EP0130215A1 - Cellule a membrane monopolaire, bipolaire et/ou hybride. - Google Patents

Cellule a membrane monopolaire, bipolaire et/ou hybride.

Info

Publication number
EP0130215A1
EP0130215A1 EP84900568A EP84900568A EP0130215A1 EP 0130215 A1 EP0130215 A1 EP 0130215A1 EP 84900568 A EP84900568 A EP 84900568A EP 84900568 A EP84900568 A EP 84900568A EP 0130215 A1 EP0130215 A1 EP 0130215A1
Authority
EP
European Patent Office
Prior art keywords
electrolyzer
back plate
cell
current
anode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP84900568A
Other languages
German (de)
English (en)
Other versions
EP0130215B1 (fr
Inventor
Donald W Abrahamson
Marilyn J Harney
Andrew J Niksa
James J Stewart
Elvin M Vauss Jr
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eltech Systems Corp
Original Assignee
Eltech Systems Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eltech Systems Corp filed Critical Eltech Systems Corp
Priority to AT84900568T priority Critical patent/ATE42580T1/de
Publication of EP0130215A1 publication Critical patent/EP0130215A1/fr
Application granted granted Critical
Publication of EP0130215B1 publication Critical patent/EP0130215B1/fr
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R4/00—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation
    • H01R4/26—Connections in which at least one of the connecting parts has projections which bite into or engage the other connecting part in order to improve the contact
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B7/00—Electrophoretic production of compounds or non-metals
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
    • C25B9/60—Constructional parts of cells
    • C25B9/65—Means for supplying current; Electrode connections; Electric inter-cell connections
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
    • C25B9/70—Assemblies comprising two or more cells
    • C25B9/73—Assemblies comprising two or more cells of the filter-press type

