US2900319A - Dissociable gaseous hydrocarbon anode for igneous electrolytic furnaces, particularly for aluminum-making - Google Patents

Description

Aug. 18, 1959 FERRAND 2,900,319

DISSOCIABLE GASEOUS HYDROCARBON ANODE FOR IGNEOUS ELECTROLYTIC FURNACES, PARTICULARLY FOR ALUMlNUM MAKING Filed Oct. 14, 1957 5 Sheets-Sheet 1- 2,900,319 RBON ANODE FOR IGNEOUS ELECTROLYTIC FURNACES, PARTICULARLY FOR ALUMINUMMAKING L. FERRAND Aug. 18, 1959 DISSOCIABLE GASEOUS HYDROCA 3 Sheets-Sheet 2 .Filed Oct. 14, 1957 Aug. 18, 1959 FERRAND 2,900,319

DISSQCIABLE GASEOUS HYDROCARBON ANODE FOR IGNEOUS ELECTROLYTIC FURNACES, PARTICULARLY FOR ALUMINUM-MAKING Filed Oct. 14, 1957 5 Sheets-Sheet 3 Unite States DISSOCIABLE GASEOUS HYDROCARBON ANODE FOR IGNEOUS ELECTROLYTIC FURNACES, PARTICULARLY FOR ALUMINUM-MAKING Louis Ferrand, Paris, France Application October 14, 1957, Serial No. 690,060

Claims priority, application France October 19, 1956 7 Claims. (Cl. 204-284) This invention relates to novel arrangements applied to the anodes of the dissociable gaseous hydrocarbon type utilized for the continuous and automatic operation of igneous electrolytic furnaces, notably for manufacturing aluminum.

The US. Patent No. 2,593,741, granted on April 22, 1952 to the applicant recites with reference to its second exemplary embodiment illustrated in Figs. 3 and 4 of the drawings the use of relatively narrow passages formed through the anode mass for introducing in the molten electrolyte, in the specific case of aluminum manufacture, an intimate mixture of pulverulent alumina with a dissociable gaseous hydrocarbon, the output of this mixture fed through the anode being such that the atomic carbon resulting from its dissociation at the electrolyzing temperature is effective in the anodic oxidation reactions as a substitute for the carbon of the supporting mass.

This dissociation, in the specific case of methane, takes place according to the following reaction:

wherein the variation in free energy is positive for temperatures close to the room temperature, zero at 850 C. and negative thereabove, so that the dissociation of one molecule of methane at the temperature required for electrolyzing aluminum will absorb about 22,000 calories.

Extensive research work demonstrated that it was preferable to prevent the methane gas from entering-even through very narrow passages-the interpolar gap and being dissociated therein, but that on the contrary this dissociation should preferably be allowed to take place within the very heart of this anode mass, that is in its lower strata.

These works also made it possible to ascertain the mechanism of this dissociation and the critical distance to be maintained between the methane delivery point and the anode surface in view of enabling the chemically pure carbon issuing from this dissociation to agglomerate on the anode surface in the form of a perfectly adherent spongy layer constantly renewed as it undergoes the anodic oxidation.

Moreover, these experiments proved that specific arrangements must be provided to prevent the hydrogen resulting from this dissociation from contacting the electrolytic bath, for the water vapor resulting from its anodic oxidation might produce at least partially the decomposition of one of the four component elements of the bath, that is, the aluminum fluoride, as the decomposition reactions concerning the other sodium and calcium fluoride are thermodynamically not feasible.

In view of the foregoing it is the object of this invention to provide an anode of the type adapted to be fed with dissociable gaseous hydrocarbon type for effecting an igneous electrolysis, which is characterized in that the carbon resulting from the dissociation of the gaseous hydrocarbon will agglomerate at the end of the anode surface in the form of a perfectly adherent spongy layer, and that the hydrogen released by this dissociation is prevented from leaking in the bath by the provision of adequate suction means.

