US1554002A

US1554002A - Electric furnace

Info

Publication number: US1554002A
Application number: US423867A
Authority: US
Inventors: James H Gray
Original assignee: Individual
Current assignee: Individual
Priority date: 1920-11-13
Filing date: 1920-11-13
Publication date: 1925-09-15
Anticipated expiration: 1942-09-15

Description

Sept. 15, 1925.

J. H. GRAY ELECTRIC FURNACE 1920 2 Sheets-Sheet 1 Filed Nov. 13

HEJI

lllllllllllln II/VEIIT0R James H Gray Wad, nronmsy Patented Sept; 15, 19251 UNITED STATES PATENT OFFICE.

JAMES H. GRAY, OENEW YO'RK, N. Y.

ELECTRIC FURNACE.

Application filed Fovember 13, 1920. Serial No. 423,86 7.

To all whom it may concern:

Be it known that L'JAMES H..GRAY, a

citizen of the United States, and resident of v Figs. 3 and 4 are sections respectively on lines 3-3 and l=4 of Fig. 2;

Fig. 5 is a section on the line 5-5 of Fig. 2;

Fig. 6 is a cross-section of an alternative form of supporting arm.

Referring to the embodiment of the inven tion illustrated the furnace 1 has on its bot tom a rocker 2 resting on a curved track 3, the furnace being tilted to the position shown in dotted lines by meansof a link 4 extending to any suitable gearing. The furnace and tilting mechanism thereof constitute no part of this invention and may be of any usual or suitable design. The roof 5 of the furnace is pierced for the passage of the electrodes 6 through the usual cooling rings 7. Each electrode has to be adjusted vertically and separately from the others and is equipped with the holder and adjusting means hereinafter described.

To permit the tilting of the furnace without moving the electrodes lengthwise, the supporting and adjusting mechanism l is mounted on the furnace and tilted with it. Each electrode is mounted in a clamp 8 which is connected at its rear end to a horizontal arm or bus, bar 9 which is connected by means of flexible cables 10 to the transformer or other source of supply, the cables being of a length sufficient to permit the tilting of the furnace as shown. The center of rotation of the tilting furnace is at 11. The cables 10 extend upward from their connection to the bus bar, or supporting arm. As

"the point of connection, therefore, swings upward as well as horizontally, during the tilting of the furnace, the amount of take-up on the cables 10, or the amount of slack which has to be allowed in these cables, is comparatively little. A much shorter connection through such cables is established than where their two ends are in horizontal alignment with each other or nearly so, as

' hasbeen the usual practice heretofore.

For the heavy currents needed in electric arc furnaces, the reactance in the cables, being proportional to their length, is very considerable. By this arrangement I have reducedsuch length and saved the loss of current by such reactance and also provided an arrangement by which a greater quantity'of current can be put into the furnace.

I have also arranged the motors and mechanism for adjusting the electrodes entirely below the cables 10 so as to avoid loss of current which has occurred in previous installations by reason of the inter-- ference of the metal in the adjusting mechanism and supports surrounding or passing between such cables.

For this purpose each of the arms 9 which with the brackets 8 form the holders for the electrodes is mounted on a post 12 extending downward therefrom along the side of the furnace and this post is elevated and lowered by mechanism also mounted on the side of the furnace below the level of the arms 9. On top of each post 12 is a cap 13 on which the arm is mounted with insulating material 1 1' interposed .in the joint. On the lower end of the post is mounted a pulley 15. Brackets 17 in the form of channels are mounted on the furnace and carry guide channels 18 between which are guided sleeves 19 and 20 (Figs. 3' and 5) fastened on the upper and lower ends of the post 12, the

sleeves

19 and 20 being formed with flanges 21 which fit into the corners of the rectangular guideway formed by the channels 18. Fastened on the outside of the channels 18, are reinforcing channels 22.

