|Publication number||US3767542 A|
|Publication date||Oct 23, 1973|
|Filing date||Oct 4, 1971|
|Priority date||Oct 4, 1971|
|Also published as||DE2248432A1|
|Publication number||US 3767542 A, US 3767542A, US-A-3767542, US3767542 A, US3767542A|
|Original Assignee||Diamond Shamrock Corp|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Non-Patent Citations (1), Referenced by (10), Classifications (20), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
llnited States Patent [1 1 Carlson 1 Oct. 23, 1973  REDUCTION OF ELECTROLYTIC CELL 2,919,235 12/1959 Roller 204/273 VOLTAGE BY ANODE VIBRATION FORElGN PATENTS OR APPLICATIONS  Inventor: Richard C. Carlson, Euclid, Ohio 1,284,288 10/1970 U.S.S.R 204/273 [7 Assignee: Diamond a k Corporation 1,111,392 2/1956 France 204/99 Cleveland, Ohio OTHER PUBLICATIONS  Filed: 4 1971 Modern Electroplating by Lowenheim, 2nd Ed., 1963,
pages 18-19.  Appl. No.1 186,082
Primary Examiner-H0ward S. Williams 52 us. Cl 204/98, 204/128, 204/129, Andrews Attorney-R0y Dav1s et al.
 Int. Cl C0lb 7/06 58 Field of Search... 204/261, 273, 98,  ABSTRACT 204/128, 162 S, 163 S, 129 The operating voltage of an electrolytic cell in which gaseous evolution occurs at the anode is reduced by  References Cited a lyin high s eed mechanical vibration to the an- 7 PP g P UNITED STATES PATENTS 3,580,833 5/1971 Cooper 204/99 2 Claims, 1 Drawing Figure VOLTAGE PATENTED 0B! 23 W73 BY v R y U INVENTOR RICHARD C. CARLSON ATTORNEY REDUCTION OF ELECTROLYTIC CELL VOLTAGE BY ANODIE VIBRATION BACKGROUND OF THE INVENTION A variety of electrochemical reactions is known wherein electrical current is passed through an aqueous electrolyte between an anode and an opposed cathode, the current being such as to result in the generation of a gas or gasses at the anodic surface. Electrowinning of metals from aqueous solution, the electrolysis of water and the production of chlorine, caustic and the chemical compounds thereof are but a few examples of such reactions. As the applied anode current density in these processes is increased, the rate of production and the amount of gaseous evolution increase, as does the operating cell voltage. At least initially, this increase in voltage is, for all practical purposes, in direct relation to the increase incurrent density. However, it has been noted at the higher current densities desirable in order to increase the production rate of a given electrolytic cell that the voltage begins to increase at a rate greater than theoretical, resulting in an increase in power consumption per unit of product.
Attempts have been made to counteract this undesirable rate of increase in voltage. For example, following the suggestion of certain prior art, the electrolyte has been subjected to ultrasonic vibrations with, unfortunately, no detectable effect.
STATEMENT OF THE INVENTION Therefore it is an object of the present invention to I provide a method for reducing the operating voltage of rate of production is such that considerable quantities of gas are evolved and rapid decomposition of the electrolyte occurs at the anodic surface. These conditions of high current density have become increasingly common-place in recent years with the advent of dimensionally stable anodes that are not subject to the usual decomposition and attrition of, for example, graphite at increased current densities.
The action to which the anode is subjected is stated as being high speed mechanical vibration. As suggested by this phrase, together with the word directly, it is intended that the anode itself, especially the working face thereof, be caused to vibrate, preferaaqueous electrolyte between an anode and an opposed DESCRIPTION OF THE DRAWING The FIGURE is a graph illustrating the improved performance of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the invention is applicable to those electrochemical reactions wherein an electric current is passed through an aqueous electrolyte at a voltage sufficient to achieve the desired reaction and result in the evolution of a gas or gasses at the anodic surface. Generally the gas evolved either is desired product (e.g., chlorine) or is required for a subsequent chemical reaction resulting in the desired product (e.g., chlorine reacting to chlorate). However, the invention functions equally as well where the gas evolved is an unavoidable by-product, the desired reaction occurring predominantly at the cathodic surface (e.g., oxygen at the anode in electrowinning).
The advantage of the instant invention is most marked at relatively high current densities wherein the bly at a rate in excess of 6,000, especially in excess of 9,000 vibrations per minute and up to speeds which may be considered ultrasonic (e.g., 20,000 vibrations/- second). The vibrations are applied directly to the anode and/or its supporting and connecting framework up to and including the current lead in (busbar). Vibrations applied to other of the cell components, such as the cell supports or sidewalls, or to the electrolyte have been found to have substantially no effect.
The means for inducing the mechanical vibration is of little or no consequence to the invention, although obviously important from a practical standpoint. It has been found that in order to be effective the vibrations must be continually applied, that is, upon cessation of the vibrations the operating voltage immediately increases to its prior, excessive, value. For this reason the vibrating means should be chosen for its durability and simplicity of operation and maintenance. Typical of such are those vibrators in which compressed air is used to impart unbalanced rotation to balls or rollers which in turn induce vibrations in members in contact therewith.
Illustrative of the present invention is its effect upon the electrolysis of an aqueous alkali metal halide solution in a cell employing a dimensionally stable anode and a flowing mercury cathode. The cell used is a horizontal-type mercury cell employing an anode suspended above a steel cathode base plate, the assembly being enclosed to contain the electrolyte and products of electrolysis. The dimensionally stable anode is constructed primarily of titanium, is supported by an anode frame and is connected to a copper busbar. An anode riser leads from the busbar connection to the interior of the cell, the active working face of the anode consisting of a plurality of elongated rod-like elements positioned in a plane parallel to the flowing mercury surface and connected by welding through secondary conductors to the anode riser. The surface of these titanium rods is coated with an electrically-conductive electrocatalytically active material, in this case a titanium dioxide-ruthenium oxide deposit. The anodecathode gap is established at 0.136 inch. A 305 grams/- liter sodium chloride solution is employed as the electrolyte at an average cell temperature of 76C.
The Figure shows the relationship between applied anode current density and the operating cell voltage at the above-described conditions. The first line (1) charts the theoretical straight line relationship between voltage and current density for the given conditions. Line 3 is a plot of the anode current density versus the actual cell voltage obtained, measured from anode face to mercury. Line 2 is again a plot of the measured voltage at the various current densities, all conditions being the same as those of Line 3 with the exception that mechanical vibration is employed.
Vibration is effected by placing a commerciallyavailable compressed air-driven vibrator (Vibrolator Model BDR-l6, Martin Engineering Co.) directly on the anode busbar. The vibrator operates within the range of 9,000-1 1,000 vibrations per minute. The location of the vibrator on the copper busbar is a matter of convenience, attachment to the anode per se and the anode frame having been found to give equivalent results.
The substantial reduction in voltage obtained by the application of vibrational force is readily seen from the attached figure, reductions of up to 300 millivolts having been observed.
While the invention has been described with reference to certain preferred embodiments thereof, it is not to be so limited since changes and alterations may be made therein while remaining within the scope of the appended claims.
1. An improvement in the method of electrolyzing alkali metal halide solutions by passing a current between an anode and an opposed cathode, said current being sufficient to cause gaseous evolution at the anode, which improvement consists essentially of causing said anode to vibrate rapidly and continuously by the direct application of mechanical force to the anode structure.
2. In a method of electrolyzing an aqueous alkali metal halide by passing current through said aqueous halide between an anode and an opposed cathode at an anode current density of greater than 8 amperes per square inch, the improvement which consists essentially of reducing the operating voltage by causing said anode to vibrate continuously at a rate of from 6,000 vibrations per minute up to ultrasonic by the direct application of mechanical force to the anode structure.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2919235 *||Nov 6, 1956||Dec 29, 1959||Roller Paul S||Electrolytic method and apparatus for the production of metal hydroxide|
|US3580833 *||Apr 30, 1969||May 25, 1971||Olin Mathieson||Mercury cell having rotating anode|
|FR1111392A *||Title not available|
|SU1284288A *||Title not available|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3969214 *||May 31, 1973||Jul 13, 1976||Mack Harris||Permanent magnet hydrogen oxygen generating cells|
|US4169035 *||Oct 31, 1977||Sep 25, 1979||Firma Hans Einhell Gmbh Industriegelande||Electrolytic cell for treatment of water solutions|
|US4188278 *||Jan 23, 1978||Feb 12, 1980||Institut Fur Biomedizinische Technik||Apparatus for degerminating fluids|
|US4250013 *||Feb 23, 1979||Feb 10, 1981||Ppg Industries, Inc.||Method of depositing a catalyst to form a solid polymer electrolyte membrane|
|US4323435 *||Sep 10, 1980||Apr 6, 1982||Ppg Industries, Inc.||Method of operating a solid polymer electrolyte chlor-alkali cell|
|US4329209 *||Jan 23, 1981||May 11, 1982||Ppg Industries, Inc.||Process using an oxidant depolarized solid polymer electrolyte chlor-alkali cell|
|US4336122 *||Sep 8, 1980||Jun 22, 1982||Ernst Spirig||Electrolysis apparatus|
|US4517064 *||Sep 23, 1983||May 14, 1985||Duval Corporation||Electrolytic cell|
|US4744873 *||Nov 25, 1986||May 17, 1988||The Dow Chemical Company||Multiple compartment electrolytic cell|
|US20120231574 *||Sep 13, 2012||Jiaxiong Wang||Continuous Electroplating Apparatus with Assembled Modular Sections for Fabrications of Thin Film Solar Cells|
|U.S. Classification||205/528, 204/261, 204/273|
|International Classification||C25B1/40, C02F1/34, C25B1/00, C25B1/36, C02F1/461, C02F1/467, C25B15/00|
|Cooperative Classification||C02F1/46109, C02F2001/46123, C25B15/00, C02F1/4674, C25B1/40, C02F2001/46142, C02F1/34|
|European Classification||C25B1/40, C25B15/00, C02F1/461B2|
|Oct 29, 1984||AS||Assignment|
Owner name: ELTECH SYSTEMS CORPORATION, 6100 GLADES ROAD, BOCA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:DIAMOND SHAMROCK CORPORATION, 717 N. HARWOOD STREET, DALLAS, TX 75201;REEL/FRAME:004357/0479
Effective date: 19841024
|Nov 7, 1983||AS||Assignment|
Owner name: DIAMOND SHAMROCK CHEMICALS COMPANY
Free format text: CHANGE OF NAME;ASSIGNOR:DIAMOND SHAMROCK CORPORATION CHANGED TO DIAMOND CHEMICALS COMPANY;REEL/FRAME:004197/0130