US2330415A - Electrolytic alkali chlorine cell - Google Patents

Description

p 23, 1943- -J. A. FLYNN ETAL. 2,330,415

' ELECTROLYTIC ALKALI CHLORINE'CELL Filed Sept. 11, 1940 s Sheets-Sheet 2 4 p 28, 1943- J. A. FLYNN E'l'AL ELECTROLYTIC ALKALI CHLORINE CELL Filed Sept. 11, 1940 3 Sheets-Sheet 3 Peteetet seetes, 1943 I 2,330,415

UNITED STATES PATENT OFFICE 2,330,415 ELECTROLYTIC ALKALI CHLORINE CELL John A. Flynn and John W. Ingersol, Tacoma, Wash., assignors to Hooker Electrochemical Company, Niagara Falls, N. Y., a corporation of New York Application September 11, 1940, Serialllo. 356,338 s Claims. ((1204-6257) More particularly our invention relates to an fills the entire space between the uppermost alkali chlorine cell for production of caustic alflanges of I beam I nearly to the upper edges of kali, chlorine and hydrogen from alkali metal the flanges. It is formed by pouring the molten chlorides. lead into the channel and allowing it to flow t Our invention is a modification of the alkali around the ends of the anode blades. Each anode chlorine cell disclosed in Patent No. 1,866,065. blade has the holes drilled through it below the One object of our invention is to provide a cell level to which the blade is to be immersed in the having certain of the characteristics of the cell molten lead. Each blade is also notched where disclosed in this patent, but adapted to replace it is contiguous with the adjo in blade, to P cells of the elongated type in cell houses already vide clearance between the ends of conti constructed and provided with foundation piers blades. The lead flowing through these holes spaced for cells of that type. Another object of and clearances anchors the blades in the lead our invention is to provide a cell of the general slab securelytype referred to but having no concrete in its In order to protect the steel and lead of the construction. anode assembly against electrolysis, their upper- Referring to the drawings: surfaces are coated with a layer of bitumen H. Fig. 1 is a side elevation of our cell, in section hi i likewise poured n le mo n fl w along the line a-a of Fig. 2, to show its interior through the clearances between contiguous blades, construction. In Fig. 3 the plane of the section is behind the Fig. 2 is a plan view of our cell, in section left hand anode and in front of the right hand along line 19-12 of Fig. 1. blade so that the bitumen is in section on one Fig. 3 is an end elevation of our cell to a larger side only. scale, in section along the line c of Fig, 2, The cathode assembly comprises an elongated Figs. 4, 5 and 6 are perspective views showing rectangular main fr me formed of two io s details of construction of the cathodic electrode 05 and two short members, of Cha section. e

membe s. ed at the corners. The shape and proportions of Fig. '7 is an enlargedplan view showing further frame l2 conform to those of the anode assemdetails of construction of said members. y base member and the lower flange of frame Referring to the figures: I2 is adapted to rest at the ends of the frame The cell comprises an anode assembly, a cath- 3 upon insulating blocks 6 and bitumen layer ll. ode assembly resting upon it and a cover resting The active surface o the Cathode a s y upon th th d assembly, consists of a series of flattened, tubular, forami- The anode assembly comprises a built up elonnous cathodic electrodes l3, preferably of steel gated rectangular steel structure consisting of Wire screen. extending transversely ,Of .frame large I b a I, laid flat n it sid angles 2 placed with their flat sides vertical and alternatand filler strips 3, which make up the bottom ing With anode blades 8. The thickness of these nd id n of a trough-shaped base member, cathodic electrodes 13 is somewhat less than the the ds of whic r closed by plates 4 and 5 space between the faces of adjacent anode blades,

and insulating blocks 6, which are retained i so that clearance is left for circulation of the position by straps 1. Blocks 6 serve not only to 41 e e ro yte. T e height of these cathodic elecinsulate the cathode assembly from the anode trodes is the same as that Of frame The passembly but also to carry its weight. per and lower edges of these electrodes are I The uppermost flanges and web of I b l rounded; that is to say, the flat side walls are form between them a channel within which the J ined by fillets, pre e y semicircular, at p anodic electrodes, consisting of graphite blades and bottom. thus aveidihg sharp a es- The f 8, are mounted. 'Anode blades 8 are thin, fiatlength of anode blades 8 is such that their upper faced elongated plates. They are placed with ends extend to about the e e htastheupth i longer d e d hence th i flat face per edges of cathodic electrodes I3. Between the.