Definitions

  • Membrane-type electrolytic cells gen ⁇ erally comprise an anode chamber and a cathode chamber which are defined on their common side by a ' hydrau- lically impermeable ion-exchange membrane, several -types of which are now commercially available but are generally fluorinated polymeric materials.
  • Membrane-type electrolysis cells generally com ⁇ prise one of two distinct types, that is the mono- polar-type in which the electrodes of each cell are -directly connected to a source a power supply, or the bipolar-type in which adjoining cells in a cell bank have a common electrode assembly therebetween, said electrode assembly being cathodic on one side and anodic on the other.
  • these two designs have been so different that few parts of these electrolytic cells have been interchangeable.
  • each type of cell has required substantially completely different components for each. Further, even when components -have been similar they have generally required com ⁇ pletely separate manufacturing tools and processes.
  • anode pan was formed from titanium or other valve metals -or their alloys in sheet form.
  • cathode ⁇ nMhalt PCT/US83/01999 02537
  • pans were formed from ferrous metals such as steel, stainless steel, as well as metals such as nickel.
  • ferrous metals such as steel, stainless steel, as well as metals such as nickel.
  • An example of such pans in a monopolar cell is described in U.S. Patent 4,244,802.
  • a disadvantage is -this patent requires expensive lamination of the highly conductive metal outer layer to the pan, which is unnecessary when pans are employed in the present invention.
  • a low resistance conductor In a monopolar cell, in addition to the necessity of corrosion resistance, there is the necessity of conducting current from the external power source into, and out of, the monopolar elements and evenly -distributing the current across the active electrode surfaces. In order to carry and distribute this cur ⁇ rent with low ohmic losses (especially in large area electrodes) a low resistance conductor must be used.
  • This conductor may be made of a large cross section of -the corrosion-resistant metal or of a smaller cross section of a metal such as copper or aluminum, for example, which has a specific resistance 5 to 50 times lower than the corrosion-resistant metals. Obviously, these low resistance metals must be protected from corrosion by the electrolytes in order to make them viable materials for use in electrolytic cells.
  • a second approach which has been used in the past is to eliminate the copper and carry the current in the corrosion-resistant metal electrode structure. Since the electrical resistance of the corrosion resistant metal (e.g., titanium, nickel, stainless steel) is high compared to copper and aluminum, the voltage loss is increased and the length of the current path must be kept as short as possible (i.e., small electrode dimension parallel to the current path). This then limits the size of an electrode active area, increases the sealing perimeter to active area ratio, and requires many smaller components to create the same total active area. Thus, a larger active area to sealing perimeter would also provide the additional benefit of a more efficient use of the membrane area (i.e., active area/purchased area ratio is higher). Current distribution in connection to external buswork is also difficult with this approach.
  • the corrosion resistant metal e.g., titanium, nickel, stainless steel
  • the advantages of this invention are to reduce the ohmic loss in monopolar or bipolar electrolyzer structures, by reducing the electrical resistance due to structural components and mechanical connection problems, to improve current distribution, to allow for greater electrode active areas and to decrease the sealing perimeter to active area ratio.
  • these advantages are enhanced in the bipolar membrane-type cell by using novel low pressure, high surface contact area, low current density mechanical connections between the back plates of the anode and cathode elements of a bipolar electrode assembly.
  • a similar novel low pressure, high surface area contact between the back plates of the cells in the assemblies of a hybrid electrolyzer combination of monopolar and/or bipolar cells is utilized.
  • This invention also provides a structure for membrane cells which requires little or no retro ⁇ fitting. As newer and better electrode elements are developed they may be retrofit without loss of the novel current distributor member ' and/or the novel monopolar, bipolar, or hybrid cell to cell low pres ⁇ sure contact feature.
  • OMPI This invention also contemplates a cathode design, anode design, and current distributor member design which are usable for both bipolar and monopolar membrane cell arrangements without modification allowing a single production of items to be used in both types of electrolyzers by simply changing the assembly sequence. Because of this unique ability another electrolyzer configuration is contemplated which is a hybrid or combination monopolar, and/or bipolar arrangement of cells within one electrolyzer.
  • the hybrid electrolyzer then may comprise a number of monopolar sections electrically arranged in a series (i.e. bipolar) fashion or a number of bipolar sections electrically arranged in parallel (i.e. monopolar) fashion or any combination of bipolar and monopolar.
  • Additional advantages of the invention include the ability to change current distributor members without changing other components, the ability to change cell elements without changing other com ⁇ ponents, the ability to allow for current density changes optimizing power cost versus capital costs, and the ability to obviate any need for conductor bars.
  • the present invention provides for a filter press electrolyzer comprising at least one electrolytic cell for electrolytic processes; said electrolyzer being provided with end plates which for ' - 7 -
  • said cell having vertically disposed electrode assemblies and at least one membrane positioned therein; said cell including means for introducing and removing liquids, gases and electrical energy; said electrode assemblies having back plates of electrically conductive material which is corrosion resistant to the internal cell conditions and through which current is introduced into and removed from the electrodes; the improvement comprising an electrical connection between an opposing electrode assembly back plate and a current supply means via a contact joint wherein the dimensions of electrical contact area are substantially the same as the dimensions of said electrode assemblies of said cell, and said contact joint comprises a low pressure, high surface contact area, low current density mechanical connection without metallurgical bonding, and wherein said current supply means is selected from an anode back plate, a cathode back plate, a current distributor member, or combinations thereof, whereby said electrical contact joint is separated from the electrolyte via the opposing back plate.
  • the present invention also provides for use of the electrolyzer in the above paragraph to produce caustic and halogen from brine.
  • the present invention also provides for a process for the production of caustic and halogen from brine comprising the steps of (1) placing brine in intimate contact with a filter press electrolyzer comprising at least one electrolytic cell for electrolytic processes; said electrolyzer being provided with end plates which form end walls for said electrolyzer; said cell having vertically disposed electrode assemblies and at least one membrane positioned therein; said cell including means for introducing and removing liquids, gases and electrical energy; said electrode assemblies having back plates of electrically conductive material which is corrosion resistant to the internal cell conditions and through which current is introduced into and removed from the electrodes; and (2) introducing electrical energy into said cell thereby producing caustic and halogen; the improvement in said process comprising an electrical connection between an opposing electrode assembly back plate and a current supply means via a contact joint wherein the dimensions of electrical contact area are substantially the same as the dimensions of said electrode assemblies of said cell, and said contact joint comprises a low pressure, high surface contact area, low current density mechanical connection without metallurgical bonding, and wherein said current supply means
  • the current supply means referred to in the paragraphs above may be an anode back plate, may be a cathode back plate, or may be a current distributor member.
