US2647936A

US2647936A - Electrode clamp

Info

Publication number: US2647936A
Application number: US86989A
Authority: US
Inventors: Moore William Enoch
Original assignee: Delaware Engineering Corp
Current assignee: Delaware Engineering Corp
Priority date: 1949-04-12
Filing date: 1949-04-12
Publication date: 1953-08-04
Anticipated expiration: 1970-08-04

Description

1953 w. E. MOORE 2,647,936

ELECTRODE CLAMP Filed April 12, 1949 2 Sheets-Sheet l JNVENTOR. WILLIAM E. MOORE.

F A'ITORNEYS.

Aug. 4, 1953 w, MOORE 2,647,936

ELECTRODE CLAMP Filed April 12, 1949 2 Sheets-Sheet 2 INVENTOR. j] WILLIAM E. MOORE.

ATTORNEYS.

Patented Aug. 4, 1953 UNITED STATES PATENT OFFICE 2,547,936 I ELECTRODE CLAMP William Enoch Moore, Pittsburgh, Pa., assignor to Delaware Engineering Corporation, Pittsburgh, Pa., a corporation of Delaware Application April 12, 1949, Serial No. 86,989

5 Claims.

1 V This invention relates to an electrode clamp, and more particularly to one that is useful for electric arc smelting furnaces. This application is a continuation-impart of my application, Se rial No. 653,271, filed March 9, 1946, and entitled Electrode Clamp, now United States Letters Patent No. 2,477,077, issued July 26, 1949.

Electrodes of relatively large size, and electrodes having a diameter of about fifty (50) inches are not unusual, and are commonly used in electric arc type smelting furnaces. Such electric furnaces are generally of two types, the closed top type which includes a refractory roof, and the open top type. The heatfrom an electric arc furnace is quite intense, and particularly is this true in the open top type furnace'such as carbide and ferro-alloy furnaces, wherein the electrode clamp which surrounds and supports the electrode is subjected to severe radiant heat and abuse from charging material as well as from charging and stoking tools.

Considerable difiiculty has been encountered in electrode clamp constructions for sizable electric smelting furnaces, particularly insofar as obtaining suitable electrical contact between the electrode supporting means or clamp and the electrode so as to enable transmission of the neoessarily 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 as Well as the electrode so as to withstand the abnormal heating effects of the furnace.

The electrode clamp of my invention includes a sufficient number of adjustable segments or contact shoes so as to make proper electrical contact with the electrode to satisfactorily transmit the necessary electric current from the clamp into the electrode, and to insure good contact even though the electrode may vary (usually from 2% to 4%) in diameter. The shoes are water cooled, and are made of high electrical conducting material.

The contact shoes and fixedly attached connector pipes useful in a large furnace are necessarily quite heavy, and since the shoes must be changed at intervals it is highly desirable to so attach the connector pipes to the bus pipes that connections both for electric power and cooling water can be made and broken in a minimum of time, at the same time remembering that the connections must have high electric conductivity and possess strength. Difficulty has been experienced in making such connections, and my inthe third function is to conduct electricity from the bus pipes to the shoes. vIt is highly desirable, that the connector pipes be secured to "the bus pipes by readily disconnectable couplings or clamps, which afford adequate support for the connectors and connected contact shoes, and also provide good electrical connection between the connector pipes and bus pipes while at the same time the connector pipes are secured to the bus pipe in water conducting relationship.

The bus pipes from which I suspend my contact shoes, by means of connector pipes, are electrically connected in multiple and are arranged to extend from a point reasonably distant from the electrode, tosubstantially surround the electrode and be radially spaced from the electrode. The two bus pipesvertically spaced apart must conduct cooling water under pressure from a distant point to and from the connector pipes, and also supplya highly conductive path to the connectors for conduction of the electric current to which, in turn is conducted through the connector pipes, to and through the contact shoes and from them to the electrode. I make the bus pipes preferably from strong wall copper tubing.

It is an object of my invention to provide an electrode clamp for an arc furnace, which clamp includes a plurality of contact shoes which will closely embrace the electrode and which shoes are relatively flexibly. connected to supporting Another obiectof my inventionis to provide an electrode clamp which has spaced watercooled contact shoes whichare connected to bus pipes by relatively laterally flexible connectors which are both water conductors and electric. conductors, and which are readily disconnectably clamped to the bus pipes.

