SK165496A3 - Method and furnace for making a molten product - Google Patents

Abstract

A method and a furnace for melting a solid material to form an electrocast product, including at least two electrodes (4, 5). According to the method, the melting process is started by contacting the tops (13) of the electrodes (4, 5) with said solid material (23) to be melted while holding the electrodes close enough together to enable an electric current to flow therebetween, an electric arc is then generated between said electrodes to melt the solid material adjacent the tops (13) of the electrodes (4, 5), and said tops are subsequently gradually moved apart without breaking the contact with the material or cutting off the current flow between the electrodes.

Description

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A method for melting solid materials and apparatus for making the same. i j j Q k 1 and t - techniques.

The invention relates to spots. .built e 1 ec L rotated p u u t t. the rigidity of solid materials. in particular metals or ceramics. in an electric oven. equipped with at least two electrodes. honey from both the free and the end of which h p rec had for eleki.i. eg im. in the form of an electric arc.

The present invention relates to a simple and economical method of producing an electrothermal product by melting solids, electrolytic materials. materials. which was carried out at relatively high temperatures.

To t :, i and r and j f f t t and v_t e r Im i k y

The fasting would be preferable to use in the field of solids. If the charge is electrically non-flowing. it is necessary to implement a special measure, e.g. add. into the charge carbon or graphite, so that the electric current can be overloaded -

The prior art processes can be applied only at relatively low temperatures, e.g. from 1500 to .1.600 * Ό. and therefore do not suit refractory processing.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION The subject of the invention is a method which largely eliminates the disadvantages of the established methods and can be used in the case of melting electrically conductive and non-conductive material, and with respect to non-conductive materials it is not necessary to implement additional measures.

In order to trigger the melting according to the invention, the free ends of the electrodes are placed on a solid material to be melted, and at the same time are strong against each other so that an electric current can pass therebetween. If an electric arc is formed between the electrodes 1, the solid material melts in the immediate vicinity of the free electrodes. Pi il'.nn is free com: l * l * 11. * K to rodu in! i.1 '. · i :: 11 «1 ·. I. j to | > ns t.n | i | ifí -sa 1 iúee ohnisko taveu i ny t m! sea odďaľu i ú. 1 »1 '11» ii: st * .. ί 11 * astonish in contact with melted solid m.il.rT i á 1 on and med: · ?: electrodes ac ex kvol iac i l..w: ni The passage between the electrodes and the free electrodes is the passage of the electrodes. Thus, it is an object of the present invention to provide an electric furnace for the manufacture of a product which is melted. which is arranged so. to switch the conditions of the method according to the invention.

The furnace is characterized by the fact that the electrodes are free of each other, and the copper is also movable by the position of the approach, when their free ends are in contact with each other and by the position of the distance between them. these free ends a certain distance ·. The furnace is equipped with means for continuously moving the electrodes between the surfaces.

Each electrode is mounted in a support arm electrically insulated.

According to the invention, the electrodes are introduced into the melting pan from the side so that they can move, between the approach and withdrawal positions.

11a of the drawing

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a schematic diagram of an electric furnace according to the invention (partly in a lateral section); FIG. 2 is a sectional view along line II-II of FIG. 1, FIG. 3 shows the circuit diagram of the electrodes in the electrical circuit.

The cross-section is also made and carried

In particular, the invention relates to a process for producing e I e to I. n. melt refractory product by melting a solid material of various kinds, in particular refractory materials

The melting is carried out in an electric oven, which is provided with at least two electrodes, between which the electric current supplying the sweat passes through the connection. m Ί can r: n t. I * i i iut I. iv * mi t.

Ak j 1; the batch in the box, in the box, in the box. »≪ I i v á ».υοΓίϋ ju u.ipr. solid ki · r: i c: ké to t., i · -ľ r i .11 y. in such a way 1 • - i r; l:: so voli .; end o i. ; k f. n id when running melted or edited while touching e. and solid material that will be melted. After being connected to the circuit, an electric arc is formed between the electrodes, which heats and melts the solid material in the first and second electrodes.

The free kriiir.-e elekkréd are gradually being rolled apart. how the fusion focus expands, while maintaining the fusion focus. melt with melted solid has a thickness of 1 nm. Also, care must be taken to maintain the passage of electric current between the electrodes 1 and through the melt, which is also free ends. The heating is in this melting step caused by the heat of the heat due to the resistance of the molten material. which is located between the electrodes, often immersed in the melt, for the passage of electric current. As a result, the non-conductive solid fusible material becomes conductive, since it has been liquid.

