US655783A - Electrolytic apparatus for decomposing metallic salts. - Google Patents

Description

No. 655,783. Patented Aug. l4, I900.

C. KELLNER.

ELECTROLYTIC APPARATUS FOR DECOMPDSING METALLIC SALTS.

(Application filed Mar. 3, 1896.)

.(No Model.)

2 Sheeta Sheet Mummy.

No. 655,783. Patented Aug. l4, I900.

C. KELLNER. v ELECTROLYTIC APPARATUS FOR DECOMPDSINGMETALLIC SALT S. (Application filed Mar. 3, 189B.) (No Model.) 2 Sheets-Sheet 2.

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CARL KELLNER, OF VIENNA, AUSTRIA-HUNGARY.

ELECTROLYTIC APPARATUS FOR DECOMPOSING METALLIC SALTS.

SPECIFICATION forming part of Letters Patent No. 655,783, dated August 14;, 1900. Application filed March 3, 1896. $eria1 No. 581,641. (No model.)

To aZZ whom it may concern.-

Be it known that I, CARL KELLNER, a subject of the Emperor of Austria-Hungary, residing at Vienna, in the Province of Lower Austria, in the Empire of Austria-Hungary, have invented certain new and useful Improvements in Electrolytic Apparatus for Decom zerland, No. 9,232, dated October 23, 1894; in

Belgium, No. 112,396, dated October 23, 1894:, and in Italy, Reg. Gen. Vol. XXIX, No. 37,504, and Reg. Att. Vol. LXXIII, No. 324, dated December 31, 189%,) and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference beinghad to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification. 1

This invention has reference to an apparatus for the electrolysis of alkaline salts with the aid of a stationary mercury cathode, in which the amalgam formed by electrolytic action has its location changed from the decomposing-chamber, in which it is produced, to a combining-chamber, in which it is decomposed, and the cation combined with water, an acid, or other body by the shifting of a partition which is adapted to be moved to and fro in the mercury and serves to separate the two aforesaid chambers from each other. The partition is in this case made in the form of a bell closed at its lower edge by a mercury seal and inclosing the decomposing-chamber, so that the amalgam formed in the latter is caused by the shifting of the bell to have its location alternately on one side and on the other side of the bell without itself changing or moving its position, and is thus caused to gain access to and become situated in the combining-chamber, while the mercury on the other side of the partition, which was previously situated in the combining-chamber, effects in the decomposing-chamber the amalgamation of the metal that is being separated by the electrolytic decomposition of the electrolyte. In this way a considerable output can be obtained from the appa ratus with a comparatively-small quantity of mercury, because'both operations can take place simultaneously and uninterruptedly.

In the annexed drawings, Figure 1 is a vertical section taken through one cell of an apparatus constructed according to this invention. Fig. 2 is a longitudinal section, to a smaller scale, taken through the whole apparatus. Fig. 3 is a horizontal section on the line y 1 of Fig. 2; and Fig. 3 is a horizontal section of the cellular cover E E, Fig. 2. Figs. 4 and 5 are sections through the bell showing two different forms of construction of the latter. Fig. 6 is a longitudinal vertical section illustrating a modified construction of the apparatus shown in Fig. 2. Fig. 7 is a detail sectional view of a portion of apparatus such as shown in Fig. 1, but provided with a short-circuited secondary electrode for the purpose of rapidly removing the alkaline metal from the amalgam that has been formed. The apparatus shown in Figs. 1, 2, and 3 comprises a vessel A for the reception of the electrolyte to be decomposed and a trough B inserted or suspended in the vessel A,-this trough having in its bottom openingslnwhich are surrounded by projecting borders 1), that serve to prevent the escape through the said openings of the layer of mercury O, which serves as a cathode and covers the bottom of the trough. Theanodes D are arranged in the electrolytic space of the vessel A horizontally or vertically, and in the latter case may, as shown, also project through the openings Z) into the trough B. Each of the trough-open. ings is covered over by a bell E, of non-conducting material such, for example, as glass,

stoneware, porcelain, or ebonitewhich dips at its lower free edge into the mercury and is of greater width than the opening I), so that it can be moved to and fro through a certain distance over this opening, the extentof this movement being limited by the upwardlyprojecting border Z9. The bell thus incloses the decomposing-chamber communicating with the vessel A and forms an electricallynon-conductin g partition between the decomposing and the combining chamber of the a stares trough B, which is charged above the mercury cathode G, which constitutes the seal, with Water, acid, or other substance with which it is desired to cause the cation previously taken up by the mercury cathode to combine.

