US2115004A - Electrolytic apparatus - Google Patents

Description

W. H. BITNER ELECTROLYTIC APPARATUS unna unan April 26, 1938.

Apn'l 26, 193s. w. H. BITNER 2,115,004

ELECTROLYTYIG APPARATUS Original Filed Feb.' 14, 1935 5 Sheets-Sheet 2 ATTORNEY April 26, 1938. w. H. BlTNER 2,115,004

ELECTROLYTIC APPARATUS Original Filed4 Feb. 14, 1935 5 Sheets-Sxec-ziI 5 Y E :t AA

y y F mm. xNMN WN .m un A .m W M Patented Apaze, 1938 ELEGTROLYTIC APPARATUS William H. Bitner, Metuchen, N. J., assignor to American Smelting and Refining Company, vNew York, N. Y., a corporation of New Jersey Application February 14, 1935, Serial No. 6,427 Renewed July 13, 1937 10 Claims.

The present invention relates to an improved form of electrolytic apparatus adapted for the electrodeposition of metals, such as, for example, copper, cadmium and zinc, and it pertains more especially to an improved construction and mounting of a multiplicity of anodes and cathodes in the cell whereby the cathodes of a given cell may be removed readily and simultaneously for stripping the deposited metal therefrom, after which the cathodes may be readily replaced in the cell for receiving further deposit of metal. A

It has been the customary practice in the production of electrodeposits of metal as indicated above, for the purpose of maintaining the correct alignment of the electrodes, to employ wood strips attached to the vertical edges of the cathodes, these strips being customarily in the form of frames held in place by a structure within the cell. If the metal electrodeposited on the cathode surfaces is to be detached or stripped from the cathode, these strips or guides prevent the deposition of .metal on the edges of the cathodes thereby facilitating detachment of the electrodeposited metal from the cathode.

The use of such frames held in place within the cells prevents ready manipulation of the cathodes, particularly when a plurality of cathodes are used in a cell and it is desired to remove them for stripping, as with such frames, individual replacement of the cathodes is required.

Furthermore, it is important that a good circulation of electrolyte be maintained in the cells. The use of the frames above referred to possesses the advantage of permitting such circulation to take place, since they maintain the electrodes in properly spaced relation; but, where the installation is a large one, unless the cathodes of a unit or bank of cells can be removed and replaced simultaneously, it is evidentthat there is required a substantial increase in the amount of handling of the cathodes with consequent loss of efliciency and increased operating costs. 4

The present invention has for one of its objects, the provision of an improved electrode structure and mounting for the anodes and cathodes of electrolytic cells wherein the cathodes may be removed and replaced readily and simultaneously, while automatically coming into correct alignment with the anodes, the improved structure and mounting retaining the advantages of the aforesaid framework heretofore customarily ernployed.

A further object of the invention is to. provide an electrode construction wherein'the electrodes Other objects and advantages of the present inn vention will become apparent as the description proceeds, and the features of novelty will be particularly pointed out in the appended claims.

Referring more particularly to the drawings, Fig. 1 is a vertical sectional view through a plurality of electrolytic cells installed in accordance with the present invention.

Fig. 2 is a fragmentary plan view showing certain features of the mountings of the electrodes in the cells of Fig. 1.

Fig. 3 is a fragmentary sectional plan view through one of the cells of Fig. 1, the view being taken on the line 3-3 of Fig. 1, looking downwardly as indicated by the arrows.

Fig. 4 is a fragmentary vertical sectional view showing details of the electrode arrangement in the cells, the View being taken on the line 4--4 of Fig. 1, looking inthe direction of the arrows.

Fig. 5 is a fragmentary elevational view taken on the line 5-5 of Fig. 1, looking in the direction of the arrows, a portion of the cell being broken away to show the 4arrangement of the electrodes, the view showing also the arrangement of contacts for the electrodes at the top of the cell.

Fig. 6 is a fragmentary plan view on an enlarged scale, showing the contacts between the electrodes at the tops of adjacent cells, as indicated also on Fig. 1.

