PL145260B1 - Filter press type electrolyzer - Google Patents

Description

The subject of the invention is a filter press type electrolyser with a bipolar electrode. The electrolyser of this type uses selectively permeable ion exchange membranes placed in the plane between flat, parallel, porous and metal cathodes, when these anodes and cathodes are mounted at a certain distance from the liquid-impermeable structure a bipolar electrode that physically separates adjacent electrolysers. Such electrolysers are particularly suitable for the electrolysis of aqueous solutions of alkali metal chlorides, and in particular for the electrolysis of aqueous solutions of sodium chloride (brine). The electrolyser can also be used to electrolyze other solutions to obtain products such as potassium hydroxide, iodine, bromine, hydrogen bromide, persulfuric acid, hydrochloric acid, deater, tritium, adipic nitrile, and other organic compounds obtained by electrolysis. Such an electrolyser comprises a central element separating the anolyte chamber from the catholyte chamber. This type of construction reduces the cost of producing the electrolyser, reduces the labor consumption of their assembly, simplifies their production, significantly reduces the warping of the electrolyser parts and gives a more durable structure than in the previously used electrolyser type filter press with a bipolar electrode. Reducing the warping of the electrolyser structure allows His work more efficiently, that is, to produce a greater number of units of electrolysis products per unit of electrical energy. Reducing the warping reduces the deviation of the gap width between the anode and cathode of each electrolyser from the design value. This gap should be of equal width in the entire area between the anode and cathode so as to obtain an even distribution of the current density between the electrode surfaces. Among other things, the deformation of the structure causes the change of this gap, as a result of which some parts of the anode and cathode are closer to each other than others.2 145 260 In these places the resistance is lower, the intensity of the electric current is higher, and therefore the electric heating is greater * This is electric heating in many cases it is sufficient to damage the diaphragm at these points. Such places of unacceptably high electric current and high heat are called hot spots. To avoid these hot spots, electrolysers are constructed with a gap between the anode and cathode greater than desired * This increases the operating voltage of the electric components - Trolyser 1 reduces the efficiency of the electrolyser. Another disadvantage of such cells is the complex construction and production method. Examples of bipolar electrode filter press electrolysers arranged in series are also described, for example, in U.S. Patent Nos. 4,111,779 and 4,017,375. Other electrolysers. of the type of flat plate filter press, bipolar plate electrode are also disclosed in U.S. Patent Nos. 4,364 81 $; 4,115,236; 3,960,698; 3,859,197; 3,752,757; 4,194,670; 3,788,966; 3,884 781; 4 137 144 and 3 960 699 There are also known complicated and intricate ways of electrically and / or mechanically connecting different parts of the electro-coil *, in which one hundred Titanium and titanium alloys are used. The complication is especially related to the spacer parts that connect the flat plate anode and cathode of the bipolar electrode structure to the electrically conductive center baffle, for example as shown in U.S. Patent Nos. 4,111,779 and 4,194. 670. Other spacers are used to support flat plate electrodes and to electrically and mechanically connect them through openings in a non-conductive baffle, for example, as shown in U.S. Pat. Nos. 3,752,757 and 3,960,698. Welding and / or screws are used to connect the spacers to the electrodes and to the center wall, and to the opposing spacers passing through the center wall, by welding and / or screws. There are many problems with such combinations in ensuring an adequate distribution of the electric current. The cell according to the invention is of the filter press type, with a bipolar electrode, it can be combined with other cells to form a series of cells, with each cell in the row being separate from its neighbor. by a selectively permeable ion exchange membrane sealed between the electrolysers, each electrolyser having a central element that separates the anolyte chamber situated on one side of the electrolyser element from a catholytic chamber situated on the opposite side of the electrolyser element, and the central element of the electrolyser has an anode fitted on one side to form an anolyte chamber and a cathode on the opposite side to form a catholyte chamber, said electrolyser element having an anode electrically connected therewith to the cathode, the central element being y is integrally made of a single unitary die-cast metal and includes a planar baffle, a circumferential flange, and anodic and cathodic spacers to hold the anode and cathode of two adjacent cells at a predetermined distance from the planar baffle. The anodic spacers are multiple anode projections projecting a predetermined distance outward from the planar partition to the anolyte chamber adjacent to the planar partition, which anode projections are mechanically and electrically connected either directly to the anode or indirectly to the anode via at least one compatible anode. intermediate, located between the anode and the anode lugs. Furthermore, the cathode spacer elements comprise a plurality of cathode projections projecting a predetermined distance outwardly from the planar baffle to the cathode chamber adjacent to the planar baffle, which cathode extensions are mechanically and electrically connected either directly to the cathode or through at least the cathode indirectly at least. one compatible intermediary metal, located between the cathode and the cathode lugs. The anode lugs are arranged so that the anolyte freely circulates through the anolyte chamber and the cathode lugs are arranged so that the catholyte freely circulates through the catholyte chamber 145 260 3 The center piece is preferably cast from a metal selected from the group consisting of iron, steel, and stainless steel. , nickel, aluminum, copper, chrome, magnesium, tantalum, cadmium, zirconium, lead, zinc, vanadium, tungsten, iridium, rhodium, cobalt and their alloys. On the anolyte side of the central element there may be an insert made of a metal sheet matched to the surface of the element, the insert being made of electrically conductive metal which is resistant to corrosion caused by the anolyte chamber environment and is adapted to the