US2673232A - Feed device for electrolytic cells - Google Patents

Description

March 1954 c. c. SILSBY, JR

FEED DEVICE FOR ELECTROLYTIC CELLS Filed Jan. 24, 1950 INVENTOR. I CHRISTOPHER c. SILSBY, JRQ

IDIOD'I'BU 0 o Patented Mar. 23, 1954 J 2 FEED DEVICE FOR ELECTROLYTIC CELLS Christopher C. Silsby,

to Diamond Alkali Company,

Jr., Euclid, Ohio, assignor Cleveland, Ohio,

a corporation of Delaware Application January 24, 1950, Serial No. 140,327

2 Claims.

This invention relates to a stream-breaking feed device for delivering a solution of electrolyte to an electrolytic cell, and more particularly relates to a means for disintegratin said stream into discrete droplets to prevent unwanted flow of electricity from a cell and for regulating the rate of delivery of the electrolyte stream to the cell.

It is of paramount importance in commercial electrolysis plants for the electrolysis of aqueous solutions of electrolytes that the electrolytic cells be isolated electrically from the source of the feed stream of electrolyte solution fed thereto in order that there be no dissipation of electric current to the stream outside the cell. Likewise, it is of importance that there be no means by which arcing of the electric current may take place between electrical conductors within the cell, since such arcing may touch ofi a chemical reaction of the evolved gases, i. e., hydrogen and chlorine or hydrogen and oxygen, which reaction may then proceed with explosive violence. An explosion may be touched off by arcing of the electric current between droplets of the electrolyte solution where the droplets of the feed solution are projected directly into the body of electrolyte within the cell. H

Stream-breaking means heretofore proposed for disintegrating a feed stream of electrolyte solution have included devices in which the stream is projected at high pressure from an orifice longitudinally against the inside surface of a tubular member opening into a cell, whereby the stream impinging upon the inside surface of the tube spreads around the inner periphery thereof and is said to leave the end of the tube in the form of a conical sheet which ultimately disintegrates into a mass of discrete particles. A more simple device for the same purpose includes an orifice inserted in the feed line, the orifice directing the feed stream vertically into the cell through a distance sufficient to permit the stream to disintegrate by disrupting intermolecular cohesive forces of the solution during its fall.

In addition to the dangers of the phenomenon o1 arcing between droplets noted hereinabove with such prior art stream disintegrating feed devices, the range of solution feed rates which will prevent electrical grounding of the cell through the feed stream is relatively narrow in the spray-type disintegrator because low feed rates preclude the feed stream moving with sufi'icient speed to maintain the formation of a thin liquid sheet and the subsequent disintegration ofthis sheet into discrete droplets, and in the electric current between single orifice type because high feed rates preclude allowance for sufficient practicable vertical distances through which the stream must fall before its disintegration is effected.

An object of the invention is to provide a metering feed device for feeding electrolyte to an electrolytic cell which shall insulate the feed supply from the cell at all times.

Another object of the present invention is to provide an electrolyte solution stream disintegrator for electrolytic cells, which disintegrator may be operated over a relatively wide range of feed rates within which the disintegration of the feed stream, and of the cell electrically, is assured.

Another object of the-invention is to provide an electrolyte solution disintegrator for an electrolytic cell feed device, the capacity of which may be varied as the capacity of the cell changes from time to time.

A further object of the invention is to provide a feed device for feeding a solution of electrolyte to an electrolytic cell, which device precludes due to arcing of an droplets of the electroexplosions Within the cell lyte solution fed thereto.

These and other objects of the invention will be apparent from the detailed description of the invention set forth hereinafter.

The drawing attached hereto and forming a part hereof is a vertical sectional elevation. through an apparatus representing one form of the invention.

In the drawing, 2 is a take-off from a manifold electrolyte solution header line, in which a metering orifice 4 is inserted and is supported by tube or reservoir 8 formed by supand stopper Ill; a plurality of 6 entering chamber porting member l2 jets iii are seated in the floor of supporting member l2 which forms the sides and floor of reservoir 8; jets I6 discharge from chamber 8 into the interior of cage 30, which is fabricated from an electrical insulating material, preferably a transparent material, such as glass or transparent synthetic plastics, and is vented to the atmosphere as at 38; cage 30 is supported by base 24, in which stopper 26 and line 28, emptying cage 30, are inserted; base 24, in conjunction with stopper 26, line 28, and the cage 30, forms a liquid-tight catch basin for droplets 20; base 24 and jet support l2 may be of electrical insulating material, similar to that of cage 30, and are held in rigid assembly by means of top and bottom rings 3 6 secured by buck-stays 32, which may consequently the isolation lower portion of also, if desired, be of.

electrical insulating material, which are held in place by nuts 36. The object, of course, is to isolate the top and bottom zones of the apparatus electrically by whatever arrangement of non-conducting parts may be feasible in a given application of the invention.

In operating the feed device of the present invention, a solution of electrolyte is fed from takeoil tube 2 through metering orifice 4 under suitable hydrostatic head of pressure into chamber 8; the rate of flow of the electrolyte solution into this chamber, and consequently the rate at which the solution is fed to the cell, is governed by the size of the opening in orifice 4 and the hydrostatic pressure upon the solution above the orifice; the stream of electrolyte solution is discharged from chamber 8 through jets l6 initially as a solid stream l8, which ultimately disintegrates into droplets 20, which are collected at the base of cage 30 as a continuous body of solution, which then flows to the cell through line 28.

