Fluid flow switching valve assembly and system

A valved system for providing selective fluid flow communication between a plurality of fluid processing vessels, comprising:

• two valve members having respective engaged surfaces relatively rotatable to provide valving action, said valve members including a first valve member having a plurality of through apertures for respective communication with said vessels, and a second valve member including a pair of separate flow passage means for selectively and separately interconnecting first and second variably paired combinations of said apertures through said first valve member in order to enable separate fluid flow between each said aperture pair;
• drive means for driving continuous relative rotation of said valve members in order to enable rotationally cycled, variable interconnection and fluid flow through said aperture pairs;
• a pair of fluid processing vessels having respective intake conduits respectively connected to one of said through apertures;
• a source of fluid for processing in said vessels and a waste vessel for receiving backflow of waste fluid from said processing vessels, said fluid source and said waste vessel being separately connected to respective ones of said through apertures different from the apertures connected to said processing vessels, each said processing vessel further including a respective discharge conduit for processed effluent therefrom, said discharge conduits being interconnected for flowing a portion of processed effluent from one of said processing vessels into said discharge conduit of the other of said processing vessels for backflow therethrough, in order to direct said backflow through said respective intake conduit and respectively connected aperture into said waste vessel interconnected by one of said flow passage means, whereby one of said processing vessels processes said fluid from said respectively connected intake conduit while the other of said processing vessels simultaneously receives and purges backflow in cycled manner alternating with said continuously alternating aperture interconnection by said respective flow passage means.