US2477077A - Electrode clamp - Google Patents

Description

July 26, 1949. w. E. MOORE 2,477,077

ELECTRODE CLAMP Filed March 9, 1946 3 Sheets-Sheet 1 w. E. MOOR E ELECTRODE CLAMP July 26, 1949.

5 Sheets-Sheet 2 Filed March 9, 1946 INVENTOR. PVZ'ZZz'amE Moore 8X46? JMZ/ W. E. MOORE ELECTRODE CLAMP July 26, 1949.

3 Sheets-Sheet 3 Filed March 9,' 1946 INVENTOR. W4 Wz'lliamliflloare Patented July 26, 1949 ELECTRODE CLAMP William Enoch Moore, Pittsburgh, .Pa., assignor to Delaware Engineering Corporation, Pittsburgh, Pa., a corporation of Delaware Application March 9, 1946, Serial No. 653,271

2 Claims.

This invention relates to an electrode clamp, more particularly to one that is useful for electric type smelting furnaces.

Electrodes of relatively large size are commonly used in electric arc type smelting furnaces. Electric furnaces are generally of two types, the closed top type employing a refractory roof and the open top type. The heat from the furnace is quite severe, particularly in the open top type furnace, such as carbide and ferro-alloy furnaces, wherein the electrode clamp is subjected to severe radiant heat and abuse from charging material as Well as charging and stoking tools.

Considerable difiiculty has been encountered in electrode constructions for electric smelting furnaces, particularly insofar as the obtaining of suitable electrical contact between the electrode supporting means or clamp and the electrode so as to enable transmission of the necessarily high electric current from the supporting means or clamp into the electrode without fusing or burning at the points of contact. Another difficulty has been that of cooling the electrode clamp or supporting structure so as to withstand the abnormal heating efieets of the furnace.

An object of my invention, therefore, is to provide an electrode clamp for an arc furnace;

which clamp is relatively flexible and self-adjusting with respect to the arc electrode so as to provide good electrical contact betwen a plurality of contact shoes and the electrode and thus provide minimum contact resistance to the flow of current.

Another object of my invention is to provide a novel water cooled construction for contact shoes used to clamp a furnac type electrode, wherein such water cooled shoes are adjustable radially with respect to the electrode.

A further object of my invention is to provide a novel bus pipe construction for furnishing electric current as well as cooling fluid to a plurality of contact shoes disposed about the periphery of an arc electrode and at the same time serve'as supporting means for suspending such shoes in a manner that the shoes may be moved or collapsed radially inwardly to the electrode.

A further object of my invention is to provide a novel clamping structure for water cooled bus pipes to provide a readily detachable fluid and electrical connection between the bus pipes and a plurality of shoes clamped about the electrode.

Other objects and advantages of my invention will become apparent from a study of the following specification taken with the accompanying drawings wherein:

Figure 1 is a top or plan view of a liquid cooled bus pipe construction embodying my invention and which supplies electrical current and cooling liquid to a plurality of contact shoes clamped to an arc furnace electrode;

Figure 2 is a side view of the structure shown in Figure 1 which more clearly illustrates a plurality of clamped contact shoes suspended by bus pipes;

Figure 3 is a top or plan view of the electrode clamping structure or chain shown in Figure 2 for clamping the contact shoes against the electrode;

Figure 4 is a longitudinal cross-sectional view taken through one of the contact shoes shown in Figures 1, 2 and 3, and

Figure 5 is a side view of the shoe shown in Figure 4.

The electrode clamp according to my invention, in its broadest aspects, is made up of a sufficient number of adjustable segments or contact shoes to provide a flexible clamp giving good electrical contact with the electrode, which shoes are water cooled to prevent overheating and are made of suitable electrically conductive material.