  • Figure 1 is an exploded view of a monopolar filter press electrolytic cell of .the invention
  • Figure 2 is an exploded view of a cell
  • Figure 3 is a plan view partial cross section of the monopolar filter press electrolytic cell of the invention
  • Figure 4 is a cross sectional view of an integral manifold
  • Figure 5 is a graphic view of a monopolar cathode assembly
  • Figure 6 is a graphic view of a monopolar anode assembly
  • Figure 7 is an exploded partial cross sectional view of one integral manifolding assembly of the in ⁇ vention
  • Figure 8 is an exploded view of a bipolar filter press electrolytic cell of the invention.
  • Figure 9 is an exploded view of one version of a hybrid polarity filter press electrolytic cell of the invention.
  • Figure 10 is an elevation view partial cross section of a bipolar section of a filter press electrolytic cell of the invention
  • Figure 11 is an elevation view partial cross section of a monopolar section of a filter press hybrid polarity electrolytic cell of the invention
  • Figure 12 is a plan view partial cross section of one version of a hybrid polarity section of a filter press electrolytic cell of the invention.
  • Figure 13 is a graphic view of a cathode pan
  • Figure 14 is a graphic view of an anode pan
  • the present invention relates to an electrolyzer having a monopolar filter press electrolytic cell for use in electrolytic processes.
  • Cells of this type generally contain anodes, cathodes, membranes and are contained within bulkheads connected by tie rods which may or may not be spring loaded.
  • the monopolar em ⁇ bodiment of the present invention -contemplates having current distributor members situated between adjacent cathodes and between adjacent anodes thereby allowing current to be brought into and removed from said anodes and cathodes within said cells via the novel low pressure, low current density, high area connection of the present invention.
  • the present invention also relates to an electro ⁇ lyzer having a bipolar filter press electrolytic cell for use in electrolytic processes.
  • Cells of this type generally contain bipolar electrode assemblies, and membranes, and are contained within bulkheads con ⁇ nected by tie rods which may or may not be spring loaded.
  • the bipolar embodiment of the present invention contemplates the present, novel current distributor member situated between each end plate and a bipolar electrode assembly, with an anode side facing one end plate and a cathode side facing the other end plate, thereby allowing current to be * brought into and removed from said cells via the novel low pressure, low current density, high area connection of the present inventi.on. Further, conducting electrical current from cell to cell is accomplished via a novel low pressure, high surface contact area, low current density mechanical connections between the back plates of the anode and cathode elements of the bipolar electrode assemblies.
  • Electrolyzers of this type may be made up of a number of bipolar sections arranged in a monopolar fashion, that is each bipolar section electrically connected in parallel within the end walls of one electrolyzer; or it may be made up of a number of monopolar sections arranged in a bipolar fashion, that is each monopolar section electrically connected in series within the end walls of one electrolyzer; the electrical connections to the electrodes being made using the novel low pressure high area, connection between either a current distributor member of the back plate of another electrode.
  • the hybrid embodiment of the present invention contemplates any arrangement of monopolar and/or bipolar assemblies within one electrolyzer.
  • the hybrid embodiment contemplates use of the novel low pressure, high area, low current density connection, with the contact area for said connection substantially the same dimensions of the active area of said electrodes.
  • a method of sealing the system so as to prevent leakage of feedstocks and products produced in said cell as well as there is provided a means, either external or integral, of receiving raw materials and removing resulting pro- ducts. Also provided is a method, of introducing and removing electrical energy into and out of the cells.
  • This electrical system is generally referred to as a bus system and in the present invention is external to the cells.
  • Anodes suitable for use in the instant invention comprise an anode back plate and an active anode sur ⁇ face area.
  • the active anode sur ⁇ face area comprises a foraminous anode of a type which is generally known in the art comprising valve metal substrate having an electrocatalytic coating applied thereto of precious metals and/or oxides thereof, transition metal oxides and mixtures of any of these materials.
  • the anode member- is generally planar in form and may be constructed of any foraminous material such as expanded metal mesh, perforated plate or wire screening. It is to be understood that this foraminous material has a high surface area and large number of points of contact with the membrane brought about by having a large number of small perforations, for example: expanded metal mesh having what is commonly known as having "micromesh size" pores.
  • a reticulated anode of titanium- metal coated with DSA TM an electrocatalytic coating
  • This active anode area is mechanically and electrically attached to the anode back plate preferably by welding. Further, preferably, the active anode area is attached to the back plate via springs.
  • the anode may be spring loaded against the membrane to help provide a large number of points of contact.
  • These springs may take many forms and be of various metals, preferably the same metal as used to form the active anode area.
  • the welding may take the form of resistance welding, TIG welding (tungsten inert gas welding), electron beam welding, diffusion welding (diffusion bonding) and laser welding for example. Presently preferred at this time is the technique of resistance welding.
  • the active reticulate material may be cast in place and diffusion bonded into the pan or may be welded by any of the above suitable welding techniques.
  • Cathodes suitable for use in the present inven ⁇ tion may be generally described as comprising a cathode back plate and an active cathode surface area.
  • the present invention contemplates a cathode pan preferably stamped from a planar sheet of nickel, iron, steel, stainless steel, or other similar alloy material.
  • the active cathode surface area is likewise made of a material such as iron, steel, stainless steel, or other similar alloy _,-. reg__ 537
  • the cathode active surface area is forami ⁇ nous in nature and preferably is a reticulate metal member formed as described, i.e. in Application Serial No. 386,934, filed June 10, 1982, in the name of Stewart et al,.which is herein incorporated by reference. It is understood, however, that nickel mesh, steel mesh, etc., and spring loaded systems similar to those described hereinabove in relation to anodes are also suitable. Also, other known types of' cathodes for use in zero gap and/or finite gap cells are suitable for use in the current invention.
  • the cathode active surface area is electrically, and mechanically attached to the cathode pans.
  • the cathodes being fabricated from metal mesh analogous to the mesh anodes described hereinabove welding is the preferred method of attachment.
  • the pre ⁇ ferred method of attachment is plating, most preferably galvanic plating. This contact can be realized solely by mechanical pressure if so desired.
  • the present invention is also completely suitable for use in finite gap cells which are well known and understood in the art and therefore will not be further described herein.
  • the electrodes of the present invention utilize pans with a single back plate configuration.
  • pans for the anodes and pans for the cathodes are both formed on similar dies and are substantially identical in size and shape.
  • the anode pan generally being made of a valve metal preferably titanium or a titanium alloy or other metal resistant to corrosive conditions of the anode chamber, and the cathode pan being made of nickel, steel, stainless steel or alloys thereof or other metals resistant to corrosive conditions of the cathode chamber; the location of the sealing means or groove to contain the sealing means.
  • the pans are formed to create an integral frame attached to the back plate which forms a chamber for containing electrolytes and electrode active areas.
