Abstract: A membrane electrolysis cell comprising an anodic compartment and a cathodic compartment is described, wherein at least one of the two compartments contains an electrode fed with gas and a porous planar element is interposed between the membrane and the gas-fed electrode. A flow of chemically aggressive electrolyte crosses the porous planar element downwards under the effect of the gravity force. The planar element consists in a plastic element withstanding the aggressive operative conditions: The use of perfluorinated plastics such as ECTFE, PTEFE, FEP, PFA is preferred, even though they are strongly hydrophobic. When the gas-fed electrode is a cathode and the gas contains oxygen, the gas crosses the cathodic compartment upwardly so as to minimize the risk of hydrogen build up. The cell equipped with the oxygen cathode is particularly advantageous for the sodium chloride electrolysis.

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: The invention relates to an electrolysis device for halogen gas production from an aqueous alkali halide solution in several plate-type electrolysis cells stacked and arranged side by side, with electrical contacts, each of the cells with a housing consisting of two half-shells made of electrically conductive material, said housing being equipped with devices for feeding electrolytic current and the electrolysis plant reactants and devices for discharging electrolytic current and discharging the electrolysis products, with anodic electrode, cathodic electrode and a membrane arranged therebetween, built-in components being fitted in at least one of the two half-shells and permitting a defined increase in the liquid level and thus minimizing the remaining gas volume accordingly.

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.

Abstract: The invention relates to an electrolysis device for halogen gas production from an aqueous alkali halide solution in several plate-type electrolysis cells stacked and arranged side by side, with electrical contacts, each of the cells with a housing consisting of two half-shells made of electrically conductive material, said housing being equipped with devices for feeding electrolytic current and the electrolysis plant reactants and devices for discharging electrolytic current and discharging the electrolysis products, with anodic electrode, cathodic electrode and a membrane arranged therebetween, built-in components being fitted in at least one of the two half-shells and permitting a defined increase in the liquid level and thus minimising the remaining gas volume accordingly.

Abstract: The invention relates to an electrochemical half cell (1) which consists of at least one membrane (4), an electrode (3) as anode or cathode which optionally produces gas, optionally an outlet (8; 16) for the gas and a support structure (12) linking the electrode which optionally produces gas with the back wall (15) of the half cell. The support structure (12) divides the interior (13) of the half cell (1) into vertically arranged channels (5, 9). The electrolyte (14) flows upwards in the electrode channels (9) facing the electrode (3) and flows downwards in the channels (5) facing away from the electrode (3). The electrode channels (9) and the channels (5) facing away from the electrode (3) are interlinked at their upper and lower ends.