vertical. In the embodiment illustrated, they are lower edges of these cathodic electrodes and lay r arranged in pairs, edge to edge. each pair e H clearance is likewise provided for circulation tending transversely of the channel formed by of electrolyte. i I beam B t adj cent pairs of anode Cathodic electrodes 13 not only lie between blades extend the hollow foraminous cathodic anode blades 3 but Preferably also enclose their electrodes to be described in detail later. The Outer Vertical edges. as Will Clearly pp a t lower ends of the anode blades are embedded for Fig. 2. The construction of the cathodic elecn. short distance in slab 9, of low melting metal trodes will be more readily understood by refer- 1 or alloy, such as solder or lead, preferably the ence to Figs. 4, 5 and 6, which illustrate one latter, which serves not only to hold the anode method of forming these electrodes. As thus blades in position, but also to conduct electric constructed each electrode is made up of two current to them from steelIbeam I. Lead slab 9 sheets of wire screen l5. Each sheet is first wrapped around a form having the dimensions of the active upper portion of a pair of contiguous anode blades, as they are s et up in the anode assembly, plus the clearance desired for circulation of electrolyte at the flat faces and edges. The two ends of the sheet are butted and welded together along seam I6, forming a flattened cylinder (in the mathematical sense, in which a cylinder is any surface generated by a straight line moving parallel to itself). The upper and lower edges of the "cylinder" are then peened outward, preferably over a 90 degree circular fillet, until they form flanges at top and bottom of the "cylinder." Two of these sheets are then butted and welded together along seam I'I. When the desired number of cathodic electrodes I3 have been formed in this way (depending upon the current under which the cell is designed to operate and other practical considerations), scallops are cut out of four strips of wire screen, of which short sections are illustrated at I8 (Figs. 4, 5 and 6). The radii and pitch of these scallops are the same as those of the rounded ends of the flanges of cathodic electrodes I3. The scallops.of strips I8 are then welded to the corresponding rounded ends of the cathodic electrode flanges, as illustrated by the dotted lines in Fig. 7. The completed assembly of cathodic electrodes I3 and strips I8 is then placed inside frame I2 and the straight outer edges of the strips I8 butted against and welded to frame I2 along the sharp edges which the upper and lower surfaces of the flanges make with the inner surface of the.

web of the channel section. As cathodic electrodes I3 are of the same height as the channel of which frame I2 is formed, strips I8 are flush with the top and bottom surfaces of the flanges of frame I2. Finally, rods I 9 are pushed transversely through holes in the web of frame I2 and the hollow interior of the cathodic electrodes I3 and welded to frame I2 at their ends. These rods are of a diameter slightly less than the clear interior width of members I3, so that they slide through freely, but are nevertheless adapted to support the side walls of electrodes I3 against collapse under hydrostatic pressure. The clearance between the rounded ends or roots of electrodes I3 and the inner faces of the web of the channel forming frame I2 provides a space into which the liquid and gaseous products of electrolysis are received. This space forms a passage extending along each side of the cell and across the ends, through which passage the liquid and gaseous products of electrolysis are conducted to their respective exits, to be indicated later.

The top or cover of the cell comprises an elongated rectangular steel main frame 20, formed by two long and two short members, of angle section, welded at the corners. The shape and outer dimensions of frame 20 conform to those of frame I2 and the horizontal leg of the angle is adapted to rest upon the upper flange of the latter frame. Between the upper legs of the angles forming the long sides of frame 20 is sprung an arch of wire screen 2|, welded along its edges to the frame. The ends of this arch are likewise closed by wire screen 22, welded to the screen of the arch at the edges. Screen 2I and 22 is coated on both sides and through the mesh with bitumen 23, or equivalent chlorine-resistant, non-conducting, preferably thermo-plastic material, the coating of bitumen extending down inside the vertical legs of the angles comprising frame 20 and beneath their horizontal legs. Bitumen coating 23 is protected on the outside by a covering 24 of fibrous material, which may be asbestos fiber and cement.

