US903951A - Process for the electrolysis of liquids. - Google Patents

Description

J. BILLITER. PROGESS FOR THE ELEOTEOLYSIS OF LIQUIDS. APPLICATION I'ILED AUG. a, 1908.

903,951 PatentedNov. 17, 1908.

Witnesses. Inventor.

UNITED STATES PATENT OFFICE.

JEAN BILLITi-TR, OF .\i t,-llICRSLI'IIHCN, GERNIAXY.

PROCESS FOR THE ELECTROLYSIS OF LIQUIDS.

fication of the electrolyte, for the purpose of better separating the products atthe anode and cathodefrom each other. Examples oil such processes, which especially relate to the electrolysis of chlorids, have been described c. y. in German latents H116? and 191234. On the other hand Le Sueur, llargreavcs and Bird, Carmichael and others have sought to preventthe mixing ol the anode and cathode solutions by supplying the cathode-ehamber with electrolyte-solu tion from the anode, so that the solution fed in flows in the opposite direction to the movement of the ()II-ions. As is known, such arrangement of the tlow is not snflicient to prevent the electric transfer of the OH-ions to the anode. A more ett'ectual method of combating this is to cause the solution containing the alkali to separate itself as a heavier layer from the anode oln tion above itand to control the supply of fresh solution in such a manner that the com-cntration ot' chlorin ions in the layers next to the anode is at a maximum. This arrangement l-iowever is also Insufficient alone.

A process, which seeks-to combine the advantages of the two methods of working above mentioned, has been described in German Patent 1912-34. As in the bell cell process (German Patent H1187), however, there is required in the said patent, a motion of the lower layer, in order to maintain the stratification or to continuouslyreform the separating layer. The circulation of the solution must therefore take place ata relatively rapid rate as in the bell cell process.

Bty this means, however, the concentration he lyes which can be obtained with good yields would again set an upper limit fairly soon. Moreover, cells of this kind are very sensitive to variations of pressure in the gas chamber, such as frequently occur in technical work, since the oscillations of the liquid caused thereby involve destruction of Specification of Letters Patent.

Application filed August 3. 1908.

by this means is considerable.

Patented Nov. 17, 1908.

Serial No. 446.720.

the stratification. \Yith the same'current, however. higher concentrations. of the alkali can be obtained and the method of operation is made much more convenient and simple, it the. stratilication is maintained without. lateral motion of the layers of liquid. and it', using. closed cells (without overflow) only the lowermost, densest layer, which contains lnost' alkali, is employed for feeding the cathode chamber. This object can be attained by making a cell with a horizontal arrangement that maintains a hil'illlllftlllOll by heating from above, which has the supply of feed solution at the level of the heating pipes and in which the cathmle-chamber is ted solely by the passage through the diaphragm ol t-hc heaviestlayer which is richest in alkali, lying directly above the dia phragm and contained in the diaphragm.

Extended technical investigations on a large. scale have shown that the stratification. is produced more advantageously by heating the solution which is in the neighborhood of theupper electrode and which is to separate itself as the upper layer, instead of allowing it to become weak. The heating is preferably affected by heating pipes, which in contradistinction to all known arrangements are arranged above the upper electrode. when this is mounted horizontally, and at the level of this electrode when it is arranged vertically (for example in the form ot vertical downwardlyextending rods). or by means ol steam which isconducted into the space above the surface of the liquid. The advantage which is obtained Hot concentrated salt-solution can be clectrolyze d lat I the upper electrode, so that the resistance of the bath' is lower and the current density (with the same pressure) is higher, and the life of the electrodes is increased since they are generally more rapidly destroyed 'in dilute solutions, in cases in which soluble gases are given olt' at the upper electrode (for example in the electrolysis of the chlorids of alkalies) their solubility is decreased by the elevated temperature and the interaction between the dissolved gases and the products of electrolysis in the lower heavy layer is reduced. and so on. By means of a cell constructed as hereinafter described from this point of view, it is possible to employ the heaviest layer containing the greatestauiount of alkali alone for feeding the cathmle-chamberarranged beneath the diaphragm, this being efl"ected solely by the supply through the diaphragm.

