SU1214998A1 - Induction melting furnace - Google Patents

Description

The invention relates to metallurgy, 3 in particular to the structures of induction melting furnaces for the smelting of ferrous and colored metals.

The aim of the invention is to increase the operational durability of the furnace.

Figure 1 shows the oven, front view; Fig. 2 shows a casing with slots location indications (the inductor in Fig. 2 is not shown for convenience); Fig. 3 shows a section A-A on flg-2; in FIG. 4, node 1 in FIG. 2; Fig. 5 shows the furnace life of the furnace. The magnitude of the angle is chalk, tsu pairwise convergence of the slits.

The induction melting furnace is made of a metal body 1, equipped with lining 2, which forms the bath of furnace 3 for melting the mixture. Under the bath of furnace 3, inductor 5 is placed in the holes formed by quartz ramming mass 4, and around the inductor 5 there are melting channels 6 in the lining and elots On the inductor 5, an eternit cylinder 7 is mounted on top. Between the quartz ramming mass 4 r and the eternit cylinder 7 there is a precast cover 8 with a through section 9. The through section 9 has a siliconized shell and cylindrical inserts in her.

A uniform gap of 10 me; the inner surface of the casing 8 and the outer surface of the eternit cylinder 7 is formed by means of an S2 insert, slotted 13, in the dimly circumferential protrusion 11 of the insert S2, which are parallel to the angle between them 20-40. The fan 14 serves to cool the inductor 5 and the protective casing 8,

Basically, induction melting furnaces have failed because of the flow of liquid metal from the melting channels to the inductor.

The change in furnace design, i.e. the introduction of precast protective siliconized graphite with inserts, in the annular projections of which there are air guiding slots, makes it possible to increase the duration of the smelting furnaces.

The casing is installed by me; vdu quartz stuffed lining and eternitic cylinder. In the gap formed by the inner surface of the casing

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The outer surface of the eternit crown generator is supplied with cooling air from the fan.

The depth of the slits is less than the height H of the annular protrusions by the value of the thickness-Pz h of the wall of the siliconized shell, which is connected with the cutting by a cylindrical insert. Therefore, after the shell is connected to the inserts, i.e. after assembly of the protective casing, the depth of the slots becomes equal to the height of the gap 10 between the diameter of the inner surface of the casing (shell) and the diameter of the external surface of the eternitic cylinder.

The casing material is high-temperature sprout and has a high thermal conductivity (10 times greater than that of alloy steel). This contributes to intensive heat removal from the place on the skin where the breakthrough of the liquid metal occurred, provided that the surface is well blown out.

Air-guiding slots play a major role in cooling the casing and the cylinder, since they, being located at an angle, give a rotational-vortex motion of the air supplied by the fan, i.e. laminar flow turns into a turbulent.

As is well known, with the vortex motion, the kinetic energy of air particles increases, and consequently, the convective heat transfer from the heated surface.

During laminar movement, the main part of the air flow contacts the surface to be cooled, while at the vortex movement of the flow, a much larger part of O is in contact with the heated surface, and the heat removal from the surface increases.

Besides; Making the slits pairwise convergent allows at the very beginning of the exit of the jets to the cooling zone: to achieve an intense vortex of the air flow.

The addition of the slots makes it possible to increase the heat removal from the inductor to the protective casing by a factor of 5–2.0, which makes it possible to increase the power of the furnace by 10–15% without overheating the inductor and the lining.

This is performed by short-circuit short-circuit blocks and inserts placed in

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its end parts x. Face inserts can be made of graphite of any brand or other material that is easily processed mechanically,

In the event of a breakdown, the inserts are easily removed without damage and can be used again. The breakthrough of the metal usually occurs at the place of the smallest distance between the melting channels and the shell. The silicon oxide graphical shell covers the dangerous zones of possible flow of the liquid metal.

Therefore, it makes no sense to make the casing one-piece, as this is expensive - if it is damaged in one place, the entire casing must be replaced.

The furnace works like a core transformer. The primary winding is the inductor 5, the secondary winding is a coil of molten metal in the annular melting channel 6. The furnace is connected to a voltage of 220-280 V with a frequency of 50 Hz. Molten metal is placed in the melting channels 6. The currents generated in the metal due to induction are heated and melted. From above, through the lid, the charge is charged into the furnace bath 3. The molten metal is squeezed out of the melting channel 6 into the steam 84 due to electrodynamic forces.

A furnace with H1TM bath 3 and melts the mixture located there.

Induction furnaces are one-, two- and three-phase with a corresponding increase in the number of inductors. In many cases, two or even three melting channels are used around the inductor.

Operating experience induction

The melting furnaces showed that they were mainly destroyed by the flow of liquid metal from the melting channels to the inductor. The furnace stops for repairs, and again

the inductor and quartz lining of furnaces vary.

Changing the furnace design, i.e. the addition of an additional protective casing into it allows to increase the service life of induction melting furnaces. In addition, an increase in heat dissipation from the protective casing and inductor leads to the possibility to increase the power of the furnaces by 10-15%

without overheating of the inductor and lining.

Experiments were carried out using inserts having different angles between the slots in the annular ledges (10–50 °). According to preliminary data, the service life of the furnaces

increases on average by a factor of 1.5 when using covers with inserts having an angle between the slits in the annular ridges 20-40.

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Compiled by M. Vnlkova Editor N. Shvyschka Tehred M. Gergel Corrector M. Pojo

Order 900/51 Circulation 561 Subscription

VNIIPI USSR State Committee for Inventions and Discoveries 113035, Moscow, Zh-35, Raushsk nab, d. 4/5

Branch ShSh Patent 5 Uzhgorod, st. Project, 4

UOLO Slotholes (deg. 1 / s)

Claims (1)

Induction melting furnace containing an inductor, a lined body with a bathtub and ring melting channels, a protective casing in the form of a hollow cylinder with a cut along the generatrix, characterized in that, in order to increase the operational stability of the furnace, the protective casing is equipped with hollow split cylindrical inserts mounted on its end surfaces and provided with inner annular protrusions having pairwise converging slots at an angle of 20 - 40 °. s © s © 00 «121