Gas hold-up in a reactor with dual system of impellers

Results of experimental studies of gas hold-up in a liquid stirred mechanically in a reactor, which was equipped with double stirrers on a common shaft, are presented. Coalescing and noncoalescing gas-liquid systems were tested. The measurements were carried out for aqueous solutions of glucose and glucose sirup, as well as for different configurations of dual high-speed impellers. Stirred tank with inner diameter D = 0.288 m was filled with a liquid up to the height H = 2D. Experimental studies of gas hold-up in the coalescing and noncoalescing gas-liquid systems stirred using dual system of high-speed impellers show that gas hold-up W for the noncoalescing systems is considerably higher than that for the coalescing ones. The configuration of dual system of impellers used in the study slightly affects only gas hold-up and this effect can be neglected. The dependence of gas hold-up W on the specific power consumption P-g/V-L and superficial gas velocity w(og) for coalescing and noncoalescing systems can be described by means of eqns (2) and (3), respectively.