  • the back plate is generally planar and preferably flexible to allow it to conform to a current distributor member or another electrode back plate to provide a good electrical connection.
  • the frame of the pan may contain an area which may be rigidified by applying a grouting or filler material and also contain a face area which may be sealed by flat gaskets, O-rings or other gasket shapes when pans are arranged in a facing relation with a membrane therebetween.
  • One purpose of rigidifying the pans with a grout or filler material is to provide a reinforcement of thin pan metal enabling it to withstand a compressive gasket force without collapse thus allowing economic US e of the expensive corrosion resistant metals through the use of thin material, i.e., on the order of .015 to 0.10 inch (.038 to 0.254 cm) thick sheet metal.
  • Other purposes include making handling of the electrodes easier and increasing the internal pressure holding capacity.
  • Suitable for use as grouting or filler materials are, for example, thermoplastics, elastomers, resins, urethanes, formed metal shapes, and various polyfluorinated materials. Presently preferred are epoxy group and- fiberglass reinforced polyester or vinyl esters.
  • the instant invention contemplates anode pans generally of a valve metal sheet stamped into the form of a pan.
  • the preferable anode material is titanium metal or an alloy thereof.
  • the anode active surface area is electrically and physically attached to the anode pan.
  • the electrode enclosure may be a frame which forms the chamber to contain the electrolytes and the electrodes, and the frame may be detachable from the back plate in lieu of being permanently attached to the back plate.
  • the frame may be of alternate materials, such as plastic, metals, et cetera.
  • the perimeter frame is a separate member which is gasketed to the electrode structure as opposed to the pan.
  • Both anode and cathode elements are completed by a frame to create an enclosure for the electrolytes surrounding the electrodes and provide means of feed and discharge through passages in the frame.
  • the frame is gasketed to the corrosion resistant plate around its perimeter and also gasketed on the opposite side which will seal to the membrane, thus creating the electrode enclosure.
  • Anode and cathode elements are alternately stacked with membranes between and compressed by end plates (bulkheads) and tie rods.
  • the frames may be (1) molded of any suitable corrosion resistant plastic (anode: kynar, CPVC, teflons, elastomers, ABS, etc., cathode: CPVC, polypropylene, ABS, elastomers, teflons, etc.) or (2) fabricated by welding, gluing, etc. of these plastic materials, o (3) fabricated of solid or tube - hollow - corrosion resistant metals (anode: titanium or alloys, cathode: steel, nickel, stainless steel, etc.) fabrication being by pressing, drawing, roll forming, welding, extruding, forging, etc. or a combination.
  • the gasketing may be "0" rings, flat gaskets, extruded gaskets or other well known means (U.S. #4,344,633).
  • Membranes suitable for use in the instant in ⁇ vention are of several types which now are com- briefly available but are generally fluorinated polymeric materials which have surface modifications • necessary to perform the ion-exchange function.
  • One presently preferred material is a perfluorinated co- polymer having pendent cation exchange functional groups.
  • These perfluorocarbons are a copolymer of at least two monomers with one monomer being selected from a group including vinyl fluoride, hexafluoro- propylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, perfluor ⁇ (alkylvinyl ether), tetrafluoroethylene and mixtures thereof.
  • the second monomer often is selected from a group of monomers usually containing an SO ⁇ or sulfonyl fluoride pendant group.
  • Rl in the generic formula is a bifunctional perfluorinated radical comprising gen ⁇ erally 1 to 8 carbon atoms but upon occasion as many as 25.
  • One restraint upon the generic formula is a general requirement for the presence of at least one fluorine atom on the carbon atom adjacent the -SO2F group, particularly where the functional group exists as the -(-S0 2 NH)mQ form.
  • Q can be hydrogen or an alkali or alkaline earth metal cation and m is the valence of Q.
  • the R., generic formula portion can be of any suitable or conventional con- ' figuration, but it has been found preferably that the vinyl radical comonomer join the R, group through an ether linkage.
  • perfluorocarbons generally are available commercially such as through E.I. duPont, their pro ⁇ ducts being known generally under the trademark NAFION RTM.
  • Perfluorocarbon copolymers containing perfluoro (3,6-dioxa-4-methyl-7-octenesulfonyl fluoride) comonomer have found particular acceptance in Cl 2 cells.
  • membranes having their preponderant bulk comprised of perfluorocarbon ⁇ opoly er having pendant sulfonyl fluoride derived functional groups, and a relatively thin layer of perfluorocarbon copolymer having carbonyl fluoride derived functional groups adjacent one membrane surface. It is presently preferred to have these membranes further modified with inorganic surface treatments which impregnate the surface of said membranes with metallic materials such as, i.e. Zr0 2 , and Ti0_. This modification is believed to help prevent the problem of gas bubble buildup along the membrane electrode interface. By removing this problem the cell is able to operate more efficiently. A more detailed description of this type of membrane modification can be found in U. S. Application S.N. 277,918, filed October 22, 1982, in the name of Covitch et. al. and incorporated herein by reference.
  • the present invention utilizes a novel current distributor member for introducing current into or removing it from the cells. It is used in monopolar cells, or in bipolar cells at the connections to the external power source, or in hybrid cells to connect to external power sources or other sections of the electrolyzer. This results in the ability evenly and with lower IR losses to introduce and to distribute current into and out of the cell without the constriction of cell size due to the IR loss of the anodes and cathodes. This is possible by utilizing current distributor members having dimensions of electrical contact that are substantially the same as the dimensions of the electrode assemblies. It is possible, of course, to utilize current distributor members which are smaller di ensionally than the electrode assemblies with the clear understanding that as the size of the current distributor member is reduced the IR losses will increase.
  • the current distributor members may be dimensionally greater in size than the electrode assemblies. However, since this would not increase the contact area it would provide no advantage.
  • dimensionally is meant the dimensions of length and width which determine the surface area available for mechanical and electrical contact with the electrode assemblies. Since copper and aluminum are far better conductors of current than valve metals, certain stainless steel alloys cells may be greater in size while maintaining an acceptably low IR loss level. It is to be understood, however, that while copper and aluminum are preferred because of the weight and cost savings and lower volume of metal needed, any conductive metal will work if enough volume is provided to carry the necessary current with acceptable IR losses. In addition, this novel current distributor member allows for higher current densities to be used within the cell and therefore allows for ⁇ greater caustic and chlorine production from a cell that must be run at a lower current density per unit area.
  • the current distributor member is generally a solid copper planar sheet but may also be any suitable conductor having sufficient cross sectional area to carry the required current with low IR loss and good current distribution.
  • suitable examples of these other conductive metals include, for example, nickel, iron, steel, as well as alloys of these metals and alloys of copper and aluminum.
  • the current distributor members are placed between anode pans with the back side of each pan facing the current distributor member to form a single monopolar anode element.
  • current distributor members are placed between cathode pans with the back side of each pan facing the current distributor member to form a single monopolar cathode element.
  • a current distributor member between each cell back plate and a bipolar electrode assembly, an anode side facing one back plate and a cathode side facing the other back plate.
