US1115027A - Electrode. - Google Patents

Description

R. L. SEABURY.

ELECTRODE.

APPLICATION FILED AUG 2 l 9 1 l.

1,1 15,027. Patented Oct. 27, 1914.

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ELECTRODE,

APPLICATION FILED AUG.2, 1911.

Patented Oct. 27, 1914.

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RALPH I1. SEABURY, OF LAKEWOOD, OHIO, ASSIGNOR T0 NATIONAL CARBON COM- IPANY, 0F CLEVELAND, OHIO, A COREORATION OF NEW JERSEY.

ELECTRODE Specification of Letters Patent.

Application filed August 2, 1911.

To all whom it may concern Be it lmown that I, RALPH L. SEABURY, a citizen of the United States, residing at Lakewood, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Electrodes, of which the following is a full, clear, and exact description.

This invention relates to carbon electrodes, primarily intended for use in electric furnaces, and seeks to provide an electrode which will more uniformly distribute the heat generated incident to its use, to the charge of material operated upon and also will apply the heat over a greater area of the furnace charge than is possible with electrodes as at present constructed.

Furthermore, the invention comprises a method by which it is possible to form electrodes of a greater size by forcing them through dies than is possible under the present method of forming electrodes.

The invention also includes the fastening of the electrodes together to form a continuing electrode which may be lowered into the furnace as it is used.

Generally speaking, the invention comprises the elements and combinations thereof set forth in the accompanying claims.

Reference should be had to the accompanying drawings, in which Figure 1 is a front elevation, partly in section of one form of my invention; Fig. 2 is a horizontal cross section thereof; Fig. 3 is a front elevation partly in section of another form of electrode; Fig; 4: is a horizontal cross section thereof; Fig. 5 is a vertical elevation partly in section of a third form of electrode; Fig. 6 is a horizontal section thereof; Figs. 7, 8, 9, l0 and 11' are longitudinal cross sections of abutting electrodes showing means for securing them together.

At the resent time, in the making of electrodes or electric furnaces and in general electrodes of large size, it is customary to form them by forcing a proper mix through dies which deliver the electrode as one solid piece of carbon. These electrodes may be made in various shapes, but the most common form is round. The electrodes are next baked and are then ready for use. When suchsolid electrodes are used in an electric furnace, but a short time elapses until the active end of the electrode or the end I of the electrode which is adjacent the charge in the furnace, becomes pointed, and by so much reduces the area of the electrode which is adjacent the arc, and from which the arc must spring. Inasmuch as the arc travels over all the surface of the electrode which is presented to the charge, it will be apparent that as the end of the electrode approaches a point, the area of the charge upon which the arc is acting is being constantly reduced, and by so much, the zone of activity in the furnace is reduced.

In Fig. 1 there is shown an electrode 1 which is cylindrical, although not necessarily so, this form being merely illustrative; Through the center of the electrode there is a cored out portion or cylindrical opening 2, which may be of any suitable dimension, and of course is proportional to the external diameter of the electrode. This electrode may be formed in the usual manner by forcing through dies, to use a form of die which will produce the central opening. Such an electrode is baked in the usual manner and is then ready for use.

When an electrode, such as has been de' scribed, is used in an electric furnace, it will at once be seen that the electrode cannot burn to a point, and therefore this electrode overcomes a serious cause for objection in solid electrodes which has heretofore been pointed out, but further, the construction shown has a positive advantage in that for a given cross sectional area of carbon, the zone of operation of the electrode, or in other words, the area of the bath to be treated, which is aifected by the are spring from the electrode is much greater than where a solid electrode is used. Therefore from the fact that the heat developed by the passage of the current is distributed over a,-

greater area of the bath, it follows that the zone of activity in the furnace is also enlarged.

In some instances, it may be undesirable to use 'an electrode having an open assage throughout the length thereof, and m such an event, means may be employed to obstruct the continuity of the passage or central opening, and as one means for accomplishing this result, I have shown the con-. struction disclosed in Figs. 3 and 4, wherein the electrode body l is provided with the it merely being necessary has been baked and in this condition used in the electric furnace. Aside from the advantages to be derived by the use of an electrode constructed as shown and described, additional advantage is gained in the ease of manufacture, particularly of electrodes of large size.

