Abstract: An electrolysis cell provided with a separator, suitable for chlor-alkali electrolysis, has a planar flexible cathode kept in contact with the separator by an elastic conductive element pressed by a current distributor and an anode consisting of a punched sheet or mesh supporting the separator suitable for being individually pre-assembled and used as elementary unit of a modular arrangement to form an electrolyzer whose terminal cells only are connected to the electric power supply; the electrical continuity between adjacent cells being assured by conductive contact strips secured to the external anodic walls of the shells delimiting each cell with the stiffness of the cathode current distributor and of the anodic structure and the elasticity of the conductive element cooperate in maintaining a uniform cathode to separator contact with a homogeneous pressure distribution meanwhile ensuring a suitable mechanical load on the contact strips.

Abstract: The invention relates to a cathode for diaphragm chlor-alkali cells delimited by a conductive foraminous surface and having an internal volume containing two juxtaposed elements aimed at improving the fluid and electrical current distribution.

Abstract: The invention relates to a current collector for electrochemical diaphragm or membrane-type cells, comprising a layer obtained by interlacing or weaving of a multiplicity of first sets of metal wires with a multiplicity of single metal wires or of second sets of metal wires and provided with substantially parallel corrugations. Such layer is coupled to a planar element consisting of a cloth or a flattened stocking formed by weaving of a single metal wire. The current collector is characterised by a low angular coefficient of the pressure/thickness ratio over a wide range of compression levels.

Abstract: An electrolysis cell provided with a separator, suitable for chlor-alkali electrolysis, has a planar flexible cathode kept in contact with the separator by an elastic conductive element pressed by a current distributor and an anode consisting of a punched sheet or mesh supporting the separator suitable for being individually pre-assembled and used as elementary unit of a modular arrangement to form an electrolyser whose terminal cells only are connected to the electric power supply; the electrical continuity between adjacent cells being assured by conductive contact strips secured to the external anodic walls of the shells delimiting each cell with the stiffness of the cathode current distributor and of the anodic structure and the elasticity of the conductive element cooperate in maintaining a uniform cathode to separator contact with a homogeneous pressure distribution meanwhile ensuring a suitable mechanical load on the contact strips.

Abstract: It is described a bipolar plate consisting of a single wall and a perimetrical sealing frame obtained by folding and provided with a planar abutment surface for the frame-to-wall welding. The wall is further provided with projections on one face thereof preferably obtained by moulding, and with supports on the other face consisting of sheet strips housed in the recesses formed by the concave part of the projections. The projections substantially extend along the entire length of the bipolar plate. The projections and supports are connected to electrodes or current distributors. The projections, the supports, the single wall and the perimetrical frame are made of the same metal or alloy. The electrode or current distributor supported by the projections, the same projections and the supports are welded together by a single pass of arc-welding or preferably laser-welding.

Abstract: A distributing element for an electrolyte percolating-type electrochemical cell comprises an external feeding manifold and an assembly formed by a gas diffusion electrode, a percolator and optionally an on-exchange membrane. The element is particularly suitable for chlor-alkali electrolysis cells and alkaline fuel cells. It is also disclosed a method for retrofitting membrane electrochemical cells by inserting the distributing element of the invention therein.

Abstract: The invention relates to a process for wine evolution by electrochemical way, with reduced treatment times and controlled selectivity. The process may be carried out at the anodic compartment of an electrochemical reactor subdivided by a semipermeable membrane on a valve metal anode, for instance a titanium anode, provided with catalytic coating containing platinum or other noble metal.

Abstract: The invention relates to a current collector for electrochemical diaphragm or membrane-type cells, comprising a layer obtained by interlacing or weaving of a multiplicity of first sets of metal wires with a multiplicity of single metal wires or of second sets of metal wires and provided with substantially parallel corrugations. Such layer is coupled to a planar element consisting of a cloth or a flattened stocking formed by weaving of a single metal wire. The current collector is characterised by a low angular coefficient of the pressure/thickness ratio over a wide range of compression levels.

Abstract: The invention relates to a cathode for diaphragm chlor-alkali cells delimited by a conductive foraminous surface and having an internal volume containing two juxtaposed elements aimed at improving the fluid and electrical current distribution.

Abstract: An electrolysis cell comprising an anodic compartment and a cathodic compartment separated by an ion-exchange membrane, at least one of said compartments equipped with a gas-diffusion electrode having two major surfaces, the first major surface of said gas-diffusion electrode facing the membrane and being in contact with a planar porous element to be traversed by an electrode flow, the second major surface of said gas-diffusion electrode being in contact with a current distributor comprising a multiplicity of elastic conductive protrusions for compressing said gas-diffusion electrode against said planar porous element.