Referring more particularly to the drawings, numerals I, 2 and 3 denote some of a plurality of segments or contact shoes disposed about the periphery of an arc electrode E for an electric furnace. The shoes are made of suitable electric conducting material, such as copper. Each shoe is internally water cooled and includes a plurality of baflle plates 4, such as shown in Figure 4, for circulating cooling fluid or liquid, such *as water, about a circuitous path to effectively cool the shoe. The shoes are preferably provided with coarse ratchet-like serrations 5 to assure good contact through a wide area, and for cleaning dust and other films or coatings from the electrode surface by scraping action, as well as to increase the mechanical-gripping power of the shoe on the electrode to prevent slipping. The shoes have aplurality of radially projecting horizontal flanges B and 'l which are adapted to fit above and below, respectively, the links of a flexible clamp or chain 8 extending about a circle surrounding the shoes.

Copper shoes are inherently weak mechanically, especially when overheated and are not susceptible of being made into satisfactory collapsing mechanism by means. of casting chainlike hinges directly on the shoes.

The contact shoe is provided at the sides of the bottom with horizontally and circumferentially proiecting lugs 3a cast integrally therewith.

3 The flanges 6 and I and the lugs 3a together serve to protect, in part, the chain 8 from direct heat or flame of the furnace.

Since the current fed into the electrode necessarily has to be conducted through the encircling chain 8, then if the chain "were merely made of ordinary steel, it would ofierundesirable netic properties which would I tend to lag the current flowing and drop the voltage at the electrode arc. For this reason, the chain links are preferably made of non-magnetic material, such as austenitic or non-magnetic alloy steel. The chain is formed of links which are of a length so that they are articulated at the'line of separation of the shoes. V

The chain may be collapsed onto the electrode by tightening nuts I6 and II on bolts I2 and I3; I

respectively, at diametrically opposite portions, the bolts extending through suitable flanged portions of the links. Of course, only one such bolt or perhaps-more than. two bolts may be used, instead, if desired. The radii of the shoes may be made to correspond to the radius of the electrode; I prefer to make the radii of the outside of the shoes less than the radius of the bore of the clamping chain sothat the shoes will have a slight rocking, eflect when contacting the elec-' trode. It will also be noted that the collapsible chain is located substantially centrally of the height of the shoe so asto give some rocking adjustment compensation in the axial direction.

Since the shoes are arranged for a small amount of radial movement by collapsing or loosening of the chain, it is necessary that the connections thereto be made sufficiently flexible to permit such movement. Thus a plurality of flexible connectors, or electrically conductive drop pipes, such as I4, I5 and I6, are provided which are of suflicient length so as to flexibly suspend the shoes and chain. It will be noted that the diameters of drop pipes I 4, I5 and I6 are substantially reduced compared to those .of bus pipes I1 and I6 in order to provide suflicient flexibility. The lower ends of such connectors or pipes may be threaded and then welded to the lugs 3a of the shoes as shown best. in'Figures 2 and e. Connectors I4, I5 and I6 are made of electrically conductive material, such as copper, in tubular form so as-to conduct electricity as well as cooling liquid or fluid to the shoes.

The electrically conductive water cooled bus pipes I7 and I8, of substantially annular form, which surround the electrode E are likewise made of electric conducting material, such as copper, since they serve as bus bars for conducting electriccurrent to connectors I4, I5 and I6. They also act as conduits or pipes for conducting cooling liquid therethrough to connectors I4, I5 and I6, etc. An electrical, parallel path is provided through bus pipes I1 and I8 to the connectors. One of the bus pipes, such as I1, may conduct cooling water to all'of. the shoes while the other, suchas I8, may conduct the warm water'away from the shoes as indicated by the arrows, or vice versa.

The connectors I4, I5 and I6, etc. are supported on the bus pipes I1 and I8 by means of split bolted clamps, such as U, 22 and 23, which are integrally formed on or: brazedto the bus pipes or conduits by electrically conductive material. Suitable pipes, such as .25 and 26, are provided for conducting cooling fluid from bus pipes I! and I8 to the tops of the clamps 2|, 22, 23 etc. for making a readily detachable connection-therethrough withconnectors such as- I5 and I6 by means of suitable fittings and unions.