anode islands and is connected to the anode protrusions * In addition, the insert is pressed sufficiently around the spaced anode protrusions towards the planar barrier in the spaces between the protrusions, to allow free circulation of the anolyte between the encased electrolyser element and the membrane of the adjacent electrolyser. not by means of an intermediate metal plate which is located between the lugs and the insert, but the intermediate plate is made of a weldable metal, which is also compatible with both the metal of the insert on the anolyte side and with metals m from which the central element is made * It is advantageous if the central element is made of a ferrous material, and the analytical side insert is made of a metal selected from the group consisting of titanium, tantalum, niobium, hafnium, zirconium and their alloys * Between anode and The insert on the anolyte side is preferably provided with metal intermediate plates, each of which has at least two layers of metal bonded together, the outer metal layer on one side of the intermediate plate resting on the anode shoulder and the outer metal layer on the opposite side of the intermediate plate. it rests on an anolyte side insert * The metal layer of the intermediate plate resting on each anode protrusion is compatible with the anode protrusion material and is properly welded to the anode protrusions, and the metal layer on the side of the intermediate plate resting on the anode side insert is compatible with the metal from which it is made This anolyte side liner is suitably welded to the liner so that the liner is welded to the anode lugs via the intermediate plates. Preferably, the vanadium intermediate lamellae are positioned between the anode lugs and the adjoining titanium anolyte liner, the titanium liner being welded to protrusions of the iron material through the vanadium intermediate plates * It is advantageous if the electrolyser on the catholyte side of the central element has a catholytic insert made of a metal sheet that fits the surface of the element. * This catholytic insert is preferably made of an electrically conductive metal that is resistant to Corrosion caused by the environment of the cathode chamber and is fitted around the cathode projections, and is connected to the cell element at the cathode projections. Moreover, the insert is pressed sufficiently around the distributed cathode projections towards the planar barrier in the spaces between the heights. tepami, to allow free circulation of the catholyte between the encased element of the electrolyser and the membrane of the adjacent catholytic chamber * This insert replaces the surfaces of the cell adjacent to the catholytic chamber, as a septum in contact with the catholyte * The catholyte insert is attached to the cathode element by welding by welding placed between the protrusions and the insert * The metal of this intermediate piece is not only suitable for welding as such, but is also compatible with the metal of the catholyte side insert and with the metal of the electrolyser central element * The central element is preferably made of an iron material, and the metal of the catholic plug is selected from the group of metals consisting of ferrous metals, nickel, nickel alloys, chromium, tantalum, cadmium, zirconium, lead, zinc, vanadium, tungsten, iridium and cobalt. is between the cathode out and out stepami and the Catholic insert. Each intermediate piece has at least two layers of metal bonded together and one layer of the intermediate piece metal in contact with each cathode shoulder is compatible with the ferrous metal from which the cathode projections are made and is suitably welded to the cathode shoulder. In addition, the metal layer on the side of the intermediate piece bearing on the catholyte plug is compatible with the metal of the catholyte plug when welded and is suitably welded to this plug so that the plug is welded to the cathode projections through the intermediate pieces. The catholyte insert and the cathode metal of the adjacent electrolyzer are selected from the ferrous metals * Preferably the membrane is in contact with the anode * Each electrolytic cell of the electrolyser preferably comprises a bipolar depolarized electrode and is of the filter press type. Casting spacers in the center partition eliminates many of the connections by screws and welding, which have previously caused uneven distribution of electric current. In addition, the joints used to connect the central baffle to the circumferential structure of the anolyte and catholyte chambers are also eliminated, due to the integral casting of these structures in the center baffle. Cast individual electrolyser structures have eliminated most of the problems common to welded, welded and bolted structures. As a result, the electrodes of the electrolyser remain parallel. There is a more uniform distribution of the electric current and the reaction of the electrolyte in the electrolyser during its operation. The solution of the invention also significantly reduces the risk of titanium hydride formation by creating a structure that has a titanium insert with a very small number of stress points and by locating these stress points a long distance from the source , relative to the path through the steel to be traveled to achieve any of these stress points. The only points of stress found in the hot stamped titanium liner are at those locations where it is welded to the ends of the integrally cast anode lugs. Although the present invention has been discussed in general with respect to the generally used steel and titanium, it is not limited to these materials, although they are preferred materials for the construction of the electrolyser components. The subject matter of the invention is explained in an example embodiment in the drawing in which Fig. 1 shows a single element of the electrolyser in a disassembled state, partially broken away, with accompanying parts forming one filter press type electrolyser with a bipolar electrode composed of several such cells, Fig. 2 - three filter press type electrolysers with individual electrolyser elements according to the invention, in a section along the line 2-2 of Figs. 4 and 5, Fig. 3 - the structures of the electrolyser in a section along the lines 3-3 of Figs. 4 and 5 in a disassembled state, Fig. 4 - the electrolyser in a front view from the cathode side with partial tearing, and Fig. 5 shows the electrolytes in a view from the anode side with a partial cutout. tearing up. 1, 2 and 3 illustrate an electrolyzer 10 of the type of a double-pole electrode filter press, using a preferred embodiment of a single-unit central element 12. Such