If the molten material is sufficiently electrically conductive and is e.g. o metals, it is not necessary to touch the free ends of the electrodes when the melting starts. In this case, it is sufficient for the distance between the electrodes to correspond to the possibility of creating an electric arc. The heating generated in this melting step is partly due to the heat emitted by the electric arc and the propellant solid, partly by the heat of the melt due to the resistance of the molten material to the electric current in that part of the melt to which the electrodes are partially submerged.

Obviously, the distance between the electrodes can be foamed. according to the type of melted material. In the case of an electrically non-conducting material, the electrodes are in contact with, or almost touching, an electric arc between their free ends, while in the case of an electrically conductive material they may be. free electrode ends ba '" I d i a 1 e n. V a t i n e. Thus, the conductivity of the molten material, as well as the strength of the electrical installation, is at least one of the reasons that the distance between the free ends of the electrodes would be at 1.1 µm. NPF. the power t a v e n i a. before the discharge from the ladle of the ladder i. According to the invention, this is done shortly after the melting of the free ends of the electrodes is completed.

The accompanying drawings illustrate an electric furnace for producing an electrothermal product by the process of the invention.

An electric furnace is a type that uses a submerged system.

The furnace is equipped with a ladle 1, which is closed in the upper part by a vault 2 with a hopper 3, through which a charge is placed in the ladle.

On both sides of the ladle side, two electrodes 4 and 5 are attached to the support arms 6 so that their free rails 13 are inclined at an angle. The support arms 6 are electrically insulated. The electrodes are held in the support arms so as to be able to slide between the approach position when both their free ends are in contact with each other and the position of the distance when there is a certain distance between the free ends. For this reason, the electrodes pass freely through the openings in the side walls 1 of the ladle 1, their cross-section being designed so that a circular passage 19- is formed around the electrodes, through which air penetrates into the furnace and is sufficiently large. to allow the electrodes to be deflected there. The electrode axes can hold therein an angle α of 1.5 ° to 165 °.

The electrodes deflect around the outer deflection point 28, which is sufficiently distant from the furnace wall 1, so that the deflection of the free ends of the electrodes 4 and 5 in the furnace is as large as possible, thereby achieving an accurate control of the melting independent of the quantity of material being fused. The outer deflection point 28 is practically located on the support arm 6.

Each support arm 6 is disposed from a base 7 in which a column 8 is embedded, and at its upper end, which is identical to said outer deflection point 28, a holder 9 is mounted in the pivot pin. The electrode is slidably supported by the sleeves 10 in the holder. The holder 9 is provided with a control body 11, which can be operated. C, or by motor), moving the electrodes in the direction of the arrows 12 and thereby varying the distance between their free ends 13 inside the ladle 1. This distance can also not be offset by the electrodes around it

The outer diameter of the bottom 1.5 of the basin is as described above, and in the base 1, the base is inserted into the rails L? in the cylindrical wall 15 of the pan base. Approximately in the middle and in the height of the side of the wall p, and n is the load. n ý aperture 18. and pelvis vyi.di 1 i na pod s f a v i :: i 1_4 v s m e p t. arrows 2ó (fig. 2). The fact that the electrodes 4 and 5 do not come into contact with the furnace walls and do not touch them. According to the present invention, the furnace has been used to a significant degree. \ ≪ In the art, the electrodes in the markets are inclined to the stems and hingedly hinged to a relatively loose mesh. However, these compositions are the reason why they can only operate at temperatures of the order of 1,600 ° C.

Because compared to the current technique. the furnace according to the invention is provided with circular passages 19 which are sufficiently large and allow the flow of cold air along the apex and each electrode passing through the aperture is held in a lateral support arm 6 which is sufficiently spaced from the side wall 1. it is not necessary to provide sufficient protection against the high temperatures inside the ladle to protect the electrodes and their support arms. It is possible to process refractory products at temperatures above 2500 ° C.

FIG. 3 schematically illustrates the connection of electrodes 4 and b to an electrical circuit. The circuit is connected to the mains at terminals 29 in a conventional manner via a circuit breaker (not shown). A self-inductive coil 20 is connected to the circuit, which is connected in series with the electrodes 4 and 5 when the electrodes are in the approach position.

The switch 21 can be briefly coupled to this coil when the electrodes 4 and 5 are in the withdrawal position.