Opening 38, shown above the normal liquid level of cage 39 but suitably below the lower limit of unbroken electrolyte stream from jets It, serves a two-fold purpose, in that it is open to the atmosphere and therefore permits the stream issuing from orifice 4 and jets 16 to be discharged against a substantially constant head of pressure, whereby the flow of brine or the like through the apparatus may readily be maintained at any desired constant rate, and in that the opening 38 serves as an overflow in the event of blocking along line 28 from cage 30 to a cell suitably to prevent the flow of current through the disintegrator. If cage 30 is not vented to the atmosphere, pressure variations within the cage, due to the hydrostatic head of pressure above orifice 4 and the pressure within the electrolytic cell exerted through line 28, may cause erratic operation of the metering orifice, for example, by increasing the pressure within the cage and thereby diminishing the flow to an amount substantially v less than the capacity of the cell to electrolyze the solution, and thereby allow the level of electrolyte in the cell to fall below the top of the electrodes, which in turn permits intermixing of cathodic and anodic gases, for example, hydrogen and chlorine Or hydrogen and oxygen, and increases the danger of explosion within the cell.

The rate of flow of electrolyte solution through orifice 4 at any given time is necessarily determined by and is proportional to the working capacity of the cell, i. e., the amperage, at that time, and is controlled directly by the hydrostatic head of liquid in line 2 above orifice 4. The effectiveness of the apparatus to disintegrate the feed stream is not impaired as the flow of liquid through the jets it approaches zero, and therefore flow rates less than that required to satisfy the maximum capacity of the cell need not be taken into account in designing the apparatus. This follows from the fact that at a given solution flow rate, for example, a fiow rate equal to the maximum capacity of the cell to which it is fed, the streams issuing from the jets will disintegrate within a determinable distance proportional to the size of the openings in the jets and the speed with which the issuing stream moves. Any lesser rate of flow will cause these streams to disintegrate within a lesser distance. The length of cage .30 and the size of the openings in jets [6,, as well as the number of jets, may thus be in tegrated to the maximum working capacity of a cell toelectrolyze the solution and to the requisite rate or flow of solution through orifice l-to satisfy that capacity. In determining the size of the orilice 4 and the number and sizes of jets IE to be used in the stream disintegrating mechanism, it is important first to determine the available hydrostatic head above orifice 4 and to co-ordinate the size of the opening in the orifice with the hydrostatic head, so as to obtain a flow somewhat greater than the maximum capacity of the cell to electrolyze the solution fed thereto. Thereafter, the number and size of the openings of the jets It to be employed are suitably adjusted to the maximum allowable length of cage 30 in order that the streams of liquid issuing from the jets disintegrate into discrete droplets before reaching the body of solution at the base of cage 30.

In gauging the size of the openings in jets Hi, the diameter of the orifice 4 is suitably less than the sum of the diameters of the openings in the total of jets l6, whereby the disintegration of the streams issuing from the jets is effected within a distance less than that required theoretically to disintegrate a stream issuing from orifice 4; suitably orifice 4 is within the range 0.1 to 0.8 the sum of the diameters of the total of jets IE, but preferred value of operations lies in the range from 0.6 to 0.8. In ordinary commercial practice, a suitable allowable length for cage 30 has been found to be of the order of 12 to 20 inches.

Data relative to these features of the invention are tabulated below to show the relationship of the size of the openings in the jets to the flow rates obtainable therethrough and the distance through which the stream issuing from the jets must fall in order to effect the disintegration thereof into discrete particles.

grate, Inches In designing cage 30 for a cell having a maxlmum capacity within the range of flow rates given in thetable above, it is preferred practice to have the length of the cage at least 3-4 inches more than the corresponding distance of stream fall which may occur within cage 30 is ineffective in initiating an explosion since intermixing of .anodic and cathodic gases cannot occur in this region in the apparatus and therefore, a much saferopelifl tion of an electrolytic .cell is assured.

While there has been illustrated and describ in detail an embodiment of the invention, the described structure is not intended to be understood as limiting the scope of the invention asit is realized that changes therewithin are possible i and it is further intended that each element or instrumentality recited in any of the followmg claims is to be understood as referring .to

equivalent elements or. instrumentalities for accomplishing substantially the same results-yin. substantially the same or equivalent manner. it

5 being intended to cover the invention broadly in whatever form its principle may be utilized.

What is claimed is:

1. An electrolyte solution feed device for an electrolytic cell including an electrolyte solution feed line, a fixed metering orifice in said line controlling flow of solution to an enclosed reservoir having a plurality of jets in the floor thereof, the diameter of said orifice being less than the sum of the diameters of said jets, said jets opening directly into a vessel wherein the distance of the free fall of streams issuing from said jets is sufficient to allow for the disintegration of said streams into discrete droplets, said vessel having a vent to the atmosphere and having a zone electrically insulated from said reservoir, in which zone droplets of said solution from said streams are collected to form a body of said solution.

2. An electrolyte solution feed device for an electrolytic cell including an electrolyte solution feed line, a fixed metering orifice in said line opening directly into an enclosed reservoir having a plurality of jets in the fioor thereof,

the diameter of said orifice being within the range of 0.1 to 0.8 the sum 01' the diameters of said jets, the floor of said reservoir forming the roof of an electrically nonconductive vessel wherein the distance of the free fall of streams issuing from said jets is greater than that required for said streams to disintegrate into discrete droplets, said vessel having a vent to the atmosphere at a level lower than that at which said streams disintegrate into discrete droplets, and having below said vent a catch basin wherein said droplets are collected to form a continuous body of said solution.

CHRISTOPHER C. SILSBY, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 636,234 Baker Nov. 7, 1899 679,050 Girouard July 23, 1901 1,106,719 Lake Aug. 11, 1914 2,414,741 Hubbard Jan. 21, 1947

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