US1580469A

US1580469A - Apparatus for the manufacture of earth metals

Info

Publication number: US1580469A
Application number: US746149A
Authority: US
Inventors: Dolter Henri
Original assignee: Individual
Current assignee: Individual
Priority date: 1924-09-17
Filing date: 1924-10-27
Publication date: 1926-04-13
Anticipated expiration: 1943-04-13
Also published as: FR599844A; GB240163A; DE447687C

Description

.April 13' ,'1926.

- H. DOLTER APPARATUS FOR THE MANUEACTURE oF EARTH METALS Filed Oct. 27

v A IIHHMNIH I April 13 1926. 1,580,469 H. DOLTER APPARATUS Fon THE MANUFACTURE oF EARTH'METALS Filed ot..27, 1 924 's sheets-sneu 2 April 13, 192s. `1,580,469

- H. DOLTER APPARATUS FOR THE MANUFACTRE- OF EARTH METALS Filed oct. 27, 1924 s sheets-shed s plates covering the tank ratus resides in that Patented Apr. 13, 1926 Pari-:Nry orrica.

HENRI DOLTER, OF LIMOGES, FRANCE.

APPARATUS FOB THE MANUFACTURE 0F EARTH METALS.

Application tiled October 27, 1924. Serial No. 746,149.

Metals, of which the following is a specifi-- cation.

The present invention has for its object an apparatus for the manufacture of earth metals and articularly ada )ted for carrying outthe improved metho of electrolytic manufacture ot said metals which consists in melting the electrolyte within the electroic tank and maintaining the saidelectrote in the liquid state, by means of gas raiators and preferably nameless combustion gas radiators, immersed within the electroyte.

One advantage of the use of my new appathe electric current is now yused solely to decompose the already melted electrolyte, whereby I obtain a great econom in electric power, which considerably re uces the cost of the metal.

A further feature of my improved appara` tus consists in that the electrolytic tank forming part of the apparatus, has a low electric resistance, whic i is possible since no Joule e'ect for heating the electrolyte and melt-ing the same is now necessary, and which permits of connecting in series a greater number of tanks than is admissible with the known apparatus, and hence of employin electric generators of usual construction an working normally at usual voltage.

The appended drawings show by way of exam le an embodiment of the apparatus accor ino to the invention and particularly ada ted or the manufacture of aluminium.

ig. 1 is a plan view of the apparatus, the

being removed.

Fig. 2 is a cross section on the line 242, Fic. 1.

Fig. 3 is a longitudinal section of the tank on the line 33, Fig. i.

Fig. 4 is a diagrammatic plan view ot a plant consisting of'a plurality according to the said invention.

The apparatus,'or eleotrolytic tank, com prises a metallic tank i. which is strengthcned by outer iron fittings 2 and is line with a good electric conducting substance 3 which preferably consists of bricks of coniprcssed coal or pretroleum coke and the faces ot apparatus whereof are plunished alter baking. Said bricks are jointed by means of a liquid mortai' oi thc suine material made up with glucose and ground into an impalpablc powder. In certain cases it may prove advantageous to cover the parts ot` the said lining which are not to enter into Contact with the electrol te withv a metallic coating, for instance of t ie same metal than that produced in the tank, of an electrolytic deposit or obtained by spraying pulverized metal by means of any known apparatus such as a Schopp pistol. But in the particular case of the production vof aluminium, this layer is not required.

The resulting tank will form an excellent conducting mass and it is connected to negative pole of the source of current. The tank and its lining are electrically insulated from earth by insulating supports l made ot i any suitable substance.

The apparatus comprises also gas radiators designed for heating the electrolyteand melting the same within the tank; said radiators com rise one, two or a greater number of meta lic tubes 5, for exam le of steel or nickel, extending longitudinally through the tank and Ldisposed in recesses 6 formed in the' conducting lining of the tank. Said tubes are electrically connected to the tank 1, i. e., to the cathode, in order to obviate any difference of potential between the radiators and the inner lining of the tank, whereby all chemical action upon the tubes will be avoided. For this purpose, the said tubes are immersed in a mass of melted aluminium 7 filling each of the recesses 6, said mass being for exam le obtained during the first operation per ormed in the tank and consisting ottheportion of melted metal which is situated below the inlet 8 of the channel 9 for pourin the metal, said channel being nermally c osed by a carbon plug 35.