Fig. 7 is a vertical section taken on the line 'l-'l of Fig. 6, looking in the direction of the arrows.

Fig. 8 is a Vertical section taken on the line 8-8 of Fig. 6.

Fig. 9 is a fragmentary side elevation showing the anode and cathode assembly as mounted on a bus bar, the view being taken substantially at right angles to Fig. '7.

Fig. 10 is a sectional elevational view taken on the line lll-Ill of Fig. 2, looking in the direction of the arrows.

Fig. 11 is a sectional elevational view taken on the line 'I I-Il of Fig. 2, looking in the direction of the arrows.

Referring more particularly to the drawings, A and B represent two electrolytic cells of adjacent cell banks installed side by side in substantial parallelism-in a cell room of an electrolytic plant. These cells are adapted for the electrolytic recovery of metals such, for example, as zinc, copper or cadmium, though not limited to these metals; but for purposes of illustration, it will be 'ity, facilitating handling the cathodes.

considered that these cells are employed for the recovery of zinc from zinc sulphate solutions produced by the leaching of non-sulphide zinc Aores or concentrates by sulphuric acid.

rWithin each cell there are positioned a plurality of anodes anda plurality of cathodes. The anodes are designated at II and the cathodes at I3. It will be seen that looking in a direction longitudinally of the cell banks there is an anode between each pair of cathodes, and in the transverse direction, across adjacent cell banks, the anodes and cathodes are staggered.

Where, as in the present illustration, the de- ,posit is to be stripped from the cathodes, the

cathodes are desirably of sheet aluminum to enable ready stripping of the deposit without likelihood of injuring the electrode surface, the aluminum also, by reason of its low specific grav- The anodes I I are, in accordance with the present illustration, insoluble in a zinc sulphate electrolyte and may comprise, for example, Ia silverlead alloy as disclosed in U. S. Letters Patent No. 1,759,493 to Urlyn C. Tainton.

Referring rst to the construction of the anodes, it will be seen that, in the illustrated form, they are made of substantially rectangular sheets provided with a multiplicity of holes I5 disposed substantially uniformly over the surface of the anodes. These holes serve a two-fold purpose, namely, that of reducing the weight of the anodes While increasing the amount of active surface thereof. The edges of the anodes are encased in strips I1 of suitable insulating material such as Wood, rubber, synthetic resins, glass, etc., and they are attached to the edges of the anodes by suitable fastening members, such as dowel pins I9. The anode strips I1 are substantially shorter than the anodes themselves, the tops of the strips in practice being approximately four inches below the solution line in the cells. The anode strips I1 are beveled at their tops, as indicated at 2|, for a purpose to be hereinafter described; and

these strips I1 reinforce the anodes and maintain them fiat, overcoming any tendency of the anodes to buckle under their own Weight, along any of the holes I5. The anodes are supported CII across the cells on bars 23 which rest on strips 25, positioned along the top of the cells, as will be pointed out hereinafter in greater detail.4

The bars or hangers 23 are desirably made up of an internal bar of high conductivity metal, such as copper, designated at 21, which is encased in a lead sheath 29 cast around the bar 21, the sheath 29 encasing the upper edge of the anode plates II and forming a substantially integral union therewith.

The cathodes I3 alternate with the anodes I I in the assembled cells, there being an anode II between each pair of cathodes I3. The cathodes I3 are formed of sheets of somewhat greater Width than the anodes I I, aluminum being a very desirable cathode material, where the deposit is to be stripped, as its lightness enables the cathodes to be handled more readily, and the properties of aluminum are such that the deposited metal is readily stripped therefrom.