A further object of my invention is to provide a novel bus pipe connection for furnishingelectric current as wellras 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. The contact shoes bein connected to the bus pipe by means which are readily disconnectable from the bus pipes.

A still further object of my invention is to provide an arrangement whereby bus pipes may supply cooling water and electricity to electrode contact shoes connected to the bus pipes by connector pipes which pipes are secured to the bus pipes by a secure but simple make and break or split clamp which will ensure good electric conduction and water connections.

Other objects and advantages of my invention will become apparent from a study of the follow ing specification and the accompanying drawings wherein I have shown the preferred embodiment of my invention. V

In the drawings:

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 Fig, 1 which clearly illustrates a plurality of clamped contact shoes suspended from bus pipes by means of connector pipes;

Figure 3 is a view along the line III-III of Figure l, but to an enlarged scale showing a side View of the clamping means;

Figure 4 is a view along the line IVIV of Figure 1, but to an enlarged scale, and showing a vertical end view of the clamping means;

Figure 5 is a top plan view of the clamping means shown in Figure 4;

Figure 6 is an enlarged view of the connection at the top of the connector pipes, and

Figure 7 is a view partly in section along the line VII-VII of Figure 2, but to an enlarged scale showing the connections to the bus pipes.

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 very good electrical and physical contact with the electrode, which shoes are water cooled to prevent overheating, and are made of suitable electrically conductive material. The contact shoes are suspended from suitable bus pipes by connector pipes which connector pipes are firmly secured to the bus pipes by clamping means so that the connector pipes are readily disconnectable from the bus pipes. The connector pipes carry cooling water to and from the contact shoes as well as conduct electric power to the shoes.

Referring more particularly to the drawings, numeral 3 denotes some of a plurality of segments or contact shoes disposed in spaced relationship around the periphery of an arc electrode E of an electric furnace. The shoes are made of suitable electric conducting material, such as copper, and each has a circuitous passage therein through which cooling water may be passed to eifectively cool the shoe. Each shoe has two radially projecting horizontal flanges 4 and 5 which are spaced vertically so as to fit above and below, respectively, the links 6 of a flexible chain or clamp '1 extending in a circle surrounding and in contact with the outer faces of the shoes. The chain may be tightened to urge the contact shoes radiall inwardly against the electrode by means of appropriate nuts and bolts 8 and 9 received at diametrically opposite portions of the chain. The chain links are preferably made of 4. non-magnetic material, such as austenitic or non-magnetic alloy steel.

Each contact shoe is provided at the sides of the bottom with horizontall and circumferentially projecting lugs l0 cast integrally with the shoe. Each lug has an opening which is the end of the circuitous passage formed in the contact shoe.

The electrode clamp includes two electrically conductive water cooled bus pipes II and I2 both of which extend from a point distanct from the electrode in parallel straight portions [3 and I4, and each has a portion I5 and [6 respectively, substantially annular, which substantially surround or embrace the electrode E so as to leave a space between the annular portion and the electrode. I prefer to make the bus pipes of suit able double extra strong copper tubing since the bus pipes conduct electric current to the clamp as well as conduct water. The straight portions of the bus pipes are joined by vertical metal braces I1, and by horizontal metal braces l8. These braces strengthen the bus pipe construction, and connect the bus pipes in multiple and thus insure good electrical conduction in the bus pipe system.

The contact shoes are spaced below the bus pipes and are suspended therefrom by connector pipes or down pipes 20 and 2| which are formed from suitable copper tubing and serve to support the contact shoes while at the same time they conduct electricity from the bus pipes to the contact shoes as well as carry cooling water to and from the contact shoes.

Since the contactshoes 3 are arranged to allow radial movement so that they may be forced into close engagement with the surface of the electrode E by tightening the chain 1 by manipulation of nuts and bolts 8 and 9, or may be released from engagement by the loosening of the nuts and bolts 8 and 9, it is necessary that the

connector pipes

20 and 21 be somewhat flexible laterally to permit such movement. The connector pipes or drop pipes 20 and 2| are of substantially less diameter than the bus pipes, and are of such length as to allow the desired flexibility. The lower ends of the connector pipes 20 and 2| are received in the lugs H3 and are securely fastened thereto as by screwing and/or welding so that the passages in the connector pipes 20 and 2|, and the openings in the lugs ID are in register so as to permit the flow of cooling Water from bus pipe H down through the connector pipe 20 through the contact shoe 3, and thence upwardly through the connector pipe 25 to the bus pipe l2 as indicated by the arrows in Figure '2.