To this end, the anode comprises a stationary metal casing closed at its upper end by a fluid-tight partition and containing the anode mass; through this wall and with the interposition of a plurality of gland packings extend one or more steel studs having an axial passage formed therein, adapted to be supplied with a gaseous hydrocarbon under pressure, these studs also acting both as means for supporting the anode mass and as lead-in terminals.

Moreover, the following dispositions are preferably resorted to:

Each stud is surrounded by a cylindrical metal sheath in which the level of the anode mass'is higher than at the outside.

These sheaths are slightly longer than said studs and shorter than the height of the metal casing.

The lower end portion of this anode mass is substantially concave and has a flat peripheral or marginal portion.

The volume defined by the stationary outer metal casing, by the horizontal sealing partition overlying it, by the outer surface of said metal sheaths and by the upper level of the anode mass is vacuumized through a duct connected to a suction device.

According to the present invention, the anode mass consists essentially of either a mixture of sintered rare earths having a sufficient electrical conductivity, such as tantalum oxide, or more simply a mixture of carbon paste the grain size of which--in the burned state-is calculated to impart a sufficient porosity to the supporting mass, either of these mixtures being enclosed according to known means in a stationary outer casing of square, rectangular or cylindrical shape.

If the selected supporting mass is a carbon paste, the latter will have its height limited to that currently provided for pre-burned anodes and be burned beforehand all along its height in the electrolytic furnace proper so that it will have an adequate porosity before the gaseous methane is fed thereto.

The above-described means will indisputably lead to a novel industrial result in that they make it possible to carry out the anodic reduction with the assistance of chemically pure carbon from the dissociation of a gaseous hydrocarbon without allowing the latter or the hydrogen resulting from its dissociation to penetrate the electrolyte and cause the decomposition, even to a limited extent, of one or several component elements of this electrolyte.

In order to afford a clearer understanding of this invention and of the manner in which the same may be carried out in the practice, reference will now be made to the accompanying drawings forming part of this specification and illustrating diagrammatically by way of example a few typical embodiments of the invention. In the drawings:

Figure 1 is a vertical section showing structural details of an anode constructed in accordance with the teachings of this invention.

Figure 2 is a plane View of the same'anode.

Figure 3 is a vertical fragmentary section showing on a larger scale the lower portion of theanode.

Figure 4 is an elevational View of an electrolytic furnace equipped with anodes according to a modified embodiment of the invention.

Figure 5 is a fragmentary vertical section showingthe furnace on a larger scale, and

Figure 6 is a view partly in horizontal section,. partly in plane view, showing the furnace equipped with the anodes of this invention, the section being taken upon the line VIVI ofFig. S.

According to a first embodiment of the invention which is illustrated in Figs. 1, 2 and 3 of the drawings, the anode mass or each of the anode masses ifa plurality of them are provided in the furnace has an elongated shape and the top of the outer metal casing 1 is closed in a fluidport the anode mass according to the known technique in view of permitting the vertical sliding displacement of this mass in the outer metal casing 1; of course, these studs 5 also act as current lead-in terminals and in the specific case of this invention they are adapted to supply the furnace with gaseous methane under a pressure P higher than the atmospheric pressure. Moreover, each stud 5 is surrounded by a cylindrical sheath 8 secured to the horizontal lid 6 and somewhat longer than the studs themselves so as to create around each stud a neutral zone free of any 'gas circulation.

The lower face of the supporting mass 2 proper is slightly concave as shown at 2:: except for a Hat outer peripheral or marginal portion 2b affording a sufiicient contact area between this mass and the conducting bottom of the furnace to permit the passage of current and, by the Joule effect, cause firstly the burning of the raw mass until it has a sufiicient porosity, and then the smelting of the bath. The upper level of this supporting mass is much higher at 9 than inside the sheaths so as to create a sufficient adherence between the studs 5 and the paste 12,

zmolten electrolyte 4 in which the supporting mass is immersed.