In addition, a transformer 27 is inserted into the circuit, which supplies voltage to the electrode terminals and provides the necessary current density to effect melting. It can be a classical transformer with a constant voltage of 220 / 1.1000 V. ii I y ν. »M vy um ii ii ii ii ii it it it ii ii ii ii ii ii ii ii ii the network is connected to the network.

At the start of the operation, the main circuit 22 is closed on the circuit, the coffee switch is switched on, the electrodes 4 and 5 are in the proximity loop, and the circuit is free. the ends are immersed in the charge or at least in contact with it.

Once a certain amount of solid material is melted and a melt 2.4 is formed, the electrodes 4 and 5 are gradually removed from the salt and the switch 21 is switched on to short-circuit itself. In addition to the expansion of the melt, an increase in the distance between the electrodes is made, taking into account that the current density between the electrodes is melt 24, painful enough to allow the temperature of the body to be transferred to the surrounding solid material 23.

After melting all of the solid material, it is preferred that the electrodes 4 and 5 are again. they approach each other at their current deep immersion below the surface of the melt, releasing the switch 2.1 as needed to reduce the current in the electrical circuit. As a result, relatively considerable energy is concentrated in a small volume of molten material. which causes 1 to no temperature increase. This results in convective flow, resulting in perfect mixing of the molten material and the formation of a relatively homogeneous mass of high quality.

The following are some specific examples to illustrate the application of the method of the invention in a previously described furnace.

Examples:

In the furnace there is a material having a total weight of about 0 kg in the following composition: 33% zirconia, alumina, 14% silica and 3% alkali salt in the form of sodium carbonate. The average grain size varies from 0.1 mm to 15 cm (size, diameter). firm

Before the melting is started, the two free ends 13 of the electrodes 4 and b, which are graphite in this example, are brought together and at the level of the solid material inserted previously in the ladle 1. Both free ends 13 of the electrodes are partially covered with material so as to be immersed therein . I'Ví'i un s n 11 1 jv nýľi v; y p í m ^ ιΓ: *. »Ri

. ··!. ·!:! ii r-ký (- I ok f. rodai-i i 3 -'i '' 300 k V / - A s .i pi · M υ; '; · ι t vi i í olivut.1,' | u There is an electric arc in between. E! neiqia na a 1 * ;. · kk ródach is in the order of mimics around the free ends of the 13 electrodes ne and 3 a sufficient amount of melt 2A, and it is possible to use the mage 21 to shortly connect the inductor 20 to the same time.

For example, since the melt 2.Λ is a liquid state, the electric current passes between the okródan i over the melt. The total time of melting and i, ie, about dM minutes and l.ep I ok,; C.

The resulting temperature is large enough to allow the entire charge to melt while continuously increasing the distance between the electrodes which is present until the batch is completely melted.

Other types of materials were treated similarly in the furnace; It was mainly a charge that contained MO% of iron and MO% cobalt, batches containing 95% of aluminum oxide and M% and alkali salt, MO% of cobalt and MO% of nickel, bronze, brass, and when.

Another example relates to the melting of glass shards. In this example, molybdenum or graphite ions were also used.

The inclined cells were melted in the previously described furnace. together with the fired waste containing e.g. heavy metals. In particular, Isio is a solid extract furnace waste extract.

By melting, a glassy product was obtained, containing said heavy metals, which could be used as the basic raw material for the production of beads by known technology, in order to remove heavy metals.

The melting was carried out continuously in an inclined pan so that the glassy product with the melting process was drained through the outlet port 10B, the ladle being filled with a hopper 3 in the furnace vault: i.

The same continuous melting process was also used in batches of other material.

A method according to the invention and an electric furnace arrangement, V (-. Torr;]. Ι; Π t -1 I The method of forging, does not use. it is possible, for example, to solidify a portion of the batch in the pen, but it is funeral to cause the electrodes A and S to be placed above the surface If the charge is in the form of a charge, which will be carried out by the above-described method, if the charge is conductive, this is not necessarily the case. realffovat.

It is possible to keep some of the furnace's erics. A layer of electrotreated product can be left on the ladle walls to protect the ladle walls.

The furnace may be connected to a direct current, a single phase current, or a phase current. The preferred arrangement and positioning of the electrodes A and δ with respect to the ladle 1 makes it possible to control. vel. angle a taking into account the charge level. To this end, it is necessary to ensure that the electrodes can be burned out. on the column g of the support arm 6 in an arc of relatively large span. Accordingly, it is necessary that the outer deflection point bo 1 be sufficiently in the wall of the wall.

