US1690795A - Electric furnace - Google Patents

Description

Nov.- 6, 1928. 1,690,795

- G. SAGRAMOSO ELECTRIC FURNACE Filed May 19, 1924 2 Sheets-Sheet 1 Nov. 6, 192a 1,690,795

v G. SAGRAMOSO ELECTRIC FURNACE Fi'led May 19, 1924 2 Sheets-Sheet 2 Patented Nov. 6, 1928.

UNITED STATES sumo saemoso, or 111mm, ITALY.

ELECTRIC FURNACE.

Application filed Ilia y 19, 1924, Serial No. 714,480, and in Italy Kay 28, 1923.

of the operation and to insure that the operation will take place under the most favourable conditions; by protecting the furnace charge from the action of the outer air.

Further objects of the invention are to render the charging of "the furnace easier and more expeditious and-in particular to enable thecharging with pieces of large sizes; permit the use of several crucibles havin a different kind of lining according to t e different kinds of material under treatment and according to the different stages of the treatment; render it ssible to subject the furnace charge to t ermal or chemical actionsprior to or after the electric treatment for which the furnace is built; and to facilitate the renewal of the crucible lining.

In the annexeddrawin s are schematically shown the constructive e ements embodying the invention.

Figs. 1 and 2 are an external view and section respectively.

85 .F'g. 3 shows the electrodesupport in sec tion. 4

The furnace essentially I comprises the crucible and the furnace operating means.

The crucible consists of a c lindrical 40, p or prismatic shell or container ma e of sheet iron, cast iron plates, or cast steel plates, the container being internally lined with refractory material and rovi'ded. with one-or more doors ,bas we 1 as with a pouring spout 4, The upper portion ofthe-lrcontainer is closed by an arched roof or ceiling d the container is carried track -f-, the displacement 'beih eflected either by hand or mechanicall t rough a winch, screw-spindle, rack "an pinion, an hydraulic cylinder or .other. device.

The furnace o erating means comprise on the cradle carriers h-- four wheels e which permit of its being displaced on at the bottom which has the form of a segment can mock-with or without interposed rollers, or other friction reducing device (which may either be curved or straight) and is secured to the foundations. The rocking of the cradle is effected by means of a lever zactuated by a screw spindle or other device. The said rockin movement of the crucible permits the pourlngof the molten metal and slags v To the outer face of the cradles or to brackets fixed thereto are secured the iron uprights L- servin to guide and sup ort the horizontal cross beams,-mbywhich the electrodes -m are carried. The weight of the crossbeams and electrodes may be'bala ced by counterweights o.

e vertical displacement of the crossbeams, and therewith of theelectrodes, is operated by screw spindles or fitted up between the uprights Z--.. I

On the top face of the cross beams --m-- restthe brass terminals p, which grip the electrodes and sup'l them with current means of horizontal ars and flexible caes. r

The electrode passes downr through the .inetal' jackets suspended from the cross beams m-, a ong with which they can be slid up and down in the bells r-. The jackets -g are perfectly tightl fitted in the bells r-, and both are dou le-walledand constantly cooled by circulating water.

The length pf the jackets q-- ,and bells 4-0'- is such that the electrodes can be lowered till they touch the lowest level of the metal bath or raised till theytouch the inner surface'of the crucible ceilin and yet re.- maifi constantly enclosed in t eir envelope, where they are protected against all contact with'the outside a d cooled so astoavoid the action of the hot crucible gases.

The bells rest on the'furnace roof in sandsealed circulargrooves; and are carried by an horizontal cross beam -7'-- which can be securedto the crossbeams by meansof books or other connectin devices as indicated at e--in Fig. l'an raised along with the latter when it-is desired to free the cru- 1 cible from thesuperincumbent structures in order to remove it from the electrode framingleither for renewal 'ofthe refractory lining or. for introducm into it the material tobe melted or refin andespecially steel blocks, large scraps or large unsuccessful castings and the like that could not get through doors b. 7

It is to be ointed out that in the event of damage to t e jackets g or bells r-, temporary lack of cooling water or the like, the furnace, after removal'of the jackets and bells, can continue working with bare elec-' trodes as are at present employed in most of the other furnaces. I

As to the crucible, due to the fact that it is independent from the,electrical equipment and removable, more than one or cible can be kept, in readiness either for avoiding interruption of work when the refractory lining must be renewed or in order to permlt working with different kinds of lining (acid, basic or neutral) according to the different materials to be treated and to the different stages of the treatment dr finally in order to subj set the crucible contents to thermal or chemical actions other than those determined by the electric current.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is An electric furnace, a support therefor, a pair of vertical standards mounted on said support, a crossbeam, adjustably mounted 'on' said standards, an electrode secured to said crossbeam and movable therewith, a double walled jacket secured to said beam and surrounding said electrode, a double walled bell adapted to 'be supported by said furnace surrounding-said jacket and within which said jacket is adapted to slide, and releasable means to connect said bell with said some SAGRAMO St).

said furnace.

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