To this end, the free space surrounding the sheaths 8 is partly vacuumized by means of a pipe line 10 connected to a suitable suction device (not shown) operating at a pressure P lower than the atmospheric pressure.- The lower ends of these sheaths 8 (which, as already stated, are somewhat longer than the studs 5) form together a surface designated by the dotted line 8a in Figs. 1 and 3, substantially at an equal and very short distance from the lower concave surface 2a of the supporting mass, whereby the gaseous methane issuing from the lower ends of the studs 5 must necessarily flow along substantially downward paths in the sheaths 8 as its temperature rises until its dissociation begins, that is, when the gaseous stream enters the layer 3.

Finally, the outer metal casing 1 has fitted around its lower portion a frusto-conical hood 11 adapted, according to the known fashion, to collect the electrolysis gases formed above the carbonaceous layer 3 on account of the anodic oxidation at a pressure approximating the atmospheric pressure P,,.

The ratios of the pressures P and P to the pressure l will be determined presently in connection with the description of the mechanism by which the carbon layer 3 is formed and the residual gases resulting from the dissociation of the gaseous methane are discharged.

Now this descriptionwill bear:

Firstly, on the means to be used during the period in which the atomic carbon layer 3 is pre-formed when starting the electrolytic furnace;

Secondly, the means to be used when, as this atomic carbon layer has attained a sufficient thickness, the gasfed anode according to this invention begins to operate normally.

(A) Pre-formation period Fig. 3 illustrates in section and on a larger scale the lower end of one of the hollow steel studs 5 surrounded by its circular sheath 8 and formed with at least one orifice 5a through which the gaseous methane under the pressure P is fed to the furnace. The distance X measured between the lower end 5b of these studs 5 and the lower face 2a of the supporting mass is determined by construction according to the teachings of experience, so that, with due consideration for the porosity of the supporting mass utilized and for the velocity at which the gaseous methane is fed (this velocity being obviously.

subordinate to the pressure P the time of travel of the methane fed to the furnace, as measured from the outlet end of the hollow stud 5 to the lower face 5a of the supporting mass, enables the methane to attain the temperature of the electrolytic bath proper, that is, about 950 C., at which the dissociation according to the reaction CH =C+2H, in the case of gaseous methane, is

practically instantaneous.-

During the pre-formation period the methane output fed through the anode must be greater than the output required under normal operating conditions in order to permit only the anodic oxidation reactions according to the strength of the electrolyser, so that the weight of carbon black deriving from the methane gas dissociation be substantially greater than that oxidised as a consequence of the electrolysis of alumina, and that a re- .serve of carbon black represented by the layer 2a, 3a

-carbonaceous layer 3 may take place beforehand either in a special electrolytic furnace fed with alternating current, so that this pre-formation will be faster and more economical, or in a neutral atmosphere maintained in a furnace equipped with heating resistors providing a temperature of about 950 C.

(B) Normal operation period When the carbon layer 3 has attained a sufficient thickness the free spaces surrounding the sheaths 8 are vacuumized through the pipe 10 to a negative pressure P of such value that the hydrogen released by the dissociation of the methane cannot penetrate in the bath but is caused to travel by suction around the sheaths 8 as indicated by the arrows in Fig. 3.

Each bubble of hydrogen is released during the dissociation at the pressure P at which the gaseous methane was introduced in the supporting mass minus the loss of pressure J1 resulting from the travel of this bubble from the outlet end of stud 5 to the point where its builds up, but only within the layer 3 provided that the distance X was correctly calculated.

around the sheaths 8 above the level 9:: of the supporting mass, and 11 the loss of pressure resulting from the travel of the residual gases through the supporting mass 2 above the sheaths 8, it is evident that each hydrogen bubble thus formed will not penetrate the liquid bath but will be sucked up around the sheaths 8 if the pressure P +h is slightly lower than the surface pressure existing at the lower face 3a contacting the liquid bath, that is, the atmospheric pressure plus the pressure corresponding to the height or head of the liquid bath in which the supporting mass is immersed, this last-mentioned pressure being about 1.06 kilograms in the specific case of the manufacture of aluminum electrolysis.

