Patent ID: 7264231

Claim:
An aeration apparatus comprising: a cylindrical passage tube including an inner surface, a lower end, an upper end opposite the lower end, and a central axis extending between the upper end and the lower end; a static mixer positioned in the passage tube adjacent the upper end of the tube and including a plurality of perforated blades extending inward from the inner surface of the passage tube forming inter-blade passages and including an opening along the central axis and between the blades forming a central passage continuously joining the inter-blade passages so fluid flowing through the inter-blade passages and fluid flowing through the central passage interact as these fluids flow past the blades during operation of the apparatus; a gas blowoff portion positioned adjacent the lower end of said passage tube and connectable to a pneumatic line attached to a gas source for supplying gas upward into said passage tube during operation of the apparatus, the gas blowoff portion being separated from the static mixer by a space; and a liquid-introducing portion adjacent the lower end of the passage tube by which liquid is introduced into the passage tube so the liquid flows upward in the passage tube during operation of the apparatus; wherein the gas supplied to the passage tube by way of said gas blowoff portion, and the liquid introduced into said passage tube from the liquid-introducing portion at the lower end of said passage tube during operation of the apparatus come in gas-liquid contact as the gas and liquid flow upward together through said space between the gas blowoff portion and the static mixer of said passage tube and come into additional gas-liquid contact in the static mixer before being discharged from the upper end of said passage tube.