One constructional form of the improved cell is shown in the accompanying drawing. 5 I For receiving the solution, a tank 2 of heavy iron plate lined with cement 1 is employed. The heating pipes 14 and the supply pipe 17 for the solution to be fed in are arranged at the level of the upper electrodes 9 for the purpose of maintaining the stratification and to enable the solution sup plied to be brought directly to the maximum temperature in the tank by means of the heating pipes, in order that their chlorinions shall have the highest ossible velocity of diffusion. The, horizontally mounted d iaphragm 4 lies directly on the wire net-work 3'forming the cathode- In order to provide room for the easy escape of the gases gener- 20 ated on this network-,- Iicarriers 16 are employed which are mounted on the one hand on the iron bottom of the "tank and which support the slightly corrugated wire network at several places, which would other wise bend under the load of the conten'tstof the bath. 'Av double bottom is thus. pro duced, through which the gases pass-linorder'" to be conducted away through a branehjiipe or the like, while the lye runs away at the 80 bottom... The carriers can .be made of metal and can then simultaneously serve as terminals for the supply of the current.

The rapidity of the flow through the diaphragm can obviously be regulated by the composition and thickness of the latter. If the thickness and composition of the -diaphragm are already chosen, the rapidity of flow can be varied by adjusting the height of the liquid in the interior of the tank. 40 Since however the permeability of the dia phragms decreases somewhat in the course of time by the impurities which deposit themselves thereon, an arrangement can be. adopted for the uniform feeding of the cathode-chamber, which permits a smaller or greater degree of vacuum to be produced in the lower space or chamber, in order to increase the flow oflye through the .diaphragm. For this purpose, the run away pipe 11 is provided with abranch 12, through which the gas :can be drawn off. This branch pipe preferably extends upwards at an inclination in order that the currentof shall not carry away any lye with it. Any drops of liquid which maybe carried along with the gas may be kept back by transversely mounted wire grids 18; by this means it is also possible to insure that any explosions of gas which may take place ex- 'ternally shall not extend into the interior of the bath. A slight vacuum can be produced in a very simple manner by causing the branch pipe12 to extend upwards, thus producing the vacuum by th'e'suctiomefiect liquid' which contains the greatest amount of the produgts of electrolysis at the cathode. The siiidjarrangement therefore gives the highest concentration of the lye with the best yield. The apparatus can obviously be also employed for the electrolysis of other than .chlorid solutions, and. the lower electrodechamber under special conditions may form the anode-chamber.

\Vhat I claim is 1- 1. The process of electrolyzing liquids, which comprises feeding the liquid to the upper one of electrode chambers at different levels and separated by a diaphragm and heating the liquid in the upper chamber.

2. The process of electrolyzing liquids, which comprises feeding the liquid to the upper one of superposed electrode chambers separated by a diaphra 'm and heating the electrolyte at or above the electrodes insaid chambers.

, 3. The process of electrolyzing liquids which'comprises feeding the liquid on to a heated surface contained in the upper one of superposed, diaphragm separated, .electrode chambers at or above the level of the electrodesin said chainber.

A. The process of. electrolyzing liqpqids which compriscs'feeding thediquid to he dipper one of two, diaphragm scpajlfit al, gelectrode chambers at difi'erentdevels, heat-- ing the liquid at anupper level in the upper l1 chamber and maintaining a suction'in. the v lower chamber beneath the rhaphragm to control the movement throiigh the diaphragm.

The process of electrolyzing liquids, which comprises feeding the liquid to a heated surface in the upper one of two superposed diaphragm separated,electrode cham-i hers and controlling the withdrawing ofthe gas generated from the lower chamber beneath the diaphragm at a greater rate than the rate of formation of said gas to maintain a suction beneath the diaphragm.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

JEAN BILLITER. Witnesses:

ALBERT B. GREEN, WILHELM AnnNnRo'rH.

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