Abstract: A fluid separation device, utilizing tubular or flat sheet membrane materials, bounded on the membrane side of the sheet by a sheet of a porous feed spacer material, and bounded on the support side of the membrane sheet by an optional porous permeate backing material, to facilitate the flow of fluids. The layered assembly is formed into multiple pleated thin flat channels, surrounding a solid center rod mandrel, glued at the ends, wrapped with a porous sheet material, taped, and sealed into a tubular shell. The fluid to be separated flows into one end of the pleated element, and discharges from the opening at its opposite end in a concentrated form. The fluid passes through the membrane in a purified form and discharges from an opening in the side of the tubular shell.

Abstract: A spirally-wrapped reverse osmosis membrane cell employing an envelope of semipermeable membrane sheets spirally wound or wrapped about a tubular mandrel. The convolutions of the membrane assembly are separated to form an open channel, directed feed flow path leading into a lateral opening or series of openings in a communicating tubular member defining an unobstructed bore throughout its length. The feed separator may comprise a plurality of substantially parallel strips of impermeable material of a thickness sufficient to provide desired separation between membrane sheets and wherein the strips define a meandering fluid flow path throughout the length and width of the membrane sheet.

Abstract: A threshold scale inhibitor for aqueous solutions containing calcium and magnesium scale forming ions comprises a mixture of three components: a maleic acid or anhydride homopolymer, an organophosphonate and a sulfonated styrene-maleic acid copolymer. Synergism results from the use of such inhibitor. The inhibitor is useful for inhibiting scale formation with seawater distillation apparatus, reverse osmosis apparatus, electrodialysis apparatus, boilers, heat exchange systems, etc. and is employed in small amounts, such as 0.1 ppm to 200 ppm.

Abstract: An electrodialysis method for deacidifying a feedstream comprises a first cell defined by anion-selective membranes and bounded by a pair of cells defined by the anion-selective membranes and a pair of cation-selective membranes. The solution to be treated is fed to the first membrane cell, a basic solution and a concentrating solution are delivered, respectively, to one of the adjacent cells, and an electric field is applied across the assembly. Hydroxyl anions from the basic solution pass into the first cell for neutralizing the acid hydrogen cation while the acid anion passes into one of the adjacent cells through which also flows the basic solution cation to maintain electrical balance.

Abstract: A method is provided for fabricating separators, particularly thin cell electro-membrane separators used in electrodialysis stacks for the desalination of water. The method includes placing a master stencil or mask on top of a plastic mesh which is laid out on a rigid backing sheet and pouring massive amounts of a curable polymer such as silicone rubber through the hole pattern formed in the stencil. The polymer is then spread out to fill the pattern, the stencil removed and a cover sheet applied. The polymer is then pressed into the pores of the mesh using a roller applied against the cover sheet. The sandwich of the mesh and cover and backing sheets is placed into a pile between metallic sheets, and the pile is compressed during the curing of the polymer. The cover and backing sheets are then scupped off and the polymer impregnated mesh die cut to produce the required edge shape and flow holes.

Abstract: An electrode system for use in an electrodialyzer which comprises a plurality of depletion compartments and concentration compartments bounded by ion selective membranes and electrodes in compartments at opposite ends of apparatus. The end compartment electrodes comprise a plurality of elongate members that are each mounted in holders which permit exchanging electrodes in the end compartments or, advancing the electrodes as they are consumed, without requiring that the end compartments be removed to gain access to the electrodes.