Patent ID: 6135430
Filing Date: 2000-10-24
Classification: B01F

Abstract:
A process for the dissolution of gas in a large uncovered body of liquid system comprising:(a) providing impeller means positioned below the surface of the large body of liquid, and adapted to cause the passage of a gas-liquid mixture downwardly in said large body of liquid;(b) providing a hollow draft tube submerged below the surface of said large body of liquid, said, hollow draft tube having open ends at the top and bottom thereof, said impeller means being positioned within the hollow draft tube so that the gas-liquid mixture is caused to pass down in said hollow tube for discharge from the bottom thereof,(c) providing baffle means positioned over said impeller means and of sufficient size to capture most of the undissolved gas that separates from a liquid rich in dissolved gas and floats and to the surface of said large body of liquid for recirculation to said impeller means; and(d) providing conduit means for introducing a feed gas stream beneath said baffle means so that bubbles of the gas are caused by the suction of said impeller means to pass with liquid, as a gas-liquid mixture, downward in said large body of liquid, whereby the liquid rich in dissolved gas, because of the absence of container vessel walls, is dispersed into the large body of liquid, while undissolved gas due to its buoyancy, floats to the surface of said large body of liquid and is captured for recirculation, resulting in essentially complete utilization of the gas stream, the process further comprising energizing the impeller with rotational speed sufficient to cause (i) vortex formation downward from the surface of the liquid above said impeller means such that gas is drawn into and down said draft tube and (ii) turbulence in said draft tube.