JPS58126694A - Electrode supporting base for arc furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric arc furnace comprising a water-cooled metal shaft and a working part made of a consumable material, the metal shaft being at least partially surrounded by a molding material made of a high temperature resistant material. This invention relates to an electrode pedestal.

Two basic types of electrodes with electrode supports of the type described above are used. The first type consists of two axially aligned parts, an electrode pedestal forming the upper part consisting of a cooled metal shaft and an active part of consumable material producing the arc at its lower end. This type of electrode is commonly known as a combination one electrode.

In the second type, the active part made of consumable material is axially movable within the confines of an electrode support consisting essentially of a cooled metal shaft. The active part of the consumable material that was once consumed at its lower end can then be compensated by axial movement. This type of electrode is commonly known as a feed-through electrode.

A common feature of these types is that the electrode pedestal, ie, the liquid-cooled metal shaft, protrudes at least partially into the furnace at the center of operation.

However, arc furnace electrodes are exposed to high temperatures and high mechanical stress. Temperature stress conditions arise due to the high working temperatures that are partially reached during electrical steel manufacturing. Mechanical stress can occur, for example, when an electrode is inserted into the furnace and hits a small piece, or due to movement of the molding material or piece.
Or it can result from vibrations caused by an arc.

To ensure the usefulness of these electrodes, therefore, the cooled metal shaft of the electrode pedestal present in the furnace during operation must be effectively protected against the aforementioned thermal and mechanical stresses. A number of solutions have been proposed for this problem.

The electrode support of the combination electrode described in Belgian patent application No. 867,876 takes the form of a metal shaft which contains a cooling system and is coated on the outside with a high temperature resistant coating. To improve the adhesion of the coating on the covering, the metal shaft has hooks that hold the coating in place.

A similar combination of electrodes is described in German patent application no. 1223162. This electrode is completely covered with a protective ceramic coating. In such a solution, attention should be paid to the extent of application to keep the thickness of the ceramic coating as small as possible and to wrap the appropriate electrode support in order to ensure the insulation of the pipe.

These pipes provide not only a passage for cooling water but also a means of supplying electrical current to the active part of the graphite.

European Patent Application No. 0010305 describes current transfer (
(Current-Carrying) A combination electrode with an electrode support consisting of a metal shaft electrically insulated from the cooling system and sufficiently cooled by a high temperature resistant material between the cooling system and the metal shaft is described. There is. The lower part of the metal shaft constituting the electrode support is covered with a ceramic coating fastened with a hook.

The combination electrode described in German Patent Application No. 2725537 also has a metallic liquid-cooled upper part forming an electrode support insulated by a high temperature resistant material covering a thermally conductive projection.

The purpose of these protrusions is to prevent direct mechanical contact with the line system in case the high temperature resistant material is locally damaged by hard particles as a result of high local stresses. At the same time, these protrusions also act as fuses, thereby preventing overcurrents in the path.

German Patent Application No. 2,730,884 also describes a conventional feed-through having a cooled metal shaft which constitutes the electrode abutment, provides a supply path for the active part of the graphite, and is coated with a high temperature resistant material. Electrodes are listed. At the same time, the metal shaft has a radially outwardly directed projection to which a high temperature resistant material is fastened. These protrusions, distributed as evenly as possible axially along the periphery, are designed to ensure more reliable cooling and better adhesion ability to high temperature resistant materials. This method corresponds to the above-mentioned protective coating along with the combination electrode. According to the state of the art, the same solutions have been proposed for electrode supports of combination electrodes and conventional electrodes.

However, these electrode pedestals have one drawback in common. That is, even if the protective jacket is slightly damaged locally, it must be removed from the metal shaft of the electrode support and a new protective jacket replaced, resulting in long shutdowns and high costs. .

A further disadvantage of conventional electrode supports is the formation of slugs and metal layers on the protective jacket made of ceramic material, which leads to malfunctions of the furnace.

Electrode supports have therefore been proposed which have a cooled metal shaft protected by a ring of material containing carbon, preferably graphite. By using this type of electrode support, the protective jacket has proven to be extremely useful. The graphite ring acts as an excellent protective coating, not only from a thermal but also from a mechanical standpoint. One advantage of such a protective ring is that the intermediate graphite ring can be replaced in case of partial damage, and complete removal of the jacket is only required when a continuous protective coating is used. . Yet another advantage lies in the fact that the formation of a slazo or metal layer that isolates the protective jacket and destroys the graphite surface by oxidation is avoided. However, in some cases there is a tendency for cracks to form due to tensions in the protective ring due to differences in thermal expansion of the protective jacket and the metal shaft forming the electrode support.

