US1334809A - Electric resistance-furnace - Google Patents

Description

1. srmom'mvn P. F. SARRON.

ELECTRIC RESISTANCE FURNACE.

APPLICATION FILED NOV. :3. 1918.

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Patented Mar. 23, 1920' J. SIMON AND P. F. SARRON.

ELECTRIC RESISTANCE FURNACE. APPLICATION man NOV. as, 1918.

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UNITED STATES PATENT OFFICE.

Jonas amen aim PAUL rnanco s saaaomor LYON, amen.

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To all whom it ma hat we, Jonas SIMON, of

Be it known t Lyon, France,.'and PAUL FnANgois SARRON, o Lyon, France, citizens of the French Republic, have invented acertain new and useful Improvement in Electric Resistance- Furnaces, of which the following is a specification. v

The invention relates to apparatus for producing in general changes of physical condition or endothermic chemical reactions used in industry, such bein eifected by means of. a continuous eircu ation of hot ases forming a 0 Ie, the gases being eated by means 0 an electric furnace. Examples ofthe a plication of .the invention to an electric ast furnace, to a fur nace for calcining carbonates, and to a gas enerator employing the carbonic acid of t e carbonates, will be hereinafter described.

In the rocess of operating the improved furnace t e provision of the necessary calories is effected by means of a suitable gas or gaseous mixture, which we call .the cyclic as, which gas is previous] brought to the eslred temperature, and w ich, after having fiiya nsmitted its heat to the materials to be treated, is again heated, and employed for a fresh addition o'rf calories to the materials, this cycle of operations 'being indefinitely repeated. In the case where the 1 treatment of the materials causes the disengageinent of a gas, the latter mixes with the cyclic s, and the volume of gasi'tlius obtained 1S collected at its issue from the furtrace, the amount of gas which is to be again used-in the cycle is abstracted and the remaining gas is available for any use.

In the accompanying drawing Figures 1 and 2 represent a portion ofa blast furnace, {which is of similar construction to a. blast urnace heated ,with coke or charcoal, and'a roup, of elect ic gas heaters associated t erewith. q

Fig. 1 is a vertical section through line '1--1 of Fig. 2, and shows the crucible, the twyersiind a resistance furnace for heating the cyclic gas, a Fig. 2 is a horizontal section on line 22 ofFignL i Figs. 3 and 4 show a furnace for calc ning carbonates. I

Fig. 3 is a sectional elevation on the line of Fig.4, and

Specification of Letters lateiit.

Application filed November 18, 1918. Serial No. 283,858.

Patented Mar. 23, 1 920.

F Figs. 4 is 1 section on the line 44 of n the apparatus shown in Figs. 1 and 2 the twyers 5 are of a special type, because they are to irgec't a at'a tem statute of about 1,800" whifd in the or inary blast furnaces, the air injected is only at a tein perature of 700 or 800 C. The metal tgart 6 is similar to that of the ordinary greater diameter, allowing the introduction of a highly refractory protecting lining 7 made of a material such ascarborundum or cast quartz. The metal part being cooled. is itself in the usual manner, this lining somewhat cooled, which .insures its lasting a long time. These twyers are each provided with a flange 8, keyed on the flange '9 of the tube' 10 of the. resistance furnace This furnace is formed of an outer est furnace twyers, but they have an orifice of F is itself lined with a.

by casting at the time of its manufacture and connecting the upper chamber 18,an

the lower chamber 19 through the arch 155 the latter chamber is connected, by means of the pipe 20, to the conduit 21', the pipe 22 of which is provided with a suitable sliding valve 23. The whole installation also comprises, as in the ordinary "blast fur naces, a blower, gas-inlets at the furnace top, apparatuses for suitable recuperators.

The working of this electrical furnaceis similar to that of theo'rdinary blast fur naces the loading of the materials is efi'ected in the same manner, but the amount of carbon introduced into the same is only 5 that required for the reduction of the oxi and of a part of the carbonic acid, since the heat re ui'red for the various reactions and for the usion of the dross is sup lied by the cyclic gas. The latter, coming mm the repurifying the gases and cuperators through the conduit passes ucts, etc.)

After havingjn its rising course transferred its calories to the materials to be treated,

while causing the usual reactionsand alter ations of physical condition, itreaches the furnace-top mixed with the gas arisin from,

the reactions: the gaseous mass thus ormed then passes through thepuri'fying appa' ratuses and the amoun of the eye ic gas constitutm is then suc ed out bythe ventilator and riven back into the recu raters, whichih'ave been previously hea' by the combustion of thegas arisin from previous reactions the burnt gases ing collected while still hot in order to serve for dossicatin the materials which are to compose the c arge. The uantity of calories dis; charged y t the reactions can be more or Jess mcreas by enrichin this'gas by means of gas or fuels of high calorific capacit (gases from coking ovens heavy oils, p'etro iferous prodln this case the refractory masonry of the recuperatorsis. constructed for the temperatures required to be reached. By this method the cyclic gas can be brou ht to a very high temperature, which a ows of expendi'n less electric energy in the superheaters. n all cases, in view of producing'a raplid ,superheating of the cgaclic gas, the super to a mperature distinctly higher than t at which the gas is to have when it passes into the crucible.

The principal advantages obtained by this electric furnace are as follows (a) Consumption of carbon reduced to that necesa'ry or the reduction of the ore and a portion of the carbonic acid.

(b) Consum tion of electric energ less than that of the known electric bl furnaces, owing to the utilization of the gas from the reactions (c) Possibility of treating large quantities of ore as in ordina blast furnaces.

