copper sheet and are connected to the upper or lower coil winding, for example by soldering, welding or

009 679/442

Rivets connected. Also other coherent types of connection are possible.

Now the two rings that are connected to the upper and lower coil turns, for example connected and braced in the usual way by bolts made of insulating material. This coil arrangement is then potted with a filler, so that a compact, mechanically rigid body results. Foam concrete, molten cement or a mixture of plastics can preferably be used as the filler Resin concrete serve. Another way of fixing the end rings is to use shorter bolts like the Pour stone screws into the casting compound and using these bolts after solidification the respective To tighten end ring. These bolts to be cast must be provided with barbs or the like; at least they must have a rough surface to hold in the solidified filler.

Reinforcement pieces can be used for additional reinforcement and to hold the individual coil windings suitable shape be distributed on the outside of the turns. This makes a secure fix achieved in the sense of a vibration-proof clawing of the coil turns in the filler.

The upper and lower end rings can, if they are not covered by the potting compound, through Paint or oxidation, etc., must be insulated so that they are safe to touch. Then such coils can be used in forging, Soldering or annealing systems without special housing can be used safely. The connections to the coil are in place usually on the end rings. It is advisable to have an eye on each end ring for the electrical connection welded on, which allows power connection to cable or rail.

The water can be supplied to the end ring by means of nozzles, quick-release fasteners or the like. Are several If power or cooling circuits are required, connections can also be made from the solidified filler to the outside at any time be led.

The figures give an example of the coil arrangement according to the invention.

Fig. 1 shows a section along a diameter through a coil arrangement according to the invention. the Coil is denoted by 1. The two end rings according to the invention, each with the upper and lower Coil turns are labeled 2 and 3. The outer diameter of these end rings is larger than the spool diameter. The space thus created between the end rings is filled with a filler 4 poured out. 5 are bolts made of insulating material that brace the end rings.

FIG. 2 contains the same reference numerals as FIG. 1. Here, the coil shown in plan view. 6 is the eye for the power connection in the upper, 7 in the lower end ring. The end rings have a slot at 8. Cooling water connections are for the sake of clarity of the figure not shown. The shape of the coil is shown in the figure ίο round. But it can also be oval or be rectangular.

Claims (4)

Patent claims: 1. Induction coil arrangement for heating or melting electrically conductive materials, characterized in that that the upper and the lower coil turn each with one of the power supply to the coil serving end ring of approximately the diameter that corresponds to the diameter of the potted coil Soldering, welding or riveting is firmly and electrically connected and that these two end rings so mechanically braced against each other by insulating bolts or by fastening in the filler that the coil after filling the space between the two end rings with foam concrete, Melt cement or a pourable mixture of plastics with resins is cast in such a way that it is inherently stable and results in a rigid, compact body. 2. Induction coil arrangement according to claim 1, characterized in that the end rings, for example are insulated so that they are safe to touch by painting or oxidation. 3. induction coil arrangement according to claim 1, characterized in that the individual coil turns are provided on their outer periphery with suitable reinforcement pieces, which after Solidification of the filler improves the retention of the turns. 4. induction coil arrangement according to claim 1, characterized in that the coil is round, oval or rectangular. Considered publications:
German Patent No. 496,462;
British Patent No. 501027;
U.S. Patents Nos. 2180,513, 2,743,345,
780 706, 2 806 117. 1 sheet of drawings