an electrolyzer is also referred to as a flat-plate electrolyser. it is made of steel. It has a solid center baffle 14, a circumferential flange 16 extending laterally from both sides of the circumference of the median baffle 14, protruding and spaced anode projections 16, and protruding and spaced cathode projections 20. Due to the fact that all these parts are integrally cast into with one central element 12, many problems are eliminated or significantly reduced simultaneously. For example, most of the sample-145 260 5 test related to warping, fluid leakage, poor current distribution, and complications in the design of the electrolyser in mass production are significantly reduced. This simplicity of the electrolyser structure allows the construction of electrolyser elements that are more reliable and cheaper. * On the right side of the central element 12 the anolyte chamber 22 of an adjacent element is shown, and on the left side of this central element 12 the catholyte chamber 24 of the other adjacent element of the cell is shown. The central element 12 thus separates the two links. A very important feature of this type of electrolyser is that electricity is transferred from one cell to another cheaply. On the anolyte side of the central element 12 there is an insert 26 made of a single titanium sheet. The insert 26 is hot stamped to conform to the surface of the unit central element 12 on its side facing the anolyte chamber of the electrolyser. This is to protect the steel of the centerpiece 12 from the corrosive environment of the analysis chamber 22. The insert 26 also forms the left hand boundary of the anolyte chamber 22, while the right hand boundary (as shown in FIG. 3) forms an ion exchange membrane 27. The center piece 12 is molded so that its circumferential structure forms a flange 16 which serves not only as the circumferential boundary of the anolyte chamber 22, but also as the circumferential boundary of the catholyte chamber 24. The titanium liner 26 is preferably made without stress to provide a liner that cannot attack. rapidly atomic hydrogen with the formation of brittle, electrically non-conductive titanium hydrides. As is known, atomic hydrogen attacks titanium faster with stresses. Such stresses in the liner were avoided by hot forming the liner in the press at a temperature of 482-538 ° C. Both the metal of the liner and the press are heated to this temperature prior to pressing the liner to give the desired shape. The insert is then kept in the heated press for about 45 minutes. to avoid stress formation in it when cooled to room temperature. A titanium insert 26 is attached to the cast steel center piece 12 by resistance welding. This is done indirectly by welding the liner 26 to the flat ends 20 of the cone-shaped anode shoulders 18 through the vanadium plates 30. Vanadium is a metal readily welded and compatible with titanium and steel for welding. The term "compatible when welding" means that one metal to be welded forms a ductile steel solution with the other metal to be welded after the two metals are welded together. Titanium and steel are not compatible when welded together, but are compatible when welded to vanadium. For this reason, the tray plates 30 are used as an intermediate metal between the steel anode protrusions 18 and the titanium insert 26 to allow them to be welded together to establish an electrical connection between the insert 26 and the central element 12 of the electrolyser, as well as to provide support. mechanical for the central element 12 of the electrolyser to support the insert 26. The advantageous fit of the insert 26 on the anolyte side with the central element 12 of the electrolyser can be seen in FIG. 2 of the drawings. The insert 26 is embossed with 32. These embossings are in the shape of a truncated cone with an embossing inside. The embossings 32 have such dimensions and are positioned so as to conform to the anode protrusions 18. The depth of the embossings is such that their inner ends 34 abut the vanadium plates 30 when the plates 30 abut the flat ends 28 of the anode protrusions 18. and when these elements are welded together. The shape of the islands and embossments is not critical. They may be square or any other convenient shape, however their ends 28 should be flat and they should all be on the same geometric plane. In fact, the anode studs and embossments may be shaped and positioned to allow anolyte and gas circulation. The liner 26 is resistance welded at the inner ends 34 of the embossings 32 to the steel flat ends 28 of the anode extrudates 18 through compatible vanadium plates 30 between them. welding. Anode 36 is essentially a flat sheet of expanded metal or titanium wire mesh, preferably coated with ruthenium oxide as catalysis. * It is welded directly to the outside of the flat ends 38 of the embossing 32 in the liner 26, such welds form a joint. electrical and mechanical support for the anode 36. Other catalytic coatings can be used * In Fig * 2, a diaphragm 27 is placed between the anode 36 of one electrolyser unit 10 and the cathode 46 of the next adjacent electrolyser unit 10 to form the electrolyser between the central partition 14 of each of two adjacent individual cells. central elements 12 of the electrolyser * The types of selectively permeable * membranes * suitable for use in the present invention are given in the following US patents: 3,909,378, 4,329,435, 4,065,366, 4,116,883, 4,126,588, 4,209,635, 4 212 713, 4 251 333, 4 270 996, 4 123 336, 4 151 053, 4 176 215, 4 178 218, 4 340 680, 4 357 218, 4 0 25 405, 4 192 725, 4 330 654, 4 337 137, 4 337 211, 4 358 412 and 4 358 547 A preferred solution according to the invention is a multi-chamber electrolyser with more than one membrane, e.g. a three-chamber cell with two membranes positioned in spacing from each other such that a chamber is formed therebetween, as well as a chamber formed on the opposite side of each membrane between each membrane and the electolyser unit 10 adjacent to it. The location of the anode 36 in the anolyte chamber 22 in relation to the membrane 27 and the central partition 14 clad with titanium is determined by the relationship between the distance that the flange 16 extends laterally from the central partition 14t the distance where the anode projections 18 extend from the central partition 14, the thickness of the vanadium plates 30, the thickness of the inserts, etc. of the drawing / fig * 2 / the anode 36 can be moved from a position where it rests against the membrane 27 to a position where there is a significant gap between the membrane on 27 and the anode 36, by varying the aforesaid relationships, e.g. by changing the distance that