JPS6364040B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an improvement of a clamped portion of a water-cooled electrode used in an arc furnace for steelmaking.

<Prior art> Generally, in an electric furnace, about three graphite electrodes 1 are used in series, as shown schematically in FIG. This is a semi-permanent electrode that is used in place of the upper 1/2 to 2/3 of the entire length of the electrode 1. The water-cooled electrode 2 is
It is a cylindrical body made of copper with a cooling water circulation passage inside, a cooling water supply and drainage pipe at the upper end, and a screw hole for connecting a graphite electrode at the lower end. In addition,
In the figure, 3 is an electrode support arm, and 4 is a back-up spring of the electrode clamp device.

In the conventional method shown in Fig. 3a, when the graphite electrode 1 wears out and becomes short, it is added to the upper end and moved downward.
It was used by regripping the grip. With water-cooled electrodes that have recently come into use, only the lower graphite electrode 1 is replaced, and the upper end of the water-cooled electrode remains in place.

Further, the structure of the clamp device that holds the electrode is approximately the same as that of the conventional method, as shown in an enlarged view in FIG. That is, as shown in the figure, the inner surface of the back-up spring 4 is provided with receiving-side conductive liners 5, 5 formed into three segment blocks and a push-side conductive liner 6. It is biased by a strong spring 7 and includes an air cylinder 8 for opening when attaching and detaching the electrode. The above liner 5, 5,
6. Since water-cooled electrodes came into use,
Graphite segment blocks 5a, 5a, 6a can now be interposed on the inner surface of the conventional copper liners 5, 5, 6. Note that the conductive liners 5, 5, and 6 are connected to a power transmission main pipe, and power is transmitted to the electrodes through this.

<Problems to be Solved by the Invention> Since the use of water-cooled electrodes, the clamping device has to keep gripping the same part and is gripped strongly enough to support the weight of the electrode. The soft water-cooled electrode began to deform (dent). This deformation prevents the liner from coming into close contact with the water-cooled electrode when the liner is replaced with a new one. For this reason, sparks occur due to energization, creating further unevenness, resulting in a problem of shortening the lifespan of the water-cooled electrode and liner.

The object of the present invention is to extend the life of the water-cooled electrode and the lyre section by preventing deformation of the water-cooled electrode.

<Means for Solving the Problems> The means according to the present invention is such that the clamped part of the water-cooled electrode of an electric furnace has a copper cylindrical part having a cooling water circulation passage inside and a male thread on the outer periphery, and a female thread on the inner periphery. The female thread is formed by a graphite ring screwed onto the male thread.

<Function> According to the means of the present invention, since the entire circumference of the clamped portion of the water-cooled electrode is formed of a graphite ring,
The conductivity between the liner and the water-cooled electrode has been improved, there is no wear and tear caused by sparks, etc., and since the clamping force is received by the graphite ring and the copper cylindrical part, there is no deformation, so there is no need to replace the graphite ring. Even if something happens, its good conductivity will not change.

<Example> In FIGS. 1 and 2, 10 is a water-cooled electrode, which has a male thread 11 at its upper end.
Graphite rings 12a, 12b, and 12c are screwed together. In the figure, 13 is the internal thread of the inner hole of the graphite ring, 1
4 is a graphite ring receiver with a copper ring screwed onto it. In addition, the lower part of the water-cooled electrode 10 is a refractory ring 1.
5, and a graphite electrode 1 is attached to the lower end. A cooling water passage is formed in the water-cooled electrode 10 by a stainless steel pipe 16.

This water-cooled electrode 10 is a clamp device similar to that shown in FIG. 4 (shown by phantom lines in FIGS. 1 and 2).
It is used by supporting the graphite links 12a, 12b, 12c so as to grip their outer peripheries (clamped parts). Parts equivalent to those shown in FIG. 4 are indicated using the same drawing reference numerals.

In the above embodiment, the graphite rings 12a, 12
Three pieces, b and 12c, were used, and these were intended to have a certain degree of locking effect and to allow partial replacement in the event of damage. Therefore, the object of the present invention can be achieved even if three pieces are formed together.

<Effects of the Invention> According to the present invention, since there is no deformation of the water-cooled electrode or wear due to sparks, etc., the water-cooled electrode can be used semi-permanently.

[Brief explanation of drawings]

FIG. 1 is a partial longitudinal sectional side view of one embodiment of the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1, FIG. 3a is a schematic side view of a conventional graphite electrode, and FIG. 3b is a conventional graphite electrode. FIG. 4 is a schematic side view of the water-cooled electrode of FIG. 10...Water-cooled electrode, 11...Male thread, 12a,
12b, 12c...graphite ring, 13...female thread.

Claims (1)

[Claims] 1. The part to be clamped of the water-cooled electrode of an electric furnace includes a copper cylindrical part that has a cooling water circulation passage inside and a male thread on the outer periphery, and a graphite ring that has a female thread on the inner periphery and the female thread is screwed into the male thread. A water-cooled electrode for an electric furnace, characterized in that it is formed by: