US1084991A - Furnace for refining metals. - Google Patents

Description

E. G. WILLS.

PURNAGE FOR REFINING METALS.

APPLIOATION FILED JAN. so, 191s.

Patented 3311.20, 19.14.

2 SHEETS-SHEET 1.

E. C. WILLS.

FURNAGE FOR RBFINING METALS.

. APPLICATION FILED JAN. 30, 1913. 1,084,991. Patented .13.11.20, 1914.

2 SHEETSrSHEET 2.

l ZZ' 24% Z5 l M Arron/VHS UNITED sTATEs PATENT OEEIOE.

EDWIN COOPER WILLS, OF FREDERICK, MARYLAND.

FUBNACE FOR REFININ G METALS.

Specification of Letters Patent.

Patented Jan. 20,1914.

4To all whom it may concern:

naces for Refining Meta s, of which the following is a specification.

My invention relates to improvements in furnaces for refining metals and it consists in the combinations, constructions and arrangements herein described and claimed.

An object of my invention is to provide a device which may be rocked or Oscillated so as to cause a movement of the liquid metal, so as to bring the latter in the most advantageous position for air treatment and also causing the dross to be more easily eliminated.

A further Object of my invention is to provide a furnace .having a plurality of means for heating the metal to be treated such as gas or the electric arc, in which any of the means or all of them may be used in the refining process.

A further object of my invention is to provide an improved furnace which is so constructed that the heating medium may be treated first in one direct-ion and then in the other, thus insuring the uniform treatment of all the metal.'

Other objects and advantages will appear in the following specification and the novel features of the device will be particularly pointed out in the appended claims.

Myinvention is illustrated in the accompanying drawings forming part of this application in which- Figure 1 is an end View of the device, Fig. 2 is a side view,a portion of the exit flue being shown in section, Fig. 3 is a transverse section, Fig. v4 is a longitudinal section through the device, Fig. 5 is a longitudinal sectionxalong the line 5 5 of Fig.

1, Fig. 6 is a detail sectional view of a pory tion of the apparatus, Fig.- 7 is a detail view showing the means for oscillating the furnace, and Fig. 8 is an enlarged section along the line 8-8 ofFig. 5.

In carrying out my invention I provide a track consisting of the rails 1. Heads 2 are provided each having a circumferential groove 3 -arranged to lit over the rails 1.

' The heads 2 have laterally extending peripheral flanges 4. Each peripheral flange bears integral segmental flanges 4". These segmental langes are arranged in pairs with a T-shaped Opening between the members of each pair arranged to receive the ends of rail-shaped members 5. The latter extend thro-ugh the heads 3, as shown in Figs. 4 and 5 and between the pairs of segmental flanges 4", and are secured to the outer portions of the flanges 4 by means of U-shaped bolts 6. This forms an exceedingly strong and rigid construction.

Secured to the base plates of the rail members 5 on the interior side thereof are retaining plates 7 (see Fig. 6). The space between the adjacent rail-shaped members is bricked up7 as shown at 8 and upon this brick layer or Outer Wall is a hearth 9 of the shape shown in Figs. 3, 4 and 5, con structed of refractory material of any suitable kind.

In Fig. 3 I have shown an exit flue 10 for the products of combustion, this flue being at an angle to a perpendicular line, through the furnace when the latter is in its normal position. This angle is approximately thirty degrees and the reason for naking the Hue angular will be explained ater.

On one side of the furnace thus constructed is a charging port or passage 11, while a discharge port 12 is provided for draining off the refined metal. In Fig. 3, it will be seen that on the opposite side from the ports 11 and 12 are the twyers 13. These twyers communicate with a common air chamber 14 which is provided with a series of screw plugsA 15. An air supply pipe 14x communicates with the air chamber 14 and extends forwardly to one end of the device. An elbow 14y is provided so as to bring the pipe toward the center of the furnace where another elbow 14Z permits the extension of the pipe 14-along the axis of the furnace. This permits the rocking of the furnace with the mere rotation of the extended portion of the pipe 14 about the axial line and thus does away with the necessityl of having a flexible connection to the air chamber 14. The plugs 15 are in alinement with their respective passages 13 and may be removed so as to permit the cleaning out of the twyers in casethe latter should become clogged.

Referring now particularly to Fig. 4 it will be seen that I have provided the gas inlet ports 16 and 17 respectively which enter from o posite ends of the furnace. They are pre erably arrangefdfin pairs, as will be insulation 281 '2 Loggen i seen from Figs. 1 and 3. On each side of the exit iiue 10 are gates `such as those shown at 18 and 19, these gates being controlled by suitable levers 20 and 21 respectively. At one end of the furnace is a flue 22 which communicates at the top with the interior of the furnace, and ywhich passes downwardly and inwardly to "an exit passage 23 (see Fig. 2) leading to the stack 24.y A similar passage or iiue 25 communicates with the interior of the furnace and passes downwardly and inwardly to the common exhaust passage 23. A damper 26 (see Fig. 3) is disposed at the junction of the .flues 22, 23, and 25 which may be manipulated by a rod 27 extending to the outside of the furnace (see Fig. 3) so as to permit communication of either of the fiues 22 or 25 with the exit passage 23 and to shut oil' the other one.

In addition to the heating means already described l provide electrodes such as those shown at 28 and 29 in Fig. 5. Secured to' the heads or to the end of the furnace are the slides such as that shown at 28b in which a casing 28l is mounted to move. The casing carries the electrode and is provided on the outside with a rack 28% arranged to be moved by a pinion 28d. The inner end of the electrode slides through a refractory ,sleeve 28e, the electrode being insulated from the sleeve inany suitable manner, as by the At the end of the insulating sleeve 28e and between it and the electrode 28 is disposed insulating and refractory material 28g which forms a seal for the sleeve 28e. Both the electrodes 28 and 29 areI mounted in the same manner.

The means for oscillating the kfurnace is best shown in Figs. 1, 3 and 7. To this end a frame 30 is mounted on a hinged bearing 31. rThis frame bears a motor 32 whose shaft 33 is provided with a worm 34 arranged to engage a gear 35 on a shaft 36; which extends longitudinally of the device.y @n the shaft 36 are the worms 37 and 38, the former engaging a gear 39 carried by the frame 30. This gear is disposed on a threaded rod 40 which is pivotally connected at 41 to the furnace. A similar gear 42 is disposed in a hinged frame 30x and operates a threaded rod 4()X which is secured at 41X to the other end of the furnace. When the motor is actuated the shaft 36 will be driven through the medium of the worm 34 and the' vthe outlet.

In order to compensate for the movement of the furnace with respect to the fixed stack I provide a telescopic device like that shown -in Fig. 3. From this figure it will be seen that the flue 23 communicates with a curved pipe section 23*l which is provided with means for cooling the same, such as by water pipes 23h. The pipe section 23 extends into a pipe section 24, the latter beingheld by an extended ortion of the base of the stack. Secured to t e end of the pipe section 24"L is a gasket or ring of asbestos or other suitable material 24b which bears against the pipe section 23a so as to prevent the entrance of air or the escape of the products of combustion between these two movable sections.

From the foregoing description of the various parts of the device the operation thereof may be readily understood.

ilhe molten metal jwhich may have been heated in any suitable auxiliary furnace is introduced through the port 11 until the hearth is filled up to the point X shown in F ig. 3 when the port 11 is plugged up in any suitable manner. ln some instances it may be desirable to charge the furnace directly with the cold metal, and in such case the metal may be introduced through the doors 45 or directly through the outlet 10. The gates 18 and 19 are now lowered and air is turned on in the twyers and the furnace is tilted in the manner already described until the liquid metal just covers the openings of the twyers 13. rlihe passage of the air into the heated metal immediately raises the temperature to a considerable degree-in some cases as much as a thousand degrees Fahrenheit. The current of air causes a rotary movement or eddy of the metal, the current being away from the mouth of the twyer at the top of the metal, thence downwardly and around again to the point where air enters the molten mass. This treatment tends to burn out certain of the impurities and causes a movement of the metal so as to bring the dross or slag to the top. While the air is being forced into the metal the cover 43 of the outlet 10 is raised as shown in Fig. 2, the hot gases passing upwardly into the stack 44. rlflois stack, as has been before explained, is at an angle to the per-y pendicular'drawn to the center of the furnace when the latter is in its normal position. lt will be understood that during this air treatment there is considerable agitation of the mass in the furnace so that particles of metal and cinder are thrown upwardly. lin the present construction. these particles strike the inclined surface 1()YL and fall back into the furnace instead of passing out of At the end of the operation the cover 43 is lowered into the position shown in Fig. 4.

Some'metals require only the air treat- Y ment for 'their proper refining, but other metals require additional heat. In case additional heat treatment is required the furnace is tilted back to its original position shown in Fig. 3 and the gates 18 and 19 are raised. Gaseous fuel is admitted through either of the ipes 16 or 17. We will consider for the time bein that the fuel is coming in through the pipe 16. It is passed above the molten metal and the latter is heated to an intense degree. The products of combustion pass outwardly through the flue 25 into the discharge passage 23 and thence to the stack 24, the damper 26 being turned to permit the gases to escape. When the damper 26 is first turned the door or closure 46 in the flue 22 is opened. IrThis permits the entrance of air which passes up through the flue 22 and enters the furnace at a point in close proximity to the incoming fuel. The air mixes with the fuel and thereby aids in promoting combustion. A similar door 47 1s provided in the flue 25 on the opposite side of the dani er 26 to permit air to'pass up the flue 25 or aiding in the combustion of the fuel passin in through the pipe 17. After ten or fi teenl minutes the vpipes 16 are closed. The pipe 17 is now opened and fuely enters from the opposite end of the furnace. The damper 26 is also shifted so as to permit the prod- /ucts of combustion to pass outwardly through the flue 22 Aand thence by means of the exit passage 23 to the stack 24. This part of the process may be continued until the metal is thoroughly refined,4 when the metal is drained oil through the discharge port 12.

Certain metals require an additional 4refinement and for this purpose the electrodes 28 and 29 are used. In this instance both gates 18 and 19 are closed. It is desirable that the fluid metal-shall fill the hearth 9 approximately up to the electrodes. The current is turned on and the heat of the arc between the electrodes of opposite polarity raises the temperature of the metal to a high degree. I desire to call attention to the act that the heating action takes place along the surface of the metal from one side to the other of the hearth. v

I am aware of certain electric furnaces having electrodes which project down to a point at approximately the surface of the metal in which there is an arc from one electrode to another through the metal, but such a construction would not fulfil the purpose of the device which forms the subject of the present application for the realson that where these electrodes are relatively close together, the arc which is formed heats only a small portion of the molten mass, lthose portions outside of the zone of the arc being colder. There is therefore no such tendency for currents of downwardly moving metal and upwardly movcircular heads provide lbracing lthrough said heads and through the flanges ing metal which extend practically throughout the mass of molten metal. In the pres ent instance the entire surface of the metal from one electrode to the other receives practically the same heatingl effect, since the arc must extend from one electrode to the other. There is therefore no tendency for this downward movement over the entire surface from side to side of the hearth. This movement renders the refining of the metal not only more perfect, but it takes place in considerably less time than with the ordinary construction mentioned.

As the surface of the metal in the furnace lowers on account of the driving off of the impurities the electrodes 28 and 29 are moved downwardly and inwardly by the rack and pinion already described, so

las to keep the end of the electrode practically in alinement with the surface of the molten metal, thereby causing the arc to take place along the surface of the metal.

The ease with which the various heatingl `steps in the process may be brought into play I consider one ofthe main features of my invention, since 1t is essential in the refining of metal that as little heat as possible shall escape, and that. each step shall be taken immediately after the preceding step has been finished.

1. In a metal refiningfurnace, a pair ofcircular heads provided with flanges, a series of longitudinal rail-shaped parallel bracing members arranged to extend through said heads and through the flanges carried thereby, means for securing the bracing members to the heads, said bracing members being equidistant'froin the longitudinal axis of the furnace, a lining of re- A fractory material disposed between said parallel bracing members and arranged to cover said bracing members, and a hearth ofrefractory material carried by said first named lining.

2. In a metal refininl furnace, a pair of with flanges, a series of longitudinal rail-shaped parallel members arranged yto extend carried thereby, means for securing the `bracing members to the heads, said bracing members being equidistant from the longitudinal axis of the furnace, a lining of reffractory material disposed between said parallel bracing members and arranged to cover said bracing members, a hearth of refractory material `carried by said first named lining, means for charging the hearth with metal, means for drawing'off the refined metal, and a stack, said refractory-lining having exit fines leading to said stack.

3. In a metal refining furnace, a pair of circular heads provided with flanges, a series of longitudinal rail-shaped parallel nace, each of said fines leading to the stack,

and means for drawing the products of combustion through one flue or the other at will.

4. ln a metal refining furnace, a pair of circular heads provided with flanges, a series of longitudinal rail-shaped parallel bracing members arranged to extend through said heads and through the flanges carried thereby, means for securing the bracing members to the heads, said bracing members being equidistant from the longitudinal axis of the furnace, a lining of refractory material disposed between said parallel bracing members and arranged to cover said bracing members, a hearth of refractory material carried by said rst named lining, means for charging the hearth with metal, means for drawing off the refined metal, a stack, said refractory lining having exit flues leading to said stack, said refractory lining having an exit fiue at each end of the furnace, each of said flues leading to the stack, means for drawing the products of coml'iustion .through one fiue or the other at will, and means disposed adjacentv to one end of each of said exit flues for introducing duid fuel into the furnace.

5. ln a metal refining furnace, a pair of circular heads provided with fianges, aseries of longitudinal rail-shaped parallel bracing members arranged to extend through said heads and through the flanges carried thereby, means for securing the bracing members to the heads, said bracing members being equidistant from the longitudinal axis of the furnace, a lining of refractory material disposed between said parallel bracing members and arranged to cover said bracing members, a hearth of refractory material carried by said first named lining, means for charging. the hearth with metal, means for drawing olf the refined metal, a stack, said refractory lining having exit fiues leading to said stack, said refractory lining having an eXit flue at each end of the furnace, each of said fiues leading to the stack, means for drawing the products of combustion through one flue or the other at will, and means disposed adjacent to one end of each of said exit flues for introducing fluid fuel into the furnace, each of said exit fiues being provided with an air inlet for admitting air into one flue while the other is being used as a discharge flue.

6. ln a metal rening furnace, a cylindrical chamber, an elongated hearth within said chamber, means for admitting fluid fuel at each end of said hearth, a stack, a curved telescopic fiue communicating with said stack, exit passages connecting the interior of the furnace with said flue, the ends of said exit passage being disposed near the fuel inlets, a series of twyers carried by the wall of the hearth, the mouths of said twyers being normally above the level of the liquid metal on the hearth, electrodes of opposite polarity carried by the walls of the hearth, a gate for shutting off each of the exit passages, and means for rocking the furnace to bring the level of the molten metal above the mouths of the twyers. l

7. lln a metal refining furnace, a cylindrical casingcomprising circular heads, a series of longitudinal members carried by said heads, a lining of refractory material disposed between adjacent longitudinal members and arranged to cover said members, said lining being provided with exit passages, a stack communicating with said exit passages, an air chamber formed in said refractory lining, a plurality of twyers leading from said air chamber through said lining into the interior of the furnace, a refractory hearth, means for charging' the hearth with metal, and means for rocking the furnace to bring the level of the molten metal above the mouths of the twyers.

EDWIN COPER WlLLS.

Vitnesses:

lnvrNo E. STALEY, CHAs. A. FRAGA.

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