Thus the electrode shoes may be disconnected by loosening the clamps at the bus pipes and dropping the shoes downwardly from engagement 5 with the collapsible chain after uncoupling of the water pipes.

The bus pipes are preferably fitted at their ends remote from the electrode with contact wings or fins, such as 21, 28 and 29, to which flexible cables connections such as 36, may be removably attached for supplying electrical current to the bus pipes.

The electrode and its clamping structure are supported by support loops 3I and 32 preferably of non-magnetic material, which loops encircle bus pipes I! and I8 and are connected together at their top ends by a supporting plate 33 which may be moved vertically by any suitable operating hoist mechanism (not shown) of any type well-known in the art. A support loop of nonmagnetic material 3311 is connected to the fin bearing ends of bus pipes I1 and I8. Hose nipples 34 and 35 are connected to bus pipes I1 and I 8 and serve as inlets and outlets, respectively,

. for cooling water.

Thus it will be seen that I have provided an efiicient clamp suitable for electrodes used in electric smelting furnaces, which clamps have a substantial degree of flexibility, thus providing extremely good contact with the electrode so as to avoid pitting and the like; furthermore, I have provided an efliciently cooled supporting and current carrying clamping structure that is able to withstand deleterious eflects normally caused by the intense heat and gases of the furnace and at the same time embodying in its construction parts'that are readily replaceable.

While I have illustrated and described certain specific embodiments of my invention, it will be understood that this is by way of illustration only and that various changes and modifications may be made within the contemplation of my invention and within the scope of the following claims:

I claim:

1. An electrode clamp comprising a plurality of electrically conductive shoes arranged in spaced circumferential relation, said shoes having an arcuate shape for clamping engagement with the surface of an electrode, a clamping chain extending around said electrodes for applying a clamping force to said shoes, each of said shoes having a pair of axially spaced and parallel flanges extending outwardly from the outer surface thereof and straddling said chain to position said chain substantially centrally of said shoes, said clamping chain comprising a plurality of arcuate shaped links, a clamping connection between the end links of said chain for ap- 60 plying a clamping force thereto, and pivotal connections between the other links respectively positioned opposite the space between adjacent shoes so that there is provided an arcuate link for applying a clamping force to each of said shoes, each of said arcuate links having a radius of curvature on its inner surface greater than the radius of curvature of the shoe surface'engaged thereby so that said links will engage with said 70 shoes in an area substantially centrally thereof to allow slight rocker-like movement of said shoes with respect to said chain to compensate for irregularities on the surface of the electrode with which it is moved into clamping engage- 751 ment, said clamping member being operable through said links to move said shoes into clamping engagement with an electrode. r

2. In an electrode clamp for an electric furnace which includes an electrode, a plurality of electric conductive shoes arranged alongside each other circumferentially of the electrode, a chain embracing said shoes and having links substantially as long as the circumferential width of each shoe, said shoes having two spaced apart" radially projecting horizontal flanges forming with the outer side of the shoe an open channel in which channel the chain is disposed, said shoes having lugs projecting circumferentially from the bottom of the shoes, a water passage through the shoes and opening at each end through the lugs, and a plurality of flexible pipes of electrically conductive material connected to the lugs and aligned with the lug openings.

WILLIAM ENOCH MOORE.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,552,619 Klugh Sept. 8, 1925 1,809,656 Walter June 9, 1931 1,827,852 Marshall Oct. 20, 1931 1,972,849 Wisdom Sept. 4, 1934 2,135,408 Moore Nov. 1, 1938 2,290,030 Brooke July 14, 1942 FOREIGN PATENTS 15 Number Country Date 385,127 Germany Nov. 16, 1923 609,461 Germany Feb. 15, 1935

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