Abstract: An electrode reversal system for an electrodialysis cell is disclosed in which acidic anolyte produced in the anode chamber is collected and simultaneously recirculated through both the anode and cathode chambers. The cathode effluent is removed from the cell and on reversal of electrical polarity, the hydraulic flow paths to and from the chambers are reversed.

Abstract: A sulfonated cation exchange polyelectrolyte obtained by reacting a polyphenylene sulfide polymer with oleum containing 10 to 65% by weight of sulfur trioxide.

Abstract: A gasket for preventing fluid flow from the interior to the exterior of a chamber is disclosed in which tab members or projections from a body portion lockingly cooperate with corresponding recesses in the chamber wall. Transverse openings in the gasket body allow access to the interior of the chamber. The apparatus is particularly applicable as a means for sealing an electrode terminal extending from the interior to the exterior of an electrodialysis filter press stack.

Abstract: A liquid flow distribution screen is disclosed in which two sets of spaced apart strands are oriented at an angle to each other to form a mesh screen. A portion of the screen is composed of areas in which the two sets of strands are more or less of the same thickness and the remaining portion composed of strands in which one of the sets is of greater thickness than the other, resulting in the creation of liquid flow channels between and among the channels. Using this concept, any desired flow pattern may be achieved when the screen is placed between two surface barriers. The device is particularly suited as a membrane support and spacer in electrodialysis or electrochemical apparatus.

Abstract: An aqueous solution of a metal salt solution is converted to the corresponding acid by hydrogen ion substitution in a four compartment electrolytic cell containing three cation permselective membranes or barriers for defining the cell compartments. In one specific embodiment the salt solution initially treated in the intermediate compartment located adjacent to the cathode compartment is further treated by passing into the intermediate compartment located adjacent the anode compartment and thereafter removing the same as the final acid product. Such a flow arrangement prevents or reduces loss of hydrogen or citrate ions into the cathode compartment resulting in an increased acid yield with increased current efficiency.

Abstract: This invention describes apparatus and process for filtering liquids by employing a vertical cylindrical container divided by an immovable non-porous plate into a separate top and bottom chamber with each chamber containing a bed of filter material. The liquid to be filtered is passed upwardly through the buoyant filter material of the top chamber and then passed in series through the filter material contained in the bottom chamber. Conduit means for passing the liquid from the top chamber to the bottom chamber is located internally of the cylindrical container; passing directly through the said immovable separating plate.

Abstract: The invention is directed to an open celled polyurethane foam article, which initially is generally non-absorbent, the surface of which is subsequently rendered absorbent by decreasing the average pore cell size to a critical range while preferably also simultaneously or subsequently achieving a critical range of a wetting agent in such surface. This can be accomplished in either of two ways. The first method is to permanently collapse the cells in the surface region of the original foam so that the concentration of any residual wetting agents initially present in the structure increases in the compressed surface region, thus rendering said surface more readily absorbent. For a surgical dressing, the surface cells should be permanently but only partially collapsed to substantially less than the original size to form a microporous skin.

Abstract: A foam material for use especially as a surgical dressing of the formula containing stannous octoate and a chlorofluoromethane and comprised of a polyether based polyurethane having a compressed dense surface which is absorbent to fluids as contrasted with the remaining uncompressed foam which is non-absorbent; the compressed dense surface containing foam cells which have only been partially collapsed as compared to the uncollapsed foam cells of the non-absorbent material.

Abstract: A polyurethane foam article, preferably a surgical dressing, at least one surface of which is rendered lyophilic by applying pressure and heat to said surface.

Abstract: An aqueous solution of a metal salt solution is converted to the corresponding acid by hydrogen ion substitution in a four compartment electrolytic cell containing three cation permselective membranes or barriers for defining the cell compartments. In one specific embodiment the salt solution initially treated in the intermediate compartment located adjacent to the cathode compartment is further treated by passing into the intermediate compartment located adjacent the anode compartment and thereafter removing the same as the final acid product. Such a flow arrangement prevents or reduces loss of hydrogen or citrate ions into the cathode compartment resulting in an increased acid yield with increased current efficiency.