US1546534A - Electric furnace - Google Patents

Description

July 2l, 1925. 1,546,534

T. F. BAILY ELECTRIC FURNACE Original piled Aug. 28, 1923 Patented July 21, 19215..

UNITED STATES 1,546,534 PATENT OFFICE.

THADDEUS F. -BAILY, F ALLIANCE, OHIO.

ELECTRIC FURNACE.

Continuation of application Serial No. 659,788, lednugust 28, 1923. This application med July 29, 192 Serial No. 728,880.

To all whom-t may concern.'

Beit kno-wn that I, THADDEUS Alliance, in the county of Stark and State of Ohio, have invented certain new and useful Improvements in Electric Furnaces, of which the following is aspeciica'tion.

This invention relates to improvements in that type of furnaces in which the heating element consists in a refractory trough containing granular resistance material, through which an electric current is passed to generate heat; and the improvement is a continuation of the common subject matter of my co-pending application Serial N o. 659,738, filed August 28, 1923.

The object of the improvement is to provide an arched or dome-like resistor trough preferably supported at its base upon the side Wall of the furnace, and so shaped that the maximum intensity of current and heat generation will be produced around the inner and lower side-s of the trough for the purpose of utilizing the heat to raise the temperature of the hearth while the roof of the furnaceis kept at a considerably lower temperature; a further object being to support the resistor trough at its base entirely upon the side wall ofthe furnace, the upper portion of the trough being arched away from the furnace wall to relieve the same from the high temperature generated in the trough.

The above and ancillary objects may be attained by an arched o-r dome-like `trough of refractory material, the peripheral base portion thereof being connected at its base to the furnace wall; granular, carbonaceous material being located in the trough and electrodes extending into the lower portion of the trough, in such position as to holdthe maximum intensity of current and heat generation around the lower and inner sides of the trough.

An embodiment of the invention thus set forthv in general terms is illustrated in the accompanying drawing, in which- Figure 1 is a' vertical, sectional view ofl the impro-ved furnace, taken on the line 1- 1, Fig. 2;

Fig. 2, a horizontal sectional view ofthe furnace on the line 2 2, Fig. 1; and

Fig. 3,1111v enlarged cross-sectional view of the trough and one electrode, showing diagrammatically the lines of conductivity.

F. BAILY, a citizen of the United States, residing atV Similar numerals refer to similar parts throughout the drawing.

The brick Work 1 of the furnace may be supported upon a metal plate 2, and is preferably formed of fire brick, having the lining of suitable heat resisting material forming the hearth 4, which may be concaved as shown in Fig. 1. p A charging opening 5 is provided in one side of the furnace, above the hearth, and normally closed by a suitable door and a pouring spout 6 communicates with the hearth. The brick work may be surrounded by ametal shell 8, provided at its upper edge with a sand trough 9.

The heating element may be carried in a removable section, supported upon the structure above described, and comprising the wall 10'of fire brick or similar refractory material, surrounded by the steel shell 12, preferably spaced therefrom, and having the depending lower edge arranged to be seated in the sand trough 9, forming a sand seal between these two sections of the furnace. i

1 An annular rib 14, o-f carbon silicide or -similar refractory material, may be built in the wall 1,0 and provided with the beveled edge 15, the arched outer Wall 16, of the trough, also of carbon silicide, resting upon the rib 14. The lower portion of the wall 16 may be located in proximity to the furnace wall, while the remainder of the wall is arched inward, away from the furnace wall.

The dome-like bottom wall 17 of the trough is also formed of carbon silicide, or the like, and the outer edge 18 thereof may be beveled to rest upon the beveled edge 15 of the rib 14.

VThe inner edge of the bottom wall 17 supports the arched inner wall 18 of the trough which is also formed of carbon silicide or similar refractory material. The contacting edges of the bottom and inner walls of the trough may be beveled as shown lsistance body being designated by the numeral 22. A

Embedded in the" resistance material,

preferably at diametrically opposite sides It is, of course, understood that theseV electrodes are located in an electric circuit, in a manner well known in this art, electric conductors 24 being connected to the terminals of the electrodes and leading to a suitable source of` electricity.

As shown in Figs. 1 and 3, the electrodes are preferably located in the lower part of the trough. Since'the inner wall 18 of e trough is arched the lines of conductivity from one electrode to the other will naturally take the shortest path shown by the lines in Fig. 3, these lines indicating the maximum intensity of current and heat generation.

As will be seen from an inspection of Fig. 3, the maximum intensity is thus held around the arched bottom wall 17 and inner wall 18 of the trough, while the upper outer portion of the resistor material carries less current and will run cooler, the relieving space between the outer wall 16 of the trough and the furnace -wall preventing damage to the furnace wall.

With this construction of trough, the major portion of the heat generated in the resistance body will be directed upon the hearth, while the roof of the furnace will remain several hundred degrees cooler than the hearth. l

The termination of each electrode may be supported upon a bracket 25, connected to the shell of the removable section'of the furnace, thus permitting this section to be moved as a unit after the electric conductors have been disconnected from the electrodes.

A metallic sand trough 26 ma be provided at the upper edge of the s ell 12 of the removable section, and the brick roof 27, covered with the metal shell 28, may be provided with the depending flange 29 which enters the sand trough 26, ,forming a sand seal between the removable section and the roof.

From the above it-will be obvious that by Iconstructing the arched or dome-like resistor trough with the electrodes in the lower portion, the outer side of the trough is relieved, preventing :undue damage to the furnace wall andthe maximum intensity of current and heat generation is held around the'bottom and inner walls of the trough, producing the highest temperature upon' the. I

nular resistance trough contacting with the furnace wall only at its base.

3. In an electric furnace, a resistance trough includlng an arched bottom wall,

and inwardly inclined side walls inclined away from the furnace wall.

4. In an electric furnace, an annular resistance trough including an arched'bottom wall and arched side walls.

5. In an electric furnace, an arched rc1` sistance trough containing resistance material, and electrodes located lin the lower portion of said trough.

4 6. In an electric furnace, an annular resistance trough containing `resistance material and electrodes extending into the resistance material at opposite points in the trough, the bottoni and side walls of the trough being arched, whereby the lines of conductivity through the resistance material, between the electrodes, will produce the maximum intensity of current and heat generation around the inner and bottom walls of the trough.

7. In an electric furnace, an arched resistance trough containing resistance material and spaced electrodes in the trough, said electrodes being so located with reference to the bottom of the trough that the shortest path of the current from electrode to electrode will produce the maximum intensity of current and heat generation upon the bottom of the trough.

8. In an electric furnace, an annular resistance trough including an arched bottom wall and arched side walls and containing resistance material, and electrodes located in the lower portion of said trough.

In testimony that I claim the above, I have hereunto subscribed my name.

TI-IADDEUS F. BAILY. I

Images