Abstract: It is herein described an electrowinning cell with a spouted bed electrode of growing metallic beads, separated by a semi-permeable diaphragm and suitable for being assembled in a stack in a modular arrangement.

Abstract: The invention relates to a process for wine evolution by electrochemical way, with reduced treatment times and controlled selectivity. The process may be carried out at the anodic compartment of an electrochemical reactor subdivided by a semipermeable membrane on a valve metal anode, for instance a titanium anode, provided with catalytic coating containing platinum or other noble metal.

Abstract: The invention describes a current collector for electrochemical cells, consisting of a sandwich of compressible and resilient layers of metal wires, which imparts a predetermined mechanical load under a broad compression range.

Abstract: It is described a bipolar plate consisting of a single wall and a perimetrical sealing frame obtained by folding and provided with a planar abutment surface for the frame-to-wall welding. The wall is further provided with projections on one face thereof preferably obtained by moulding, and with supports on the other face consisting of sheet strips housed in the recesses formed by the concave part of the projections. The projections substantially extend along the entire length of the bipolar plate. The projections and supports are connected to electrodes or current distributors. The projections, the supports, the single wall and the perimetrical frame are made of the same metal or alloy. The electrode or current distributor supported by the projections, the same projections and the supports are welded together by a single pass of arc-welding or preferably laser-welding.

Abstract: It is described a finite interelectrodic gap-cell for oxygen evolving-electrochemical processes comprising a package of planar anodes secured to a rack and a package of planar cathodes intercalated to the anodes secured to a frame. The cathode package can be handled separately or jointly with the anode package by means of a lifting device. The cell is particularly useful in metal electrowinning processes and in softening processes of calcareous waters by microelectrolysis.

Abstract: The invention describes heat exchange devices for dry-type inlet end-boxes of mercury cathode chlor-alkali electrolysis cells. The devices increase the heat exchange between recycled mercury and feed brine with the purpose of reducing the temperature of mercury to a substantial extent The devices consist of a first element directed to subdivide the mercury flow into a fine and a stable dispersion of rivulets and droplets and of a second element capable of increasing the brine level to allow the prolonged contact thereof with mercury. The decrease of mercury temperature below the critical value of 90-95 ° C. determines an advantageous duration improvement of the end-box internal lining.

Abstract: It is herein described an electrowinning cell with a spouted bed electrode of growing metallic beads, separated by a semi-permeable diaphragm and suitable for being assembled in a stack in a modular arrangement.

Abstract: The invention is relative to an electrolytic cell comprising electrodes spaced apart from the back-wall by means of ribs, wherein a portion of the contact surface between the electrodes and the ribs is free from constraints in order to permit the complete removal of the electrodes once they have to be replaced by removing only partially the original contact surface, so that positioning of the substitute electrodes is allowed on the residual portion. A method for substituting the electrodes of the cell which leaves the distance between the electrode surface and the back-wall unvaried is also disclosed.

Abstract: An adjustable elastic element (19) for forcing the surfaces of expandable-type anodes for diaphragm chlor-alkali cells wherein such element consists of a U-shaped elastic sheet provided with at least one adjusting mechanism comprising both one collar (29) which fastens the elastic sheet through openings obtained in the sheet itself and one gear (23) connectable to a removable external tool consisting of a handle and a shaft whereby turning the tool, a rotation of the gears is produced, in its turn acting on the collar controlling the span of the anode surfaces. And the span is freely adjustable in order to establish a predetermined controlled gap between anode and finger-supported diaphragm surfaces, or alternatively to bring such surfaces in contact without introducing however a useless and hazardous compression.

Abstract: A bipolar assembly for filter-press type electrolyzers is described comprising a single sheet, whose two faces work respectively as anodic and cathodic wall, characterised by a design of perimetral flanges which greatly simplifies its construction enhancing its reliability. The peripheral flanges are made of a first flange obtained by folding the peripheral portion of the single sheet and of a second flange formed by a rod or a tube with quadrangular section or, alternatively, the first and second flange are pre-formed by folding of adequate strips subsequently fixed to the single sheet. The electrolyser resulting from the assemblage of a multiplicity of assemblies of the invention is particularly suited to the process of electrolysis of hydrochloric acid solutions carried out with chlorine-evolving anodes and oxygen-consuming cathodes.