US1308877A - thomson - Google Patents

Description

J. THOMSON.

meme FURNACE FOR FUSING METALS.

APPLICATION FILED OCT-7,1918. I

Patented July 8, 1919 3 sHEETPsHEEr l.

BY MW- AT RNEYS' J. THOMSON.

memo FURNACE F'OR Fusmc METALS.

APPLICATIONFILED OCT-7,1918. 1,308,877. Patented July 8, 1919.

3 SHEETSSHEE1' 2.

Q m m/r01? Br J. THOMSON.

ELECTRIC FURNACE FOR FUSING METALS.

APPLICATION HLED OCT. I, 1918.

1 ,308,877. Patented July 8, 1919.

3 SHEETS-SHEET 3.

r 1 l I J 0 g 111111,, N 0, 1 Z l/VVE/VTOR I 4 By V A TTOR/VEYS ELECTRIC summon 'FOR 'IEUSING METALS.

To all whom it may concern:

of the borough of Manhattan, at of New York, county and State of New Ybrk, have invented certain new and useful Improvements in Electric Furnaces for Fusing Metals, of which the following is a specificav tion.

This is an invention in electric furnaces for fusing metals, particularly non-ferrous metals and. alloys thereof. 'The furnace as herein illustrated and described is sistance type.

The furnace which is the basis of the of the represent invention has what may bedescribed as a rolling motion about a vertlcally extending axis and this motion is herein frequently referred toaSia gyratory movement.

Thefurnace, as will hereinafter more fully appear, has a substantially horizontally ex- 1 tending tank or bed-within whichthe metal,

or metals, to be fused is placed and within.

which the fused or molten metals are held, and the furnace structure is so made that when the rolling or gyratlng motion is taking place a vertically extending linepreferably the vertically extending center line of thetank or bedswings in a conical path about a vertically extending axis passing through the center of a support upon which the furnacestructure is carried.

As showing a specific em'bodlment of the invention reference is made to the accom-- panying drawings forming apart of this specification, in which drawings,

Figure l is a vertical center section, transverse as to the resistor.

Fig. 2 is a vertical center section, longitudinal as to the resistor.

Fig. 3 is a horizontal section alongthe zone Aof Fig. 2, also denoting the resistor in plan; and

Fig. 4: is a view which illustrates the gyratory or rolling movement of the furnace.

" The resistor B is of the type that is genorally known, in common parlance of'the art, as the zigzag resistor. It is preferably is here shown within a casing C formed of material immune to oxldization, and the design and construction'of the reslstor 1s such that the current-density progresslvely in 1 creases from its upper to its lower surface,

the resistor will be refracted Patented J ulyS, 1919.

Serial No. 257,212.

casing corresponds thereto.

A V I and therate of transfer of heat through the Be it known that I, JOHN THoMsoN, -a

citizen of the United States, and a resident From the drawings it will be observed that the furnace, while the outer end is supported in the opposite end-wall and the resistorterminals F G pass through to the outside and are connected in an electric power circuit whichis empirically denoted by H.

The sistor ferred to as the approximate central longitudinal axis of the furnace-chamber I and above an open tank or bed J whichis shown as containing a molten charge K and within which the metal is placed prior to being melted or fused. The side-walls of the furmace-chamber, to wit, the longitudinal walls which extend lengthwise of the resistor, are sloped inwardly and upwardly, as at L, Fig. 1 and support a cover or an arched roof, asM. The angle of these side-walls is a function of the angle of the sides of the resistor and its location relative to the tank,

whereby the flow of heat from the sides of from the sloped sidewalls downwardly upon the surface of the bath, as is denoted by arrows a. Heat from the lower, surface of the resistor passes directly to the bath, as shown by arrows :6. In this wise, the transfer of energy to the charge is very uniform and effective.

infusing alloys composed of such metals aseopper, zinc, lead, aluminum, etc., it is very important that the charge shall be thoroughly commingled. This is accomplish-ed to a high degree of perfection by employing a substantially horizontally extending melting tank or bed which in plan is square or rectangular, see F ig. 3, and

by so mounting the entire furnace that a gyratory movementor rolling movement about a vertically extending axis may be preferred disposal of the aforesaid reis along what may be arbitrarily reimparted thereto. Theorbit of gyration,

adequate for said purpose, is quite nominal, say about 8 or so, as is shown at C, Fig. 4, in that the flow imparted to the bath is a combination of circular movement as indicated by arrow (5 Fig. 3, with ofi-shooting swirls or eddies at the corners of the tank, as indicated by arrow 6. In fact, a demonstrative model has shown that. a swashing action is roduced of such effectiveness that,

by a few gyrations, the whole mass' is as completely mixed as in the instance of pourformed to the frustum of a'cone 7 and has g meters.

a socket 8. The conical frustum and its correlated disk (or both may be frustums of cones) chiefly sustain the over-load, the ball and socket serving as a pin and socket to maintain a fixed relationship, and as the impingement of the disk and frustu'm closely approximatesan exact rolling contact friction is reduced to a minimum. Now when the disk is caused to make acomplete orbital gyration or oscillation as it is at times designated, the path described by the central, vertical axis R isthat of a cone.- In fact, the kinematics, as a whole, has been popularly summarized as the disk-action and has been most largely employed in water This action may properly be referred to as a rolling action about avertically extending axis. If the angle of gyration is slightand the frustum, or frustums, accurately machined, there will be but a merely nominal tendency for the furnace to creep in a circulatory direction; this,

however, can be readily prevented by means of a link or chain, as Oh; one end of which link or chain is secured to the casing of the. movable furnace structure and the other end,

of which link or chain is fixedly secured in any suitable manner.