On the other hand, the residual pressure P h is obviously equal to the pressure P +h at the time the hydrogen bubble is released.

These explanations are summarized by the two relations:

wherein the Relation 2 expresses the limit value which must not be overstepped by P in order to prevent the residual gases from being expelled with the electrolysis gases.

On the other hand, it is evident that when this pressure P becomes lower than this limit, it may happen that one fraction of the electrolysis gases themselves be sucked up around the sheaths 8 in admixture with the residual gases, this condition being preferable to the reverse situation set forth in the preceding paragraph.

As the critical distance X (Fig. 3) was calculated on a reduced-scale model to the value necessary and suificient to cause the dissociation of the methane to occur in the preformed carbon layer 3, it will be relatively easy to determine the pressures P and P2 to be used by resorting to known means of which only the principle will be reminded hereafter.

In the first place it will be necessary to measure separately the volume of input gaseous methane and the volume of output residual gas; if a complete dissociation is obtained the second volume will be twice the former, in the specific case of methane, the input volume being subordinate to the desired intensity of the electrolyser. The electrolytic gas output must also be calculated.

In the second place, by assaying the residual gases de livered through the suction pipe and the electrolytic gas output issuing from the hood 11, it will be possible to check the correct adjustment of the pressures P and P according as whether hydrogen is present in the electrolytic gases (which is detrimental), or electrolytic gases (CO-I-CO is present in the residual gases (which is preferable).

Finally, according to these output measurements and gas assays, a comparison between the weight of carbon supplied with the input methane and the weight of carbon issuing with the electrolytic gases will indicate Whether the input of methane is correct or not. If the weight of carbon is greater at the outlet than at the inlet, it means that this input is insufiicient and that the anodic oxidation takes place partly at the expenses of the carbon reserve of the layer 3. If, on the contrary, the weight of input carbon is greater than that of output carbon, the logical inference is that the input of methane is too high, and in this case the only drawback will be an increase in the thickness of the reserve layer 3 and consequently a reduction in the inter-pole gap, an inconvenience that can be easily avoided by a proper voltage adjustment.

According to another form of embodiment illustrated in Figs. 4, 5 and 6 of the drawings wherein the general constructional arrangements provided in Patent No. 2,- 825,690 are described, the supporting mass consists of three concentric annular layers A, B and C of approximately equal section, enclosed between a stationary cylindrical metal casing 13 and an axial funnel 14 of stainless steel, these layers being separated from one another by cylindrical metal partitions 15 also concentric to the funnel 14, each layer being divided into approximately equal sectors by radial partitions 16 connecting these different concentric cylindrical casings with one another.

Each concentric annular layer, if considered as being developed to a fiat surface to facilitate the understanding, is arranged like each of the rectangular anodic masses of elongated form which are illustrated in Fig. 1 according to the first form of embodiment of the invention. The layers are definitely independent of one another and each of them is provided, as in the first form of embodiment, with separate means for permitting its vertical dis- 6 placement, other adjustment means for setting the current strengthto values 1,, I 1 adequately determined for each layer, separate pipe lines 17a, 17b, for supplying each layer with gaseous methane, and adjustment means (not shown) for regulating the delivery of meth ane to values D D D proportional to the aforesaid current strengths 1,, I I;,, other separate pipe lines being provided for discharging the residual gases resulting from the dissociation of the methane, as shown at 18a, 18b, 180. The only member common to the three concentric layers is the axial funnel 114 through which the electrolytic gases are expelled, thisfunnel being also. provided under its lid with a heat recuperator comprising vertical tubes 19 and having suspended therefrom a highly-polished parabolic stainless steel mirror 20 according to the means described in the aforesaid patent.

On the other hand, in this form of embodiment the reservoirs for the supply of fluidified alumina which were provided in the aforesaid patent are dispensed with, this alumina being introduced directly through the free surface of the bath according to known means. Similarly, the holes formed in the intermediate third of the axial funnel are also omitted, since it is not necessary to renew the carbon-paste supporting mass burned at the start.

