US1528542A

US1528542A - Electric furnace

Info

Publication number: US1528542A
Application number: US587442A
Authority: US
Inventors: Hancock Leslie John; Hancock Thomas Reginald
Original assignee: Individual
Current assignee: Individual
Priority date: 1922-09-11
Filing date: 1922-09-11
Publication date: 1925-03-03
Anticipated expiration: 1942-03-03

Description

L. J. HANCOCK ET AL Mar. 3, 1925.

ELECTRIC FURNACE Filed Sept. 11, 1922 /NVENTO/?S.-

THOMAS E. HAA/QocK.

Patented Mar. 3, 192$;c

UNITED STATES PATENT orsrcs.

LESLIE JOEN HANCOCK AND THOMAS REGINALD HANCOCK, OF WALLINGTON, ENG- LAND, ASSIGNORS TO OSCAR VIVIAN ASSER, OF LONDON, ENGLAND.

ELECTRIC FURNACE.

Application filed September 11, 1922. Serial No. 587,442.

To all whom it may concern."

Be it known that we, LEsLIn JOHN HAN- COCK and THOMAS REGINALD HANCOCK. of Melbourne. Works, W'allington, in the county of Surrey, England, British subjects, have invented certain new' and useful Improvements in Electric Furnaces, ,of which the following is a specification.

This invention has for its object to H) cheapen and simplify the construction of electric furnaces by obviating the use of the wire electrical resistance coils generally employed in such apparatus.

According to this invention a series of W longitudinally disposed rods of carbon or graphite surrounds a tube of refractory material, the interior of which constitutes the heating space, said rods being suitably connected together in any required order at their ends and being preferably insulated from one another and from said tube by refractory material of high melting point such as alundurn. Preferably the tubular coreand its surrounding rods and insulation are enclosed within a chamber packed .with magnesia, kieselguhr or like nonconductor.

In one form of the invention the carbon or graphite rods are disposed in a circular series of longitudinally extending apertures formed in the wall of a tube of alundum, said apertured tube being shorter in length than the tube which constitutes the heating chamber but being adapted to fit thereover. If desired the carbon rods maybe protected from oxidation by treating them in any well known manner.

The invention will be described with reference to the accompanying drawings of which Figure 1 is a longitudinal sectional elevation 'on' the line 1-1 of Figure 2 and Figure 2' is a cross sectional elevation on the line 2-2 of Figure 1. 'As shown on the drawings a tube a of carborundum or like refractory insulating material forms the muflle of'the furnace and is surrounded by a coaxial tube b of similar material but of eater diameter and smaller length. Within the annular space between the tubes a and b is arranged a circular series of longitudinally disposed carbon or graphite rods 0 0 the ends of which are mounted respectively in two sets of arcuate carbon or graphite blocks (1 (Z and e 6 (the positions of the blocks c c being shown in broken lines in Figure 2) secured by means of heat resisting and electrically insulating cement (not shown) in said annular space and near the respective ends thereof.

The rods 0 and arcuate blocks d and e are so arranged that an. electric current entering the block al may flow through the rods and blocks in succession in zig-zag fashion aroundthe series to the return lead connected with the block d The tubes at and b are retained in position by meansof two end plates f, g which are held together by longitudinal tie bars h and nuts The end plates 7 and g are centrally apertured so as to fit over the ends of the mufi le tube a whilst the outer tube 7) is clamped between said end plates f and g. The end plate f may be apertured and hushed in any usual mannor for the passage therethrough of leads such as is adapted to connect the "blocks (1 and d with a source of electric energy.

Surrounding the outer tube 6 is a casing m which may be clamped between the end plates 7 and 9 as shown and the annular space between the tube 25 and the casing m may be lightly packed with magnesia, kieselguhr or like non-conductor of heat (not shown) to serve as a lagging.

If desired the mufiie tube a. may be fur ther secured to the end plates 7 and g by means of nutsor the like (not shown) in threaded engagement with the ends of said tube a.

By suitably arranging the size of the rods 0 and their connections with the arcuate blocks d and c, an electric furnace as hereinbefore set forth may be adapted for operation with an electric current of any desired voltage.

Having thus described the invention, what is claimed as new is:

1. An electric resistance furnace comprising in combination a mufile chamber, a su rounding chamber shorter in length than said mufiie chamber and a series of conducting rods located bctween said chambers.

2. An lectric resistance furnace comprising in combination a muffle chamber, a surrounding chamber shorter in length than said mufiie chamber, insulating material between said chambers and conducting rods located within said insulating material.

3. An electric resistance furnace comprising in combination a chamber of refractory material, a series of conducting rods in proximity to said chamber, and arcuate' blocks'electrically connecting said rods together. i a

4. An electric resistance. furnace comprising in combination a mufie chamber, a surrounding chamber shorter in length than said mulile chamber,'end plates surrounding said mums-chamber in'prcximity to its ends and bearing on the ends of. said surrounding chamber and a series of conducting rods located between said chambers.

5. An electric resistance furnace comprising in combination a 'mufie chamber, a surrounding chamber shorter in length than said mufile chamber, end plates surrounding said mufile chamber in proximity to its ends and bearing on the ends of said surrounding chamber, a series of conducting rods located between said chambers and a casing around said surrounding chamber, said casing being packed with heat insulating mater al. I

6. An electric resistance furnace. comprising in combination a mufie chamber, a surrounding chamber shorter in length than said munle chamber and a series of conducting rods located between said chambers and electrically connected together toform an elongated resistance element.

7. An electric resistance furnace comprising in combination a muflle chamber, a surrounding chamber shorter in length than said muffle chamberand a series of conductlessees ing rods located between said chambers and the end of one rod,,traverse this rod, pass vto the adjacent rod and traverse it from end to end, and likewise each successive rod.

8. An electric resistance furnace, comprising in combination, amufie chamber, a surrounding chamber shorter in length than said muifie chamber, insulating material between said chambers and in contact with bothof them, and conducting rods located .Within said insulating material.

9. An electric resistance furnace comprising in combination a mulhe chamber, a. surrounding chamber shorter in len'gththan said mufile chamber, insulating material between said chambers and in contact with both of them, and platessurrounding said mufie chamber in proximity to its ends and bearing on the ends of said surrounding chamber, and a series of conducting rods located between said chambers.

10. An electric resistance furnace 7 comprising in combination a mufile chamber, a surrounding chamber shorter in length than said muflle chamber, a surrounding chamber shorter in length than said mufile chamber, insulating material between said chambers and in contact with both of them, and a series of conductin rods located between said chambers and electrically connected together to form an elongated resistance ele-' ment.

In testimony whereof we afix our signatures.

LESLIE JOHN HANCOCK.

THOMAS REGINALD HANCOCK.