  • the current distributor members protrude past the side of the cell on one side only.
  • the members between adjacent anodes extend on one side while the members between adjacent cathodes extend on the opposite side.
  • This extension is then used to connect via a bus systen, to the power source or other sections of the electrolyzer.
  • the manner of connecting the buswork to the current distributor members is not critical and methods are well known in the art and therefore will not be further discussed herein.
  • said current distributor members may also be sheets having calendered, dimpled, corrugated or serrated surfaces or having an interface material attached to, or inserted between, said surfaces as well as having conductive compounds, i.e., greases containing parti ⁇ cles of conductive metals distributed therein on its surfaces.
  • conductive compounds i.e., greases containing parti ⁇ cles of conductive metals distributed therein on its surfaces.
  • the thickness of the current distributor members may vary across the length of the member based on the current and voltage requirements, to reduce cost, for the particular sized cell. It is understood that if such tapered members are used that the taper of the anodes and the taper • of the cathode members between the cathodes are reversed so as to provide a parallel stack of cells to be compressed between the bulkheads. Finally, the current distributor member may also be used to provide struc ⁇ tural support for the cell.
  • the current distributor member or electrode back plate is held in mechanical contact with an electrode back plate over a substantial portion of the total area, by hydraulic or static pressure of the electrolytes in the pans, by the spring pressure of the anode and/or cathode structures and by supports being compressed in the filter press arrangement by the bulkhead-tie rod assemblies.
  • the novel electrical connection is made outside the cell so that it is separated from the electrolyte via the back plate.
  • the back plate restrains the electrolyte so that the electrolyte does * not contact the novel electrical connection.
  • the pressure applied is in the range of from about 0.5 to 100 psi, (0.035 to 7.03 kg/cm 2 ), preferably in the range of from about 1 to 20 psi(0.0703 to 1.403 kg/cm ) . Increased pressure reduces contact resistance.
  • a low area, high pressure (i.e., 500 - 5000 psi) (35.15 to 351.5 kg/cm ) joint is used to get a low specific joint resistance and current densities across the joint are high (i.e., 200 - 2000 asi) (31 - 310 amps/cm ) with the joint contact voltage loss equal to the product of specific resistance times current density. Also, other factors such as "current stream- line" effects enter into the total voltage loss across this type of mechanical joint.
  • the joint pressure is lower (1 - 20 psi) (0.0703 to 1.403 kg/cm 2 ) yielding a higher specific resistance, but the joint area is very large yielding a low current density (i.e., 0.5 to 10 asi) (0.0775 to 1.55 amps/cm ) and thus a low ohmic loss across the joint.
  • a copper to titanium joint as might be used on the anode, operating at 3 asi (0.465 amps/cm ) with a pressure of 5 psi (0.3515 kg/crt ) (specific resistance of 3.5
  • _ 2 have a voltage loss of 1.05 x 10 volts, and a copper to nickel joint, as might be used on the cathode, operating at 3 asi (0.465 amps/cm ) with a pressure of 5 psi (0.3515 kg/cm ) (specific resistance 7.7 x 10 -5 ohm-in ) (49.68 x 10-5 ohms/cm ) would have a voltage loss of 2.33 x 10 volts.
  • the difference between the copper to titanium and the copper to nickel is due to differences in contact resistance due to different materials and different surface preparations, oxides, etc. Modifications to the metal surfaces or the use of interface materials to take advantage of lower contact resistance of various metals is further discussed hereinbelow.
  • a thin pan is preferred because it is flexible and conforms to the current distributor member or the mating back pan in a connection creating a large con ⁇ tact area. Additionally, materials such as con- ductive reticulates (sponge metal), Multilam , con ⁇ ductive wools and the like may be used as an interface in contact with the current distributor member or back plates to increase the contact area. Because contact resistance is also dependent upon the materials in contact, the distributor member and/or the pan may be coated with a material as an interface to make the contact resistance lower. Suitable examples include, for example, coatings and plating of metals such as silver, gold, platinum, nickel and copper by methods such as, for example, plasma spraying, painting, flame spraying, sputtering, vapor deposition and combinations of the above.
  • sealing means such as a gasket may be placed between the distributor member and pan or frame, or between anode and cathode elements of bipolar electrode assemblies.
  • This seal ⁇ ing means is located so as to be around the current distributor member and/or anode element and cathode element perimeter to prevent entrance of corrosive elements which can oxidize the contact and thereby increase resistance and may also employ a conductive and/or anti-oxidation material.
  • the key to the success of the use of these connections is the fact that the low current densities required, i.e., approximately 0.5 to 10 asi (0.0775 to 1.55 amps/cm ) , with pressures at the joint of approximately less than 1 to about 100 psi (0.0703 to 7.03 kg/cm ) results in low IR losses at a high resistance junction (joint).
  • the bulkheads, tie rods and associated equipment used to hold the cells in place and seal the cells are those generally well known in the art. They are sized to be generally the same size as the cells to be pressed between said bulkheads and generally are con- structed of heavy gauge steel.
  • the bulkheads and tie rods may or may not be electrically isolated from the cells as is preferable in each particular use. Since these types of materials are well known and understood in the art further description will not be given herein.
  • inlets and outlets may be constructed of materials that are normally attacked by the chemicals under the conditions of use but which are lined with plastics or organic polymeric materials which are inert under the conditions of practice.
  • the integral manifolding is constructed of titanium metal or nickel metal as the case warrants for particular inputs and outputs, inlets and outlets, and said inte ⁇ gral and/or internal manifolding is electrically iso ⁇ lated from the individual cells preferably by being physically spaced so as not to be in contact with the cells of polarity not desired in that particular mani ⁇ fold line.
  • the bipolar filter press zero gap electrolytic cells of the present invention are pre ⁇ ferably configured such that an anode element pan back faces a cathode element pan back;' on either exposed active surface face of said anode elements and said cathode elements is a membrane which is in physical contact with said exposed active surfaces and then on either side of the exposed surfaces of said membranes are opposite polarity active surface areas. This stack assembly is repeated until the desired number of cells is " reached and then a single current distributor member is placed at each end.
  • the monopolar filter press zero gap electrolytic cells of the present invention are preferably con ⁇ figured such that two anode pan backs face each other and are separated by a current distributor member.
  • a membrane On either exposed active surface face of said anodes is a membrane which is in physical contact with said anodes and then on either side of the exposed surfaces of said membranes are cathodes in pairs back to back with current distributor members in between each pair. This stack assembly is repeated until the desired number of cells is reached.
  • Bulkheads are provided for either the monopolar or bipolar cell on either end with connecting tie rods and associated paraphernalia to contain said so produced cells.
  • sealing of said stack is provided by either gaskets or O-rings, both of which are known and conventional in the art. It is further understood that the appropriate face or channeling necessary for gaskets and/or O-rings are provided in the respective anode and cathode pans.
  • Figures 1, and 3-7 relate to the monopolar embodiment of the present invention.
  • Figure 1 shows a preferred embodiment of the present invention as it relates to a monopolar cell configuration.
