Patent ID: 7156995

Claim:
An aeration control apparatus for a fluid filtration system for removing contaminants from a supply of fluid, comprising: an aeration tank, having an interior, a fluid inlet into the interior, a diffuser between the fluid inlet and the interior, a fluid outlet from the interior, and a bleed-off tube connecting the tank interior to a drain that allows the fluid and/or gas to bleed off to the drain; a source of compressed oxidizing gas; a first valve; a second valve downstream of the first valve, wherein the first valve has a first position connecting the source of compressed oxidizing gas through a first flow passage to the second valve, the second valve being displaced by gas pressure from the source of compressed oxidizing gas to a first position to open a second flow passage between the source of compressed oxidizing gas and the aeration tank and to connect the bleed-off tube to the drain, and the first valve has a second position closing the source of compressed oxidizing gas from the first flow passage and opening the first flow passage to an atmospheric exhaust; and a controllable actuator operatively connected to the first valve and having a first state for causing the first valve to assume the first position, and a second state for causing the first valve to assume the second position, wherein the controllable actuator is operable to repeatedly switch between the first state and the second state.