Yet another opening problem is how to mount the metal parts common to all of the electrode supports on the furnace lid. Generally this is achieved by means of a tightening device. Taking into account the aforementioned factors such as ease of handling and the quality of the electrical contact, mechanical lamps also have advantages as current transfer means. Furthermore, graphite or element moldings are usually used between the metal parts of the electrodes and the fasteners of the carrying arm; these moldings have good mechanical and thermal properties and have favorable electrical conductivity.

However, there are problems with the method of attaching these moldings to the electrodes, and the moldings can be destroyed by force without the necessary clamping. Therefore, when tightening changes position,
For example, when it is necessary to remove the clamp, moldings are lost.

The object of the invention is to provide a protective jacket for the cooling metal shaft of an electrode pedestal of the type mentioned above, which meets all the thermal, mechanical and electrical requirements and has a possible hook-and-simplify shape. , easy to install and repair, and ensures good heat transfer to the cooling metal shaft of the electrode pedestal, improving the service life of the protective jacket.

This problem with respect to the electrode supports in question is solved by the connection of the metal shafts and/or the moldings between one another in a removable manner by means of lock-shaped and/or elastic connection elements.

The solution according to the invention provides a protective jacket that meets all electrical, thermal and mechanical demands.

If an elastic link is used, the prestressing of each molding of the protective jacket allows it to settle onto the metal shaft of the electrode pedestal, resulting in good heat transfer between the protective jacket and the metal shaft over the entire area. . This good heat transfer can be achieved without inserting any filler between the protective jacket and the metal shaft of the electrode pedestal.

In addition, in the elastic connections of the sectors, each profile balances the tension caused by the difference in thermal expansion of the material of the protective jacket on the one hand and the material of the metal shaft of the electrode support on the other hand. I can do it. In this way there is no risk of damage to the protective jacket due to thermal expansion.

The protective jacket therefore meets all thermal requirements.

The same applies to mechanical stress. By connecting the sectors according to the invention, i.e. to each other or to the metal parts, it is possible to balance the manufacturing tolerances of the moldings, in which case the internal sheathing is always relative to the sheathing of the metal shaft of the electrode support. It's properly pressed. In this way, compressive and refractive forces can be transferred from the protective jacket to the metal shaft of the electrode pedestal without any tension in the material of the protective jacket due to poor contact between the protective jacket and the metal shaft. . At the same time, the metal shaft of the electrode support is also protected by the molding. Therefore, the molded product can be easily placed or removed as required. For this purpose, each individual molding or group of moldings can be moved axially along the metal part. For example, connecting several moldings or sectors that partially form a ring,
Or it is possible to connect several partial rings to form one complete ring. This means that the protective ring can be placed directly on the metal shaft of the electrode pedestal. If one or several sectors of the protective ring are damaged, the damaged sector can be easily replaced. If the protective jacket is made up of several rings consisting of sectors, the rings at the lower end of the metal shaft of the electrode pedestal are exposed to higher stresses in the furnace and are more likely to be damaged or damaged than the rings located at the top of the furnace. Easily worn and removed first. The ring is a new ring,
Or in the lower part it is still good to replace the ring used in the upper part of the metal shaft. In this way it is possible to continuously replace the rings in the protective jacket of the electrode pedestal, reducing assembly time and maintenance costs.

Preferred shapes of the electrode support of the present invention are also clear from the other claims.

According to one embodiment, the sectors may consist of carbon-containing non-graphitic material or partially graphitic material. This makes the number of uses of the guard ring economical, while also favoring the performance of the carbon material with respect to slag or metal flying. If the dimensions of the protective ring are correct, a certain gradual oxidation of the carbon will occur, especially in the hot outer periphery of the ring, preventing the build-up of slag and metal parts, which is a drawback often seen when using ceramic coatings. I can do it.

Since the solution of the invention provides good heat transfer from the protective jacket of the electrode pedestal to the metal shaft, the protective jacket may be made of a material with low thermal conductivity. Among the previously carbon-containing materials, so-called non-graphitic materials and partially graphitic materials are particularly preferred.

Ceramic materials may be used if the user does not wish to take advantage of self-cleaning of the surface of the guard ring.

It is preferable to use a ceramic material for the upper sector of the metal shaft of the electrode support, or to use a carbon-containing material for the lower sector. A mixed arrangement of rings or sectors of different materials is also possible.

The non-protruding connection of the sectors with each other and the formation of a prestress that securely seats the ring of sectors on the metal shaft of the electrode support is achieved by the force of the spring.

There are many possibilities as far as the arrangement of the springs that produce the spring force is concerned. Each guard ring may have one or several spring rings, each spring ring being formed by one spring or by several springs connected in series.

The spring is arranged in a sector concentric hole or recess with respect to the ring. This is very advantageous since the spring is attached to the sector and protected against excessive thermal and mechanical stresses.