The edges of the cathode sheets I3 are covered with strips 3|, generally similar to the anode strips I1, but being held in frictional engagement therewith, so that they may be readily removed from the cathode plates when the deposit is to be stripped from the cathodes. The cathode strips 3| extendxsubstantially the entire length of the cathodes, and are beveled at their bottoms as indicated at 33. Thus when the cathodes are inserted in the cel1the beveled portions 2I of the anode strips I1 come into engagement with the beveled portions 33 of the cathode strips 3|, the cathodes thus being guided into proper alignment with the anodes. The combination of the strips I1 on theanodes, together with the strips 3I on the cathodes space the anodes and cathodes relatively to each other so as ,to produce compartments between each cathode, the compartments being closed at their sides by the engagement between the strips I1 and 3|, the compartments being open at their tops and bottoms. During electrolysis, oxygen evolved at the anode surfaces causes a gas lift within the electrolyte which produces an upward ow of the electrolyte along the electrode surfaces, this circulation of electrolyte being designated by the arrows in Figs. 1 and 4. These arrows show the flow of electrolyte upwardly through the compartments, over the tops of the anode strips, and down the cell Walls to again recirculate.

Thevcathode sheets may be, preferably, quite thin in order to reduce the weight thereof, being in practice sheets of aluminum foil of only suflicient thickness to prevent destruction thereof during the stripping operation. The strips 3I comprise reinforcing or stiifening means for the sheets I3, preventing their deformation during handling and maintaining them rigid during the deposition thereon.

Referring now in greater detail to the mountngs of the anodes and cathodes in the cells, it will be recalled that it has been mentioned above Ithat the hangers for the anodes and cathodes rest on strips 25, 25A`positioned on the side walls of the cells. Fig. 10 illustrates the position oftheelectrodes 'relative tojthesestrip's y'25. AIt, will be' are notched as indicated at 35, 35A, respectively@Y the. notches 35, 35A being formed lbetween' the-'"5 lugs 31, 31A, respectively. The ynotches and lugs with the lugs 31A and notches 35A of the opposite strip, so that the strip 25 and the anode hangers 23 will be supported at one end by the lugs 31, while at the opposite strip 25A the anode hangers 23 register with the notches 35A, there being a substantial clearance between the anode hangers 23 and the said notches 35A.

'I'he cathode hangers 39 are positioned in like manner, the hangers 39 being supported on the lugs 31A adjacent to the clearance between the notches 35A and the anode hangers 23, and clearing the notches 35 of the strip 25 upon the lugs 31 of which rest the anode hangers 23. 'I'his arrangement effectively prevents any tendency for short circuits to be formed between the anodes and cathodes.

A It has been said that the anode hanger 23 comprises an internal copper conductor bar 21 with a lead sheath 29 cast therearound. Contact is between the anode plates II and the conductor bar 21, the function of the lead sheath being to protect the .conductor bar 21 from spray from the electrolyte; for when zinc sulphate is the electrolyte, the sulphuric acid present therein has a markedly corrosive action on copper, and there would result a very harmful contamination of the electrolyte with copper sulphate were not this conductor bar 21 protected by the sheath 29. At a 75 CTI point adjacent to one end, the conductor bar 21 is benty downwardly as indicated at 4|, and the lead sheath 29 slopes similarly as indicated at 43. These sloping portions extend beyond the inner walls of the cells and cause any condensed electrolyte which may contact with the exposed end of the conductor bar 21 to run outside of the cells, thereby serving as a further preventative of electroyte contamination, as above referred to. When the anodes are assembled in the cells, they are mounted so that the ends of the anode hangers are clear of the strips 25A, the

plain ends of the anode hangers resting upon the lugs 31 of the strip 25. Theremaining details of the anode mountings will' be referred to fully hereinafter.

The cathode hanger 39 comprises an aluminum bar 45 which is grooved as indicated at 41. The cathode plate I3 is inserted in this groove and Welded in place. Of course, metals other than aluminum may be used, but aluminum is preferred owing to its low specific gravity. The cathodes are removed from the cells when not in use.

It will be observed, see Figs. 1 and 2, for example, that the cells A and B are spaced from each other, and that on the sides of the cells are mounted wooden brackets 53 which carry bus bars 55, suitably of copper.

As will be seen from the drawings, each of the anode conductor bars 21 has secured to its bent end, by rivets 51, or the like, a copper contact shoe 59, these being secured to the bus bars 55 by cap screws 6|, thereby holding the anodes in proper spaced relationship when they are assembled. These shoes 59 are comparatively wide and flat, aring outwardly as indicated at 63. They also taper outwardly from top to bottom, as will be seen at 65, being substantially wider at their bottoms than at their tops.

