US1359735A - Electric furnace - Google Patents

Description

c. E. PARSONS.

ELECTRIC FURNACE.

APPLICATION FILED FEB. 19. 1920.

1,359,735. Patented Nov. 23, 1920.

a sums-su'm 2 C.E.Paraana C. E. PARSONS.

ELECTRIC FURNACE.

APPLICATION FIL'ED FEB. 19, 1920.

1 ,359,735. Patented Nov. 23, 1920.

3 SHEETSSHEET 2- div-Parsons C. E PARSONS.

ELECTRIC FURNACE.

APPLICATION FILED FEB. 19, 1920.

3 SHEETS-SHEET 3- Patented Nov. 23, 1920.

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Gi -Parsons, b 74 WW UNITED STATES CHARLES E. PARSONS, OF ENGLEWOOD, NEW JERSEY.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented Nov. 23, 1920.

Application filed February 19, 1920. Serial No. 359,838.

To all whom it may concern:

Be it known that I, CHARLES E. PARSONS, a citizen of the United States, residing at Englewood, in the county of Bergen and State of New Jersey, have invented certain new and useful Improvements in Electric Furnaces; and I do hereby declare the followingto be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to electric furnaces of'the resistance type, and has for its object to provide a device of this character which will be simple in construction, and more efficient inaction than those heretofore proposed.

With these and other objects in view the invention consists in the novel details of construction, and combinations of parts more fully hereinafter disclosed and particu larly pointed out in the claims.

Referring to the accompanying drawings forming a part of this specification in which like numerals designate like parts in all the views Figure 1 is a sectional view of a furnace made in accordance with'this invention;

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1; and

Fig. 3 is a plan view of a furnace with a portion of its internal parts shown in dotted lines.

1 indicates any suitable refractory structure preferably composed of brick work, 2 an outer metal casing or support for the same, 3 electrodes preferably of graphite, 4 lead wires, 5 an upper container or silo communicating, by the connection 6 having the valve 7, with the lower'container or silo 8, and 9 a valve connection controlling the admission of charge material to the container 5.

The lower container 8 is provided with an outlet 10 leading into the passage 11, of

19, mounted on the hollow shaft or pipe 20, carrying the bevel gear 21, meshing with the bevel gear 22, rigid with the shaft 16 as shown.

The vertically disposed passage 18 is flared at 1ts upper end as at 23, and merges into the square or cubical shaped chamber 24, from which lead, on opposite sides thereof the refuse or slag passages 25 and 26 as indicated. Said passages 25 and .26 are inclined toward the vertical passage 18 as indicated in dotted lines, and they lead to the common passage or connection 28 which is joined to-the receptacles 29 and 30 by the connections 31 and 32 respectively.

Said connection 31 is provided with the valve 33 and the connection 32 is provided with the valve 34 as shown. The hollow shaft or pipe 20 leads into the receptacle 35 containing water, and from said receptacle 35 ,leads the pipe 36 as illustrated.

Said receptacle 35 may be filled by any suitable connection such for example as the pipe 37, shown in Fig. 2. The receptacles 29 and 30 are provided with the valves 40 and 41 respectively, controlling their outlets as illustrated.

Above the square or cubical chamber 24 is the space 45 from which leads the suction pipe 46 joining said space 45 and the separator or' condenser 47, see Fig.3. Into this space 45, from above, projects a pointed or wedge shaped member 48 preferably made of carbon and which has the function of splitting or dividing the charge material 50, should it stick or become agglomerated sufficiently to be carried up to the pointed end of said member 48. As more or less gases will be formed in said space 45, it is preferred to provide the said member 48 with a plurality of holes 51 through which a free escape of gas may be had when suction is applied to the pipe 46.

In order to supply this suction, a suitable vacuum or suction apparatus 55 is installed understood from the foregoing but may be,

briefly summarized as follows :Charge material 50 is admitted into the-upper receptacle 5 through the valve or connection 9, which receptacle may act as an air lock by suitably manipulating the said valves 7 and 9.

The material next free from contact with the atmosphere enters the receptacle 8 and the screw conve er chambe: 11 whence it is carried by the orizontally disposed chamber 18 whence it is lifted by the vertically disposed screw 19 to the chamber 23. From the chamber 23 the square or cubical chamber 24 is entered whereupon current being turned on the charge material is heated to incandescence, and if it be of the usual character such as a mineral bearing substance, and cok said material will be heated to incandescence.

In order to more efficiently start the fur nace, it is preferred that the first portion of the material passing the electrodes 3 shall be sufficiently rich in carbon to readily effect the desired heat, after which less carbon may appear in the charge.

The rotation of the screw conveyers 12 and 19 will cause a uniform flow of materials to the chamber 24, and there will also be a uniform overflow of materials into the passages 25 and 26 after the charge has been subjected to the action of the current.