  • Figure 1 shows an assembly (1) consisting of a plurality of vertically disposed anode assemblies- (4) and cathode assemblies (5) in physical contact with the permselective membranes (6) (zero gap). Also shown are integral discharge and inlet ports (100). Additionally bulkheads (2) and tie rods (3) are illustrated.
  • Figure 2 shows an exploded view of a filter press cell, as used in Example 1 and Example 2. As in Figure 1 the cell (1) comprises bulkheads (2), tie rods (3), anode assembly (4), cathode assembly (5) and membrane (6).
  • Figure 3 shows a partial cross sectional plan view of Figure 1.
  • This view shows anode pans (10) located on either side of current distributor member (30).
  • cathodes pans (20) are located on either side of current distributor members (30).
  • the anode pans have active anode areas (11) attached to said pans via springs (12) and also incorporate a sealing means (13).
  • the cathode pans (20) have active cathode areas (21) attached to them, in this particular case reticulate without springs, and also utilize a sealing means (23).
  • These anode and cathode assemblies are alternated and are in contact with and separated by membranes (6). Spacers (40) are utilized as necessary to maintain proper cell dimensions. Finally, grouting material (50) for making the pans more rigid is shown.
  • FIG 4 is a cross sectional view of one embodiment of integral manifolding showing the position of the integral manifold (100) with rela- tion to membranes (6), spacers (40), cathodes as ⁇ semblies (5) and anode assemblies (4).
  • Integral mani ⁇ fold (100) is comprised of spacer (101), sealing means (103), manifold sealing means (106) and manifold sec ⁇ tions (107).
  • Figure 5 shows a monopolar cathode assembly (5) in greater detail. Shown are two cathode pans (20), active cathode area (21), sealing means (23), current distributor member (30) and integral manifolds (100).
  • Figure 6 illustrates a monopolar anode assembly (4) comprising two anode pans (10), active anode area (11), sealing means (13), current distributor member (30) and integral manifolds (100).
  • Figure 7 represents a detailed view of an integral manifolding embodiment showing an anode assembly (4), a cathode assembly (5) and in integral manifold (100).
  • the integral manifold (100) is shown as comprising spacer section (101), sealing means (103), coupler (104) and manifold sections (107).
  • current distributor member (30) and spacer (40) are also shown for the anode manifolding.
  • Figure 8 shows a preferred embodiment of a bipolar electrolyzer of the present invention as it relates to cell configuration.
  • Figure 8 shows a
  • KEAi bipolar cell assembly consisting of a plurality of vertically disposed anode pan assemblies (35) and cathode pan assemblies (36) in physical contact with the permselective membranes (37) (zero gap).
  • a single current distributor member (61) is located on each end of the electrolyzer and interface material (38) are located between and in contact with the backs of adjacent anode and cathode pan assemblies.
  • integral discharge and inlet ports are also shown.
  • Ad- ditionally bulkheads (33) and tie rods (34) are illus ⁇ trated.
  • Figure 9 shows a preferred embodiment of one version of a hybrid polarity electrolyzer of the present invention.
  • the cell (32) comprises bulkheads (33), tie rods (34), anode assemblies (35), cathode assemblies (36), membranes (37), interface material (38), current distributors (61) and integral discharg and inlet ports (131).
  • Figure 10 shows a partial cross sectional elevation view of Figure 8. This view shows anode pans (35) and cathode pans (36). Located on either end of the electrolyzer is a single current distributor member (61). The anode pans have active anode areas (42) attached to said pans via springs (43) and also incorporate a sealing means (44) .
  • cathode pans (36) have active cathode areas (52) attached to them, in this particular case reticulate without springs, and also utilize a sealing means (54).
  • These anode and cathode assemblies are alternated and are in contact with and separated by membranes (37).
  • Interface materials (38) are utilized as necessary to help maintain proper electrical con ⁇ tact.
  • grouting material (81) for making the pans more rigid is shown. It is understood that as many cells as desired may be placed between the bulk- heads, in a variety of monopolar and/or bipolar sections arranged and connected together in an electrolyzer.
  • Figure 11 shows a ' partial cross sectional elevation view of a monopolar electrolyzer or a monopolar section of a hybrid polarity electrolyzer.
  • This view shows anode pans (35) located on either side of current distributor member (61).
  • cathode pans (36) are located on either side of current distributor members (61).
  • the anode pans have active anode areas (42) attached to said pans via springs (43) and also incorporate a sealing means (44).
  • the cathode pans (36) have active cathode areas (52) attached to them, in this particular case reticulate without springs, and also utilize a sealing means (54).
  • These anode and cathode assemblies are alternated and are in contact with and separated by membranes (37). Spacers (71) are utilized as necessary to maintain proper cell dimensions.
  • grouting material (81) for making the pans more rigid is shown.
  • insulators (91) are shown.
  • Figure 12 shows a partial cross sectional plan view of Figure 9. This view shows anode pans (35) and cathode pans (36) as well as membranes (37), interface materials (38), current distributor members (61), insulators (91), grouting material (81), cathode active area (52)*, cathode sealing means (54), anode sealing means (44), anode active area (42) and anode springs (43).
  • Figure 13 shows a detailed view of a cathode pan assembly (36) with cathode pan (51) , .cathode active area (52), sealing means (54) and integral discharge and inlet ports (131).
  • Figure 14 shows a detailed view of an anode pan assembly (35) with anode pan (41), anode active area (42), sealing means (44) and integral discharge and inlet,ports (131).
  • the present invention is further illustrated by the examples which follow without any intention of being limited thereby.
  • This example shows how contact resistance and therefore -low voltage drop between the current dis ⁇ tributor member and the anode as well as between the current distributor and the cathode.
  • An electrolytic cell having an active surface area of 10 inches (25.4 cm) by 30 inches (76.2 cm) was assembled utilizing a compressible spring loaded titanium DSA RTM anode and a reticulate nickel cathode made following the teaching of U. S. Patent
  • the cell also utilized a NAFIO RTM membrane separator between the anode and cathode.
  • the cell was run at zero gap.
  • Electrolube a conductive grease, was utilized between the anode back and copper current distributor as well as between the cathode back and copper current distributor.
  • contact resistance between the. current distributor member and the anode was approximately 10 mV and * approximately 3 V between the current distributor member and the cathode. These contact resistances were measured using a millivolt meter from the back of the pan ' to the current distributor member.
  • This example shows the usefulness of a- reticulate interface material.
  • the 300 square inch (1935 cm ) monopolar cell was operated with a compressible mesh DSA coated anode and a reticulate cathode fabricated as described in U. S. Application No. 386,934, filed June 10, 1982 in the name of Stewart et al, with a NaCl electro- lyte feed.
  • the membrane was a NAFIO RTM ion exchange membrane.
  • the cell was run both with and without a copper reticulate material, of substantially the same surface area as the active membrane area, placed between the back of the titanium anode plate and the copper metal current distributer member, also having a surface area substantially the same as the active membrane area.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Metallurgy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Electrochemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Molecular Biology (AREA)
  • Health & Medical Sciences (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)
  • Polyesters Or Polycarbonates (AREA)
  • Silicon Polymers (AREA)
  • Secondary Cells (AREA)
  • Electric Double-Layer Capacitors Or The Like (AREA)
  • Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
  • Water Treatment By Electricity Or Magnetism (AREA)
  • Filtration Of Liquid (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Polysaccharides And Polysaccharide Derivatives (AREA)
  • Developing Agents For Electrophotography (AREA)
  • Bipolar Transistors (AREA)
  • Inert Electrodes (AREA)

