US921228A - Electric furnace for metallurgical purposes. - Google Patents

Description

P. GIROD. BLEUTRIU FURNAGE FOB. METALLUBGIGL PURPOSES. Arrmoyrrox rILnn mso. no. 1905.

921,228. Patented May 11, 1909.

2 SHEETS-SHEET 1` Figi.

P. GIROD.

ELEGTEIG FURNAGE POB. METALLURGICAL PUBPGBES.

APPLIUATION FILED DEG. zo. 1905.

'921 ,228. Patented May 11, 1909.

2 SHEETS-SHEET 2` A Fig@ PA illlil NT (l F FIC lil.

lAUL GlROD, F UGlNl, l'lltANGl.

ELECTRIC FURNACE FOR METALLURGICAL PURPOSES.

T o all whom it may concern.'

' Be it known that 1, PAUL Guion, residing at Ugine, Savoie, France, have invented a new and useful Improvement in Electric receiver of the material to e melted or ofthe molten material.

This nventionhas for its object an electric `furnace for the manufacture of steel or soft metal in which one ofthe electrodes is replaced bv a pole piece embedded in the furnace heart in such a manner that it may not be ex osed to too great a temperature and that t e metal in contact with 1t may be soliditied to an extent determined by experience. .This pole may be formed of graphite ormetal or of any other suitable conducting substance, its interior may or may not be cooled.

, The accompanyin r drawingr illustrates two furnaces constructs in accordance with this invention.

In this drawing: Figure 1 is a view in longitudinal section through a 'furnace construct ed in accordance with the present invention.

exhibiting the same as it appears when empty. lrig. 2 is a horizontalsectional view of t e same. Fig. 3 is a view similar to Fig. Lexhibiting the furnace at work. Fig. 4 is a view in longitudinal section of a modiiied form of furnace. Fig, 5 is a horizontal sectional view of the furnace shown in Fig. 4.

The rectangular furnace consists ofa metal frame, mounted on a pair of trunnions 1, carried by su ports 2, which allow the furnace to be tilte( yby hand or by suitable mechan- The bottom 3 (provided as shown in Fig. 2 with a laterally projecting portion 4, which serves to introduce the current) carries two electrodes 5 and 6, embedded in frames 7 and 8, formed of an le irons furthe purpose of insuringbetter eectric contact with the bottom These electrodes are surrounded by mason 9 and 10. formed of refractory bricks, pre erably of magnesia oralumin'ous silicates, because such bricks, when exposed to heat, do not become appreciably conduct- Specication of Letters Patent.

Application led December 530, 1905.

Patented May 1.1, 1909.

Serial No. 292,61'7...

Us... ive. The remainder of the i'ul nace is bricks or oi' the mineral lo be treated or of any other materials fulfilling the desired object.

A simple or multiple movable electrode 11 ma be moved by hand or mechanically in suc 1 a manner as to he lowered into the inte ri'or of the furnace. i

The tapping holes land 13, shown in dots in Fig. 1, are arranged at different levels either at the same side of the furnace or on opposite sides. At this point the refractory mass is made thicker as shown in Fig. 2. This thicker portion is arranged in such a manner that it is ossible to remove the part of the metal Whic surrounds it and'to thus re lace the tapping holes `which it bears.

fit ybe desired for example to manufacture soft ferro-chrome, the electrodes 5 and 6 are preferably merely composed of blocks of graphite. It Wilbe necessary therefore to cover them with a layer of metal for the purpose of preventing their contact with the metal in a state of fusion. For this )urpose the ferro-chrome may be cast into t e cavi; tics or melted in situ by means of the electric current or again by merely placing pieces of ferro-chrome above these electrodes.

,ln order to commence working the furnace, number of small pieces of carbon or of metal are arranged upon the bottom between the electrodos 5 and 6 which arc covcrcd with cast metal or with small pieces of the manufactured product. T he upper electrode is then lowered and an arc is formed, the furnace is now charged, the material fuses and the fused charge and the slag form al rcsistancc, which usually causes the extinction of the are. the electrodes have been previously iilled with east metal which has solidified the heat at this point is not sufficiently great to again fuse the metal; if, on the contrary, pieces of ferro-chrome or otlu L" products have been placed in the cavities for starting the furnace, the metal in. the process of formation flows into the said cavities and,

in view of the distance of the cavities from the main source of heut, amalgamates all the pieces previously introduced into one and solidifiies on top of the electrodes. On

then entirely surrounded w1th masonry as shown 1n Figs. 1 and 2, formed either oil' refractory the other hand, the size of the electrodes, and therefore of the solidified metal, is made sufficiently' large that no heating by resistance takes place as this would cause the fusion of the metal. We have therefore a furnace with one or more uppe'r electrodes and one or more lower electrodes, the por tion of the lower electrodes in contact with the metal in fusion being in this case of the same metal as that which is beingr fused, ferro-chrome for example. In such a furnace therefore the carbon of the lower electrodes is never in contact with the fused. metal and the upper electrode is regulated. in such a manner that it also does not touch the fused metal, but only the slag formed by the fluxes and the fused ore.

Fig. 3 shows the furnace at work. The

electrode 11 is immersed in the layer of slag 16, floating on the layer 17 of fused metal. which covers the deposit 18, 19 of metal solidified at the lower electrodes 5 and 6.

The furnace thus constituted may work with a continuous or alternatingr current etc. and at various voltages; one or more upper electrodes form one of the poles, and one or more electrodes, embedded in the masonry and protected by a layer of solidified metal, the other pole.

'l he lower electrodes may be rendered electrically independent of the hearth, by forming in the masonry a space for the assage of the electric leads and by insulating these leads in their passage through the sheet metal bottom In this case the different electrodes may be connected together in parallel or inseries. The electrodes embedded in the masonry may also be placed at the sides of the furnace, how ever, they should always be arranged in such a manner that the metal in their neighborhood may be solidified, that is to say, they should not be too near to the upper electrode.

The regulation of the temperature in the furnace moreover allows the zone of fusion to be limited.

'The metal and slag may be separatelyT tapped through holes arranged at different levels if necessary or at the same time through a single hole.

The furnace may Without departing from this invention be a fixed one and it may if necessary be provided with a cover.

Figs. 4 and 5 show an oscillating circular furnace, especially designed for the man facture of steel, cast iron. etc. `In this case the pole embedded in the masonry 20 is preferably formed of a cast iron ring 2l, provided with a water circulation 22. This ring becomes immediately covered with a layer 23 of solidified metal which then itself .leads the current to the metal 24 in a state of fusion. The upper pole is formed of one or several electrodes 25 and the current passes through the slag 26 and the fused ore.

As above stated, the electric lead embedded in. the masonry may equally well be arranged at the sides or anywhere else, either by means of a circular continuous ring, as is the case in this furnace, or by means of separate electrodes, the said'electrodes being formed either of cast iron, graphite, or of any other conductin material. It is sufficient merely that tiey are always placed in such a manner as not to attain too high a degree of tem erature which Vwould melt the metal whic is intended to serve as a connection between the 'fused metal and the said electrodes. The slag serves as a resistance between the fused metal and the electrodes. The furnace may moreover be used e uall as a simple arc furnace by causing the e eetrode to project above the slag.

The manufacture of steel and of cast iron takes place in exactly the same manner as in the usual methods of manufacture; refining decarbonization, desulfurizing, dephos horizing etc. may take place by any o the usual methods.

The voltage is chosen in a suitable manner for each manufacture; in certain cases it maybe fairly lour andthe la er of slag above the fused metal be extreme y thin; in other cases it is.made higher if the resistance be greater.

Having thus fully described my invention, what I claim is: l

l. An electric metallurgical furnace comprisin alower electrode, means for causin part o the metal to unite with the same, an an upper electrode held in contact with the flux ut out of contact with the fused metal.

2. An electric furnace having opposed that portion of one of the electrodes in contact with the metal in fusion being of the same metal as that which is being fused, and the other'electrode being adjustable whereby it ma be kept out of contact with the fused meta and in contact onl`5T with the slag formed by the fluxes and the fused ore.

5. An electric furnace embodying op osed upper and lower electrodes and forme with a metal-receivin cavity at the end of one of the electrodes, t e other electrode being arranged to remain in Contact with the slag [n testimony whereof l have signed this formed by the fluxes and the fused ore. l specification in the presence of two subscrib- 6. All electric furnace embodying upper' irg Witnesses. and lower electrodes out of vertical aline- PAUL' GIROD. ment, the lower electrode being annular, and Witnesses:

the furnace having e, metal-receiving clieml A. NEYRET,

ber over said lower annular electrode. T. W. MURTON.

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