the anode projections 18 extend from the central partition 14 * It is preferable, however, that the collar 16 on the anolyte side of the middle partition 14 extends the same distance as the anode projections 18 from the center partition 14 * This simplifies the construction of the central element 12 of the electrolyser, since in this case the end surfaces 28 of the anode projections 18 and the flange surfaces 11a can be processed simultaneously in such a way that these surfaces are located in the same geometric plane * The same applies to similar surfaces on the catholyte side of the electrolyser center piece 12, i.e. it is preferred that the flat ends 40 of the cathode projections 20 and the surface -6c of the collar 16 on the catholyte side of the center piece 12 are machined to be positioned in same geometric plane * For the seal between diaphragm 27 and the eyelid The collar I6a is preferably cup-shaped with a rim 42 around the periphery * The rim 42 is flush against the flange face I6a * The circumference of the diaphragm 27 is flush with the rim 42 of the anolyte and the perimeter gasket 44 is flush with the flange 42 on the other side of the perimeter of the diaphragm 27 * In the series of electrolysers shown in FIG. 2, the gasket 44 is flush-fit with the flange face 16c on the catholyte side of the next adjacent central member 12 of the electrolyser and with the diaphragm 27 when there is no insert 48 * Although only one gasket is shown 44, the invention also includes the use of gaskets on both sides of the diaphragm 27. It also includes situations where there is no rim 42. On the side of the central element 12 of the electrolyser, opposite to the anolyte chamber, i.e. the catholyte side, there is no none of the Catholic clasps shown in Fig * 1, although show The catholytic insert 48 is shown in Figures 2, 3 and 4 * The existence of two inserts is sometimes desirable and sometimes not * Most often the metal from which the central element 12 of the electrolyser is cast is also suitable for use in either the catholytic chamber 24, or in an anolyte chamber 22.For example, in a series of electrolysers where electrolysis of aqueous sodium chloride solutions is carried out to generate a liquor and / or hydrogen gas in a catholytic chamber 24, ferrous materials such as steel are completely suitable for metal gels The components of the catholytic chamber at most of the cell operating temperatures and most of the slurry concentration * eg at a slime concentration below 22% and at an operating temperature below 85 ° C. Thus, if the central element 12 of the electrolyser is made of steel, and if a lye of less than 22 ° C is produced and the cell is operated at a temperature below 85 ° C, then the safety plug is not necessary on the catholyte side of the central element 12 to protect the steel element 12. against corrosion. However, a titanium liner 26 on the anolyte side is still needed *. So, for this reason, Fig * 1 does not show the liner 48 on the Catholic side. Instead, a flat, porous metal cathode 46 (also made of steel in the example of FIG. 1) is resistance-welded directly to the ends 40 of the cathode projections 20. Central element 12 of the electrolyser shown in FIGS. 2 and 3 on the catholyte side (left side) / is a mirror image of the anolyte side. The flange 16 forms the circumferential boundary of the catholyte chamber 24, while the central partition 14 and diaphragm 27 form the remaining boundaries. The spaced cathode projections 20 are solid cone-shaped projections extending outward from the central partition 14 into the catholytic chamber 24. A flat porous steel plate cathode 46 is welded directly to the flat ends 40 of the cathode projections 20, 3 and 4. a catholytic insert 48 is shown on the catholytic side made of a metal with high resistance to environmental corrosion in the catholytic chamber 24 * The metal must also be sufficiently ductile and workable so that a single sheet of metal can be extruded into the flat shape shown. This also includes the ability to emboss 70 on the sheet. The embossings 70 are positioned at gaps to match the gaps between the cathode projections 20. It is preferred that the catholyte plug 48 has an embossed rim 72 extending around its perimeter and abutting the flange surface 16c on that side of the electrolyser central element 12. which faces the cathode chamber 24. The catholytic plug 48 is preferably attached to the central element 12 of the electrolyzer by resistance welding of the inner ends of the insert extrudates to the flat ends 40 of the cathode lugs 20. Preferably, the metal of the catholyte insert 48 and the central element are 12 are compatible when welding together. If these metals are not compatible with welding, then intermediate metal plates or combinations of intermediate plates should be used which are compatible with the metals of the insert 48 and element 12. The plates 78 are positioned between the flat ends 40 of the cathode projections 20 and the inner ends 74. embossings 70 of the insert which correspond to the ends of the 40 protrusions and are welded to the ends of the 40 cathode protrusions 20. The catholytic insert 48 is then welded to the ends of the 40 cathode protrusions 20 through the metal plates 78. The cathode 46 is then welded to the outer ends 76 of the extrusions 70. The connection of each insert embossment 70 through the metal plate 78 to the end 40 of the cathode extension 20 can be made by only one welding operation, i.e. the metal plate need not be welded beforehand. The metal plates 78 and 30 can be made of a metal which is compatible for welding both to the metal of the electrolyser central element 12 and to metals m the corresponding inserts 26 or 48. It should be noted that the metal plates can have more than two layers of metal, so that, for example, a three-layer plate of titanium, copper and iron is formed. Both the flat anode 36 and the flat cathode 46 have their peripheral edges curled into the central element 12 and unwrapped from the membranes 27. This is done so that the sometimes sharp edges of these electrodes do not come into contact with the membranes 27 and do not damage them. It should be noted that the corners I6b of the circumferential flange 16 of the central element of the electrolyser are strengthened so that the electrolyser can operate at a pressure above atmospheric. The electrolyser may be round or rectangular, or any other shape that is convenient for you * The round shape will probably be the most practical for very high pressure operation. When energizing the electrolyser brine it works as follows. The brine is continuously supplied to the anolyte chamber 22 via channel 60, while fresh