Abstract

Cellules électrolytiques monopolaires, bipolaires et hybrides de filtre-presse pour des processus électrolytiques utilisant un nouveau procédé d'introduction et d'extraction d'énergie électrique. L'invention prévoit un nouvel organe de connexion à surface de contact étendue et à basse pression, permettant de relier l'élément d'anode et l'élément de cathode d'assemblages d'électrodes. L'invention prévoit également un contact à surface de contact étendue et à basse pression de l'organe distributeur de courant sur la contre-électrode.
EP84900568A 1982-12-27 1983-12-20 Cellule a membrane monopolaire, bipolaire et/ou hybride Expired EP0130215B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT84900568T ATE42580T1 (de) 1982-12-27 1983-12-20 Monopolare-, bipolare und/oder hybride membranzelle.

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
US45357382A 1982-12-27 1982-12-27
US453573 1982-12-27
US52969183A 1983-09-06 1983-09-06
US529691 1983-09-06
US55885083A 1983-12-07 1983-12-07
US558850 1983-12-07

Publications (2)

Publication Number Publication Date
EP0130215A1 true EP0130215A1 (fr) 1985-01-09
EP0130215B1 EP0130215B1 (fr) 1989-04-26

Family

ID=27412573

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84900568A Expired EP0130215B1 (fr) 1982-12-27 1983-12-20 Cellule a membrane monopolaire, bipolaire et/ou hybride

Country Status (18)

Country Link
EP (1) EP0130215B1 (fr)
JP (1) JPS60500454A (fr)
KR (1) KR910003644B1 (fr)
AT (1) ATE42580T1 (fr)
AU (1) AU565760B2 (fr)
BR (1) BR8307663A (fr)
CA (1) CA1225964A (fr)
DE (1) DE3379737D1 (fr)
DK (1) DK406684D0 (fr)
ES (2) ES8501453A1 (fr)
FI (1) FI77270C (fr)
GR (1) GR79738B (fr)
IL (1) IL70543A (fr)
IT (1) IT1197764B (fr)
NO (1) NO163575C (fr)
NZ (1) NZ206668A (fr)
PT (1) PT77900B (fr)
WO (1) WO1984002537A1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4588483A (en) * 1984-07-02 1986-05-13 Olin Corporation High current density cell
IT1200403B (it) * 1985-03-07 1989-01-18 Oronzio De Nora Impianti Celle elettrolitiche mono e bipolari e relative strutture elettrodiche
US20160199784A1 (en) * 2013-08-20 2016-07-14 Trish Choudhary Separating and Demineralizing Biomolecule Solutions by Electrodialysis
DE102018209520A1 (de) 2018-06-14 2019-12-19 Thyssenkrupp Uhde Chlorine Engineers Gmbh Elektrolysezelle

