US1626656A - Electric-furnace heating unit - Google Patents

Description

1,626,656 May 3 1927' J. c. wooDsoN Y ELECTRIC FURNAGE HEATING UNIT Filed D60. '7, 1923 Patented May 3, 1927.

UNITED STATES IGATENT OFFICE.

JAMES C. WOODSON, 0F EAST PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURINGy COMPANY, A CORPORATION OF PENNSYL- VANIA.

ELECTRIC-FURNACE HEATING UNIT.

My invention relates to electric heating devices and particularly to heating units for electric resistance furnaces.

The object ot my invention is to provide a self-contained electric heating unit, of relatively small and compact construction and of relatively high heat capacity, that shall have both terminal members of the heating unit extending therebeyond at both ends thereof.

In practicing my invention, 1 provide a. pair of spaced resistor members, each comprising a plurality of end connected, return bent, and substantially straight convolutions located a short distance apart and havingtheir rounded end portions located in a plurality of spaced pockets provided inthe refractory supporting members.

Intermediate, refractory supporting bars, having co-operating spaced grooves in their-adjacent surfaces are provided intermediate the ends of the convolutions and all of the refractory members are supported by an assembled metal skeleton frame. At each side of the heating unit there extends a. ielatively heavy rod or bar of metal to which the respective ends of the resistor member are electrically connected.

In the single sheet of drawings,

Figure 1 is a view, partially in side elevation and partially in section, of an electrical heating unit embodying my invention,

Fig. 2 is a view, partially in end elevation and partially in section therethrough, taken on the line II-II of Fig. 1, and

Fig. 3 is a view, in section therethrough, taken on the line III-III of Fig. 1.

An electric heating unit 11 comprises a pair of vresistor members 12 each made ofv metal wire or rod of relatively heavy crosssection and preformed to comprise a plurality of return-bent and end connected convolutions lying in a single plane.

At each end of the heating unit, there is provided a refractory bar or member 13 that may be substantially rectangular in crosssection and that is provided With a plurality of sets of spaced and aligned pockets 111 in one face thereof, the dimenslons of each pocket being such that it will receive one of the rounded end turns of the respective resistor members 12.

The adjacent sets of pockets may be located in staggered relation relatively to each other, as is illustrated in Fig. 2, in order that the individual straight convolutions of the adjacent resistor members 12 shall be located in' staggered relation, thereby permitting of the unobstructed dissipation of radiation of the heat of the rear resistor member 12 past the front resistor member 12 of the same heating unit.

If the length of the convolutions is relatlvely great, or if the lateral area of the cross-section ofthe resistor members 12 is relatively small, I may employ intermediate refractory bars in order to. prevent accidental contact of the adjacent convolutions at the intermediate portions of their length. I may employ two outer bars 15, of suitable refractory electric-insulatin material having a plurality of spaced, sustantially semicircular, grooves in one face and an intermediate bar 16 having a plurality of spaced and substantially semicircular grooves in each face co-operating with the grooves in the members 1-5 to form a. plurality of spaced grooves 17, of substantially circular form, in the assembled members, through which the convolutions of the resistor 'members 12 may loosely entend. v

- Side members 18, of substantially channel section and made of ja .substantially nonoxidizable metal, such as nichrome, are provided into which the ends of the refractory members 13 may fit to be thereby supported in their proper operative positions. End members 19 that may comprise bars or elongated plates of al substantially nonoxidizable inet-al are suitably bolted at their ends to the end portions of the members 18 into which they fit in order to prevent any til) relative movement thereof during the operaltion of the heatingy unit.

A plurality of spaced rods 21 of relatively large lateral section and of a suitable nonoxidizable material such as nichrome are located at the respective sides of the resistor members and extend through suitable openings in the members 13 and in the member 16 of refractory electric-insulating material.

Bushings 22 may be provided in the end members 19 to suitably insulate the terminal rods 21 therefrom. One of the ends of each of the resistor members 12 is electrically connected to one of the terminal rods 21-by any suitable or desired means to effect a secure electrical connection, 'that will withstand the relatively severe operating conditions of such a heating unit.

The terminal rods 2l eXtend through the end members 19 and any suitable distance therebeyond in order that both terminal members of the heating unit may be provided at each end thereof, thereby permit- 'ting of connecting supply circuit conductors thereto at either end thereof, or permitting any desired connection at either end to other adjacently located heating units.

Various modifications and changes may be made Without departing from the spirit and scope of the invention, I desire, therefore, that only such limitations shall be placed thereon as are imposed b v the prior art.

I claim as my invention:

1. In an electric heating unit, in combination, a plurality of resistor members located in parallel planes and in staggered relation relativelyv to each other, refractory spacing and supporting members for the ends and an intermediate portion of said resistor members, and a metal frame for holding said refractory members in their proper operative positions.

2. In an electric heating unit, in combination, a metal frame, refractory members at the ends of said frame, each having a spaced plurality of sets of alined and spaced pockets in the inner face thereof, a plurality of `resistor members, each comprising a plurality of return-bent convolutions lying '1n one plane, the return bent end portions bein located in said spaced pockets, and a pair spaced 4terminal members for said resistors supported by said refractory members and extending therebeyond at both ends of the unit.

3. In an electric heating unit, in combination, a metal frame, refractory members'at the ends of said frame, each having a spaced plurality of sets of alined and spaced pockets in the inner face thereof, a plurality of resistor members, each comprising a plurality of return-bent convolutions lying in one plane, the return-bent end portions being located in said spaced pockets and a pair of terminal rods, each having one end of each resistor member electrically connected thereto, and extending through and beyond said heating unit at each end thereof t0 provide a terminal member for each end of said resistor members at each end of said unit.

4. In an electric heating unit, in combination, a metal frame, refractory members at each end of said frame, each having a spaced plurality of sets of alined and spaced pockets in the inner face thereof and the pockets in the respective sets being staggered relativel to each other., a plurality of resistor mem rs, each comprising a plurality of return bent convolutions lying in one plane, the return bent end portions being located in sai-d pockets and serving to maintain said refractory members in roper spaced relation in said frame, and) a pair of spaced terminal members for said resistors supported by said refractory members and extending therebeyond at each end of the frame.

In testimony whereof, I have hereunto subscribed my name this 20th day of November, 1923.

JAMES C. WOODSON.

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