In addition, each of the concentric layers A, B, C described hereabove is provided, according to its. thickness, with one or two rows of hollow fixation bolts. 21 secured for each of these layers on either side of a separate ring member 28, these bolts being surrounded by sheaths 22 having their ends positioned within a short distance of the inner surface of each layer, this surface having in the radial direction the slightly concave shape described hereabove and intended to improve the adherence and the formation of the pre-formed carbon black layer.

Of course, the outer metal casing 13, the axial funnel 14 and the intermediate cylindrical partitions 15 are interconnected in a fluid-tight manner at their upper portions by means of a horizontal partition 23 on which are secured the cylindrical sheaths 22 through which the aforesaid hollow bolts 21 extend with the interposition of gland packings 24, each of the closed annular gaps A, B, C thus formed being provided with separate suction ducts 18a, 1812, and 180.

In each annular space A, B or C the level of the carbonaceous mass 25a is much lower than the level 25 of the same mass but inside the sheath 22 in order to permit the venting of the residual gases from the dissociation of the gaseous methane under the negative pres sure P while a pressure P higher than the atmospheric pressure obtains in these sheaths 22 so that the gaseous methane can flow through the carbon black layer 24 where its dissociation takes place.

According to the means described hereinabove a com parison between the outputs, complemented bya quantitative analysis between the gaseous methane delivered by the studs of each layer and the residual gases restituted by each of these layers may be effected for each of the concentric layers A, B and C, in order to permit the proper adjustment, for each layer, of the respective values of the aforesaid pressures P and'P However, no specific comparison can be made in view of checking whether the weight of carbon introduced with the methane is actually equal to the weight of carbon delivered with the electrolytic gases for each layer A, B, C under permanent operating conditions. As the whole of the electrolytic gases resulting from the anodic oxidation of the carbon black surface layer is vented through the axial funnel 14, only a global comparison will permit to ascertain Whether neither a fresh supply nor an extraction from the carbon black layer 26 taken as a whole is made.

To simplify the procedure, if the upper portions of the intermediate cylindrical partitions 15 and the axial fun nel 14 are perforated the vacuum created in this axial funnel by its separate duct 27, provided that it is properly adjusted, may be sufficient to simultaneously direct the residual gases through the carbonaceous mass surround ing the sheaths 22 and discharging these gases in admixture with the electrolysis gases, so that in this specific case the separate suction ducts 18a, 18b and 180 of the concentric layers A, B and C may be dispensed with.

Thus, a mixture of hydrogen, carbon monoxide and carbon dioxide would be collected as if the dissociation had not taken place and the anodic oxidation had therefore been effected at the expenses of the gaseous methane itself according to either of the following two reactions, in the case contemplated herein:

It is known that these reactions occur secondarily in the cracking of methane (which is effected at 850 C.) so that the residual gases thus collected, in admixture with the electrolysis gases, may be treated as they actually are in the cracking of methane in view of extracting pure hydrogen intended for the synthesis of ammonia.

This final remark lays stress on the interest of the present invention consisting essentially in reducing the alumina by means of chemically pure carbon, this method necessarily producing pure metal, this carbon issuing from the dissociation of gaseous methane or any other adequate gaseous hydrocarbon, being however much more economical than any other pre-burned or self-burning oxidizable anodes manufactured from oil coke as is customary in this kind of electrolysis. Moreover, a gaseous mixture suitable for producing pure hydrogen for the manufacture of ammonia would be available by way of by-product.

