US1266329A - Electro-osmotic extraction of water from animal, vegetable, and mineral substances. - Google Patents

Description

: snares rarnnr ora ion.

BOTHO SCHl/VERIN, 0F FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNGP. TO GESELL- SCHAFT IEI TR ELEKTRO-OSMOSE M. B. .H., 01' FRANKFURT-ON -THE-1VIAIN, GERMANY,

A CORPORATION.

ELECTRO-OSMOTIC EXTRACTION OF WATER FROM ANIMAL, VEGETABLE, AND MINERAL SUBSTANCES.

No Drawing. Application filed November 20, 1912, Serial No. 732,546. Renewed October 24, 1917.

Specification of Letters Patent.

Patented May 1%, H918.

Serial To all whom it may concern Be it known that l, Bo'rno SCHWERIN, a subject of the German Emperor, and residing at Frankfort-on-thc-lllain, Germany, have invented certain new and useful 1mprovcments in the l llectrollsmotic Extraction of \Vater from Animal, Vegetable, and lilineral Substances, of which the following is a specification.

There are a large number of substances such as peat, clay, kaolin and the like from which water cannot be entirely removed by mechanical means, or only with extreme ditliculty.

The water can be extracted from such substances however on a commercial scale by elcctro-osmotic processes, generally used in conjunction with mechanical pressure.

In one known process the material subjected to osmotic action is contained between the concentric walls of a cylindrical vessel, the inner wall forming the positive pole and the outer Wall the negative, the material passes through a worm revolving between the electrodes, and in order that there should be good contact between the electrodes and the particles, the latter can only escape, when they exert sufiicient pressure to open the exit orifice against the action of a spring. In another arrangement the material flows between two conveyor bands, the electrodes being intermittently moved toward each other, so as to press againstthe material, or boxes attached to an endless band are used. the bottom of the boxes being connected with one pole, while the other pole is connected with covers fitting the boxes and pressed onto the material. In another method the apparatus is arranged in a vertical stage, in which tiers of boxes are placed one above the other and pressure is exerted on the material by movable electrodes. In all these constructions, which are intended for substances in a state of pulp, the electrodes are movable and serve at the same time as plates for applying pressure to the material, or pressure is eXerted on the moving particles.

According to the present invention neither the electrodes nor the particles of the material in the compact condition are moved. The method employed in the present invcntion is to place, in a space of constant volume, the substance from which water is to be extracted, this substance being acted upon by an electric current and pressure or suction exerted or transmitted by the substance itself.

The electrode toward which the water migrates is constructed in known manner so that the water can flow off.

The electrodes are preferably made of hard lead and arranged behind the filter cloth of a filter press. During the electr0- osmotic process the substance is pumped in under slight pressure, according to the amount of water removed, until the coinpact mass left has attained the desired degree of dryness. Then after the current has been switched off and the hydraulic pressure released, the press is emptied in the usual manner.

Filter presses of previously known construction have Worked fairly satisfactorily as long as the solid particles in suspension are comparatively large grained. But they operate less and less satisfactorily and with increasing expense. the finer the particles becomc and when the colloidal size of particles is reached these filters are quite impossible, since as the degree of fineness of the particles increases, the pressure used must becorrespondingly increased. and as the pressure increases more filter cloths are used up and more energy is expended.

lVith the present method only a very small pressure is required compared to that usually employed. ll 'hereas in previously known methods pressures up to 20 atmospheres have been necessary, with the present method the pressures may be reduced, even to 1 atmos phere. and under certain conditions suction may be used instead.

Also when working according to the present method, at the electrode toward which the water migrates. that is generally at the cathode or negative electrode. substances, such as peat and clay, chalk. ferric hydro- 'oXid and other substances. separate out,

which gradually prevent the water from passing out or choking the filter. This disadvantage ean be obviated by reversing the flow of current after each or several charges. The deposited substances are then freed 01' Q we migrate in the opposite direction into the cakes of compressed material and are re lnOYGd with these.

The method is especially suitable for colloids in suspension such as clay, dyestuffs and the like.

Having now particularly described and ascertained the nature of my said invention and in What manner the same is to be performed, what I claim is:

l. The method herein described which consists in subjecting material in suspension to the action of an electric current While subject to pressure exerted by said material confined Within a space the capacity of which remains constant, and maintaining the suspension free from disturbance.

'2. The method herein described 7 which consists in pressing material in suspension in a filtenchamber of constant volume, maintaining the suspension free frorn'disturbance, causing a continuous electric cur rent to pass through the mass confined in the chamber, and passing the liquid through filter-cloths and perforated electrodes fixed in the said chambers.

3. The method herein described which consists in pressing material in suspension in a filter-chamber of constant volume, maintaining the suspension free from disturbance, causing an electric current to pass through the mass confined in the chamber, allowing the liquid to How off through filtercloths and perforated electrodes fixed in the said chambers, and changing the direction of the electric current at intervals, for free ing the filtering devices.

BOTHU SCH-WERIN.

"Witnesses JEAN GaUND, CARL German.