Gas-liquid dispersion agitated by closed impellers with flat blades

Abstract

Gas-liquid agitation by turbine type impellers having shrouds structurally (closed impellers) was studied by visual observation of the flow behavior of gas-liquid mixture in the impeller region. Impellers were used in designs of the 6 and 12 flat blades of standard width (6F and 12F) and the 6 flat blades of tapered width (6T). The way in formation of the gas cavities and dispersion as the gas bubbles through the closed impellers differed from that through the open impellers without the shrouds. In comparison of the flow behavior among the impeller designs, the 6T closed impeller was suggested to be operable for more effective gas-liquid dispersion.