water may be supplied to the catholyte chamber 24 via channel 64 (FIGS. 4 and 5A). Electric power (direct current) is supplied through a series of electrolysers such that the anode is 36 of each electrolyser has a positive potential with respect to the cathode 46 of that electrolyser. Excluding depolarization of the cathodes or anodes, electrolysis is carried out as follows. Chlorine gas is continuously produced at the anode 36, sodium ions are transferred through the membrane 27 to the catholyte chamber by electrostatic attraction of the cathode 46. In the catholytic chamber 24, hydrogen gas and an aqueous sodium hydroxide solution are continuously produced. Chlorine gas and depleted brine flow continuously from anolyte chamber 22 through channel 62, while hydrogen gas and sodium hydroxide continue to flow from catholyte chamber 24 through channel 66. Depolarized electrodes may be used to inhibit the production of hydrogen or chlorine, or both if When several electrolysers are operated with a brine supply, certain operating conditions are favorable. In the anolyte chamber, it is preferable to maintain the pH in the range 0.5-5.0. The supplied brine preferably contains only small amounts of multivalent cations (less than 0.8 g / l based on calcium). Higher concentration of multivalent cations is possible with the same favorable results if the brine feed contains less than 70 ppm carbon dioxide when the pH of the brine feed is below 3f5. Operating temperatures may be in the range of 0-250 ° C, but preferably above 60 ° C. The brine purified from multivalent cations by ion exchange resins after conventional treatment is partially suitable for extending the life of the membrane. A low iron content in the brine feed is desirable in order to extend the life of the membrane. Preferably, the pH of the brine is kept below 4.0 by the addition of hydrochloric acid. Preferably, the pressure in the catholyte chamber is kept slightly higher than in the anolyte chamber, but preferably with a differential pressure of no more than 0.3 m head of water. This pressure difference is preferably controlled by expansion tanks as described in U.S. Patent 4,105,515. The operating pressure is preferably kept below 7 atm. Typically the electrolyser operates at a current density of 0.155-0.62 amps / cm2, but in some cases working with a density of 0.62 A / cm is perfectly acceptable. Where a metal insert is used on both sides of the electrolyser structure, a catholytic insert 48 made of nickel is desirable when the concentration of hydroxide in the catholytic chamber 24 is kept above 22% by weight and the operating temperature of the electrolyser is kept above 80C. Such a nickel plug 48 is fabricated, dimensioned, and mated with the electrolyser centerpiece 12 in substantially the same manner as the titanium plug 26 on the anolyte side. Since nickel and steel are compatible for welding, there is no need for a metal intermediate plate between them. It cannot be said, however, that the present invention precludes the use of compatible materials when welding metal plates between the cathedrals 20 and the catholyte plug 48 when an anolyte plug 26 is attached to the anode bosses 18 with or without an intermediate metal. The plug may be used on one side. on both sides, or it will not be used on the far side of the central element 12. Anolyte chamber inlet 56, anolyte chamber outlet 50, catholyte chamber inlet 56 and catholyte chamber outlet (not shown) are cast in the peripheral body flange 16, in that part of the flange which is connected to the anolyte chamber 22 and the catholyte chamber 24, respectively. When these chambers are provided with inserts 26, 48, corresponding openings are provided in the inserts. These openings are shown in Figures 1 and 2. The conduits connected to the respective openings are shown in Figures 4 and 5 as anolyte inlet channel 60, anolyte outlet channel 62, catholyte inlet channel 64 and catholyte outlet channel 66. 145 260 9 In addition to ferrous materials. such as iron, steel and stainless steel, the electrolyser center 12 can also be cast from other castable material such as nickel, aluminum, copper, chromium, magnesium, titanium, tantalum, casing, zircon, lead, tin, vanadium , tungsten, iridium, rhodium, cobalt and their alloys. Y / shutters 48 on the catholyte side are typically selected from these materials as well, usually excluding magnesium and aluminum * Inserts 26 and 48 on the anolyte and catholyte side are preferably made of machinable metal materials so that they can be formed from a single sheet to a shape in which they are shown in the figure. This includes the ability to be stamped to have the cone-shaped embossments 32 and 70 * The invention is not limited to the cone-shaped embossments 32, 70, nor to the anode and cathode studs 18 and 20 in the cone-shape . They can be shaped and positioned to direct the flow of electrolytes and gas in chambers 22 and 24 * Lugs 18 and 20 should have ends 28 and 40 flattened and parallel to the flat surface of the electrode to which they are to be connected * Ends 28 and 40 lugs 18 and 20 should have a sufficient surface area to which electrical connections to the respective electrodes can be made to obtain an electrical path of sufficiently low resistance. The lugs 18 and 20 should be arranged so as to provide a uniform and appropriate low electric potential gradient across the surface the electrodes to which they are attached * They should be arranged so as to allow free circulation of the electrolyte from any unoccupied point in the corresponding electrolyte chamber to any other unoccupied point in this chamber * The protrusions will therefore be uniform not arranged with respect to each other in the respective chambers * It should be noted that although the anode islands 18 and the protrusion The cathode yas 20 are shown opposite to each other on opposite sides of the center partition 14, need not be * They may be offset from each other * The materials of the anode and cathode projections 18 and 20 are the same as the material of the element central12, because an important feature of the present invention is that they are an integral part of this element * The inserts 26 and 48 on the anolyte and catholyte side should be electrically conductive, resistant to the chemical effects of the electrolyte chamber environment to which they are exposed, and malleable enough to be able to emboss 32 and 70 * The metals of inserts 26 and 48 on the anolyte and catholyte sides are usually different due to the different electrical corrosion conditions to which they are exposed * It is true not only in chlorine-hydroxide electrolytes, but also in other electrolytes * Metals must therefore be selected to be adjusted to the conditions to which they will be exposed * The preferred metal for the anolyte chamber insert 26 is titanium * Other metals suitable for such conditions are usually found in the following group: titanium, tantalum, niobium, hafnium, zirconium and atopes thereof. The catholyte side of the liner 48 is usually much greater than the number of metals suitable for the anolyte chamber side due to the fact that most metals are resistant to chemical attack at a relatively high pH in the Catholic and because of the electrical cathodic protection afforded by metal on the anolyte side of the electrolyser structure * Ferrous materials are usually preferred as metals for the catholyte side liner, including steel and stainless steel * Other liner materials include nickel, chromium, tantalum, cadmium, zircon, lead, tin, vanadium, tungsten, iridium, cobalt and alloys of each of these metals * As a rule, the metal that is used for the liner 48 of the catholyte is also suitable for the cathode 4 • This is likewise true for the insert metal 26 of the anolyte side and the anode 36. When an incompatible insert metal is used when welding to the metal of the center piece 12 and when the insert 26 or 48 is to be attached to the center piece 12 by welding, then between the protrusions the central element 12 and the metal inserts at the point where the welds are to be made, intermediate metal plates are placed. They may be in the form of a single metal plate, in the form of a multilayer metal plate, or in the form of a thin metal layer formed either on the electrolyte structure 12 or on the insert 26 or 48, Example I. A sample of the cell structure was cast from WCB steel grade SA, 216. The thickness of the middle partition was approximately 1.27 cm. The diameter of the base of the cone-shaped protrusion was 7.62 cm, and the upper diameter was 3.81 cm. The overall dimensions of the structure were approximately 40.64 x 50.8 cm with the ten lugs on each side (anode and cathode) directly opposite each other. The distance between the ends and the protrusions was approximately 6.35 cm. The finished cast had surfaces of excellent quality. Wipe ground samples for further testing. The sanded samples taken from the projections had no internal pores or the pores were minimal. The construction quality of the electrolyser was determined to be suitable for operation in a bipolar electrode. Example II. A sample of the cell structure was cast from WCB steel type SA, 216. This structure constituted corner sections for the proposed electrolyser. The overall dimensions of the structure were approximately 61 x 61 cm with a 1.27 cm thick central partition. The diameter of the base of the cone-shaped projections was 7.62 cm, and the upper diameter was 3.81 cm. The distance between the ends of the protrusions was about 6.35 cm, as was the circumference. After casting, the sample was processed on the anode and cathode side to obtain two parallel surfaces. The boundary anolytic and catholytic structures have been thoroughly investigated. No large pores were found and only a few small pores. The side surfaces of the perimeter could be finished with minimal machining to meet the sealing requirements. The ground samples taken showed minimal or no pores. Example III. The cell structure was cast for an electrolytic press with nominal dimensions of 1.22 m × 2.44 nm. The purpose of this example was to test the possibility of casting a specific shape and determine the minimum thickness of the central partition. The thickness of the center partition in this construction was approximately 1.43 cm. The diameter of the base of the cone-shaped projections was 7.62 cm, and the upper diameter was 3.81 cm. The distance between the ends of the projections was approximately 6.35 cm. like the perimeter thickness, the surfaces of the anode and cathode sides were of acceptable quality with only slight surface imperfections on the upper side of the casting. No significant change in the quality of the castings was observed with the repeated use of the mold. This example demonstrates that a steel casting of this size and shape was feasible for mass production of the electrolyser structure. Claims 1. A filter press type electrolyser with a bipolar electrode comprising a central element that separates an anolyte chamber situated on one side of the electrolyte element. ¬zero from the catholytic chamber opposite the electrolyser element, furthermore the central element of the electrolyser has an anode on one side to form the anolyte chamber and a cathode on the opposite side to form the catholytic chamber, the central element of the electrolyser having anode electrically connected to the cathode. characterized in that the central element / 12 / is made integrally of a single, unitary metal casting and comprises a planar central baffle / 14 /, a circumferential flange / 16 /, and anodic and cathode spacers holding the anodes / 36 / and cathodes / 46/145 260 11 neighboring elect rollers at a specific distance from the planar central partition / 14/9, where the anodic spacer elements are many anode projections / 18 / protruding for a certain distance outside the planar central partition / 14 / to the anolyte chamber / 22 / adjacent to the planar partition, the anode projections / 18 / are mechanically and electrically connected directly or indirectly to the anode / 36 / through at least one compatible intermediate metal / 30 / placed between the anode / 36 / and the anode projections / 18 /, and furthermore as cathode the spacer has a plurality of cathode projections / 20 / projecting a certain distance outward from the planar central partition / 14 / to the catholytic chamber / 24 / adjacent to the planar central partition, the cathode projections / 20 / being mechanically and electrically connected or directly connected indirectly to the cathode / 46 / f through at least one compatible intermediate metal / 78 / placed between the cathode / 46 / f and the cathode projections / 20 /, the anode projections / 18 / are so arranged that the anolyte freely circulates through the anolyte chamber / 22 /, and the cathode projections / 20 / are so arranged that the catholyte freely circulates through the catholyte chamber / 24 / «2 * Electrolyser according to claims A method according to claim 1, characterized in that the central element (12) is cast from a metal selected from the group consisting of iron, steel, stainless steel, nickel, aluminum, copper, chromium, magnesium, tantalum, cadmium, zirconium, lead, zinc, vanadium. , tungsten, iridium, rhodium, cobalt and their alloys. 