Aeration system

An improved method for effecting gas to liquid transfer, including increasing the dissolved content of water by selectively interfacing said water with air, said improved method comprising:

• (a) defining a partially enclosed space provided with means for receiving gas and further provided with means for receiving about the top portion thereof liquid;
• (b) establishing at least one first flow path for substantial volumes of liquid to move over at least a portion of said top of said partially enclosed space;
• (c) continuously introducing at least a portion of the liquid flowing over said top of said partially enclosed space, into said partially enclosed space, in the form of a plurality of falling curtains, said curtains generally parallel to one another and generally normal to the flow of liquid over said top of said partially enclosed space;
• (d) defining liquid collection means at a lower portion in said partially enclosed space for recombining the liquid in said plurality of falling curtains into a second flow path arranged generally parallel and in substantially the same direction as said first flow path, said second flow path having an upstream portion and a downstream portion wherein entrainment of bubbles in said second flow path resulting from impingement thereon by each falling curtain comprising the plurality thereof is protracted as said flow path is subsequently subjected to additional impingement of flow curtains in the direction of the downstream portion thereof;
• and
• (e) continuously passing liquid having resulting substantial reentrainment of gas bubbles therein from said partially enclosed space;
• whereby such protracted reentrainment effects substantial increases in the effective residence time of gas-liquid interfacing and concomitant gas phase to liquid phase transfer.