Internal Optimization for Enhancing the Microbubble Dispersion Characteristics of a Stirred Tank

Abstract

Little research on the microbubble-aided transport characteristics in stirred vessels is reported. This motivates the present efforts to experimentally analyze the effects of operating condition, impeller, baffle, and sparger on the gas dispersion characteristics in a stirred tank with microbubble aeration. It is found that the number of large bubbles gradually increases with the increase of impeller speed, which is completely opposite of the results in the conventional gas−liquid stirred tank. Without baffles installed, k L a is greater than that in baffled ones, especially at the higher impeller speed. Under the same P v , the impeller type has little effect on k L a. The ring sparger shows more efficient gas−liquid mass transfer performance than a single tube distributor. Under the combination of an axial impeller and a draft tube without baffles installed, the maximal k L a exceeds 0.01 s −1 . The present study provides a useful reference for the design of stirred reactors in some applications.

Experimental Study on Scale-up of a Venturi Microbubble Generator

“…In Dth 27.0, the test tank is a stainless-steel stirred tank with a 2 m 3 volume made for bioleaching. In a recent work, it was found that the microbubble-fluid distributor has a significant impact on the gas–liquid mass transfer performance . Considering that the large volume of a 2 m 3 reactor is more likely to cause nonuniform bubble distribution, a spider-gas sparger distributor is used to disperse the microbubble–fluid mixture.…”

“…In a recent work, it was found that the microbubble-fluid distributor has a significant impact on the gas−liquid mass transfer performance. 37 Considering that the large volume of a 2 m 3 reactor is more likely to cause nonuniform bubble distribution, a spider-gas sparger distributor 38 is used to disperse the microbubble−fluid mixture. It has six arms made of 0.20 m diameter stainless-steel tubes soldered to the center cylinder of the gas sparger and dozens of holes with diameters d 0 = 2−4 mm located on the side of each arm facing downward.…”

Introducing the I&ECR Virtual Collection of Industrial and Industrially Relevant Research (2022–2023)

“…Thermodynamics, Transport, and Fluid Mechanics is the topic area in I&ECR with the highest rate of participation of industrial authors as a percentage of the articles published. The collection includes a study on thermodynamic performance of three different autothermal chemical gas looping operation modes, the extrusion of polyacrylonitrile fibers using a very high L/D extruder (recognized with a cover in May 2023), description of mass transfer in gas–liquid flow, a kinetic model for CO 2 adsorption on amine-functionalized MOFs, description of microbubble transport in stirred reactors, two articles using computational fluid dynamics, , and a view on the future of thermodynamics following the results of an industrial survey …”