On the inner edges of the guideway near the'top are mounted bearing blocks 23 carrying a guide roller 24 against which bears the inner face of the guide block 19. On the lower end of the guideway on its outer side is mounted a similar guide roller 25 an I-beam against which bears the outer face of the lower guide block 20. These

guide rollers

24 and 25 are arranged to take the lateral bearing of the post due to the weight of the overhanging armand electrode.

At the upper end of the guideway, on the outer side, are mounted brackets 26 carrying fixed guide pulleys .27. Cables 28 are attached at their inner ends to the brackets 17, passed downward over the pulleys 15 and up over the fixed pulleys 27 and thence to a winding drum 28 driven from a motor 29 which is mounted on a bracket 30 on the outer face of the guideway. When the cable is taken up on the drum it lifts the truck or 0st 12 and with it the arm 9 and electrode 6. hen the furnace is tilted all the parts described move together, retaining their relative positions and preventing longitudinal movement of the electrodes.

Each arm 9-is formed at its rear end with a hollowbracket 31 and the cables 10 are fastened around the outside thereof, as shown inFig. 4. A cooling system is provided for each supporting arm and clamp. The arm is referably made in the form of FFig. 4) with passages 32 run ning longitudinally throu h it and leading out near the rear end of the arm to the usual or any suitable water connections for supply and discharge, as indicated, for example, at 3 2 and 32", Fig. 2. One of the passa es 32 is connected near the forward end of the arm through pipes 33 to the inlet end of a water passage in the clamping arm 8, and the discharge end of the same passage is connected through a pipe 34 to the opposite passage 32 of the arm.

In Fig. 6, there is shown an alternative form of supporting arm 9* which is box shaped with a diaphragm 35 which divides the space within the arm into two passages 36 for the circulating of cooling water.

The

arms

9, or 9*, which serve both to support the electrodes and to convey current thereto may be made in various forms, in tegral or built up. They may be made of copper for greater conductivity. Or they may made of steel with copper bars extending along the top of them; the latter construction being useful particularly where the required current is so low as not to involve serious losses through reactance.

Though I have described with great particularity in detail a certain embodiment of my invention, yet it is not to be understood therefrom that the invention is restricted to the embodiment disclosed. Various modifications thereof may be made by those skilled in the art without departure from the invention as defined in the following claims.

lVhat I claim is:

1. An electric furnace having electrode holders comprising arms extending across the top of the furnace and carrying the weight of said electrodes and also serving as conductors to convey current to said electrodes, said arms having passages formed therein to permit the circulation of a cooling medium in intimate contact therewith.

2. An electric furnace having electrode holders comprising a clamp and a supporting arm therefor, said arm having passages formed therein to permit the circulation of a cooling fluid in intimate contact therewith.

3. An electric furnace having electrode holders comprising arms carrying the weight of the electrodes and serving as conductors to convey current to said electrodes and having connected to the rear ends thereof flexible cables extending to a fixed point above said holders so that cables of minimum length can be used thereby cutting down the reactance and attendant current losses.

at. An electric furnace having electrode holders comprising arms extending across the top of the furnace, posts extending down from said arms along the side of the furnace guides on the furnace for said posts located below the roof of the furnace, motors mounted on the furnace and cables operatively connected with said motors and said posts whereby the electrodes are raised and lowered.

5. An electric furnace having electrode holders comprising arms extending across the top of the furnace, posts secured below said arms, guiding means for said posts located Wholly below said arms and motors mounted on the furnace operatively connected with cables engaging the lower ends of said posts and arranged to lift and lower said arms, said guiding means being so arranged that said arms never project there between. i

6. An. electric furnace having electrode holders comprising arms extending across the top of the furnace, posts extending down from said arms alon the side of the furnace, guides on the furnace for said posts and motors mounted on said furnace and cables connected to said furnace and to said motors and engaging in their bights the said posts so as to lift and lower the same as the motors are operated.

In witness whereof, I have hereunto signed my name.

JAMES H. GRAY