In order to further reduce the thermal tension of the spring, the recess of the sector hole 1 is arranged close to the inner cladding of the sector. This brings the cooling system of the spring and the metal shaft as close as possible to each other, and the temperature in the vicinity of the spring is kept as low as possible.

The spring used here may be a helical spring or a leaf spring.

It is particularly important that the spring be made of non-magnetic material in order to avoid heating of the spring due to hysteresis losses.

Basically, springs that are characterized by high temperature resistance are used. This spring may be made of chromium-nickel-molybdenum austenitic steel or a material containing beryllium.

In another preferred embodiment of the invention, the contact surfaces of circumferentially and/or still axially arranged adjacent sectors have at least one auxiliary radial step. Even if the contact surfaces of adjacent sectors do not fit properly due to tolerances, these mutually engaging steps ensure a good sealing of the sectors, so that reliable protection of the cooling metal shaft of the electrode pedestal takes place.

According to another embodiment, the width of the sector, measured in the circumferential direction, is relatively small and the radial direction of the hollow cylinder forms an angle with the angular contact surface. This means that relatively thin sectors of the ring in relation to each radius are placed diagonally on the metal shaft. In this way, the tolerances are evened out as a result of the so-called "self-adjusting function", which has sectors that adjust their own vertical or horizontal position based on the diameter of the metal shaft and/or the internal diameter of the sector ring. by.

This "self-adjusting function" is based on the alignment of the guard ring with its oblique sectors or the tangential component of the spring tension. The tangential component of the spring tension is determined by the fact that in each sector along the periphery the spring is housed at one end of the hole or quarter in which the spring is located, or at a greater distance from the cladding of the metal shaft than at the other end of the recess. It is caused by having.

This sector adjustment is particularly noticeable when the sector 〇 inner sheath is smaller than the outer sheath theoretically obtained from the circumference. For this reason, a protective ring with gaps between sectors is preferred when placed.

Such a gap becomes wider toward the inside. The sectors are always open inwardly and closed outwardly, even though wedge-shaped gaps are formed between the sectors.

In the adjustment reservoir, the sectors have a flat inner sheath so that they are aligned over the sheath of the metal shaft. The outer covering of the sector may also be planar and need not have a circular shape. In addition, the inner and outer sheaths of the sectors may have any suitable shape.

In order to avoid heating of the closed spring, especially in the circumferential direction, taking into account the possible currents, it is useful to incorporate at least one electrically insulating coupling element into the spring. Such a connecting element may consist of highly sintered aluminum oxide, for example.

Similar considerations may be taken in connection of the electrically insulating elements between the contact surfaces of the sectors. This applies to all circumferential contact surfaces. The axial contact surfaces are also kept at a distance of less than m by means of electrically insulating elements.

If a lock-type coupling mechanism is used, the coupling element may be designed to slide on the coupling mechanism whose sliding direction is parallel to the axis of the member shaft of the electrode pedestal. In this way it is possible to raise or lower the mold or each sector by the simple method described above, with the result that a partially damaged ring or sector requires considerable assembly work and a large number of spare or replacement rings or sectors. It can be replaced without any problem.

Specifically, the sliding connection mechanism with the projections described above is in the form of a dovetail guide. This dovetail guide not only provides mechanical fixation, but also facilitates the sectoring of the covering portion of the metal shaft of the electrode support.

The grooves of the dovetail guide are located on the inner sheathing of the sector, while the connecting piece is drilled on the sheathing of the metal shaft.The position of the groove on the inner sheathing of the sector is This is advantageous because it keeps losses of the relatively expensive sector material, which has a high resistance to stress, to a minimum.

Advantageously, the contact piece is a separable element attached to the sheathing of the metal shaft by rivets, bolts, welding or similar methods. This not only saves material for the metal shaft of the electrical support, but also
Facilitates placement of the contact piece on a metal shaft with relatively thin walls.

The cooling metal shaft of the electrode pedestal is usually made of very expensive copper, so saving material is of great importance. Furthermore, the metal shafts or pipes comprising metal shafts carrying out the supply of coolant and electrical current must have relatively thin walls in order to obtain an optimum cooling effect for the entire unit.

If the protective jacket includes several rings of sectors, one one-piece ring may actually be placed anywhere between two rings of sectors. Therefore, the current carrying capacity of the protective jacket is further enhanced.

According to another embodiment of the invention, the contact pieces are separated in the axial direction of the metal shaft, the distance between two side-by-side contact piece members being less than twice the axial height of the sector in this part. not big. In this way, even in the central part of the protective jacket, damaged or worn sectors can be removed and replaced with new ones without removing the upper and lower sectors. This also reduces assembly time.