Practically all electrodes are made by forcing the carbon mixture through dies to give them their form, and it is found in forcing solid electrodes that a limit as to size is soon reached, for the friction of the material upon the sides of the die becomes so great that the portions of the mass being forced which are pressing against the sides of the die are retarded in their movement, while the central portion of the mix moves faster than the sides thereof, which, of course results in an imperfect electrode and produces cracks and check marks upon the exterior portion, which upon baking becomes more accentuated. However, if the electrode be cored, as shown in Figs. 1 and 2, the whole situation is changed, for the friction of the moving mix upon that portion of the die which forms the core, prevents the central portion of the mix from moving faster than the outer portions of the mix. Therefore, the resultant electrode is more uniform and may be forced without the objectionable vresults encountered when forcing a large solid electrode. Therefore, it is possible to force electrodes in this manner of considerably larger diameters than is possible in the case of solid electrodes. This then presents an advantagc, inasmuch as it permits the manufacture of electrodes having cross sectional surface areas which may affect larger areas of the furnace bath or charge when they are used in an electric furnace than is possible to obtain with solid electrodes. However, if it be desired to produce a solid electrode of large diameter, it may be accomplished by first forcing a hollow carbon body having an external diameter, the same as that desired for the solid electrode. Then forcing a carbon body of a diameter to snugly fit the hollow or cored out portion of the first carbon body, and while both bodies are still in their green state, placing the second carbon body within the hollow portion of the hollow carbon body, and then while the two electrodes are in this assembled condition baking them. It is found that when two bodies are treated in this way, after baking the two bodies are substantially unitary and inseparable. In this way solid electrodes may be made which it would be absolutely impossible to force through dies.

At present carbon electrodes when used in an electric furnace are supported by suitable means which permits of the lowering of the electrode into the furnace as the electrode is consumed. I The use of the electrode continues until such time as there remains only a butt or stub portion, which is that portion of the electrode grasped by the means which supports it. It is customary to remove these butts, which are then useless and to replace the consumed electrode by a new electrode.

With the hollow electrode herein shown and described, it is possible to join electrode to electrode in such a manner as to produce a continuously built up electrode.

The successive electrodes may be joined together in any suitable manner, several of which are suggested in Figs. 7 to 11 inclusive. In Fig. 7 the electrode A is joined to the electrode B, by means of a plug or rod G, which is of conducting material and is formed so as to snugly fit within the cored out or hollow portion of the electrodes A and B. In Fig. 8 there is shown a plug D for joining the electrodes, this plug being tapered from both ends toward the center. The spaces between the tapered sides of the plug and the walls of the electrode may be filled with any suitable granular conducting material which will insure good electrical conductivity between the walls of the two electrodes. In Fig. 9, the plug or rod E is inserted within the hollow portion of one of the electrodes and is caused to fit snugly therein, while the opposite end of the plug is screw threaded and is adapted to fit with a screw thread formed upon the wall of the cored out portion of the electrode, which is to be joined to the first electrode. In Fig. 10, the plug or rod F is screw threaded throughout its length. The abutting ends are screw threaded within the hollow portion for a short distance, and the threads upon the plug are adapted to engage the threads upon the two electrodes so that they are substantially united. In Fig. 11, the same idea is shown as that embodied in Fig. 10, with the exception that the plug G is made with a double taper and the adjacent ends of the electrodes are formed to complement the taper upon the plug. As will be seen from the drawing, the plug and the interior walls of the electrodes are provided with screw threads which permit the plug to join the two electrodes together.

Having thus described my invention, what I claim is 1. An electrode for electric furnaces comprising a tubular body portion of substantially uniform cross sectional area and another body of carbon occupying the interior forcing a tubular carbon body, placing carof the tubular carbon body.

bonaceous material to substantially fill the 2. The process of making electrodes for tubular carbon body, then baking the comuse in electric furnaces which consists in forcing atubularcarbon body and a second carbon body of a diameter to fit Within the tubular body, then inserting the second body Within the tubular body and baking the combined bodies.

3. The-process of making electrodes for use in-- electric furnaces, which consists in bined bodies.

In testimony whereof, I hereunto effix my signature in the presence of two Witnesses.

RALPH L. SEABURY.

WVitnesses:

RICHARD H. HANEY, HARRY R. ALLISON.

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