As is well known, it is very difficult indeed to control not only the heating effect of the current in resistance furnaces, but it is also difficult to control the path along which the current passes in such furnaces. This is due largely to the reater conductivity possessed by the heate materials over the cold materials.

In this furnace, on the other hand, the cold material is constantly fed from the bot tom upwardly, instead of from the top downwardly, so that the higher resistance of the cold material below the electrodes effectually cuts off the passage of current in the direction of the vertical screw 19, and confines the heating effect of the current to only that portion of the material 50 which lies in the immediate neighborhood of the electrode ends. As a matter of fact, as the material passes upwardly through the chamber 24 and spills over the top, its highest temperature is reached just before this spilling action takes place and therefore, the greatest heating effect is had at just the point where it is most desired.

In other words, if a metal like magnesium, for example, is being volatilized, and the metal itself is being constantly drawn off through the pipe 46, this very high heating effect taking place at or near the point 60 marking the, crest of the hot charge, causes a most efficient volatilization to take place with the result that much more of the metal is recovered than in former processes. This action is further enhanced b the fact that if the temperature is not su cient to volatilize the metal, it can readil be raised by turning on more current an this without producing the evil consequences which an increase of current engenders in the ordinary type of furnace. With some charges the material treated becomes more or less sticky before it spills 'uto the discharge chute, and therefore, it 1s liable to pass on upwardly into the space 45 and to more or less choke said space without feeding pro erly down into the chutes 25 and 26. o avoid this objection I provide refractory members such as 48 and preferably made of carbon, which project down into the space 45, and are adapted to be adjusted, as by means of the screw device 65, so that their lower pointed ends may contact with the upwardly traveling crest 60 of the charge material, and thus divide or break said material into two parts so that it will readily pass down through the chutes 25 and 26. In order to prevent these said members 48 from obstructing the passage of the gases which may be evolved, I preferably provide them with the holes 51 as shown.

In treating those materials wherein it is of particular importance that no substantial quantity of free oxy en be permitted to remain in the furnace, l readily maintain the furnace clear of all oxy en by 0 ening the valves 33 and 34, and alIowing t 1e suction through the pipe 46 to draw out all air which may be caught in the interstices of the charge, or of the slag material.

The residue left after treating the charge readily passes down into the containers 29 and 30, as above disclosed, and upon openi the valves 40 and 41 it is readil dumpe into carts, not shown, and hau ed away. Since the vertical screw conve er 19 may get more or less hot, and especially at its upper end, I preferably pass water in throu h the valved pipe 37 so that it enters the chamber 35 ascends to the to of the hollow shaft 20 and maintains all t e parts cool.

It is clear that I may treat all sorts of charge materials, b this method, and in fact may fix atmosp eric nitro en in a furnace of this character. In or er to accomplish the fixation of nitrogen, however, the charge is made up of ca cium carbid and the nitrogen gas is fed in at or near the chamber 24 by a pi e not shown, but which is indicated b the otted circle 66 in Fig. 1.

In order that there may be no slip between the hot material fed vertically upwardly by the screw 19, over the cold material which is fed horizontally by the screw 12, I make the gear 14 of a smaller diameter than the gear 13 so that the screw 19 travels say about 25% faster than does the screw 12.

t is obvious that those skilled in the art may vary the details of construction, as

well as the arrangement of parts without departing from the spirit of the invention, and therefore, I do not wish to be limited to the above disclosure except as may be required b the claims.

What claim is 1. In an electric furnace the combination of a pair of electrodes; means for feeding charge material upwardly between said electrodes; means for conveyin the treated material downwardly out of t e re ion of said electrodes; means for maintaining the interior of the furnace airtight; and means for subjecting the material to suction while bein treated, substantially as described.

2. In an electric furnace the combination of a chamber closed to the atmosphere; means for exhausting air from said chamber; a pair of electrodes adapted to heat charge material in said chamber; means for feedin said charge material upwardly to said 0 amber; means for conveying the treated material downwardly from said chamber; and means for condensin outside of said chamber the products of t e treatment in said chamber, substantially as described.

3. In an electric furnace the combination of a chamber closed to the atmosphere; means for exhausting air from said chamber; a pair of electrodes adapted to heat charge material in said chamber; means comprising a gair of conveyers for conveymg the treate material downwardly from said chamber; and means for condensing outside of said chamber the products of the treatment in said chamber, substantially as described.

4. In an electric furnace the combination of a chamber closed to the atmosphere; a pair of electrodes entering said chamber; means for exhausting the air from said chamber; means for feeding charge material upwardly into said chamber; means for conveying the treated material downwardly out of said chamber; and means for mechanically dividin said material in said chamber to facilitae its downward removal, substantially as described.

5. In an electric furnace the combination of a chamber closed to the atmosphere; a pair of electrodes entering said chamber;

. means for exhausting the air from said chamber; means for feeding charge material upwardly into said chamber; means for conveying the treated material downwardly out of said chamber; and means comprising a pointed refractory member for inc--

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