It is further advantageous if the contact piece members are in the form of a ring and if the contact pieces of one group and the contact pieces of an axially adjacent group move in the circumferential direction. As a result, a sector arrangement that can be moved ring by ring is realized, which makes it possible to significantly increase the mechanical femininity of the protective jacket.

In accordance with embodiments of the invention, at least one one-piece ring or, if used where it forms part of a protective jacket, two of the contact pieces at the location where the ring is placed.
The axial distance between two adjacent groups is somewhat greater than the axial height of the one-piece ring. Since the ring can be rotated in this position, the grooves and contact pieces of adjacent groups complement each other and the ring is pushed together in the axial direction.

The ring is thus arranged to support all sectors or rings of sectors located above the ring. Thus, if the lower sector of the ring is partially but not completely damaged, the upper sector of the ring is prevented from slipping off. This ensures that even if the protective jacket is considerably damaged, the majority of the metal shaft of the electrode mount remains protected by undamaged sectors. By such a method it is possible to minimize damage.

The sectors and/or one-piece rings may be made of a carbon-containing non-graphitic or partially graphitic material. As a result, the life of the guard ring will be sufficient from an economic point of view. A further preference for carbon-containing materials is based on their good properties with respect to slag or metal splatter. If the protective ring is of suitable size, carbon oxidation will occur slowly as expected, especially on the heated periphery of the ring, and will prevent the problematic build-up of slugs or metal parts often found on ceramic link coatings. prevent or do.

The solution according to the invention ensures good heat transfer from the protective jacket to the metal shaft. It is recommended that materials with low thermal conductivity be used as protective jackets. Among carbon-containing materials, so-called non-graphitic or partially graphitic materials are particularly suitable for this purpose.

Ceramic materials may also be used if used without the benefit of self-cleaning of the guard ring surface.

Depending on the various requirements, the material of the protective jacket can be different, i.e. carbon-containing materials as well as ceramic materials can be used for both the sectors and the one-piece ring. The upper sector of the metal shaft may be made of ceramic material, and the lower part may be made of carbon-containing material. Methods such as a mixed blue distribution of rings or sectors of different colors are also possible.

According to the invention, it is preferred to use a lock-shaped connector supported by an elastic gripper to connect the molding material arranged between the metal shaft and the gripper.

For this purpose, a pair of axially oriented rails are mounted on the metal shaft, the shape of which allows the rails to form an axial edge of the molding located between the rail projection from the metal shaft and the metal shaft itself. And you can hold the ends.

The rail is thus characterized by a portion adjacent to the metal shaft, a portion rising above the metal shaft, and a portion parallel to the metal shaft.

The present invention will be explained in more detail below based on the drawings.

FIG. 1 is a schematic diagram showing the basic structure of a combination electrode for an arc furnace. The electrode of the invention consists of an "electrode abutment" formed by a cooled metal shaft (1). The active part (2), made of a consumable material such as graphite, supports the electrode by means of a threaded nipple (3). The metal shaft that makes up the stand (
1) Attached to the lower end of the The electrode is held by a holder (4) attached to the top of the metal shaft (1) of the electrode support. Figure 1 is only schematic and shows that the electrical and cooling elements are of conventional type and surround the part of the metal shaft (1) in the furnace, which Protects against thermal and mechanical stress.

The protective jacket (5) consists of hollow tubular sectors (10) as shown in FIG. The hollow tubular sector (10)
includes an inner sheath (11) and an outer sheath (12), two peripheral contact surfaces (13) and two axial contact surfaces (14).
). Furthermore, the sector has two sector holes (15) arranged along one chord.

Figures 3 and 4 demonstrate how a partial ring can be formed by connecting the contact surfaces (13) of several sectors (10). sector of the partial ring (
10) can be connected by a spring passing through the hole (15). The spring shown in the figure is a helical spring (20). The hawk-shaped clasp (21) has a spiral spring (2
0) is fastened at the end, thus ensuring prestress. The clasp (21) is hooked onto a catch or wing at the end of the spring (20) to keep the spring (20) in a prestressed state.

Figure 4 shows how to fasten the clasp (21) on the left side, and shows the clasp already fastened on the -Mangoku side.

FIG. 5 shows how partial rings of sectors (10) can be connected to form a complete ring. The partial rings are then connected by connecting each end of the spring (2o) held in a prestressed position by a clasp (21). The clasps (21) are removable so that the contact surfaces of the sectors also fit into each other where the partial rings are connected.

The ring made by the sector (10) can be slid on the metal shaft (1) from one end and by means of the connecting part ring the metal shaft (1) can be slid in the manner described in [)1j.
1) It can also be placed in the radial direction.

The important criterion is that the ring consisting of sectors (10) or the pre-slug 1 be placed directly on the coating of the metal shaft (1) as shown in Figure 1.
It is something that is stressful. As already mentioned, this effectively results in good heat transfer between the protective jacket (5) and the metal shaft (1), reduces coating and cracking due to oxidation, and protects the thermal expansion difference between the jacket and the metal shaft. This makes it possible to completely eliminate harmful tensions in the protective link due to radial temperature gradients in the protective link.

FIG. 6 shows another possible form of connection of two springs connected by a clasp, which on the one hand has an eye-(
It is useful to connect the sectors (10) to each other by the method described in Figure 1, and on the other hand to place the ring of sectors (10) with a certain prestress on the metal shaft (1). As shown in Figure 6, the spring (
20) is connected to each recess (1) at the end of the sector hole (15).
6) and a hook (22) for each spring (
20) tightens each sector (10) and at the same time compresses the entire ring of sectors (10) with prestress against the sheathing of the metal shaft (1) in the assembly position.

7 and 8 show other specific examples of the sector (10). In this embodiment, the contact surface (13) of each sector (10) in the circumferential direction has at least one radial auxiliary step (17), which is specifically shown and interlocking.

In this case, the contact surface (13) of the adjacent sector (10)
do not stay together properly and each covered sector (1
0) Even if a crack occurs between the two, it will always be safely protected by the step (17). If the outer diameter of the metal shaft (1) is larger than specified and/or the inner diameter of the ring consisting of sectors (10) of the protective jacket (5) is smaller than specified, there may be a small gap between each sector in the assembly position. Can be seen.

FIG. 9 shows the case where the protective jacket consists of several rings assembled from sectors (10),
2 shows a possible method of axially connecting rings consisting of two or more rings. In this case, each sector (10) has a groove (14) disposed circumferentially facing the connecting ring (19).
18). For this reason, sectors of adjacent rings (1
A close connection between (14) and (14) of o) is obtained.

FIG. 10 shows another possible way of securing the spring (2o) inside the sector (1o). According to this embodiment, the surface (14) of the sector (1o) has a recess (15a) present in the circumferential direction in which the spring (2o) is accommodated in a similar manner to the hole (15). The fourth part (], 5a) can also serve as the groove (18) in the embodiment of FIG.

FIG. 11 shows its axial plane and/or contact 0n(1
4) shows a sector (10) with an auxiliary radial step (17a). This step corresponds to the adjacent sector (1
0) is positively connected in the axial direction. Adjacent sectors (10
) and/or if the contact surface (14) does not fit properly over its entirety, the resulting gap 141 is covered by these steps (17a). This ensures that the metal shaft (1) is always safely protected. Furthermore, due to the 14+- combination of the sectors (1o) in an aggressive manner, the protective jacket (5) is more mechanically resistant.

Naturally, the axial contact surface (14) of each sector can be stepped in order to tighten the overall structure of the sector together with the peripheral contact surface (13), which not only forms a lock but also Configure a protective jacket as a resistor.

FIGS. 12 and 13 show specific examples of the double contact protection ring according to the present invention. In these embodiments, the width of each sector (10) measured circumferentially is relatively small, and many sectors are required to assemble one guard ring. Here, (11) and (12) are planes. Furthermore, the shape of the sector (10) forms one or two angles α and/or β of different magnitude with the contact surface (13) and the hollow tubular radius (30a) and/or (30b). The inner cover (11) of the sector (10) is smaller than the outer cover (12) calculated based on the circular part. For this purpose there is a wedge-shaped gap (40) which is wider towards the inside or between the contact surfaces (13) of the assembly guard ring which rests with prestress on the metal shaft (1).

The tangential component of the spring tension is the metal shaft (1)
The sector (10), which is folded obliquely and has a small inner sheath (11), is compressed in the manner described above, and the wedge-shaped gap (40) is always closed on the outside. As a result, it is possible to balance the tolerances in the outer diameter of the metal shaft (1) and/or the inner diameter of the ring assembled to the sector (10). Therefore, if part of the sector (12) is corroded by oxidation, then -C
The wedge-shaped gap is basically closed on the outer diameter.

As shown in FIG. 12, the holes (15) are not located on the value of the ideal tubular sector, but rather are at an angle to the chord. This consists of a metal shaft (1
] and one end of the hole (15) is greater than the distance between the covering of the metal shaft (1) and the other end of the hole at each end having the same circumferential direction. The tangential force thus results from the tension of the spring, which produces the "self-adjusting function" described above.

In order to prevent a circumferentially closed spring from heating up due to the resulting current, it is advantageous to attach at least one electrically insulating connecting element to the spring. This embodiment is shown in FIG. 14, where an electrically insulating coupling element (5o) is used as a coupling element of two springs.