In order that the mercury shall not become displaced by the lower end of the bell E sliding over the bot-tom of the trough B when the bell is being moved, slots or notches c or longitudinal channels 19 are provided, respectively, in the lower edge of the bell, as in Figs. 1 and 4, or in the bottom of the trough, as in Fig. 5. A gas-exit pipe F leads from the decomposing-chamber to the exterior of the vessel A. g

The anode D and the mercury cathode O are connected to the terminals of a suitable source of electricity.

In an apparatus of large size, such as is intended to be employed on an industrial scale, the whole of the bells E are preferably united to form a cover,Which is provided with partitions and is adapted to be moved to and fro in the trough B, the spaces E between every other bell being arranged to communicate by means of lateral openings withthe trough B, as shown in Fig. 3 The gas-exit pipes F are then arranged in such a manner that the generated gas is led through all the bells in succession and is drawn off from the last bell. The apparatus may be provided with a sliding gas-tight cover and leading-off pipe to recover the gaseous by-products liberated in the oxidizing-cell when it is so desired and is construct-ed as shown imconnection with Fig. 6, hereinafter described.

- The manner of working the apparatus is as follows: The electrolyte-for instance, a solution of com-mon saltwithin the vessel A and the decomposing spaces or chambers becomes decomposed by the electrolytic action which takes place under the bells E, the liberated chlorin gas being led off through the pipe F, while the metallic sodium forms an amalgam with the mercury cathode O, which is situated within the bells E on one side of the anode Dviz., on the right-hand side in Fig. 1. If now the bells be shifted to the left into the position shown in dotted lines in Fig. 1, the stationary mercury cathode, together with the amalgam, becomes thereby situated in the combining-chamber of the trough B, which is charged, it may be, for instance, with water. The sodium separates out from the amalgam and combines with the Water to form sodic hydrate. At the same time by the shifting of the bells that portion of the mercury which was previously situated outside the left-hand side portions of the bellsthat is to say, in the combining-chamberwill now be located in the decomposing-chamber and acts as the cathode to again produce an amalgam with the sodium, which is continually being separated in the said decomposing-chamber. If the bells after a suitable interval of time be shifted back into the position shown in full linest'. a, to the right handthe mercury on the left-hand side of the anodes, together with the amalgam formed thereon, again becomes situated in the combiningchamber of the trough, and consequently within the sphere of action of the water in such chamber, while on the other hand the mercury situated on the right-hand side of the anodes and the amalgam portion of which has been acted upon in the meantime by water to remove the sodium therefrom becomes again situated in the decomposing-chamber for the purpose of forming fresh amalgam. It will thus be seen that by the to-and-fro movement of the bells the transposition of the amalgam formed in the decomposing-chambers to the combining-chamber and the practically-continuous formation of caustic soda in the latter are caused to take place alternately on the one side and on the other side of the anodes, while the mercury cathode itself remains at rest.

It is obvious that the arrangement of apparatus hereinbefore described can be modified by causing the generation of chlorin to take place outside and the decomposition of the amalgam to take place inside the bells E. In this case the decomposing and forming chambers are merely interchanged. Fig. 6 illustrates a construction of apparatus of this kind, in which the vessel A contains the mercury cathode O and the solution of common salt to be decomposed, While the bells E,

that dip into the mercury, are charged with water, with which the sodium that becomes separated from the amalgam on the shifting of the bells combines to form sodic hydrate. The vessel A is provided with a cover A, that is adapted to close gas-tight and from which leads a pipe F, that serves to carry off the chlorin gas generated in the said vessel. The cover is provided at a suitable place with an opening, which is closed by means of a movable cover A that preferably dips into a sealing liquid for the purpose of making a gas-tight joint at this part. Through the cover A there passes a pipe H, which serves for discharging the hydrogen that forms in the bells E and is supplied to the pipe II by connecting-pipes II. The bells are rigidly connected together and, as in the previous case, are so arranged that they can be moved to and fro in the vessel A, this movement being shared by the pipe II and the sliding cover A The positive terminal wire from the source of electricity is electrically connected to the bell E by a conductor tightly fitted in a glass tube I, that has motion through a stuffing-box in the Wall of the Vesscl A. The bells E are made of a conductive material and are provided with a non-conductive coating e for the ends dipping into the mercury electrode, thereby preventing a short circuit through the bell to the mercury cathode. The bells E being in contact with the solution to be decomposed and insulated states s.

from the mercury in the bottom of the vessel A by the coating e constitute the anode of the decomposing-cell.

