US1232362A - Electric furnace. - Google Patents

Description

C. G. MINER.

ELECTRIC FURNACE.

APPLICATION men rca. n. 19n- 1,232,362. Patented Jilly 3, 1917.

Fig.1

E INVENTOR WITNESSES Iii/W myflw ATTORNEY CLAUDE G. MINER, OF BERKELEY, CALIFORNIA.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented July 3, 1917.

Application filed February 17, 1917. Serial No. 149,248.

To all whom it may concern:

Be it known that I, CLAUDE G. MINER, a citizen of the United States, residing at Berkeley, in the county of Alameda and State of California, have invented new and useful Improvements in ElectricFurnaces, of which the following is a specification.

This invention relates to improvements in electric furnaces.

The rimary object of this invention is to provide a t pe of an electric furnace especially suita le for laboratory and sclen; tific work on a. small scale.

Another object is to provide a furnace which is adapted to the use of inexperienced operators, and more especially, capable of beingreadily altered from the arc to the resistor type by such operators.

A third object is to combine in such a furnace means by' which .rapid and intense heating is secured, together with economy of o ration.

dish these and other objects 1n view, which will appear upon perusal of themcompanying description and claims, and an examination of the drawings herewith, I have embodied my invention in the form shown and described below.

In the drawings, Fi re 1 is a sectional side elevation of the mace.

Fig. 2 is a sectional plan view taken at a point midway of the reaction chamber of the furnace.

Fig. 3 illustrates a cover block provided for the crucible of the furnace when the resistant principle is utilized. bl Fig is a sectional view of the cover Referring now to the drawings in detail, 1 designates standards servi-n as a support for the outer wall 2 of the in may be constructed of firebrick or other suitable refractory material. Inside wall 2, but separated therefrom by cavities 3, filled with heat insulating material, is a mass of refractory material 4 wherein the reaction chamber 5 is situated, said reaction chamber bein in form similar to two opposed paraboloi havin the ma'or axis thereof exe upper portion of tending vertlcally.

rnace which reaction chamber 5 is provided with an observation tube extending through the outer portions of the furnace, and similar tubes, 14 and 15, for the escape or admission of gases. Horizontally placed midway between the top and bottom of said reaction chamber is a support 6 for the crucible 7.

The purpose of giving to chamber 5 a parab oloid form is to secure greater concentration of heat upon the crucible 7, which is preferably placed in the principal foci of the paraboloids.

Another advantage of this shape of chamber arises from the fact that the cubic capacity is thereby reduced, resulting in econ omy of electrical consumption.

Economical operation is furthermore assisted by the cavity 3 filled with heat insulating material; which is preferably comosed of infusorial earth, this material bemg an excellent non-conductor of heat.

Downwardly extending throu h walls 2 and 4 into the combustion cham er 5 is an electrode 8, of. carbon or other suitable material, said electrode bein provided with a support and means of a justment 9 secured to the outer wallof the furnace, and being further provided with suitable means of electric connection. A second electrode 10 which may or may not be somewhat larger than electrode 8 and provided with a similar means of suppprt and adjustment 11,

extends upwardly through'walls 2 and 4 into thereaction chamber 5, and is similarlyprovided with means of electric connection. A third electrode 12 extends laterally through walls 2 and 4, terminating at a point slightly within chamber 5 and establishin connection with the crucible support 6. This crucible support when for use in connection with the series are rinciple is made of refractory but non-con uctin material, the crucible in this case-being 0 carbon or other refractory conducting material such as commonly is used in the art;

When operating the furnace upon 'the arc principle, the electrode 10 is raised by means of an adjustment 11 until it establishes connection with crucible 7, electrode 8 being then lowered until it contacts with the u per portion of crucible 7, and quickly withdrawn, thereby creating an arc. If desired, electrode may now be drawn out of contact with crucible 7, producing a second arc, resulting in extremely intense and rapid heating of the contents of the crucible 7.

This method of operation utilizes in series 'connection the two arcs, but as sufiicient .fractory conducting material such as commonly used in the art, forinstance, carbon,

' being substituted. Electrodes 8 and 10 are then connected to one lead from the source of current sup ly, terminal 12 being connected to the ot er lead.