The electrically insulating connecting element (5o) is made, for example, of highly sintered aluminum oxide. Similar considerations can be made if electrically insulating elements, such as asbestos, are inserted between the contact surfaces of the sectors. A first embodiment of this type is not shown. This solution is particularly recommended for circumferential contact surfaces (13), but can also be used for axial and/or contact surfaces (14).

FIG. 15 is also a schematic diagram showing the basic structure of a combination electrode for an arc furnace. This electrode consists of a cooled metal shaft (51) constituting the electrode pedestal. The active part (52), made of a consumable material such as graphite, is connected to the metal shaft (52) by means of a threaded nipple (53).
51). The holder (54) is located at the top of the metal shaft (51) of the electrode support.
is maintained by Since Figure 15 is only a schematic diagram,
The conventionally known '+ [electrical elements and cooling elements of the coffin abutment are not included. What is important in the present invention is the above-mentioned 1.
Hollow tube-shaped storage made of high-temperature resistant material for seeds → Withering jacket 1-
(55). The jacket encloses the metal shirt 1-(51) of the electrode support along the part located in the furnace, thus protecting the metal shaft from excessive thermal and mechanical stresses in the manner described above.

The protective jacket (55) is made up of hollow tubular sectors. A perspective view of one of them is shown in FIG.

The hollow tubular sector (60) has an inner sheath (61) and an outer sheath (62), a circumferential contact surface (63) and two axial shafts (64).

Nine rings are assembled by a large number of sectors (60).Nine rings are assembled by a number of sectors (60).
65).

The sectors (60) and the sheathing of the cooled metal shaft (51) are connected by means of protruding connecting elements. Specifically, the protruding connecting element is a dovetail guide. There are basically two methods.

According to FIGS. 15 and 16, grooves (61a) are provided axially in the cladding of the metal shirt I-(51), ie they divide the cladding. On the other hand, the corresponding contact piece (60
a) is provided on the inner covering of the corresponding sector (60). When this specific example is used, the groove (61a) is provided continuously over the entire length of the metal shaft (51), making it easy to manufacture the metal shaft (51). However, in this case the sector can slide on the metal shaft only from one end.

When using the embodiment of FIGS. 17 and 18, the contact piece of the dovetail guide is placed on the sheath of the metal shaft (51). These are divided into a group of contact pieces (72) as rings (73) forming two or more rings consisting of at least one ring, preferably a sector (60).

Each contact piece (72) is riveted or bolted (72).
4) to the covering part of the metal shaft (51),
and removed as necessary.

Two groups (73) and (73') of contact pieces (72)
The axial distance between is not greater than twice the axial height of the sector (60) to be placed in this part.

It is generally preferred to have an axial distance (75) somewhat larger than the axial height of the sector (6o) to be located in this part. Where the contact pieces are separated, it is possible to slide the sector (60) over each contact piece (72), thereby removing all sectors above and below the damaged or worn sector. It is possible to replace the protective jacket (55) in the central part without any need for replacement.

It is advantageous to arrange one-piece rings with constant spacing between ring-shaped groups. Such a one-piece ring (80) is shown in FIG.

The inner coating (81) of the ring (80) is a contact piece (72).
It has a groove (82) corresponding to and complementary to the groove. Naturally the ring consists of two groups (73') and (73'') of contact pieces (72).
) is placed between. The axial distance between these two groups (73') and (73'') of contact pieces (72) is therefore somewhat larger than the axial height of the ring (80).

The ring (80) is thus attached to the metal shaft (51)
can be moved from one end of the groove to the separating strip (76) and the groove (
82) and the contact pieces (72) of the group (73') and if necessary also the contact pieces of the group (73') can be moved. In this way, the one-piece ring (80) is securely attached axially to the bottom or both sides.

If the sector located below the ring (80) is damaged due to some extreme conditions, the sector located above the ring (80) will be safely held by the ring (80). As a result, damage to the protective jacket (55) and the metal shaft (51) is kept to a minimum.

The group-like movement of the contact pieces (72) described above may serve the same purpose, since this prevents the upper sector from slipping off in case of complete failure of the lower sector. An additional advantage of the group-wise movement of the contact strips (72) is that the contact surfaces (63) of the sectors (60) also move in a group, which further increases the security of the protective jacket (55).

]) 1j notation is the inner covering part (61) of the sector (60)
The latter method has been further improved, not only to obtain a reliable connection between the cladding and the sheathing of the metal shaft, but also to ensure that the contact surfaces of adjacent sectors fit neatly into each other. It is something. This improvement is shown in FIG.

Two adjacent sectors (63) located in the peripheral direction (63)
The contact surface of 0) has an auxiliary slight step in the j direction. 1st
As shown in Figure 5, the tier-1 (66) of these two auxiliary adjacent sectors (60) are latched. For this reason, the metal shaft (lid (60))
(64) indicates that the scales have a radial protective step which ensures safe protection of these parts even in the presence of large tolerances.

