1988 年 21 巻 1 号 p. 15-20
The gas-liquid volumetric oxygen transfer coefficient in a three-phase fluidized bed bioreactor was studied using Ca-alginate gels as the solid phase. The coefficient, kLa, in three-phase fluidized beds was smaller than that in bubble columns, regardless of gel diameter. This result was a new finding, and was shown to be characteristic of low-density gel beds. The value of kLa decreased with decreasing gel diameter and with increasing particle concentration in the liquid suspension. This indicates that an optimal gel diameter and particle concentration exist in application of gels to the bioreactor. Dimensionless correlations are proposed for kLa and εG.