In a somewhat similar manner, the cathode hangers 45 are provided, at one end of each, with copper contact shoes 49 adapted to enter between the anode shoes 59 and be wedged therebetween. For this purpose the cathode shoes are tapered inwardly from a point intermediate their tops and bottoms, as indicated at U, the slope of this taper being somewhat greater than the slope of the taper 65 of anode shoes 59 to enable the cathode contact shoes to become wedged between the anode shoes as clearly shown in Figs. 5 and 7, so that when the anodes and cathodes are assembled in the cell, the cathode shoes are held thereby out of contact with the bus bar 55. This wedging of the cathode contact shoe 49 between the anode shoes maintains the Vcathode plates in alignment relative to the anodes. As will be seen from Figs. 'l and 8,' the cathode contact shoes 49 need not be beveled for their'entire length. The contact shoes 49 are riveted to the cathode bars 45 by rivets 52. The beveled portions of the contact shoes 49 are indicated at 56, Fig. 7.

For lifting the cathodes from the cells, the cathodesl are provided with lifting lugs 54 which are adapted to be engaged by lifting instrumentalities on a crane, not shown, so that a number of cathodes may be removed from the cell at one time, and replaced; and the contour of the cathode contact shoes is such that the weight of an operator standing on a board or'the like laid across the cathode bars '45 of one cell while posi tioning the cathodes of the adjacent cell will cause the cathode contact shoes to become wedged between the anode shoes 59.

During operation of the cell, current ows from the cathodes of one cell to the anodes of the adjacent cell, passing through the electrolyte from anodes to cathodes in each cell, during which passage the electrolyte is circulated as-described above, and as indicated by the arrows on the drawings; current passes from both surfaces of each anode to the adjacent cathode surfaces; and because of the presence of the wooden strips 3| along the edges of the cathodes which prevent deposition of metal to the very edges of the cathodes, the deposit is rendered very accessible for stripping. These strips 3| being only in frictional engagement with the cathode plates I3 are readily removable and replaceable.

It will be apparent, of course, that the present invention is not limited to the exact detalls of construction herein specifically illustrated and described, and which are to be regarded as being only illustrative of a convenient form of -the invention as assembled and constructed; and it will be apparent that many modifications of these specific details may be readily effected by one skilled in the art without departing from the inventive concept. It'will be understood, therefore, that it is intended and desired to embrace within 'the scope of this invention suchl modifications and changes as may be necessary to adapt it to varying conditions and uses.

What is claimed is:

1. Electrolytic apparatus comprising the combination with an electrolytic cell, of spaced electrodes therein, and marginal side strips on the electrodes forming compartments through which electrolyte is adapted to be circulated during electrolysis, the strips having tapered ends to form guides upon engagement of corresponding strips with each other for guiding the electrodes into proper alignment during assembly thereof.

2. Electrolytic apparatus comprising the combination with an electrolytic cell, of spaced electrodes therein, and marginal side strips on the electrodes forming compartments through which electrolyte is adapted to be-circulated during electrolysis, the strips of one electrode being tapered at their upper ends while the strips of' the next electrode are tapered at their lower ends to form guides upon engagement of corresponding strips with each other for guiding the electrodes into proper alignment during assembly thereof.

3. Electrolytic apparatus comprising the combination with an electrolytic cell, of spaced electrodes therein defining cathodes and anodes, there being -an anode between each pair of cathodes, the cathodes and anodes comprising sheets denin-g compartments therebetween through which electrolyte is adapted to circulate, and hangers for the anodes and cathodes to which the sheets thereof are secured for suspending the cathodes and anodes vin the cell, the anode hangers being of high conductivity metal attackable by the electrolyte being electrolyzed but being provided with a sheath insoluble in the electrolyte being electrolyzed for protecting the hangers against corrosive action of the electrolyte and preventing contamination of the electrolyte by materi-al from the hangers, the said hangers and sheath being formed at one end into "a guide for electrolyte collected thereon for causing the collected electrolyte to drain outside of the cell, the cathode hangers being of material innocuous to the electrolyte.