3. The electrolyser according to claim A method as claimed in claim 1 or 2, characterized in that on the anolyte side of the central element / 12 / there is an insert / 26 / made of a metal sheet matching the surface of this element / 12 /, the insert / 26 / being made of electrically conductive metal, which is resistant to corrosion caused by the environment of the anolyte chamber and is fitted to and connected to the anode projections / 18 /, and the insert / 26 / is pressed against the around anode projections towards the planar central partition / 14 / in the spaces between the projections * 4 Electrolyser according to claim 3. A method according to claim 3, characterized in that the insert (26) of the anolyte side is attached to the anode protrusions (18) by welding through an intermediate metal plate / 30 / which is located between the protrusions and the insert, the intermediate plate / 30 / being made of a weldable metal which is compatible both with the metal of the anolyte side insert and with the metal of the center piece (12). 5. The electrolyser according to claim 39, characterized in that the central element (12) is made of a ferrous material and the insert (26) on the anolyte side is made of a metal selected from the group consisting of titanium, tantalum, niobium, hafnium, zirconium and their alloys. 6. The electrolyser according to claim 5f, characterized in that between the anode projections / 18 / and the insert / 26 / on the anolyte side / there are intermediate metal plates / 30 /, each of which has at least two metal layers bonded to each other, the outer metal layer on one side the intermediate plate / 30 / rests on the anode protrusion / 1B /, and the outer metal layer on the opposite side of the intermediate plate / 30 / rests on the insert / 26 / the anolyte side, while the metal layer of the intermediate plate / 30 / rests on each the anode protrusion is compatible with the anode protrusion material and is suitably welded to the anode protrusions, and the metal layer on the side of the intermediate plate bearing on the anolyte side insert (26) is compatible with metal when welded, which is made of an insert on the anolyte side and is properly welded to this insert. 7. The electrolyser according to claim 5. A method according to claim 5, characterized in that the vanadium intermediate plates are positioned between the anode lugs / 18 / and an adjacent titanium insert / 26 / of the anolyte side, the titanium insert / 26 / being welded to the ferrous material lugs through the vanadium intermediate plates. 12 145 260 8. The electrolyser according to claim 1 or 2f, characterized by the fact that on the catholic side of the central element / 12 / there is a catholyte insert / 48 / made of a metal sheet matched to the surface of the central element / 12 /, and the catholyte insert / 48 / is made of electrically conductive metal which is resistant to corrosion caused by the environment of the catholyte chamber and fits around the cathode projections / 20 / and is connected to the cell element at the cathode projections, and the insert / 48 / is pressed against the around cathode projections towards the planar partition of the centers Kowa / 14 / between the projections, and moreover, this insert replaces the surfaces of the electrolyser element adjacent to the catholytic chamber as a barrier in contact with catholyte 9. The electrolyser according to claim 8, characterized in that the catholytic plug / 48 / is attached to the projections cathode / 20 / by welding through a metal intermediate piece / 78 / placed between the projections and the insert, the m the steel of this intermediate piece is weldable and compatible with the metal of the catholyte side insert and with the metal of which the electrolyser central element is made. 8 or 9, characterized in that the central element / 12 / is made of an iron material, and the metal of the catholyte insert is selected from the group of metals consisting of ferrous metals, nickel, nickel alloys, chromium, tantalum, cadmium, zircon, lead, zinc, vanadium , tungsten, iridium and cobalt. 11. The cell according to claim 1 10. The intermediate element (78) is arranged between the cathode projections (20) and the catholytic insert (48/9), each intermediate element (78) having at least two layers of metal bonded together and one layer of metal. of the intermediate element / 78 / in contact with each cathode protrusion / 20 / is compatible with the material of which the cathode protrusions are made and is welded to these protrusions, and the metal layer on the side of the intermediate element bearing on the cathode insert is compatible when welding with the metal of which the catholyte insert is made and is welded to this insert, 11. The electrolyser according to claim A method according to claim 8, characterized in that the metal of the central element (12), the metal of the catholyte insert (48) and the metal of the cathode (46) of the adjacent electrolyser are selected from ferrous metals. 13. The electrolyser according to claim 14. Electrolyser according to claim 8, characterized in that the membrane / 27 / is in contact with the anode / 36 /. (13), characterized in that each electrolytic cell comprises a bipolar depolarized electrode and is of the filter press type. 145 260 145 260 Fig. 2145 260 Fig. 3145 260 Fig. 4 io- 38- ^ 26-3 2 O <* 6 fH ^ 3 2 ^ / c? 5 Printing House of the People's Republic of Poland. Mintage 100 copies Price PLN 220 PL

Claims (14)

Claims 1. Filter press type electrolyser with a bipolar electrode comprising a central element which separates an anolyte chamber situated on one side of the electrolyser element from a catholytic chamber situated on the opposite side of the cell element, and furthermore the central element of the electrolyser has an anode on one side to form an anolyte chamber and a cathode placed on the opposite side to form a catholyte chamber, the central element of the electrolyser having an anode electrically connected to the cathode, characterized in that the central element / 12 / is integrally made of a single unitary metal casting and comprises a planar central partition / 14 /, a circumferential flange / 16 /, and anodic and cathode spacers holding the anodes / 36 / and cathodes / 46/145 260 11 adjacent electrolysers at a specific distance from the planar central partition / 14/9, the anodic spacers being many protrusions anodic h / 18 / projecting a certain distance outside from the planar central partition / 14 / to the anolyte chamber / 22 / adjacent to the planar central partition, which anode projections / 18 / are mechanically and electrically connected directly or indirectly to the anode / 36 /, through at least one compatible intermediate metal / 30 / placed between the anode / 36 / and the anode projections / 18 /, and also has many cathode projections / 20 / projecting a certain distance outside the planar central barrier as cathode spacing elements / 14 / to the catholytic chamber / 24 / adjacent to a planar central partition, the cathode projections / 20 / being mechanically and electrically connected directly or indirectly to the cathode / 46 / f through at least one compatible intermediate metal / 78 / placed between cathode / 46 / fa with cathode projections / 20 /, while the anode projections / 18 / are arranged in such a way that the anolyte freely circulates through the anolyte chamber / 22 /, and the cathode projections / 20 / are so arranged that the catholyte circulates freely through the catholyte chamber / 24 /. 