It is highly desirable that the connector pipes be secured to the bus pipes in very good electrical contact, and in water conducting relationship as well as in shoe supporting relationship. According to my invention, I provide such function performing connections which are readily connectable and disconnectable so that any contact shoe or shoes may be readily disconnected from or secured to the bus pipes in a very short time, and in a very satisfactory manner. Such an arrangement is of great value in the operation of a furnace.

Each of the connector pipes 20 and 2| is formed at the upper end into a line parallel to the axis of the electrode and is secured to the bus pipes H and I2 by means or split bolted clamps 30, of electrically conductive material, there being one clamp for each contact shoe 3. These clamps are particularly well shown in ass sts 7 Figures 3-, 4, and 5. The clamp consists or a contact'block 3| and a olainping'plate 32 which isbolted to the contact block.

The contact block 3| is formed in generally rectangular shape. The back'of the block as a centrally disposed transverse partial rib 33, and two transverse grooves 34 and 35 arcuately shaped to receive the bus pipes II and I211 sp'e'ctively in closely fitted engagement. The rib 33 is disposed between theadjoining bus pipes and serves 'to join the bus pipes in spaced relationship thus contributing to the stability of the bus pipe arrangement. The front of the block 3| has two

longitudinal grooves

36 and 37 for close engagement with the upper ends of the connector pipes. The contact blocks 3| are brazed or Welded to the bus pipes H and 12 at appropriate locations, there being one clamp for each contact shoe.

.The clamp. plate 32 generally rectangular in shape has two

parallel grooves

38 and 39 for closely engaging the upper end portionsof the connector pipes. Suitable bolt holes 40 in block 3| register with corresponding bolt holes 4! in plate '32. Bolts 42 with suitable nuts pass through holes 40 and 4| and serve to bind the clamping plate 32 and contact block 3| into tight clamping engagement with the upper end portions of the connector pipes. I

Suitable tubes or conduits 43 are provided for conducting cooling fluid from the bus pipe H tothe top of the connector pipes-2o. Thse'tubes have a readily detachable connection 44 to the bus pipe II and a readily detachable pipe connection or union 45 to the top of the connector pipes 20. Likewise the connector pipes 2| are connected to the bus pipe I2 by conduits or tubes 46 having a detachable connection 41 to the bus pipe [2 and a detachable connection or union 48 with the top of connector pipes 2|. The top of each connector pipe has a nut 49 threadedly adjustable on the end of the connector p p which when seated rests against the top of contact block 3|, and serves to position the connector pipes relative to the contact block, and also insures that there will be no accidental slippage between connector pipes and the contact block when the clamps are loosened.

By this arrangement of clamps and associated tubes, an electrode shoe 3 may be readily disconnected by loosening the clamp at the bus pipes and uncoupling the

water tubes

43 and 46, after which the shoe may be dropped from engagement with the collapsing chain 4.

The bus pipes are preferably fitted at their ends remote from the electrode with electrical contact wings or fins such as 50, 5|, and 52 to which flexible cable connections such as 3 (only one being shown) may be removably attached for supplying electric current to the bus pipes.

The electrode and its clamping structure are supported by

support loops

54 and 55 preferably of non-magnetic material, which loops encircle the bus pipes H and I2 and are connected at their tops by a supporting plate 56 which may be moved vertically by any suitable operating hoist mechanisms (not shown) all of which is well-known in the art. A support loop 57 of non-magnetic material is connected to the fin bearing ends of bus pipes H and I2. Suitable hose nipples 53 and 59 are connected to the ends of the bus pipes H and 12 respectively and serve as inlets and outlets respectively for cooling water.