The above described means for conuectin the radiator tubes to the electrolytic tan;

is found to be particularly advantageous in the manufacture of aluminium. Butl it is obvious that the tubes may be connected to the cathode in any'other suitable manner; for exam le the various radiator tubes may be secure or suspended to a removable med tallic cross-piece carried by the tank, the

saine being directly electrically connected to the negative pole of the source of current or to the walls ofthe tank. ln this event, in

or of copper, said layer being formed thei " providing for the heating of order to avoid all oxidation and consequent destruction of the said tubes,y these latter must be covered with a layer of the same metal which is produced in the tank, aluminium in the present case, said layerbeing formed of an electrolytic deposit or obtained by spraying pulverized metal by any known suitable means.

The tubes 5 are filled with a granular and porous refractory substance as is usually employed in iameless combustion gas radiators.

The inlet end of each tube 5 is connected to a combustible gas supply pipe and to a compressed air pipe, but is electrically insulated therefrom, said connection being effected in the following manner.

The inlet of each tube 5 is connected by a flange 10 to a socket/11 into which open a branch pipe 12, of the gas supply main pipe and a branch pipe 13 of the air main pipe. Said branch pipe 12 is connected to the socket 11 by an electrically insulating section of pipe 111 (e. g., of porcelain). The compressed air branch pipe 13 is connected to the socket l1 by an insulating section 15 and a pipe 16 which is surrounded for a part of its length by a casing 17 which communicates, through the medium of a three-way priming cock 18, with the burnt gas outlet end of a second tube 5 adjacent the inlet end under consideration and situated at the same side of the apparatus. The casing or jacket 17 'thus constitutes a heat exchanger the compressed air before the latter is mixed with the combustible gas in each of the sockets 11. The casing 17 is also connected to the main exhaust pipe of the plant by an insulating section 19 and a branch element 36. In this manner, the set of radiator tubes 5, connected to the cathode, is well insulated from the outer piping of the plant. It will be seen in the drawing that, due to this arrangement, the apparatus comprises at each end like connectionsof the tubes 5 with the gas and the compressed air supply pipes and with the exhaust pipes and that the gases are circulated in opposite directions in any two adjacent tubes, according to the

arrows

28 and 29.

Although the radiators shown in the drawing consist of straight metallic tubes, it -is obvious that the tubes may be given any other suitable shape, and may be made of any other suitable substance having a good heat-conduction, for example graphite,

alumina or silica.

The anode which is immersed in the tank comprises one or more carbon blocks 20, each having imbedded therein a metal sus` pension rod 21. The upper part of each rod forms a rack 22, or is provided with a screw, said rack or screw being operated in any known manner, either by hand or Vby .lum `may be constituted series for instance forty apparatus suc as 1,5so,aca

means of a small electric motor, so that it may be raised or lowered-automatically or not-according to the electric resistance of the said tank. The said electrode is connected to the positive pole of the source of current.

The tank may be covered by suitable plates 23 which are for example of carbon, caving however a suiicient passage way for the anode. The saidplates are provided with apertures 24 which are closed during the initial melting period by plugs provided with handles, and through which suitable quantities of salts and oxides are supplied from time to time; said apertures also provide for theescape of the gases-produced in the tank.

Each operation carried out in the above lescribed apparatus is performed as folows: v

The salts or oxides constituting the electrolyte, i. e., a mixture of alumina and cryolite are first introduced into the tank; the gas supply valves 25 of the radiators are opened, and the three-way cocks 18 are turned so as to connect the interior of the tubes 5 directl to the atmosphere through the medium ofythe nozzles. 26 of the cocks 18. The gas issuing from said nozzles 264 is thus ignited and the air supply cocks 27 alumina are supplied according as the alu# mina becomes dissolved, and when the bath has attained the normal composition, the electric current is sent into the tank; further quantities of alumina are supplied according as the aluminium is deposited.

As above indicated, the position of the anode, according to the resistance of the whole apparatus (i. e., tank and bath), can be regulated automatically in the known manner by means of an electric motor controlled by a relay.

At stated intervals, the metal in the tank,

is cast by removing the carbon plug 35 normally closing the channel 9. I

Inasmuch as the tank and its lining are so constructed as to have but a low electricl resistance, and on the other hand the E. M. F.

required for the decomposition of the.

alumina varies from 28 to 3 volts, a complete plant for the manufacture of aluminby connecting in herein described, thus allowing the use of known types of electric generators working normally at thc usual volts.