If itbe desired that the alkaline metal shall be rapidly removed from the amalgam formed, then in the case of apparatus of the kind herein described there may be employed the method whereby the heat liberated in the formation of amalgam is converted into electrical energy. For this purpose into the trough B of the apparatus, Fig. 7, or into the bells E, Fig. 6-that is to say, always in the chamber in which the oxidation of the sodium is to take place-there is suspended a third electrode G, which is electrically connected in any suitable way to one of the terminal WlI'6S--VlZ., that extending from the mercury cathode, Fig. 7-thereby forming a short circuited secondary element composed of the mercury cathode O and the electrode G, which element effects the rapid separation or removal of the alkaline metal from the amalgam. Each third electrode G may be carried either by the corresponding bell E or by the bottom of the vessel A through any suitable connection, which should be of non-conducting material orbe covered with such material.

I claim- 1. Apparatus such as described comprising an external vessel for containing an electrolyte, suitable anodes, a mercury cathode suspended above the bottom of said vessel by suitable means, a chambered structure dipping into the cathode, means for moving said structure through the cathode and means for placing one or more chambers of the chambered structure in communication with the external vessel, substantially as described.

2. In an electrolytic apparatus in combination, a vessel for the reception of the electrolyte,containin g a suitable anode or anodes and a cathode consisting of a stratum of mercury, a series of inverted cells for the reception of a liquid capable of combining with the metallic anion in the amalgam formed, said cells dipping into said stratum of mercury, means for imparting a to-and-fro motion to the cells collectively, a source of electricity, electrical connections between the electrodes and the proper poles of said source, a third electrode or electrodes for said cells short-circuited to the supply-circuit and means for separately collecting and educting the gases evolved at the cathode, and third electrodes, for the purposes set forth.

3. In an electrolytic apparatus in combination, a vessel for the reception of the electrolyte, a vessel arranged therein for the reception of a liquid capable of combining with the metallic anion resulting from the electrolytic decomposition of the electrolyte and containing a cathode consisting of a stratum of mercury, the last-named vessel in communication above the level of the mercury stratum and at different points with the first-named vessel, an inverted bell constructed with a series of intercommunicating cells and with a series of cells open at one end and alternating with the first-mentioned cells, said bell and cell-Walls dipping into the aforesaid stratum of mercury, the intercommunicating cells encompassing the communications between the two vessels, means for imparting a to-andfro movement to the bell, a suitable anode for each of said intercommunicating cells, a source of electricity, electrical connections between the electrodes and the proper poles of said source, and means for educting the gas evolved, for the purpose set forth.

l. The combination,with a closed vessel for the reception of the electrolyte provided with a longitudinal opening in its cover encompassed by a receptacle for a sealing liquid, and a cover for said opening dipping into and adapted to move to and fro in said receptacle, a cathode consisting of a stratum of mercury contained in said vessel, a series of inverted cells for the reception of a liquid capable of combining with the metallic anion in the amalgam formed, said cells dipping into said mercury stratum and communicating with each other at their upper end, an eductionpipe connected with the last of the series of cells extending through the aforesaid opening in the cover of the vessel and fluid-tight through the cover for said opening, means for imparting a to-and-fro motion to the cells collectively, a suitable anode for each of said cells, a source of electricity, electric connections between the electrodes and the proper poles of said source, and a third electrode contained in said closed vessel shortcircuited to the electric circuit, for the purpose set forth.

5. The combination with the vessel A, having the cathodes O, anodes D and the vessel B suspended therein, said vessel 13 provided with openings 1) surrounded by a raised flange; of the bell E having alternate cells 0 and E resting on the bottom of the vessel B, said bell E provided in its Walls with notches or recesses e, and means for imparting a to-andfro motion to said bell, substantially as and for the purpose specified.

6. Apparatus such as described comprising an external vessel, anodes, a second vessel having a perforated bottom suspended in the first Vessel, a mercury cathode in said second vessel, means for retaining it therein, a hood having connected cells adapted to fit over said perforations, means for imparting motion to said cells and suitable electrical connections for the electrodes, substantially as described.

In testimony whereof I afiiX my signature in presence of two witnesses.

CARL KELLNER.

Witnesses:

DEAN B. MASON, HARRY BELMONT.

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