As it is often desirable to utilize the resistance principle of operation in such a furnace means of readily altering the furnace to eli'ect this are rovided, these means consisting of a con ucting refractory support dsimllar to that used when operating with arcs in parallel, but used in this connection i at adjustment 11, and the lower with the non-conducting crucible 7 of refractory material. A suitable cover-block 13 of refractory conducting material is pro- Vided for crucible 7. The electrode 10 is brought near crucible 7 by means of the ortion of the reaction chamber is filled with carbon, graphite, or other suitable material as commonly used in the art, to the support 6; and the operation of the furnace is started by lowermg'electrode 8 until it establishes connection with the cover 13 of crucible 7. When used as a resister furnace, electrodes 8 and 10 are connected in series.

- The above description and drawings are not to be interpreted as in any way limiting the seoege of this invention, \being merely intend embodiments thereof.

What] claim is :1,

1. In an electric furnace, a bod formed with a cavity having theshape 0 two opposed paraboloids, means in said cavity for mamtainin a substance tobe heated-in the principal of said paraboloids, said means adapted toserve as a centef electrode for' two arcsin series.

2'.- In an electric furnace, a body having outer and -inner spaced walls of refractory I material and having the space between said walls filled with heat insulating material; said body formed interiorl of said inner wall with a cavity-having t e shape of two opposed paraboloids.

3. In an electric furnace, outer and inner s aced walls and heat insulating terial in t e space between said walls; said furnace to illustrate one of many possible formed interiorly of said inner wall with a reaction chamber having the shape of two opposed paraboloids; and means whereby said furnace may be used as an arc furnace and as a resistor furnace interchangeably.

4. In an electric furnace, outer and inner spaced walls and heat insulating material in the space between said walls; said furnace formed interiorly of said inner wall with a reaction chamber having the shape of two opposed paraboloids; and a crucible coinposed of conducting material in the principal foci of said paraboloids, said crucible constituting a center electrode for two arcs in series.

5. In an electric furnace, outer and inner spaced walls and heat insulatin material in the space between said walls; and furnace formed interiorly of said inner wall with a reaction chamber having the sha e of two opposed paraboloids; and a cruci le in the principal foci of said paraboloids, said crucible constitutin a common electrode for two arcs in are el.

6. Inan e ectric furnace, outer and inner spaced walls of refractory material, heat in- Sula-ting material in the space between said walls; said furnace formed interiorly of said inner wall with a reaction chamber in the form of two opposed paraboloids; a crucible in the principal foci of said paraboloids, said crucible adapted to cooperate with means constitutin an arc heatin device; a second crucible alfapted to be su stituted for the first mentioned crucible, said second mentioned crucible further adapted to cooperate with means constituting a resistance heating device. I

7. In an electric furnace, outer and inner spaced walls and heat insulating material in the space between said walls; an arc heating means in said furnaceand a resistance heating means adapted to be substituted for said are heating means.

8. In an electric furnace, a body having outer and inner space between and walls filled with heat insulatin material; said bod -f'ormed interiorly 0 said inner wall wit a cavity, and cavi having the shape of two opposed pa loids. 9. In an electric furnace, at bod :formed with a cavity having the shape 0 t'wolopposed paraboloids, and means in said-cavity or maintaining a substance to be in the principal oci of said parabololds, said means adapted to serve as a common electrode for two arcs in parallel.

10. In an electric furnace, a body havmg outer and inner aced walls and having the space between said walls'filled heat-insulatingmatefi'al; said body formed orly of said inner wall with a cavity, and a crucible in said cavity, said crucible consti tutin a common electrode for two arcsin paral el. V

11. In an electric furnace, at body having 5 outer and inner spaced walls and having the space between sud walls filled with heat ins'ulating material; said body formed interiorly of said inner wall with a, cavity, and a crucible in said cavity, said crucible constituting a common electrode for two arcs in 10 series.

In testimony whereof I ailix my signature.

CLAUDE G. MINER.

00p!" of this patent may be obtained for he cent! each, by addressing the "commissioner of latentl, Washington, D. G.

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