I l'iave provided an iiicient electrode clamp for use' in electric arc furnaces which cramps have a substantial degree of-flexibility thus providing extremely good contact with the electrode so as to avoid burning, pitting, and the like: furthermore, fl have prtn'ided an efficiently cooled "supporting and current carrying clamping "structure that is able to withstand deleterioii'seffects norma ly cause'd'by the intense heat and gases of the furnace, and a structure which ii'ibodi'e's *init's construction contact shoes and associated co'j -e'ewr pipes which are secured to the bus l pipes by 'ieadny disconnectable clamping means whisper ing means are novel.

While I-have illustrated and described a cerpresent preferre'd specific embodiment of my invention it will 'be-understood'that this is by way of illustration only; and that various changes and i modifications may be made within the contemplation er my -'invention and within tli 'e s'c'opeofthe following claims.

man

i. For use in adjustable electrode ramp for an electrode in an electric arc furnace ineluding a plurality of electrically Conductive shoes arranged in spaced "circumferential relation around the electrodepapluralityof flexible connector pipes connected at the lower ends to said shoes for conducting electric power and water totlie shoes' and 'for' suspendi g said shoes n n mute-ter ace power conduct nests pipes embracing the electrode at a distance above the shoes, the invention which comprises means for clamping the upper ends of the connector p pes to the bus pipes, said means including a contact block in fixed electrical contact with the bus pipes, and a clamp plate bolted to the contact block, the block and plate being disposed to clamp the upper ends of the connector pipes between them.

2. For use in an adjustable electrode clamp for an electrode in an electric arc furnace including a plurality of electrically conductive shoes arranged in spaced circumferential relation around the electrode, a plurality of flexible connector pipes connected at the lower ends to said shoes for conducting electric power and water to the shoes and for suspending said shoes from two water and power conducting bus pipes embracing the electrode at a distance above the shoes, the invention which comprises means for clamping the upper ends of the connector pipes to the bus pipes, said means including a contact block in fixed electrical contact with the bus pipes, a clamp plate bolted to the contact block, the block and plate being disposed to clamp the upper ends of the connector pipes between them, and water conduits extending from the upper ends of the connector pipes to the bus pipes.

3. An adjustable electrode clamp for an electrode in an electric arc furnace comprising a plurality of electrically conductive shoes arranged in spaced circumferential relation around the electrode, a plurality of flexible connector pipes connected at the lower ends to said shoes for conducting electric power and water to the shoes and for suspending said shoes from two water and power conducting bus pipes embracing the electrode at a distance above the shoes, means for clamping the upper ends of the connector pipes to the bus pipes, said means including a contact block in fixed electrical contact with the bus pipes, a clamp plate bolted to the contact block, the block and plate being disposed to clamp the upper ends of the connector pipes between them, and readily disconnectable water conduits connecting the upper ends of the connector pipes to the bus pipes in water conducting relationship. v

4. For use in an adjustable electrode clamp for an electrode in an electric arc furnace including a plurality of electrically conductive shoes arranged in spaced circumferential relation around the electrode, a plurality of flexible connector pipes connected at the lower ends to said shoes for conducting electric power and water to the shoes and for suspending said shoes from two water and power conducting bus pipes embracing the electrode at a distance above the shoes, the invention which comprises means for clamping the upper ends of the connector pipes to the bus pipes, said means including a contact block in fixed electrical contact with the bus pipes, a clamp plate bolted to the contact block, the block and plate being disposed to clamp the upper ends of the connector pipes between them, readily disconnectable water conduits connecting the upper ends of the connector pipes to the bus pipes in water conducting relationship, and means at the top of the connector pipes for positioning the connector pipes in vertical position relative to the contact block.

5. For use in an adjustable electrode clamp for an electrode in an electric arc furnace including a plurality of electrically conductive shoes arranged in spaced circumferential relation around the electrode, a plurality of flexible connector pipes connected at the lower ends to said shoes for conducting electric power and water to the shoes andfor suspending said shoes from two water and power conducting bus pipes embracing the electrode at a distance above the shoes, the invention which comprises a contact block in fixed electrical contact with the bus pipes, and a clamp plate mounted in operative clamping position with respect to said block, the block and plate being disposed to clamp the upper ends of the connector pipes between them to thereby provide an electrical connection through said contact block for said connector pipes with said bus pipes.

WILLIAM ENOCH MOORE.

References Cited in the file of this patent UNITED STATES PATENTS Switzerland Mar. 15, 1943