SU748915A1 - Intermediate heater of induction furnace - Google Patents

Description

(54) INTERMEDIATE HEATING OF THE INDUCTION ELECTRIC PROTECTION

 I

The invention relates to an electrotherm n can be used in induction heating installations designed to work in an oxidizing gas atmosphere at high temperatures, for example, in the technology of refractory materials and products, in electronic equipment and in the cultivation of monocoperators.

Known induction heating installation, in which the intermediate heater is made in the vnde rings of refractory metals or non-metals, for example, graphite 1.

Due to the fact that the rings are made in one piece, they begin to crack due to high temperatures due to thermal stresses. In addition, they do not work well in an office environment. . Intermediate preheaters are also known, which are intended to be installed inside a vertical inductor along its axis, made in a vnde hollow cylinder, branded with three identical refractory conductive segments, arranged in a series of mn, with at least two in each row 2.

Segments can be made of refractory metal, graphite and electrically conductive material, eg, zirconium bauxate. This design improves the heat resistance of the device, however, J due to the fact that the segments are connected to each other in a lock, their cracking is possible. Touching the adjacent segments in one row of the drive to the concoction of them to the occurrence of arcs and destruction of the whole structure.

The aim of the invention is to increase the reliability of the device in cyclic mode.

For this purpose, the device is made of not less than two sets of two blocks installed with a gap from each other symmetrically relative to the axis of the indicator; in each block, the segments of all rows are aligned with the gap from each other, the gap is filled with a layer of granular refractory material identical to the segments material However, 2Q edges of the segments in the gaps between the blocks are rounded.

FIG. 1 shows the proposed device, a general view; in fig. 2 - view of a separate segment.

The device consists of two J5 blocks and 2, made in the form of a vertical set of separate segments 3, between which a grit 4 is poured in a gap of the same material grains from which the segments 3 are made. The whole assembly rests on the mounting element 5, also made of a refractory material, mounted on the support ring 6 of a material with high thermal conductivity for better cooling of the element 5.

Segments 3, backfill 4 and element 5 can be made, for example, of lanthanum chromite doped with magnesium oxide. The blocks and 2 are enveloped outside by the inductor 7. The configuration of the individual segment is half a ring, for the case of two blocks, with rounded ends.

The basis for all sizes () in a segment is its outer radius R, selectable | from the requirements of creating the necessary working volume and providing the SHShShZhS possible radial thickness of the segment.

D (Y gatgyiNb vyyyyo ShShzateSh obtained with the following constants of 5sG A 1 / 3R; B 1 / 5R; H 4R; h R;

g 1 / 6R, D 4R.- and 2R .: where A is the radial thickness of cerMetffW; B - segment thickness; H block height J h - distance from the end of the inductor to

end block; -

.: r - radius rounded segment

D - inductor internal diameter - inductor height. The device works as follows. ; ,,,

: When heating a product located inside blocks I and 2 in segments 3, the internal thermal voltages occur.

which lead to some changes in their sizes and the Offset of the segments relative to each other. The unfolding of all segments in this design ensures their free movement without sintering and touching individual segments. Due to the fact that the induced current flows almost around the perimeter of the bike, the rounding of its corners makes it possible to avoid overheating or underheating of the corners, which increases the heat resistance of the segments.

All IT Allows you to increase the reliability of the entire device when operating in an oxidizing environment in cyclic mode.

Claims (2)

Invention Formula An induction electric furnace preheater, designed to be installed inside a vertical inductor along its axis, made in the form of a hollow cylinder, made of identical fire resistant electrically conductive segments arranged in rows of at least two in each row, characterized in that, in order to improve reliability preheater in cyclic mode, it is made of at least two blocks installed with a gap from each other symmetrically relative to the axis of the inductor, in each block segments of all p to mounted coaxially with and zazorrm from each other, which is filled with a layer of particulate refractory material identical to the material of segments, the edge segments in the gaps between the blocks are rounded. Sources of information taken into consideration during examination. Pfann J. Zonna Melting. I960, p. 93 2. Drawing of heating electric furnaces, OKB-53OM and OKB-533M, 1960.