4.- An electrolytic anode comprising an anode sheet, a conductor bar to which the anode sheet is secured, the conductor bar being of high conductivity metal, and a protective sheathl about the conductor bar to protect the latter from electrolyte collecting thereon, the conductor bar and sheath having a downwardly extending portion adjacent to one end thereof for directing collected electrolyte to the outside of the cell in which the anode is used.

5. Electrolytic apparatus comprising the combinationlwith electrolytic cells in side-by-side position, of spaced electrodes in the cells defining cathodes and anodes having electrolyte circulation compartments therebetween, oppositely disposed supporting bars for the electrodes on the cells, the supporting bars comprising a series of upstanding lugs defining notches therebetween, hangers for the cathodes supported at one end on the lugs of one of the sup-porting bars and having their other ends in the notches of the opposite bar but clearing the said bar, and hangers for the anodes having one end thereof supported on the lugs of the supporting bar cleared by the cathode hangers and extending into the notches, but clearing the same, of the bar upon the lugs of which the cathode hangers are supported.

6. Electrolytic apparatus comprising the combination with electrolytic cells in side-by-side position, of spaced electrodes in the cells defining cathodes and anodes having electrolyte circulation compartments therebetween, electrode supporting bars on opposite sides of the cells and provided with spaced notches, the bars being disposed so that the notches of one bar are in opposition to the lugs of the opposite bar, electrode hangers supported on the lugs of the said bars and substantially extending into, but clearing, the notches of the opposite bar, supports intermediate thel cells for the electrode hangers, contact shoes for the anode and'cathode hangers, and means securing the anode hangers to the supports intermediate the cells for securing the anodes in proper predetermined spaced relation, the contact shoes for the cathodes being adapted to become wedged between the cath-ode shoes for the anodes, thus removably positioning the cathodes in proper alignment with the anodes when the cells are assembled.

'7. Electrolytic apparatus comprising the combination with electrolytic cells in adjacent sideby-side relation, of spaced electrodes in the cells defining cathodes and anodes, conductor bars for the cathodes and anodes extending -across the cells, means for rigidly holding the anode conductor bars in position on the cells, the said anode conductor bars defining wedge-shaped spaces therebetween, and contact means on the cathode conductor bars adapted toI be wedged in the spaces between adjacent anode conductors for removably securing the cathodes in proper alignment with the anodes.

8. Electrolytic apparatus comprising the combination with electrolytic cells in adjacent sideby-side relation, of spaced electrodes in the cells defining cathodes and anodes, conductors for the cathodes and anodes extending across the cells, and contact shoes on the conductors, the contact shoes of the cathodes of one of the cells being adapted to be wedged between the contact shoes of the anodes of the adjacent cell for removably securing the cathodes in proper alignment with the anodes While enabling current to pass from one cell to the adjacent cell.

9. Electrolytic apparatus comprising the combination with electrolytic cells in adjacent sideby-side relation, of spaced cathodes and anodes in the cells, conductors for the cathodes and anodes extending across the cells, and tapered contact shoes on the conductors, the taper of the contact shoes of the cathode conductors of one cell enabling them to be wedged between the contact shoes of the anode conductors of the adjacent cell for removably securing the cathodes in proper alignment with the anodes thereby removably positioning the cathodesin proper alignment with the anodes when the cells are assembled while enabling current to pass from one cell to the adjacent cell. l

10. Electrolytic apparatus comprising the combination with electrolytic cells in side-by-side relation, of spaced electrodes in the cells delining cathodes and anodes, conductor bars for the cathodes and anodes extending across the cells, contact shoes secured to the anode conductor bars, means for rigidly holding the anode conductor bars in position on the cells, the anode contact shoes being tapered to dene wedge-shaped spaces therebetween, and wedgeshaped contact shoes on the c-athode conductor bars adapted to be wedged in the spaces between adjacent anode conductor shoes for removably securing the cathodes in proper alignment with the anodes.

WILLIAM H. BITNER.

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