US2317933A - Furnace electrode gland - Google Patents

Description

April 1943- w. E. MOORE 2,317,933

FURNACE ELECTRODE GLAND,

Filed 001:. 31, 1941 INVENTOR Patented Apr. 27, 1943 FURNACE ELECTRODE GLAND William E. Moore, Pittsburgh, Pa., assignor to Delaware Engineering Corporation, Pittsburgh, Pa., a corporation of Delaware Application October 31, 1941, Serial No. 417,261

4 Claims.

This invention relates in general to electric furnaces and particularly to an electrode g and useful in connection therewith.

In electric furnaces where the current carrying electrodes pass through eyes or openings in the roof, which is made of refractory material, it is customary in the art to provide an electrode gland which embraces each electrode and rests on the refractory roof of the furnace. The gland, which has a loose sliding fit around the electrode, reduces the leakage of gases and flames from the interior of the furnace through the space between the electrodes and the roof. The gland is water cooled and conducts an appreciable amount of heat away from the electrodes and the surrounding refractory of the roof. This materially lengthens the life of such parts. Being cool there is -a tendency for soot from the gases to be deposited on the surface of the gland next to the electrode and this aids in sealing the electrode, and cuts down the scouring effect of the issuing hot gases against the electrode, the roof refractory and the gland. The lower the temperature at which this gland will operate, the more efficient it is and this efficiency is reflected in the furnace operation. It has been customary to make the gland of ferrous metal, a magnetic material, in the form of a continuous ring. Such a gland was unduly heated by magnetic induction caused by the current flowing through the electrodes. The heating of the gland causes the electrodes to operate at a higher heat and render them less able to resist the scouring action of highly heated gases leaking from the furnace and past the electrodes. The magnetic circuit in the gland encircling the electrode carrying alternate current impedes the flow of current through the electrode, reduces the voltage of the heating current, and consequently the capacity of the furnace.

It is one of the objects of my invention to minimize as much as possible the effects of magnetic induction in the glands. To that end I provide a gland which is in the form of an interrupted ring, the ends of the ring being secured together by ties or stay rods of rigid non-magnetic material, such as austenitic iron, stainless steel, copper, brass, etc. The magnetic effects are greatly reduced and a cooler and much more efiicient gland is thus provided.

There has also been a tendency for steam and Water vapor to collect around the top portion of the Water passage in the gland and this impairs the cooling efficiency of the gland. It is an object of my invention to avoid entrapment of water vapor or steam in the cooling chamber of the gland, and to that end I arrange the inlet and outlet ports so that the upper parts of the ports are substantially in line with the upper part of the water space.

Still another object of my invention is to provide a structure in which distortion of the gland is minimized. I do this by providing circumfer ential slots in the base of the gland.

Other objects will be apparent from the following description.

In the drawing I have shown for purpose of illustration only the present preferred embodiment of my invention. In the drawing:

Figure 1 is a view partly in section and partly in elevation of a typical electric furnace showing the electrode glands in position;

Figure 2 is a plan view to a larger scale than Figure 1 of an electrode gland made in accordance with my invention;

Figure 3 is aview in elevation of the electrode gland; and

Figure 4 is'a View along the line IVIV of Figure 2.

In the drawing wherein like numerals designate like parts in the various views, Figure 1 show diagrammatically a typical, two electrode electric furnace 2, having a refractory roof 3 in which an eye 4 is provided for each electrode. An electrode 5 projects through the eye 4 into the furnace. Resting on the roof 3 and surrounding the eye 4 is an electrode gland 6 which embraces the electrode 5 with a loose sliding fit.

The gland 6 consists of a flat base ring 1, an

upstanding vertical inner band 8 welded to the inner edge of the ring, a horizontal top ring 9, spaced from the base ring I, the inner edge of the ring being Welded to the top of the upstanding inner band 8, and a vertical outer band In which extends between the outer edge of the top ring 9 to the base ring 1 at a position between the inner and outer edges of the base ring I, and is welded to the outer edge of the top ring 8 and the base ring 1. The rings 1 and 9, and the bands 8 and Ill, which are made of ordinary steel, do not extend around the full extent of a circle. They butt against two spaced-apart end plates 1 l and i2 shaped as shown in Figure 4, which are welded to the ends of the rings and the bands.