(d) Practically comp ete absence. of ni-' i the interior of almost all known electric blast furnaces, and consequently I of the defacts which they produce, such as zones of.

excessive temperature, contact with the materials to be treated, enormous consumption etc. l I v Co; plate independence of the blast fu nace properfrom the electric apparatus,

allowing an ordinary blast furnace to be" easily transformed into an electric blast furnace by the simple addition of superheaters and special twyers.

(9) Constitution of the fusion bed as in 'tlic current to pass tfiro be com ustion of-the gas from eaters are broii ht ordinary blast furnaces, that isto say, with out previous mechanical treatment of the materials, the latter not rectuiring the elecu them.

(it) Easy regulation 0 the working of thefurnace by actin on the intensity 0 the current in the super eaters or on the speed of the c clic'g (i) ossibi 'ity of correcting, according to requirementmthe composition of the cyclic gas, by insulating with the latter carbonated power 0 the gas;

in the-apparatus shown in'Figs. 3 and 4,

roducts ca able of increasing the reduc- P 5 v g for calcining carbonates the material to be treated is fed'nto the i urnace a by means of the known cup and con device which provides air-tightness of t e furnace at its upper part. g a

his air-tightness is secured in the lower part by means of the door 0 arranged below the rati d. The cyclic gas, sucked in by t "cent on pump 0, passes into the conduit f, then into the partitioned recuperator g, arranged so as to absorb the greater part ofthe calories which the calcined materials ossess: the gas is heatedjin passi through t, and passes through the pipes]: evel with which are tubes "0 smelte quartz s" cmbedded in a mass of pulverulent substance 7',

crease by the carbonic acid proceeding from the deco tion of this carbonate;

8 where the dust theredis do sited. like lieight of thefu m aee; from th tion of the calories supplied by the cyclic the top 1s that which'allowsthe best utilize ,the smelted quartz tubes n, where its heating Ill) and iscollected "the furnace-top g, by the suctiorr pipe 17, which 'conveysit to the filter s. The whole seous mass is suclred rom the filter a s which 18 t0 the excess of avai the pipe t provided with a regulating va a and passes to a gas receiver not illustrated whichis keptconstantlyin suction. There it is collected for the tang: d. s a

V e calcined materials descend gradually at each draw and surround the regenerator g, to which they yield the greater part of y y the suction appara .tus e: .the amo'unt of o return in the cycle'lpasses mto the conduit f. able gas pass} throulgh industrial use con-- J the calories that they possess, so that, when they arrive in the hopper carryin the grat-' ng d, they are nearly cooled. 'he drawengs are made as frequent-l as sible, takmg care to stop the arriva of t e cyclic gas during these operations, in order to prevent reentrance of air, which would intro duce nitrogen into the gaseous current. If it is desired to dispense with regenerating the calories possessed by the calcined product, the regenerator can be omitted, and the height of the lower part of the furnace diminished.

The principal advantages this rocess are as follows:- W

(a As the furnace does not contain solid fuel, there are no cinder-s, whereby a very pure product may be obtained, and'caking 1s avoided.

(b) Recuperation of carbonic acid capable of being employed for any industrial use, after having, or not/having, been freed from the vapor which it may contain.

(a) Great care in regulating the tempera ture of the furnace enabling tion to be obtained. n

(d) The gaseous movement, due to the suction produced in the furnace, facilitates the disengagement of the carbonic .acid from the carbonates, the tension of dissociation being much less than that which would produce the re-combination of the carbonic acid with the lime.

The process is also applicable to a type of gas generator constructed and working in the same manner as the calcining furnace above described. However, the charges, instead of being only composed of the carbonate to be treated, comprise successive layers of carbonates and of carbonated products (any combustible bodies, even of bad quality, etc.) The gas arising from the reaetions started by the calorific addition of the cyclic gas, is then a mixture of carbonic acid, carbon monoxid, and also of hydro carbons, if'the carbonated product emp oyed contains the same. As 1n the preceding cases, the quantity of gas necessary for the cycle is previously abstracted from the gas eous mass obtained and brought in electric heating apparatuses similar to those previpresented by a regular acouslydescribed,'to the most suitable temperature for obtaining the best ratio The advantages presented by this gas generator are as follows:

(o) Utilization of a portion ofthe carbon of the carbonic ,acid of the carbonates.

(b) Utilization of a large number of carbonated products hitherto difficult or even impossible to utilize industrially {bad fuel, waste, etc.) I

(0) Production of a combustible gas free firom nitrogen.

What we claim as our invention and desire to secure-by Letters Patent of the United States is 1. In a. paratus for the purpose set forth the combination of a furnace chamber, a gas heating chamber having'a inlet, a twyer connecting saidgas heating chamber to said furnace chamber, tubes of cast quartz in said gas heatin chamber in the path of r the gas between said inlet and said twyer, a

pulverulent electric resistance incasing said tubes and composed of carborundum and graphite, and electrodes for passing; electric current through said resistance.

2. In apparatus for the purpose set forth the combination of an. air-tight furnace chamber, a heat recuperator at the base of said chamber, means for admitting gas to said 'recup'erator, a gas heating chamber, means for conducting gas from said re' cuperator to said heating chamber, tubes of cast quartz in said gas heating chamber, in the path of the gas, a pulverulent electric resistance incasing said tubes and composed of carborundum and graphite, electrodes for passing electric current through said resistance, a gas filter, and gas conduits connecting said filter to said recuperator and to the upper part of said furnace chamber respectively.

In witness whereof we have signed this specification in the presence oi two witnesses.

JULES SIMON. PAUL FRANQOIS SARRON.

Witnesses:

JEAN GERMAIN, -MARIN VAGHON.

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