Another possibility is to use a ring-shaped covering between the front faces of axially adjacent sectors, which fits into the corresponding peripheral grooves of the sector front faces, thereby achieving the desired safe covering of the possible pieces. sell.

FIG. 23 shows a cross-sectional view of the upper part of the electrode support. On the outer wall of the metal shirt (91) are arranged three graphite moldings (92) held by rails (94). Gripping tool (9
3) is compressed and mounted at a fixed axial position relative to the electrode support.

The graphite moldings (92) can be distributed evenly or unevenly along the periphery and may or may not have the same size or have the same thickness with respect to length at the periphery. The rail (94) is attached to the metal part (
91).

Since graphite moldings must be replaced frequently, bolts are more practical than fixed connections such as welds.

The rail surrounds the graphite at its axial end and holds them against the metal part (91) without tension. Gripping tool (
Excessive preliminary stress is not preferable in order to obtain the strong gripping force of 93).

In order to achieve this holding function, the rail (94 side part (96) or directly mounted on the metal part (91), another part (97) or rising above the metal part) (98) or parallel to the metal part and at a certain distance from each other. This distance (99) is basically the same as the thickness of the graphite molding.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing the entirety of an electrode equipped with an electrode support according to the present invention, FIG. 2 is a perspective view showing several hollow tubular sectors forming a protective jacket for the electrode support, and FIG. Fig. 4 is a cross-sectional view showing a part of a ring made up of several sectors; Fig. 4 is a perspective view showing protrusions on a part of the ring; Fig. 5 is a ring made of sectors made up of several partial rings. FIG. 6 shows a possible form of connection of the springs connecting the sectors forming the ring or partial ring;
Figure 7 is a diagram showing other specific examples of sectors, and Figure 8 is a diagram showing other specific examples of sectors.
Figures 9 to 11 are views showing two possible axial connections of a ring of sectors;
and Figure 13 is a diagram showing specific examples of other sectors, and Figure 14 shows specific examples of other sectors.
15 is a cross-sectional view of an electrode having an electrode support, FIG. 16 is a cross-sectional view of the electrode shown in FIG. Figure 17 is a diagram showing the metal shaft of the electrode support with the protective jacket partially omitted to show the arrangement of the contact piece on the covering part of the metal shaft, and Figure 18 is a diagram showing the arrangement of the contact piece on the covering part of the metal shaft.
19 is a perspective view of a sector in which several pieces form a protective jacket for the electrode support; FIG. 20 is a perspective view showing a one-piece ring used as a protective jacket for the electrode support; FIGS. 21 and 22 Each figure is a perspective view showing another example of a sector used as a protective jacket for an electrode support; FIG. FIG. 2 is a radial cross-sectional view of a metal shaft with a molded member. The main symbols in the figure are as follows. DESCRIPTION OF SYMBOLS 1... Metal shaft, 2... Active part, 5... Protective jacket, 10... Sector, 20... Spring. Continuation of page 1 Priority claim @November 9, 1981 ■West Germany (DE
)■P 3144520.9 @R Ming Franz Schupel Federal Republic of Germany 85050-Tenbatsch an der Pechnitz Finkengasse 94

Claims (1)