The invention is not limited to the above examples. Without going beyond its scope, it is possible to use different types of electrodes that are suitable for electric furnaces operating with the immersion electrode system, and the electrode structure and support arm may be. arranged in a different way.

That way. The batch, its composition and grain size can be varied. Can go. o powdered material, or blocks up to several tens of centimeters in diameter.

Claims (4)

?! / t λ τ ι: n τ α v ν λ r η κ ν 1. The way of melting i and solid on h? r i á 1 ον (23), hl and v metal or ceramics, i s i n e c t e c t e r e r e r in e th e product, in an electric furnace i equipped with at least two electrodes i < 4. 3),. between the free ends C13) of which the electrode or the d -h I may pass, and not in the form of an electric arc, when the free ends (13) of the electrodes C4, 5) are in contact with the thermoelement of the electrode. I '. it also allows the passage of electric current. or " create an electric arc. wherein the solid material (23) melts near the free ends / (13) of the electrodes (4.3) and the electric current also passes through the melt formed between the two free ends, characterized in that the free ends of the electrodes ( 13) are sequentially detached from each other in connection with the expanding focal point of the molten solid material (23) while still being in contact with the fused solid material (23) and ensuring that the flow of electric current is maintained between the electrodes (4, 3) . 2. A method according to claim 1, wherein the method according to claim 1. that, during melting, the melting material is fed to the vicinity of the electrodes (4, 3), in particular to the space between them, while the melt (24) is simultaneously discharged to make the melting process and / or the melting process. Method according to claim 1 or 2, characterized in that the melting is carried out in an oxidizing medium. j i 4. A process according to any one of claims 1 to 3, characterized in that it is mixed with a convection stream prior to the melt discharge. 3. An electric furnace for producing an electrothermal product by melting solid materials (23), in particular metals and ceramics, by a method according to the invention which is provided with a ladle (1), at least two electrodes (4) and (3) passing through the furnace wall (1) (20. llàl you tv / o reni · 1 e 1 ek tľ ii: ké lO a | & ri i :; i rii. ··: k. Iľi i (20. 21. 22) ol 11 úk m . · !: i free ends (J 2) r. · 1.-K »ró, I (4) and < S), which are left with cha; iuk themselves and si) sliding? between their position n in. when the ends are free (j 3) at the patina and i i. and a position separated by a distance between the free ends 1 and 1, but still in the mold with the molten material (22) while moving the free ends. (13) between these positions is substantially continuous and is performed by means O), 10, 11). who are those of the furnace, in y. characterized in that the electrodes (4) and (3) are held in the support arm (6) so as to be able to hold the electrodes. to be displaceable and pivotable in their axis about an outer point of deflection (23) remote from the wall (1) of the furnace and to pass freely through the wall opening (1), the cross-section of which is so designed. that a circular passage (19) is formed around the electrodes (4) and (ó), allowing the electrodes (4) and (9) to be deflected so that their axes have an angle of «between 15 ° and 161 ° °, the upper part closed with a vault (2) which is provided with a hopper opening (3) for filling the ladle (1) with a solid material (23) to be melted - 6 according to claim 5, characterized by that each support arm (6) is electrically insulated and is arranged from a base (7) in which a post (3) is mounted, the upper end of which is an outer deflection point (23) and is connected to the holder (9) by a hinge; The electrode (4, 5) is fixed to the holder so that it can be moved and taken up, and thus the distance between the free ends (1.3) of the electrodes (4, 11) is also varied. A furnace according to claim 5 or 6, characterized in that a self-inducing coil (20), which may be, is inserted into the electrical circuit of the electrodes (4) and (5). connected in series with the electrodes (4) and (Π) in their approach position and can be short-circuited in their compartments i and i. 7. l'iiilľ.i k torétiokoľvek v y m .1 Γ: u i ú r a s a t. ý m, i iľús I r i <: 'lkám i, v i r ebeli n tuviMiia n.ii (1) v nak I onen i ··; and the position that the melt flowed out in the U subsoils. from. x t i and e o pan C .1) 1 e pnat.iinne í V '? r: 11 .- 'i! IV t > k'I IV equipped r'áiiii pan d.Ο I * 1 y n 11 1 < I d u l i n e l i t e r i a 1 o 11 a ta v e 11: i e.