Abstract: A method and apparatus for cleaning filter elements that are vertically positioned within a filter vessel that has a tube sheet dividing the filter vessel into a lower filter compartment and an upper plenum compartment. A fixed volume of backwash liquid is rapidly directed from the plenum compartment above the tube sheet through the filter elements into the filter compartment that has been drained of liquid. The rapid movement of the backwash liquid is a result of a pressure differential between the plenum compartment and the filter compartment. The volume of backwash liquid is maintained above the tube sheet by a pressurized condition in the filter compartment, which volume may be changed by adjusting the pressure in the filter compartment.

Abstract: A process and apparatus for recovering uranium from a carbonate solution containing uranium ions whereby the carbonate solution containing uranium ions is brought in contact with a cation exchanger so that a uranium cation is removed from solution and adsorbed by the cation exchanger, and the uranium cation is then removed from the cation exchanger. The treated carbonate solution from which uranium ions hve been removed by cation exchange is then further processed by removing carbon dioxide from the treated carbonate solution to produce a decarbonated solution, and passing the decarbonated solution through a membrane process to remove some remaining impurities.

Abstract: A method and apparatus for removing dissolved solids from a liquid which utilizes the technique of reverse osmosis (RO). The liquid to be treated is directed into a pressure vessel which contains a plurality of filter elements positioned therein. The filter elements have hollow RO fibers wound around foraminous center cores such that the liquid flows in a direction from the outside of the filter elements towards the center cores. The pure permeate liquid passes into the center bores of the fibers and the concentrate liquid passes into the center cores of the elements.The method and apparatus provide for the backwashing of the filter elements when they become fouled. Further, an outer filter septum may be applied around the hollow RO fibers of the elements to remove particulate matter which would otherwise foul the hollow RO fibers.