Effect of Sparger Surface Area on Bubble Diameter in Flotation Columns

Abstract

The effect of the parameter column cross-sectional area to sparger surface area Rs , on bubble diameter db , is determined for four sparger types, ceramic, stainless steel, rubber and filter cloth. Rs should be less than about 1 for generation of uniform-sized bubbles and operation in bubbly flow conditions. For Rs ≤ 1db is related to Rs by db = C 1[Rs · Vg ]n where Vg is the superficial gas velocity and C 1 and n are empirical constants; the product [Rs · Vg ] is equivalent to volumetric gas rate per unit area of sparger. The effect of sparger type appears to be relatively minor and a general relationship is proposed db = C 1[Rs · Vg ]0.25, where C 1 is dependent on the solution chemistry. Based on the findings, a methodology for sparger scale up is proposed.