A plant of this nature is shown diagrammatically in Fig. 4. and said figure shows that i'or each of the successive apparatus 30, the anode is connected to the tank of the succeeding apparatus, the anode ot the first apparatus bein(r alone connected to the ositive terminal ot the source of current, whilst the tank ot the last apparatus is connected to the corresponding negative terminal. For each apparatus, the respective pipes l2, 13 and 36 for the gas and the compressed air supply and the exhaustof the combustion gases, are connected to the respective lnaiii pipes of the

plant

32, 83 and 34 forl the gas and the compressed air su ply and for the discharge. y,

viously, the said invention is not limited to the use ot the above-mentioned details of construction of the apparatus, `these being susceptible of all desired modifications Without departing from the spirit ot the invention.

Having now described my invention, I declare that what I claim as ner. and desire to secure by Letters Patent is:

1. In an electrolytic tank for the manufacture of earth metals, the combination of tubes extending throu h the tank, means for supplying a combusti le gas to said tubes, means for supplying compressed air to said tubes anda Vrraniilar and porous refractory r substance within said tubes, whereby a lameless combustion is obtained.

2. In an electrolytic tank for the manufacture of earth metals, the .combination of tubes extending through the tank, means for electrically connecting. said tubes to the cathode of said tank, means for supplying a combustible vgas to said tubes, means for supplying com ressed air to said tubes, and a granular am porous refractory substance within said tubes, whereby a nameless com'- bustion is obtained.

3. In' an electrolytic tank for the manufacture of earth metals, the combination of tubes extending through the tank, means for electrically connecting said tubes to the cathode of said tank, a layer of the saine metal as that produced in the tank covering said tubes, ,means for supplying a coinbustible gas to'said tubes, means for supplying compressed air to said tubes and a granular and porous refractory substance Within said tubes, whereby a nameless combustion is obtained.

s". In an electrolytic tank for the manufacture of earth metals, the combination et tubes extending through the tank` means for electrically connecting said tubes to the cathode of said tank, a layer ot the same inetal as that produced in the tank covering said tubes, pipes for supplying a conivoltage of 110 to 12() bustible gas to said tubes, pipes for supplying compressed air to said tubes, exhaust pi es for discharging the burnt gases from said tubes, electrically insulating members for connecting said pipes to said tubes and a granular and porous refractory substance Within said tubes, whereby a Ilamcless couibust-ion is obtained. l

5; In an electrolytie tank for the manufacture of earth metals, the combination et tubes extending through the tank, means for electrically connecting said tubes to the cathode of said tank, a layer ot the same metal as that produced in the tank covering said tubes, pipes for supplying a combustible gas Ito said tubes, pipes for supplying compressed air -to said tubes, exaust pipes 'for discharging the burnt gases from said tubes, the exhaust pipe o one tube surrounding a portion of the air supply ipe for an adjacent tube, electricallyinsu ating members for connecting said pipes `to said tubes and a granular and porous refractory substance Within said tubes, whereby a flameless 'combustion is obtained. 6. An electrolytic tank for the manufacture of earth metals comprisin in combination a metal tank, an 'inner dining of carbon bricks for said together with said lining constituting the cathode of the a paraus, tubes extending through the tank elow the normal level of the electrolyte in said tank, means for electrically connecting said tubes to said tank,` means for supplying a combustible gas to said tubes, means for supplying compressed air to said tubes and a granular and porous refractory substance within said tubes, whereby a fiameless combustion is obtained.

7. An electrolytic tank forthe manufacture of earth metals comprising in combination: a metal tank, an inner lining of carbon bricks for said tank, said bricks having all their faces planished, the tank together With said lining constituting the cathode of the apparatus, a layer of the same metal as that produced in the tank coating the portions of. the tank walls above the normal level of the electrolyte ir. said tank, tubes extending through the tank below the normal level ot means for electrically connecting said tubes to said tank, means for supplying a combustible gas to said tubes, means for sup- `plyin compressed air to saidtubes and a granu ar and porous refractory substance Within said tubes, whereby a flameless conibustion is obtained.

8. An electrolytic tank ture of anl aluminium comprising in com- '.bination: a metal tank, an inner lining ot carbon bricks for said tanks, said bricks having all their faces planished, the tank tank, said bricks I having all their faces planished, the tank` for the manufacllO the electrolyte in said tank,

togetherwith said lining constituting the cathode of the apparatus, channels formed in the bottom Wall 'of said inner lining, cast aluminium filling said channels, tubes eX- 5 tending through said channels and imbedded Within said cast aluminium, means for supplying a combustible gas to said tubes, means for supplying compressed air to said tubes and a granularfand porous refractory substance within said tubes, whereby a ilameless combustion is obtained. In testimony whereof I have signed my name to this specification.

V HENRI DOLTER.