The effect of the draft tube geometry on mixing in a reactor with an internal circulation loop - A CFD simulation

článek v časopise ve Web of Science, Jimp

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The main topic of this paper is to describe the effect of geometrical parameters on mixing time in a reactor with an internal circulation loop. The design of the draft tube inside the reactor is an important geometric parameter and has a big influence on two phase hydrodynamics as well as on mass transfer in the reactor. In the first section, the validation of the selected mathematical model is carried out. The results of experimental measurements (liquid velocity and gas hold-up) obtained on the laboratory scale reactor are compared with the CFD simulations. The CFD simulation (bubbly flow and mass transfer models) was made using COMSOL Multiphysics 3.5a. The results of the numerical simulation are in good agreement with the experimental data. In the second section, the study of mixing in the reactor is described with the new geometry of the draft tube. The standard experimental techniques for testing mixing processes are quite problematic because common tracers (soluble salts) have significant influence on two phase hydrodynamics inside the reactor. Though, an alternative nontrivial method had to be used. The split of the draft tube into two or three section has a significant effect on mixing (mass transfer) in the reactor.

The main topic of this paper is to describe the effect of geometrical parameters on mixing time in a reactor with an internal circulation loop. The design of the draft tube inside the reactor is an important geometric parameter and has a big influence on two phase hydrodynamics as well as on mass transfer in the reactor. In the first section, the validation of the selected mathematical model is carried out. The results of experimental measurements (liquid velocity and gas hold-up) obtained on the laboratory scale reactor are compared with the CFD simulations. The CFD simulation (bubbly flow and mass transfer models) was made using COMSOL Multiphysics 3.5a. The results of the numerical simulation are in good agreement with the experimental data. In the second section, the study of mixing in the reactor is described with the new geometry of the draft tube. The standard experimental techniques for testing mixing processes are quite problematic because common tracers (soluble salts) have significant influence on two phase hydrodynamics inside the reactor. Though, an alternative nontrivial method had to be used. The split of the draft tube into two or three section has a significant effect on mixing (mass transfer) in the reactor.

Bubbly flow; CFD; Internal loop reactor; Mixing

2015

01.08.2015

Elsevier

0255-2701

94

8

29–34

6