Fractional gas hold-up in gas inducing type of mechanically agitated contactors

Fractional gas hold up was measured in gas inducing type of mechanically agitated contactors (GIMAC) with single and multiple impellers. Three vessels of 0.57, 1.0 and 1.5 m i.d. were used. For the multiple impeller system, six different impeller designs were employed. The impeller speed was varied in the range of 0.30 to 15.45 s<SUP>−1</SUP>. The ratio of impeller diameter to tank diameter (D/T), the submergence (S) of the upper impeller, the clearance of the lower impeller from the tank bottom (C<SUB>1</SUB>) and the impeller spacing (C<SUB>3</SUB>) were varied over a wide range. The design of the lower impeller was optimized in terms of diameter (D), blade width (W), blade angle (Bø), number of blades (n<SUB>b</SUB>) and the blade thickness (t<SUB>b</SUB>). An optimum design has been proposed for the multiple impeller system. Rational correlations have been proposed