At a number of points e. g., four, spaced longitudinally of the cell, straps 25, terminating in lugs 26, are provided. The base number of the anode assembly is likewise provided with lugs 21, extending beyond angle 2 and positioned to conform with lugs 26. By means of lugs 26 and 2! and bolts 28 the three parts of the cell, namely the anode assembly, cathode assembly and cover, may be securely bolted together so as to form liquid tight joints between them.

The wire screen of the cathodic electrodes is coated with a permeable diaphragm, as indicated by the speckled surfaces, dividing the cell into anode and cathode compartments. This is preferably of asbestos fiber, and may be applied in accordance with the process disclosed in U. S. Patent Nos. 1,855,497 and 1,865,152. I

The fiber coating 24 of the cell cover serves to insulate the cell against radiation of heat through its top surface. This insulation may be augmented by a coating of similar material 29 within the flanges of the channels forming frame I2.

Current is conducted to and from the cell by means of bus bars 30 and 3I, connected to the cathode and anode assemblies respectively.

Electrolyte is supplied to the cell through orifice 32. The liquid product is withdrawn through pipe 33. The chlorine escapes at 34 and hydrogen at 35.

While we have illustrated and described one type of construction of our cell, we do not wish to be strictly limited thereto. Any equivalent construction would come within the scope of our invention. In particular, other methods of forming the cathodic electrodes I3 will suggest themselves to persons skilled in the art. Broadly speaking, we claim any construction in which flattened, tubular, foraminous, diaphragm-covered cathodic electrodes, alternating with flat sided anodic electrodes, extend between side walls in which openings are formed through which liquids percolating through the diaphragm, as well as liquid and gaseous products of electrolytic decomposition and chemical reaction,- can be drawn off.

We claim as our invention:

1, In an electrolytic alkali chlorine cell, a cathode assembly comprising a fiat, normally level, rectangular, liquid-retaining, metal plate frame structure, having end and side members adapted to carry the cell current, and housing an inner, foraminous, caustic alkali-resistant metal structure comprising a plurality of tubular, parallel, spaced, horizontally aligned, cathodic electrodes, each comprising a top wall, a bottom wall and two flat side walls and having its ends conductively fixed each to the inner surface of one of the side walls of said frame structure, adjacent cathodic electrodes being separated by clear spaces open at top and bottom and adapted to alternate and co-operate with upright, flat-sided, chlorine-resistant anodic electrodes projecting upwardly from below, said foraminous structure being adapted to be covered on its anode facing surfaces with permeable, chlorine-resistant diaphragm' material, and means for withdraw ng gaseous and liquid products of electrolysis from the interior of said cathodic electrodes.

2. In an electrolytic alkali chlorine cell, a cathode assembly comprising a flat, normally level, rectangular, liquid-retaining, metal plate frame structure, having end and side members adapted adjacent cathodic to carry the cell current, and housing an inner, foraminous, caustic alkali-resistant metal structure comprising a plurality of tubular, parallel, spaced, horizontally aligned, cathodic electrodes extending perpendicularly with respect to said side walls, each comprising a top wall, a bottom wall and two flat side walls and having its ends conductively fixed each to the inner surface of one of the side walls of said frame structure, adjacent cathodic electrodes being separated by clear spaces open at top and bottom and adapted to alternate and co-operate with upright, flatsided, chlorine-resistant anodic electrodes projecting upwardly from below, said foraminous structure being adapted to be covered on its anode facing surfaces with permeable, chlorineresistant diaphragm material, and means for withdrawing gaseous and liquid products of electrolysis from the interior of said cathodic electrodes;

3. In an electrolytic alkali chlorine cell, a cathode assembly comprising a flat, normallylevel, rectangular, liquid-retaining, metal plate frame structure, having endand side members adapted to carry the cell current, and housing an inner, foraminous, caustic alkali-resistant metal structure comprising inner end walls paralleling the end walls of said plate structure and conductively afilxed thereto at top and bottom and a plurality of tubular, parallel, spaced, horizontally aligned,

