Circulation and scale-up in bubble columns



The liquid circulation model of Rice and Geary (1990) is extended to include turbulence originating at the wall. Thus, two possible length scales are considered: one originating from rising bubbles and the other emanating from the wall. The appropriate scale for small columns should be based on bubble size, while for larger systems the proper mixing length is proportional to column diameter. It is proposed that the film Reynolds number may be the key in distinguishing the two cases.