What I claim is:

1. An anode for an electrolytic furnace, of the type adapted to be fed with dissociable gaseous hydrocarbon and immersed in the furnace electrolyte, which comprises a stationary metal casing consisting of a vertical cylinder open at the bottom, a fluid-tight horizontal plate closing the top of said metal casing, a porous anodic mass enclosed in said casing, metal studs disposed vertically in said casing and extending through said horizontal plate in a fluid-tight manner, said metal studs being formed with an axial passage adapted to supply at the lower end of said studs a gaseous hydrocarbon under pressure, said studs also serving as means for supporting the anodic mass and as current lead-in terminals, a cylindrical metal sheath secured to said horizontal plate and surrounding each of said studs, the level of the anodic mass in each sheath being considerably higher than that of the anodic mass included outside said sheaths, the length of said sheaths being slightly greater than that of said studs,

said porous anodic mass surrounding and extending below the lower open ends of said studs and sheaths.

2. An anode for an electrolytic furnace, of the type adapted to be fed with dissociable gaseous hydrocarbon and immersed in the furnace electrolyte, which comprises 3. An anode for an electrolytic furnace, of the type adapted to be fed with dissociable gaseous hydrocarbon and immersed in thefurnace electrolyte, which comprises a stationary metal casing consisting of a vertical cylinder open at the bottom, a fluid-tight horizontal plate closing the top of said metal casing, aporous anodic mass enclosed in said casing and having its lower face formed with a concave central portion and a fiat marginal portion, metal studs disposed vertically in said casing and extending through said horizontal plate, said metal studs being formed with an axial passage adapted to supply at the lower end of said studs a gaseous hydrocarbon under pressure, said studs also serving as means for supporting the anodic mass as current lead-in terminals, gland packings surrounding said studs in said fluid-tight horizontal plate, a cylindrical metal sheath secured to said horizontal plate and surrounding each of said studs, the level of the anodic mass in each sheath being considerably higher than that of the anodic mass included outside said sheaths, the length of said sheaths being slightly greater than that of said studs, said porous anodic mass surrounding and extending below the lower open ends of the studs and sheaths, the geometrical locus of the lower end of each sheath being a concave surface equally spaced from the concave central portion of the lower anodic surface.

4. An anode for an electrolytic furnace, of the type adapted to be fed with dissociable gaseous hydrocarbon and immersed in the furnace electrolyte, which comprises a stationary metal casing consisting of a vertical cylinder open at the bottom, a fluid-tight horizontal plate closing the top of said metal casing, a porous anodic mass enclosed in said casing and having its lower face formed with a concave central portion and a flat marginal portion, metal studs disposed vertically in said casing and extending through said horizontal plate, said metal studs being formed with an axial passage adapted to supply at the lower end of said studs a gaseous hydrocarbon under pressure, said studs also serving as means for supporting the anodic mass as current lead-in terminals, gland packings surrounding said studs in said fluid-tight horizontal plate, a cylindrical metal sheath secured to said horizontal plate and surrounding each of said studs, the level of the anodic mass in each sheath being considerably higher than that of the anodic mass included outside said sheaths, the length of said sheaths being slightly greater than that of said studs, said porous anodic mass surrounding and extending below the lower open ends of the studs and sheaths, a suction device and a duct connecting said a stationary metal casing consisting of a vertical cylinder open at the bottom, a fluid-tight horizontal plate closing the top of said metal casing, a porous anodic mass enclosed in said casing and having its lower face formed with a concave central portion and a flat marginal por tion, metal studs disposed vertically in said casing and extending through said horizontal plate, said metal studs being formed with an axial passage adapted to supply at the lower end of said studs a gaseous hydrocarbon under pressure, said studs also serving as means for supporting the anodic mass and as current lead-in terminals, gland packings surrounding said studs in said fluid-tight horizontal plate, a cylindrical metal sheath secured to said horizontal plate and surrounding each of said studs, the level of the anodic mass in each sheath being considerably higher than that of the anodic mass included outside said sheaths, the length of said sheaths being slightly greater than that of said studs, said porous anodic mass surrounding and extending below the lower open ends of said studs and sheaths.

suction device to the space defined by said stationary metal casing, said fluid-tight horizontal plate and the outer surface of said metal sheaths.