cathodic electrodes, adjacent cathodic electrodes being separated by clear spaces open at top and bottom and adapted to alternate and co-operate with upright, flat-sided, chlorine-resistant anodic electrodes projecting upwardly from below, said foraminous structure being adapted to be covered on its anode facing surfaces with permeable, chlorine-resistant diaphragm material, each of said cathodic electrodes comprising a top wall, a bottom wall and two fiat side walls, leaving both ends open, the spaces electrodes being bridged at the ends, forming discontinuous inner walls along the side walls of said plate structure, with corridors between into which the cathodic electrodes may freely deliver products of electrolysis, the spaces between outer side walls of outer cathodic electrodes and said inner end walls being likewise bridged at their ends, the outer edges of said top and bottom walls and upper and lower edges of the bridge walls being conductively joined through fitted filler strips to the inner surface of the side walls of said frame structure; and means for withdrawing products of electrolysis from within said corridors.

4. In an electrolytic alkali chlorine cell, a cathode assembly comprising a flat, normally level, rectangular, liquid-retaining, metal plate frame structure having end and side members adapted to carry the cell current and housing an inner, foraminous, caustic alkali-resistant metal structure comprising a plurality of flattened foraminous metal cylinders outwardly flanged at their ends, the length of the flanged cylinders being substantially equal to the height of said frame,

said cylinders being aligned with their axes vertical and joined by the edges of the flanges along their adjacent flat sides, the free edges of the resulting unitary structure being conductively joined to the walls of said frame structure by fitted filler strips, said resulting unitary structure constituting a plurality of thin, parallel,

between the side walls of aphragm spaced, aligned, tubular, foraminous cathodic electrodes open at both ,ends and separated by clear spaces open at top and bottom and adapted to alternate and co-operate with flat-sided, chlorine-resistant anodic electrodes projecting upwardly from below, said foraminous structure being adapted to be covered on its anode facing surfaces with permeable, chlorine-resistant dimaterial, and means for withdrawing gaseous and liquid products of electrolysis from the interior of said cathodic electrodes.

5. In an electrolytic alkali chlorine cell, a cathode assembly comprising a flat, normally level, rectangular, liquid-retaining, metal plate frame structure having end and side members adapted to carry the cell current and housing an inner, foraminous, caustic alkali-resistant metal struc ture comprising a plurality of flattened foraminous metal cylinders outwardly flanged at their ends, the length of said cylinders being substantially equal to the height of said frame, said cylinders being aligned with their axes vertical and having the edges of the flanges along their adjacent flat sides butted and joined, the free edges of the resulting unitary structure being conductively joined to the Walls of said frame structure by fitted filler strips, said resulting unitary structure constituting a plurality of thin, parallel, spaced, aligned, tubular, foraminous cathodic electrodes open at both ends and separated by clear spaces open at top and bottom and adapted to alternate and co-operate with fiat-sided, chlorine-resistant anodic electrodes projecting upwardly from below, said foraminous structure being adapted to be covered on its anode facing surfaces with permeable, chlorine-resistant diaphragm material, and means for withdrawing gaseous and liquid productsof electrolysis from the interior of said cathodic electrodes.

6. In an electrolytic alkali chlorine cell, a cathode assembly comprising a flat, normally level, rectangular, liquid-retaining, metal plate-frame structure having end and side members adapted to carry the cell current and housing an inner, foraminous, caustic alkali-resistant metal structure comprising a plurality of flattened foraminous metal cylinders each having two long flat and, two short rounded sides and outwardly flanged at their ends, the length of said cylinders being substantially equal to the height; of said frame, said cylinders being aligned with their axes vertical and joined by the edges of the flanges along their adjacent flat sides, the scalloped edges of the resulting unitary structure formed by the flanges of said ShOItl'Olll'ldBd sides being conductively joined to the walls of said. frame structure by fitted filler strips, said resulting unitary structure constituting a plurality of thin, parallel, spaced, aligned, tubular, foraminous cathodic electrodes open at both ends and separated by clear spaces open at top and bottom and adapted to alternate and co-operate with flat-sided, chlorine-resistant anodic 'electrodes projecting upwardly from below, said foraminous structure being adapted to be covered on its anode facing surfaces with permeable, chlorine-resistant diaphragm material, and means for withdrawing gaseous and liquid products of electrolysis from the interior of said cathodic electrodes.

JOHN A. FLYNN.

JOHN W.;'INGERSOL.

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