Abstract: An apparatus for producing deionized water, which has an ion exchanger accommodated in demineralizing compartments of an electrodialyzer having cation exchange membranes and anion exchange membranes alternately arranged between an anode and a cathode, wherein the ion exchanger is a composite ion exchanger comprising a first porous ion exchanger having a mixture of 60 to 95 wt % of cation exchange resin particles and 5 to 40 wt % of anion exchange resin particles bonded to each other and a second porous ion exchanger having a mixture of 60 to 95 wt % of anion exchange resin particles and 5 to 40 wt % of cation exchange resin particles bonded to each other.

Abstract: An apparatus for producing deionized water consisting essentially of an electrodialyzer having cation exchange membranes and anion exchange membranes alternately arranged between a cathode and an anode to form demineralizing compartments and concentrating compartments, and ion exchangers accommodated in the demineralizing compartments, wherein a pressure of from 0.1 to 20 kg/cm2 is exerted between the ion exchangers accommodated in the demineralizing compartments and the cation exchange membranes and anion exchange membranes defining the demineralizing compartments.

Abstract: An apparatus for producing deionized water comprising an electrodialyzer having cation exchange membranes and anion exchange membranes alternately arranged between a cathode and an anode to form demineralizing compartments and concentrating compartments, and ion exchange resin particles packed in the demineralizing compartments, wherein the ion exchange resin particles are a mixture of at least two groups of ion exchange resin particles having a particle size distribution such that particles having particle sizes of from 75 to 125% of the average particle size, are at least 85 wt % of the total amount, and the average particle size of a group of ion exchange resin particles having the maximum average particle size, is at least 1.5 times the average particle size of a group of ion exchange resin particles having the minimum average particle size.

Abstract: An apparatus for producing deionized water consisting essentially of an electrodialyzer having cation exchange membranes and anion exchange membranes alternately arranged between a cathode and an anode to form demineralizing compartments and concentrating compartments, and ion exchangers accommodated in the demineralizing compartments, wherein a pressure of from 0.1 to 20 kg/cm.sup.2 is exerted between the ion exchangers accommodated in the demineralizing compartments and the cation exchange membranes and anion exchange membranes defining the demineralizing compartments.

Abstract: A porous ion exchanger which has a porous structure having ion exchange resin particles bound by a binder polymer, and which has a water permeability of at least 30 kg.multidot.cm.sup.-1 .multidot.hr.sup.-1 under a pressure of 0.35 kg/cm.sup.2.

Abstract: A humidifier for an inhalant gas, which humidifies an inhalant gas having a controlled composition without invasion of bacteria by bringing a stream of the inhalant gas into contact with one side of a water vapor-permeable membrane which is in contact with liquid water on the other side.

Abstract: A dehumidifying method which comprises contacting a gas containing water vapor to one side of a vapor permselective membrane, while contacting a dry gas to the other side of the membrane, to let the water vapor selectively permeate through the membrane, wherein the membrane is made of an ion exchange membrane having ion exchange groups, of which counter ions are partly or entirely substituted by metal ions.

Abstract: An alkali metal chloride-electrolyzing cell comprises a cation-exchange membrane disposed between an anode and a cathode, characterized in that said cation-exchange membrane has on at least one side thereof a gas- and liquid-permeable, porous layer with no electrode activity, and at least one of an anode and a cathode is a voided flexible electrode having a more rigidity than that of said cation-exchange membrane, and said flexible electrode is designed to be forcibly deformed thereby closely contacting said cation-exchange membrane with the surface of each of said electrodes.

Abstract: A filter press type ion exchange membrane electrolytic cell which comprises an anode compartment and a cathode compartment partitioned by a cation exchange membrane and which is useful for obtaining a halogen, hydrogen and an alkali metal hydroxide from an alkali metal halide aqueous solution, or oxygen and hydrogen from an aqueous alkaline solution.

Abstract: An electrolytic cell comprises intercalated finger-shaped electrodes each disposed through a cation exchange membrane, in which said cation exchange membrane constitutes a cylinder or envelope enclosing a finger-shaped anode or cathode A flare is formed at one end or each end of the cylinder or at the open end of the envelope. The flare is joined with a flange to form a unitary cation exchange membrane-flange structure which liquid-tightly divides an anode compartment and a cathode compartment.

Abstract: An alkali metal hydroxide is produced by electrolyzing an aqueous solution of an alkali metal chloride fed into an anode compartment in a cell having an anode compartment and a cathode compartment formed by partitioning with a cation exchange membrane. A cation exchange membrane of a fluorinated polymer having carboxylic acid groups at a content of 0.9 to 2.0 meq./g. dry resin is used as said cation exchange membrane and a metal or a metal ion is incorporated in said aqueous solution of an alkali metal chloride to form a thin layer made of a metal hydroxide or oxide on the surface of said membrane in the anode compartment.