5. An anode for an electrolytic furnace, of the type adapted to be fed with dissociable gaseous hydrocarbon and immersed in the furnace electrolyte, which comprises a stationary metal casing consisting of a vertical cylinder open at the bottom, a fluid-tight horizontal plate closing the top of said metal casing, a porous anodic mass enclosed in said casing, coaxial cylindrical partitions in said casing a plurality of concentric annular layers in said anodic mass, radial partitions connecting said coaxial cylindrical partitions, each of said layers having a lower surface of toroidal shape which is slightly concave in the radial direction, the lower level of each layer increasing from the outside to the inside, an axial funnel extending through said central layer, metal studs disposed vertical ly in each of said layers and extending through said hori zontal plate, said metal studs being formed with an axial passage adapted to supply at the lower end of said studs a gaseous hydrocarbon under pressure, external supports of said studs acting as current lead-in terminals, gland V packings surrounding said studs in said fluid-tight horizontal plate, a cylindrical metal sheath secured to said horizontal plate and surrounding each of said studs, the level of the anodic mass in each sheath being considerably higher than that of the anodic mass included outside said sheaths, the length of said sheats being slightly greater than that of said studs, and the porous anodic mass in each layer surrounding and extending below the lower open ends of the studs and sheaths.

6. An anode for an electrolytic furnace as set forth in claim 5, comprising a suction device associated with each of said annular layers and a duct connecting each of said sunction devices to the free space defined by said fluid-tight horizontal plate, said coaxial cylindrical partitions, said casing and the upper level of the associated layer, whereby the pressure is so adjusted for each of said suction devices that the hydrogen issuing from the dissociation of the methane gas be drawn around the sheaths and will not penetrate the bath.

7. An anode for an electrolytic furnace as set forth in claim 5, comprising perforations provided in the upper portion of the intermediate cylindrical partitions above said anodic mass, perforations in said axial funnel above said anodic mass, and a suction device connected to said axial funnel, whereby the pressure is adjusted in said axial funnel to cause the hydrogen issuing from the dissociation of the methane gas to be drawn completely by this axial funnel while being mixed up with the electrolysis gases.

References Cited in the file of this patent UNITED STATES PATENTS

Claims (1)

1. AN ANODE FOR AN ELECTROLYTIC FURNACE, OF THE TYPE ADAPTED TO BE FED WITH DISSOCIABLE GASEOUS HYDROCARBON AND IMMERSED IN THE FURNACE ELECTROLYTE, WHICH COMPRISES A STATIONARY METAL CASING CONSISTING OF A VERTICAL CYLINDER OPEN AT THE BOTTOM, A FLUID-TIGHT HORIZONTAL PLATE CLOSING THE TOP OF SAID METAL CASING, A POROUS ANODIC MASS ENCLOSED IN SAID CASING, METAL STUDS DISPOSED VERTICALLY IN SAID CASING AND EXTENDING THROUGH SAID HORIZONTAL PLATE IN A FLUID-TIGHT MANNER, SAID METAL STUDS BEING FORMED WITH AN AXIAL PASSAGE ADAPTED TO SUPPLY AT THE LOWER END OF SAID STUDS A GASEOUS HYDROCARBON UNDER PRESSURE, SAID STUDS ALSO SERVING AS MEANS FOR SUPPORTING THE ANODIC MASS AND AS CURRENT LEAD-IN-TERMINALS, A CYLINDRICAL METAL SHEATH SECURED TO SAID HORIZONTAL PLATE AND SURROUNDING EACH OF SAID STUDS, THE LEVEL OF THE ANODIC MASS IN EACH SHEATH BEING CONSIDERABLY HIGHER THAN THAT OF THE ANODIC MASS INCLUDED OUTSIDE SAID SHEATHS, THE LENGTH OF SAID SHEATHS BEING SLIGHTLY GREATER THAN THAT OF SAID STUDS, SAID POROUS ANODIC MASS SURROUNDING AND EXTENDING BELOW THE LOWER OPEN ENDS OF SAID STUDS AND SHEATHS.

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