The gap or space 13 between the end plates is bridged by a series of stayrods or struts I4, which are herein shown as numbering eight. These stay rods are made of non-magnetic material, such as austenitic steel, stainless steel of the composition commonly referred to as 18-and-8, or of brass, etc. They are countersunk at both ends into and welded to the end plates II and I2, and are of such size as to be able to resist the tension and compression stresses encountered. The arrangement of bands and rings which has been described enclosed an incomplete circular cooling chamber E of rectangular cross-section, through which a cooling fluid, such as water, is circulated through the inlet nipple l8 and outlet nipple I! to which the inlet pipe l8 and outlet pipe l9, respectively, are connected. The pipes l8 and 19 are connected to a suitable supply (not shown) of cooling water.

under pressure. It will be observed that the upper edge of the inner bore of the inlet and outlet nipples is flush with the upper edge of the cooling chamber. This arrangement prevents entrapment of water vapor or steam in the cooling chamber.

The base ring 1 extends an appreciable distance radially beyond the outer band I 0, and in this extending portion a series of radially disposed slots 23 are arranged. The slots extend from the periphery of the ring I to a point adjacent the outer band Ill. This arrangement effectively minimizes distortion of the gland under operating conditions.

It is customary to fill the gap with refractory cement which may be held in position by wrapping an appropriate sheet of non-magnetic metal, such as stainless steel, around the cement.

The arrangement which I have described provides a furnace electrode gland which runs coolor under given conditions than any other gland of which I am aware. Magnetic induction is at a minimum and the life of the gland is increased as is also the life of the electrode and roof refractory. The efliciency of the furnace with which such a gland is used is increased.

While I have described the present preferred embodiment of my invention, it is to be understood that various changes may be made therein and the invention otherwise embodied within the scope of the following claims.

Iclaim:

1. An electrode gland in the form of an incomplete annular water chamber for use in an electric. ifurnace, having an electrode opening said gland including a flat base ring of larger diameter than the opening, a vertical inner band the bottom of which is welded to the inner edge of the base ring, a horizontal top ring the inner edge of Which is welded to the top of the inner band, a vertical outer band which extends between and is welded to the outer edge of the top ring and to the base ring, said bands and rings forming an incomplete annular water chamber and being made from wrought metal, the ends of said bands and rings being secured to spaced apart wrought metal radially extending end plates, the gap between said end plates having a plurality of circumferentially extending staybolts which extend between and are fastened to the end plates, said staybolts being formed from nonmagnetic metal.

2. An electrode gland for use in an electric furnace having an electrode opening said gland being formed of wrought metal parts welded together to form an incomplete annular water chamber with radially extending end plates, the end plates being joined by circumferentially extending spacers of non-magnetic material, and openings at each end of the chamber through which fluid may be passed into and discharged from the passage, the top of said openings being substantially in line with the top of the chamber the outside diameter of the gland being larger than the electrode opening.

3. An electrode gland for use in an electric furnace having an electrode opening said gland being formed of wrought metal parts welded together to form an incomplete annular water chamber with radially extending end plates, the end plates being joined by circumferentially ex tending spacers of. non-magnetic material, and openings at each end of the chamber through which fluid may be passed into and discharged from the passage, the top of said openings being substantially in line with the top of the chamber the outside diameter of the gland being larger than the electrode opening, said metal parts including a basering which encircles and projects beyond the remaining parts of the gland, said ring having radial slots extending inwardly from the periphery.

4. For use in an electric furnace having a refractory roof and an eye in the roof, through which an electrode is passed, a furnace electrode gland resting on the roof and encompassing the electrode, said gland being fabricated from wrought metal parts which enclose a water passage of incomplete ring form, wrought metal end pieces closing the water passage, and spaced apart circumferentially, and at least one spacer of non-magnetic material extending between and secured to the end pieces, the remaining space between the end pieces being filled with refractory material.

WILLIAM E. MOORE.

Images