CFD Simulation of Gas Residence Time Distribution in Agitated Tank

Abstract:

Gas residence time is an important parameter for gas-liquid agitated tank. Two approaches, i.e., Euler-Tracer method and CFD-DPM method are proposed for predicting gas residence time distribution (RTD) in an aerated agitated tank by using a Fluent 6.2 software package. The simulation results show that the characteristic of the gas-RTD is a curve with single peak and long tailing. Bubble size, stirring speed and gas inlet flow rate have great effect on gas-RTD in the stirred tank. Small bubbles have wider residence time distribution and stay in the vessel longer than the large bubbles and tend to complete mixing. With increasing of impeller speed or decreasing of gas inlet rate, gas-RTD become wider and have longer average gas residence time, which is in favor of gas effectively utilization.

• Periodical: Advanced Materials Research (Volumes 732-733)
• Pages: 467-471
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.732-733.467
• Online since: August 2013
• Authors: Liang Chao Li
• Keywords: Agitated Tank, Gas-Liquid Dispersion, Numerical Simulation, Residence Time Distribution

References

[1] M.Laakkonen, P.Moilanen, V.Alopaens, J.Aittamaa: Chemical Engineering Science, Vol.62 (2007), p.721.

[2] Z.M. Gao, J. M. Smith, H. Müller-Steinhagen: Chemical Engineering and Processing, Vol.40 (2001), p.489.

[3] S. S.Alves, C. J.Maid, J. M. T.Vasconcelos, A. J.Serralheiro: Chemical Engineering Journal, Vol.89(2002), p.109.

[4] G.L. Lane, M.P. Schwarz, G.M. Evans: Applied Mathematical Modeling, Vol.26 (2002), p.223.

[5] M. P. G. Thijert, M. H. Oyevaar, W. J. Kuper，K. R. Westerterp: Chemical Engineering Science, Vol.47 (1992), p.339.

[6] G. Benjamin, R. William: I&EC Process Design and Development, Vol. 5(1966), p.15.

[7] H. Luo& H.F. Svendsen: AIChE Journal, Vol. 42(1996), p.1225.

[8] A. Haider, O.Levenspiel: Powder Technology, Vol.58 (1989), p.63.