Patent ID: 8398928

Claim:
A flow treatment apparatus, comprising: a flow vessel with an inlet and an outlet; an ultraviolet light source in said flow vessel; said flow vessel being configured to generate a flow therethrough that provides a substantially constant residence time therein for all fractions of a flow entering said flow vessel without blocking light from said ultraviolet light source to permit said ultraviolet light source to irradiate said flow in said flow vessel; said flow vessel having a cylindrical interior with a longitudinal axis; said inlet being arranged to inject said flow at a tangent to a curved wall of said flow vessel and said flow vessel being free of any obstructions such that momentum of the flow injected at the tangent is sufficient to the flow to travel in a helical path along the longitudinal axis of the flow vessel toward the outlet without needing a flow diverter to guide the flow; the inlet being positioned remotely from the outlet and spaced apart from the outlet along the longitudinal axis such that any fluid flowing into the flow vessel through the inlet must traverse a substantial portion of a longitudinal dimension of the flow vessel to reach the outlet, the outlet having a substantially tubular shape with a first and a second opening, the first opening being further away from the inlet than the second opening, the outlet being positioned inside the vessel and spaced apart from the inlet along a radial direction such that the fluid entering the outlet at the first opening travels inside the tubular outlet along the longitudinal axis toward the inlet side of the vessel to exit the vessel through the second opening at a position which is radially spaced from the inlet; the ultraviolet light source being located at a longitudinal axis of the flow vessel, around the outlet.