Claims: (1) A water-cooled metal shaft and a consumable active part, characterized in that the molded members are removably connected to the metal shaft and/or to each other by lock-shaped and/or still elastic fastening means. An electrode support for an electric arc furnace comprising a metal shaft at least partially surrounded by a molded member made of a high temperature resistant material. (2) The part of the electrode support located in the furnace of the molded member forms a protective jacket that basically surrounds the part where the electrode support is tightened. (2) consisting of a protective jacket or at least one ring of elastic means (thus several hollow tubular sectors connected and fastened directly on the metal shaft without pressure); (3) wherein the sector is preferably made of a non-graphitic material and/or a carbon-containing partially graphitic material.
Electrode pedestal at the top. (5) the third sector in which the sector is made of a ceramic material;
] Section electrode support. (6) The upper part of the electrode support is made of ceramic material,
On the other hand, the lower member (4) is made of a material containing carbon.
Item 5 is the electrode pedestal in item (5). (7) The electrode support according to any one of the above (1) to (6), wherein the sectors are connected by a spring force. (8) The electrode support according to item (7), wherein each sector ring has one or more spring rings, and each spring ring is composed of one or more springs connected in series. (9) The electrode pedestal according to items (1) to (8) above, wherein the sector hole is located basically concentrically with respect to the spring ring and is arranged in a sector recess. @) The electrode support according to item (9), which is located near the sector hole or sector recess or the inner coating of the sector. ω) The above-mentioned (8), wherein the spring is a helical spring.
Electrode pedestal at the top. (12) The electrode support according to item (8) above, wherein the spring is a leaf spring. (13) (1) above, wherein the spring is made of a non-magnetic material
The electrode support according to any one of Items to (12). 04) The spring is made of a high temperature resistant material)
(13) The electrode support according to any one of the items. J5) Item (13) above or (
14) Electrode pedestal. 06) The electrode support according to item (13) above, wherein the spring is made of a material containing beryllium. 07) According to any one of the preceding clauses (1) to (16), the contact surfaces of adjacent sectors located circumferentially and/or axially have at least one auxiliary radial step. Electrode support 8 Q8) The inner coating of the sector is equal to the above items (1) to (
17) The electrode pedestal according to any one of items 17). c19) Paragraph (1) above where the outer covering parts of the sectors are equal.
(18) The electrode support according to any one of the items. @) The electrode support according to any one of the above items (1) to (19), wherein the width of the sector measured in the circumferential direction is relatively small. c21) Items (1) to (1) above, wherein one or two adjacent surfaces of the sector and the radius of the hollow cylinder form an angle.
20) The electrode pedestal according to any one of items 20). 12) The electrode support according to item (20), wherein the two adjacent surfaces of the sector and the radius of the hollow cylinder form different angles α and β. (23) The wedge-shaped cleft in which the entire protective ring between the sectors is wider than the inside has an eye;
Any one of the above items (1) to (22), in which the inner covering part of the sector is theoretically smaller than the outer covering part based on the annular part.
The electrode support described in . (9) The sloped sectors of the protective ring for the tangential component of the spring tension or the said (17) ) or (18) electrode support. (2) The electrode support according to item (24), in which the inclined sectors maintain a closed wedge-shaped crack on the outer surface even if the outer diameter of the protective ring on which it is placed is reduced, for example due to oxidation. (23) Items (1) through (1) above, wherein at least one electrically insulating coupling element is coupled to a circumferentially closed spring.
25) The electrode pedestal according to any one of items 25).匈) The electrode support according to any one of the above items (1) to (26), which is inserted between adjacent surfaces of the electrically insulating elements or sectors. (b) The electrode support according to item (3) above, wherein the shaped member or the hollow tubular sector is removably mounted on the sheathing of the metal shaft by means of a lock-shaped connecting element. ■) Said item (28) which is a lock-shaped connecting element or a sliding connector that allows displacement of the sector in the direction of the metal shaft.
Electrode pedestal at the top. (2) The electrode support according to item (29) above, wherein the sector is connected to the covering portion of the metal shaft by dovetail guide means. @) The electrode support according to item (30) above, wherein the groove of the dovetail guide is located on the inner sheath of the sector, and the contact piece is located on the sheath of the metal shaft. @) The electrode support according to item (31) above, wherein the contact piece is a separation element connected to the sheathing of the metal shaft by rivets, bolts, welding or similar means. 133) Always one-piece
+) 7 rings are present between any two rings made of sectors, and the protective jacket is made of several rings made of sectors, The stand. Item (1) above, wherein the distance between two arranged contact piece parts is less than twice the height of the sectors arranged in this part, and the contact pieces are spaced apart in the axial direction of the metal shaft. 1 coffin abutment described in (33). @) Any of the above items (1) to (34), wherein the contact pieces are arranged in ring-shaped groups, and the contact pieces of the group and the groups adjacent in the axial direction of the contact pieces are alternated. 1. The electrode pedestal according to item 1. (g) Where at least one one-piece ring forms part of the protective jacket, and where the one-piece ring is placed, the axial distance between adjacent groups of two contact pieces is greater than the axial height of the one-piece ring; No. (
Electrode pedestal according to items 1) to (35). (2) Electrode support according to items (1) to (36) above, in which the contact surfaces of peripheral and/or still axially arranged adjacent sectors have at least one auxiliary radial step. 03) The reprint abutment according to any one of (1) to (3) above, wherein the sector and/or one-piece ring is made of a non-graphite material or a partially graphite material containing carbon. (2) The sector and/''! or the electrode support according to any one of the above items (28) to (37), in which the one-piece ring is made of a ceramic material. (4)) The anode connecting element is made of a molded material and its shaft. The electrode pedestal according to paragraph (28) above, which comprises a rail surrounding the end. (41) The electrode pedestal according to paragraph (40), which holds the molding material on the metal shaft without pressure from the rail. (42) Metal Said item (40) or (41), which consists of one member adjacent to the shaft, one member taken out from the metal shaft, and one member arranged parallel to and at a distance from the metal shaft. Electrode pedestal. (43) The electrode pedestal according to item (42), wherein the distance basically corresponds to the thickness of the molded member.