Downflow Bubble Contact Aeration

A simple system has been developed to efficiently absorb commercial oxygen and air into water. It consists of passing water down through a submerged cone-shaped hood. Oxygen or air is injected into the hood. The water velocity entering the smaller, top end of the hood is greater than the buoyant velocity of the bubbles. The water velocity leaving the larger, open bottom is less than the buoyant velocity of the bubbles. Thus, the bubbles are trapped inside the hood for efficient absorption. Oxygen absorption in excess of 90% was achieved with very low power input. The system has potential application in activated sludge, river reaeration, fish hatcheries, yeast production and hypolimnion aeration.