Patent ID: 7014173
Filing Date: 2006-03-21
Classification: B01D,B01F,C02F,Y02W

Abstract:
1. An apparatus to aerate tank water comprising: a) at least one tank having tank water and at least one membrane module immersed in the tank water; b) an air delivery network having a plurality of distinct branches; c) one or more aerators in fluid communication with the distinct branches of the air delivery network and mountable below the at least one membrane module; d) an air supply to provide an initial air flow at an initial flow rate; e) one or more valves in a valve sat in fluid communication with the air supply and having distinct outlets in fluid communication with the distinct branches of the air delivery network; and, f) a valve set controller to control the valves of the valve set; wherein g) the valve set controller automatically operates the valves to (i) split the initial air flow such that at least one of the distinct branches of sir delivery network receives air at a higher flow rate and at least one other of the distinct branches of the air delivery network receives air at a lower flow rate, the lower flow rate being less than one half of the higher flow rate, and (ii) switch which branch or branches of the air delivery network receive air at the higher flow rate and the lower flow rate in repeated cycles; and, h) the valve set controller is operable to switch which branch or branches of the air delivery network receive air at the higher flow rate and the lower flow rate in repeated cycles of less than about 120 seconds in duration.