To produce a relatively slow and smooth gyration, a shortspindle, as S, Fig. 1, is provided, here shown as being inserted in the crown of the arch, whose vertical center- 00- incides with that of the vertical axis of the furnace. Upon any suitable means of support, such as side pillars T and channel V, a gear IV and pinion 9 may be mounted, to be driven as bv means of a motor, chain or belt, and the lower extension of the gears shaft 10 may carry an arm 11. Thus, when this armis caused to revolve in a circle it will impart orbital movement to the spindle S thereby gyrating the furnace through one complete cycle for each revolution of the gear.

The next feature of correlative impor ta-nce relates to such a construction of the furnace as will avoid deformation of the brick-work when the gyratory movement or rolling action is taking placeQand as will through the sheets an serving as a sand-joint and the effectiveprevent infiltration of air into the heating chamber and effect heat-insulation of a high order, all of which features are realized by sheathing the outside walls of the furnace with steel sheets Y, preferably flanged, as at h, and by-securing them by suitable bolts to the iron bed-plate N. Instead, however, of placing the sheets in physical contact with the brick-walls a clear surrounding space is provided into which powdered fire-brick, or

magnesia, or infusorial earth, or the like, as-

n, is tamped. Thus, if the character of the refractories is such as to expand, the powder will be the more compressed and the sheets will automatically spring outwardly; per contra, if the refractories shrink additional powder can readily be inserted and tamped to compensate. In this wise, the brick-work is very rigidly held in lace; no air can pass 5 owder (the latter .to the roof of the furnace both for the purpose of diminishing the escape of heat thereat and for the exclusion of air from the interior.

The tube m, Fig. 1, may conveniently be used for the insertion of'pyrometers; to introduce an inert gas within the furnacechamber and. also to exhaust vapor or air therefrom, as may be desired. In this connection, it is pointed out that by the very complete seal afforded by the sheathing and interposed powder, which acts as a sandjoint, it is much more feasible to obtain and maintain a partial vacuum in the furnace-chamber than has been the case-hitherto in electric furnace practice.

There are two important contingent advantages inherent in gyratory movement or rolling action of the furnace and the already described mode of effecting it which consists, firstly, in being able to revolve the furnace upon its ball and socket so that its charging-port X and tap-spout Z may be swung to any position most convenient for their operation; and, secondly, to so tilt and hold the furnace, when tapping off a molten charge, that the tank or bed can be rapidly emptied.

Various modifications may be made in the evading the purview hereof; for example, instead of usmg a single centrall disposed resistor it may be formed'of two limbs electrically incited in series or in parallel. Moreover, in certain cases, as in the refinement of zinc by distillation, the resistor casadvantageously dispensed mg can then be with.

As to the form of tank or bed, while the preferred form is shown and described as being square or rectangular, it will be manifest that other forms of tank or bed might be used and still come Within the purview of the broader aspectsof the invention.

lVhat I claim is: i i

1. In electric furnaces, a suspended car bon resistor disposed along a central longi tudinal axis of thefurnace-chamber, above an open meltin tank, and longitudinally extending cham er side-walls, sloping inwardly and upwardly, whereby the heat which flows from thecorrelated sides of the resistor is directly refracted upon the charge.

2. An electric furnace for fusing metals contained in a tank, the said furnace being sustained by an underlying oscillating disk action whose axis describes a cone, the apex of which is beneath the furnace.

3. An electric furnace for fusing metals contained in a tank, the sardfurnace be ng mounted upon an underlying oscillating disk action andmeans, located above the furnace, for imparting gyratory. movement to the structure.

4:. An electric furnace for fusing metals contained in a tank, the entire structure be-' ing mounted upon a sustaining pedestal with a coordinating ball and socket, a "disk or plate and conical frustum producing the socalled oscillatin disk action, and extrane: one means for lmparting 'gyratory movement thereto.

'5. Inan electric furnace capable of beinggyrated, a fusing tank whose. form, in plan, is approximately rectangular, whereby the circulatory flow of the molten metal, at the I corners of said tank, is diverted into swirls or eddies.

6. An electric furnace having a carbon... resistor suspended above a melting tank,

an outer casing formed of two vertically disposed series of removable steel sheets,

a space between the said sheets and the furwardly and inwardly, whi

nace-walls which is fillediwith powdered material, and interior brickwork of a char-- acter which expands when heated.

7. A furnace for fusing metals having a furnace structure mounted upon a support 'in 'such a manner that there can be imparted to the furnace structure a gyratory movegyrating movement to be imparted to the furnace-structure, and means for imparting to the furnace structure said gyrating movement, the furnace structure having therein a square or rectangular shaped tank or bed within which molten metal is contained.

9. A furnace structure mounted upon a suitable support and means for'moving the furnace. structure so that a vertically extend ing line of the furnace structure moves in a'conical path about avertically extending axis which passes through the point of support, the furnace structure having a horizontally and longitudinally extending resistor with side-walls which slope downch resistor is contained within a chamber of the furnace structure that is provided with longitudinally extending side-walls which slope upwardly and inwardly, the furnace structure having therein a substantially horizontally extending tank or bed which is rectangular in plan and above which tank or bed said resistor is located, the side-walls of said chamberbeing arranged so as to deflect heat transferred from the sides of the resistor to metal contained in the tank or bed.

This specification signed and witnessed this first day of October, A. D. 1918.

p JOHN THOMSON. Signed in the presence of- R. Aomw, Jos'nPH H. STELM.

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