Abstract: Systems and methods for regenerating mixed bed demineralizers are disclosed in this invention. Ion exchange resins are separated in a separation vessel and are separately regenerated in a regeneration vessel. No inert resins are required for separation. Fluid purification and resin regeneration may occur simultaneously, without the use of additional storage tanks or vessels.

Abstract: The invention relates to improved methods for regenerating the exhausted anion and cation exchange resins in a mixed bed demineralizer system. The exhausted bed of resin is directed into a separation vessel which contains a buffer volume of anion and cation resins remaining therein from the previous regeneration cycle. The resin in the separation vessel is classified into an upper anion resin layer, a lower cation resin layer and an intermediate layer of intermingled anion and cation resin. The cation resin is transferred from the bottom of the separation vessel to a cation regeneration vessel through a cation transfer conduit having isolation valves associated with the respective ends thereof. The resin transfer is terminated upon the detection of anion resin in the transfer conduit, at which time the isolation valves are closed so as to isolate the bulk of the intermingled anion and cation resin layer in the cation transfer conduit.

Abstract: A method and apparatus to convert a top tube sheet precoat filter apparatus to a bottom tube sheet precoat filter apparatus. A cannister member is supported within the existing filter tank in place of the existing tube sheet dividing the filter tank into an upper influent compartment and a lower effluent compartment. A plurality of precoat filter elements extend upwardly from the lower end of the cannister member into the influent compartment. An influent conduit directs liquid to be treated into the influent compartment and an effluent conduit withdraws treated liquid from the effluent compartment. The existing influent conduit is utilized as the effluent conduit and the existing drain is modified for utilization as the influent conduit. A gas surge conduit and vent are provided to permit utilization of the gas scour backwash technique.

Abstract: The present invention relates to a method for purifying aqueous solutions or condensate in a three component resin system comprising a mixed bed of a strongly basic anion exchange resin, a strongly acidic cation exchange resin and a weakly acidic cation exchange resin. According to the present method, aqueous solutions can be treated to remove metal ions and corrosion products along with ammonia and other volatile amines so that metal ion leakage is substantially reduced and the run length of the resin system is increased. A method for separating and isolating the resins of the three component system is also described.

Abstract: The method and apparatus for filtering a liquid including a filter vessel divided into an upper filter compartment and a lower plenum compartment. An external vessel is positioned at or below the elevation of the tops of the filter element fittings in the plenum compartment. A pressurized gas is supplied to the upper portion of the external vessel forcing backwash liquid from the external vessel into the lower portion of the plenum compartment backwashing filter elements within the filter compartment.

Abstract: A method for recovering and reusing liquid used to backwash a precoated filter in which the backwash liquid used in a previous backwashing cycle is passed through a filter that is about to be backwashed. The used backwash liquid is treated by the remaining capacity in the filter precoat, and is then used to backwash the filter. This backwash liquid is recovered for later treatment and use in another backwashing cycle.