2. * Electrolyser according to claim A method according to claim 1, characterized in that the central element (12) is cast from a metal selected from the group consisting of iron, steel, stainless steel, nickel, aluminum, copper, chromium, magnesium, tantalum, cadmium, zirconium, lead, zinc, vanadium. , tungsten, iridium, rhodium, cobalt and their alloys. 3. The electrolyser according to claim A method as claimed in claim 1 or 2, characterized in that on the anolyte side of the central element / 12 / there is an insert / 26 / made of a metal sheet matching the surface of this element / 12 /, the insert / 26 / being made of electrically conductive metal, which is resistant to corrosion caused by the environment of the anolyte chamber and is fitted to and connected to the anode projections / 18 /, and the insert / 26 / is pressed against the around anode projections towards the planar central partition / 14 / in the spaces between the projections * 4. The electrolyser according to claim 3. A method according to claim 3, characterized in that the insert (26) of the anolyte side is attached to the anode protrusions (18) by welding through an intermediate metal plate / 30 / which is located between the protrusions and the insert, the intermediate plate / 30 / being made of a weldable metal which is compatible both with the metal of the anolyte side insert and with the metal of the center piece (12). 5. The electrolyser according to claim 39, characterized in that the central element (12) is made of a ferrous material and the insert (26) on the anolyte side is made of a metal selected from the group consisting of titanium, tantalum, niobium, hafnium, zirconium and their alloys. 6. The electrolyser according to claim 5f, characterized in that between the anode projections / 18 / and the insert / 26 / on the anolyte side / there are intermediate metal plates / 30 /, each of which has at least two metal layers bonded to each other, the outer metal layer on one side the intermediate plate / 30 / rests on the anode protrusion / 1B /, and the outer metal layer on the opposite side of the intermediate plate / 30 / rests on the insert / 26 / the anolyte side, while the metal layer of the intermediate plate / 30 / rests on each the anode protrusion is compatible with the anode protrusion material and is suitably welded to the anode protrusions, and the metal layer on the side of the intermediate plate bearing on the anolyte side insert (26) is compatible with metal when welded, which is made of an insert on the anolyte side and is properly welded to this insert. 7. The electrolyser according to claim 5. A method according to claim 5, characterized in that the vanadium intermediate plates are positioned between the anode lugs / 18 / and an adjacent titanium insert / 26 / of the anolyte side, the titanium insert / 26 / being welded to the ferrous material lugs through the vanadium intermediate plates. 12 145 260 8. An electrolyser according to claim 1 or 2f, characterized by the fact that on the catholic side of the central element / 12 / there is a catholyte insert / 48 / made of a metal sheet matched to the surface of the central element / 12 /, and the catholyte insert / 48 / is made of electrically conductive metal which is resistant to corrosion caused by the environment of the catholyte chamber and fits around the cathode projections / 20 / and is connected to the cell element at the cathode projections, and the insert / 48 / is pressed against the around cathode projections towards the planar partition of the centers ¬kowa / 14 / between the projections, and moreover, this insert replaces the surfaces of the electrolyser element adjacent to the catholytic chamber, as a barrier in contact with the catholyte An electrolyser according to claim 8, characterized in that the catholyte insert / 48 / is attached to the cathode projections / 20 / by welding through a metal intermediate piece / 78 / placed between the projections and the insert, the metal of this intermediate element being suitable for for welding and it is compatible with the metal of the insert on the Catholic side and with the metal of which the electrolyser central element is made, 10. The electrolyser according to claim 8 or 9, characterized in that the central element / 12 / is made of an iron material, and the metal of the catholyte insert is selected from the group of metals consisting of ferrous metals, nickel, nickel alloys, chromium, tantalum, cadmium, zircon, lead, zinc, vanadium , tungsten, iridium and cobalt, 11. An electrolyser according to claim 10. The intermediate element (78) is arranged between the cathode projections (20) and the catholytic insert (48/9), each intermediate element (78) having at least two layers of metal bonded together and one layer of metal. of the intermediate element / 78 / in contact with each cathode protrusion / 20 / is compatible with the material of which the cathode protrusions are made and is welded to these protrusions, and the metal layer on the side of the intermediate element bearing on the cathode insert is compatible when welding with the metal from which the catholyte insert is made and is welded to this insert, 12. An electrolyser according to claim A method according to claim 8, characterized in that the metal of the central element (12), the metal of the catholyte insert (48) and the metal of the cathode (46) of the adjacent electrolyser are selected from ferrous metals. 13. The electrolyser according to claim 8, characterized in that the membrane / 27 / is in contact with the anode / 36 /, 14. An electrolyser according to claim (13), characterized in that each electrolytic cell comprises a bipolar depolarized electrode and is of the filter press type. 145 260 145 260 Fig. 2145 260 Fig. 3145 260 Fig. 4 io- 38- ^ 26-3 2 O <* 6 fH ^ 3 2 ^ / c? 5 Printing House of the People's Republic of Poland. Mintage 100 copies. Price PLN 220 PL