Fundamental study of bubble formation in dissolved air pressure flotation

Abstract

This paper deals with the hydrodynamic performance of very fine gas bubbles required for dissolved air pressure flotation, which are produced by dissolving air in water under pressure and subsequent flashing to normal pressure. Experiments were carried out on generated air flow rate and bubble diameter when air was dissolved in water under 1–5 Kg/cm2 gauge and flashed to normal pressure through a nozzle. The results clarify the effects of dissolved pressure, liquid flow rate and nozzle geometry, and the empirical equations for the number of generated bubbles are obtained. Also, some theoretical considerations on the generated air flow rate and diameter of generated bubbles are discussed. © 1979, The Society of Chemical Engineers, Japan. All rights reserved.