Mixed bed deionizer

In a mixed bed deionizer device having a tank containing anion and cation exchange resins, an inlet passageway for introducing raw water to be deionized into the tank, an outlet passageway for removing deionized water from the tank, and means associated with said tank for regenerating the resins in situ, the improvement comprising:

• a central pipe extending through the tank for introducing a regenerative solution in a region of the tank;
• a drain pipe of smaller diameter than the central pipe and extending axially therethrough with an end extending out of the tank and an opposite end terminating in a middle region of the tank;
• a liquid distribution block within the central pipe and mounted to the opposite end of the drainage pipe and having a plurality of passageways through which liquid in the central pipe can flow past the distribution block;
• a plurality of drainage pipes extending radially outward from the distribution block through the walls of the central pipe and into the middle region of the tank for receiving liquid therefrom, the distribution block having further passageways associated with the drainage pipes for receiving liquid therefrom and passing it into the drain pipe;
• and
• valve means for closing the drain pipe during service use of the device and for opening the drain pipe during regeneration of the resins.

A method of regenerating a mixed bed deionizer tank containing anion and cation resins, including the steps of:

• transferring raw water through first and second multi-function valve means from a raw water supply pipe to passageways in a manifold extending to a tank service water outlet pipe and transferring raw water passed through the tank and through passageways in the manifold extending to a drain pipe, during a backwash cycle;
• transferring caustic solution through the first of the multi-function valve means to passageways in the manifold extending to an upper region of the tank above the anion resin;
• transferring acid solution through the second of the multi-function valve means to passageways in the manifold extending to a service water pipe which leads to a lower region of the tank beneath the cation resin;
• removing the caustic and acid solutions through a drain means in a central region of the tank after the solutions have respectively passed through and regenerated the anion and cation resins;
• transferring raw water from the raw water supply pipe to passageways in the manifold extending into the upper region of the tank and to the service water outlet pipe so as to pass through the cation and anion resins in the tank and transfer to the drain pipe during a rinse cycle;
• shutting off all water flow through the manifold passageways and transferring water from the tank to the drain pipe during a drain cycle;
• transferring air from an air inlet pipe through passageways in the manifold extending to the service water outlet pipe and transferring air passed through the tank through passageways in the manifold extending to the vented air drain pipe during an air mix cycle;
• transferring raw water from the raw water supply pipe through passageways in the manifold extending into the tank during a refill cycle;
• transferring raw water from the raw water supply pipe through passageways in the manifold into the tank and transferring water passing through the resins in the tank and into the service water outlet pipe through passageways in the manifold extending to a purge drain outlet pipe during a purge cycle;
• sensing the quality of the water in the purge drain outlet pipe as it passes therethrough during the purge cycle;
• and then
• changing water flow from the purge drain outlet pipe during the purge cycle to the deionized water outlet pipe for use during the service cycle when the quality of the water being sensed reaches a predetermined level.