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4017375A (en) * 1975-12-15 1977-04-12 Diamond Shamrock Corporation Bipolar electrode for an electrolytic cell
US4137144A (en) * 1976-03-19 1979-01-30 Hooker Chemicals & Plastics Corp. Hollow bipolar electrolytic cell anode-cathode connecting device
US4116807A (en) * 1977-01-21 1978-09-26 Diamond Shamrock Corporation Explosion bonding of bipolar electrode backplates
US4108752A (en) * 1977-05-31 1978-08-22 Diamond Shamrock Corporation Electrolytic cell bank having spring loaded intercell connectors
DE2914869A1 (de) * 1979-04-12 1980-10-30 Hoechst Ag Elektrolyseapparat
US4244802A (en) * 1979-06-11 1981-01-13 Diamond Shamrock Corporation Monopolar membrane cell having metal laminate cell body
IT1140510B (it) * 1980-01-16 1986-10-01 Oronzio De Nora Impianti Elettrolizzatore bipolare e procedimento di elettrolisi di elettrolisi di alogenuri
IN156372B (fr) * 1980-05-15 1985-07-06 Ici Plc

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8402537A1 *

Also Published As

Publication number Publication date
AU565760B2 (en) 1987-09-24
GR79738B (fr) 1984-10-31
AU2438884A (en) 1984-07-17
PT77900A (en) 1984-01-01
KR840007608A (ko) 1984-12-08
FI843345A (fi) 1984-08-24
PT77900B (en) 1986-04-11
FI77270C (fi) 1989-02-10
ATE42580T1 (de) 1989-05-15
ES528412A0 (es) 1984-12-01
IL70543A (en) 1987-08-31
WO1984002537A1 (fr) 1984-07-05
IT8349571A0 (it) 1983-12-23
DK406684A (da) 1984-08-24
FI843345A0 (fi) 1984-08-24
ES8501453A1 (es) 1984-12-01
IL70543A0 (en) 1984-03-30
ES8706216A1 (es) 1987-06-01
CA1225964A (fr) 1987-08-25
NZ206668A (en) 1987-09-30
NO843391L (no) 1984-08-24
NO163575B (no) 1990-03-12
DE3379737D1 (en) 1989-06-01
JPS60500454A (ja) 1985-04-04
NO163575C (no) 1990-06-20
DK406684D0 (da) 1984-08-24
FI77270B (fi) 1988-10-31
ES534699A0 (es) 1987-06-01
EP0130215B1 (fr) 1989-04-26
IT1197764B (it) 1988-12-06
KR910003644B1 (ko) 1991-06-07
BR8307663A (pt) 1984-12-11

Similar Documents

Publication Publication Date Title
US4923582A (en) Monopolar, bipolar and/or hybrid memberane cell
US4732660A (en) Membrane electrolyzer
EP0137836B1 (fr) Element de cellule centrale unitaire pour structure de cellule d'electrolyse par filtre-presse
CA1094017A (fr) Dispositif de connexion anode-cathode bipolaire creux pour cellule electrolytique
CA1094505A (fr) Cellule electrolytique a membrane monopolaire
US4389289A (en) Bipolar electrolyzer
US4738763A (en) Monopolar, bipolar and/or hybrid membrane cell
CA1117472A (fr) Element de filtre-presse
GB1595183A (en) Diaphragm cell
SK363585A3 (en) Membrane electrolytic cell
EP0185271B1 (fr) Batterie électrochimique monopolaire, cellule unitaire et procédé d'électrolyse dans une série de cellules monopolaires
EP0229473B1 (fr) Electrode
EP0187273A1 (fr) Unité terminale électrochimique monopolaire ou bipolaire ayant un élément de transmission de courant électrique
US4608144A (en) Electrode and electrolytic cell
NZ202497A (en) Filter press electrolysis cell:insulation of channels supplying anode and cathode cell compartments
US4519888A (en) Electrolytic cell
JPH0569916B2 (fr)
AU565760B2 (en) Monopolar, bipolar and/or hybrid membrane cell
US5141618A (en) Frame unit for an electrolyser of the filter press type and electrolysers of the filter-press type
WO1986003789A1 (fr) Procede de fabrication d'un element unitaire de transmission de courant electrique pour unites de cuves electrochimiques monopolaires ou bipolaires du type filtre-presse
US4690748A (en) Plastic electrochemical cell terminal unit
IE910069A1 (en) Electrode for electrochemical reactors
US4271004A (en) Synthetic separator electrolytic cell
KR970004140B1 (ko) 복극식 전해조
JPS644595B2 (fr)

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19840925

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB LI LU NL SE

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE FR GB LI LU NL SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Effective date: 19890426

REF Corresponds to:

Ref document number: 42580

Country of ref document: AT

Date of ref document: 19890515

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3379737

Country of ref document: DE

Date of ref document: 19890601

ET Fr: translation filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19891231

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19941111

Year of fee payment: 12

EAL Se: european patent in force in sweden

Ref document number: 84900568.1

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19951120

Year of fee payment: 13

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19951220

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19951229

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19960109

Year of fee payment: 13

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19951220

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19961221

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19961231

Ref country code: CH

Effective date: 19961231

Ref country code: BE

Effective date: 19961231

BERE Be: lapsed

Owner name: ELTECH SYSTEMS CORP.

Effective date: 19961231

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

EUG Se: european patent has lapsed

Ref document number: 84900568.1

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19970919

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19981203

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19981230

Year of fee payment: 16

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990701

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 19990701

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000831

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20001003

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST