Flow regimes, bubble column reactor

In a properly operated bubble-column reactor, the liquid phase can be considered to be perfectly mixed, i.e. concentrations in the liquid are the same everywhere and correspond to those in the effluent. The gas is supposed to flow like a piston, i.e. the reactor is a plug-flow reactor with respect to the gas. These two assumptions are not entirely true, but within a certain flow regime they are not far from the reality. 

Flow regimes in slurry bubble column reactors... 

The hydrodynamics of bubble columns and slurry bubble column reactors depend strongly on the flow regime (Figure 3.27). There are three flow patterns that prevail in these reactors (Wallis, 1969 Shall et al., 1982) ... 

For the heterogeneous flow regime, the Akita-Yoshida correlation derived for bubble column reactors is proposed (Akita and Yoshida, 1973 Ramachandran and Chaudhari, 1984 Behkish, 2004 Koide, 1996) ... 

The recent progress in experimental techniques and applications of DNS and LES for turbulent multiphase flows may lead to new insights necessary to develop better computational models to simulate dispersed multiphase flows with wide particle size distribution in turbulent regimes. Until then, the simulations of such complex turbulent multiphase flow processes have to be accompanied by careful validation (to assess errors due to modeling) and error estimation (due to numerical issues) exercise. Applications of these models to simulate multiphase stirred reactors, bubble column reactors and fluidized bed reactors, are discussed in Part IV of this book. 

Olmos E, Centric C, Midoux N (2003) Numerical description of flow regime transitions in bubble column reactors by multiple gas phase model. Chem Eng Sci 58(10) 2113-2121. 

Figure 3. Flow regimes and bubble formation in a bubble column reactor and bubble formation (references 17, 18).

Krishna, R., and EUenberger, J. (1996), Gas holdup in bubble column reactors operating in the churn-turbulent flow regime, AIChE Journal, 42(9) 2627-2634. 

Zahradnik, J., Rialova, M., Ruzicka, M., Drahos, J., Kastanek, R, and Thomas, N.H. (1997), Duality of the gas-liquid flow regimes in bubble column reactors, Chemical Engineering Science, 52(21/22) 3811-3826. 

Microstructured falling film and micro bubble column reactor Single micro channel operating in annular flow regime Microstructured falling film reactor Microstructured falling film reactor... 

Shaikh A, Al-Dahhan M. (2013a) A new method for online flow regime monitoring in bubble column reactors via nuclear gauge densitometry. Chem. Eng. Sci., 89 120-132. 

Van der Laan [82] reported attempts to model FT in a bubble column reactor. His model exhibited well-mixed liquid and two gas bubble regimes small bubbles that were well mixed and large bubbles that showed plug flow behavior (Figure 12.21). Van der Laan [82] also provided a summary of bubble column reactor models that others have utilized (Tables 12.1 and 12.2). He concluded that the FT slurry bubble column reactor is reaction controlled due to the low activity of the iron catalyst and the... 

Figure 12.21 Hydrodynamic model of a slurry bubble column reactor in the heterogeneous flow regime [82]. (Source van der Laan [82]. Reproduced with permission of Elsevier.)...

Shnip AI, Kolhatkar RV, Swamy D, Joshi JB. Criteria for the transition from the homogeneous to the heterogeneous regime in two-dimensional bubble column reactors. Int J Multiphase Flow 18 705-726, 1992. 

Olmos E, Gentric C, Midoux N (2003) Numerical description of flow regime trtmsitions in bubble column reactors by multiple gas phase model. Chem Eng Sci 58(10) 2113-2121 Onken U (1988) Bubble column as chemical reactors. In Bubble columns. Preprints from the German/Japanese symposium (by DVCV - Deutsche Vereinigung fiir Chemie- und Verfahren-stechnik, VDI - Gesellschaft Verfahrenstechnik und Chemie- ingenieurwesen), Schwerte/ West-Germany, 13-15 June, 1988... 

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