Prokop A, Janík P, Sobotka M, Krumphanzl V
Institute of Microbiology, Czechoslovak Academy of Sciences, 142 20 Prague 4, Czechoslovakia.
Biotechnol Bioeng. 1983 Apr;25(4):1147-60. doi: 10.1002/bit.260250420.
A bubble column fitted with an ejector has been tested for its physical and biological performance. The axial diffusion coefficient of the liquid phase in the presence of electrolytes and ethanol was measured by a stimulus-response technique with subsequent evaluation by means of a diffusion model. In contrast to ordinary bubble columns, the coefficient of axial mixing is inversely dependent on the superficial air velocity. The liquid velocity acts in an opposite direction to the backmixing flow in the column. The measurement of volumetric oxygen transfer coefficient in the presence of electrolytes and ethanol was performed using a dynamic gassing-in method adapted for a column. The data were correlated with the superficial air and liquid velocities, total power input, and power for aeration and mixing; the economy coefficient of oxygen transfer was used for finding an optimum ratio of power for aeration and pumping. Growth experiments with Candida utilis on ethanol confirmed some of the above results. Biomass productivity of 2.5 g L(-1) h(-1) testifies about a good transfer capability of the column. Columns fitted with pneumatic and/or hydraulic energy input may be promising for aerobic fermentations considering their mass transfer and mixing characteristics.
对配有喷射器的鼓泡塔进行了物理和生物学性能测试。采用刺激-响应技术测量了存在电解质和乙醇时液相的轴向扩散系数，随后通过扩散模型进行评估。与普通鼓泡塔不同，轴向混合系数与表观气速成反比。液体流速与塔内返混流的方向相反。采用适用于塔的动态进气法测量了存在电解质和乙醇时的体积氧传递系数。将数据与表观气速和液体流速、总功率输入以及曝气和混合功率相关联；使用氧传递经济系数来确定曝气和泵送功率的最佳比例。利用产朊假丝酵母在乙醇上进行的生长实验证实了上述一些结果。2.5 g L(-1) h(-1)的生物质生产力证明了该塔具有良好的传递能力。考虑到其传质和混合特性，配有气动和/或液压能量输入的塔对于需氧发酵可能很有前景。
