Abstract
Pressure fluctuations in a three phase bubble column reactor operating at relatively low pressure (92 KPa) have been analyzed by adopting the spectral and fractal analyses to get the engineering informations for the on-line control and fault diagnosis of the reactors. The mean value, standard deviation, skewness and kurtosis of the pressure fluctuations have been obtained. The local fractal dimension has been determined from the Pox diagram obtained by means of the rescaled range analysis of the pressure fluctuations based on the fractional Brownian motion. The local fractal dimension of pressure fluctuations has increased and thus the pressure fluctuation signals have become less persistent and irregular, with increases in the gas flow rate reaction temperature, particle size and solid content in the slurry phase. The local fractal dimension has been well correlated in terms of the operating variables.
Similar content being viewed by others
References
Bendat, J. S. and Piersol, A. G.,“Engineering Applications of Correlations and Spectral Analysis”, Wiely, N.Y. (1980).
Deckwer, W. D.,“Bubble Column Reactors”, John Wiely & Sons Ltd. (1992).
Deckwer, W. D. and Schumpe, A.,“Improved Tools for Bubble Column Reactor Design and Scale-up”,Chem. Eng. Sci.,48, 889 (1993).
Drahos, J., Bradka, F. and Puncochar, M.,“Fractal Behavior of Pressure Fluctuations in a Bubble Column”,Chem. Eng. Sci.,47, 4069 (1992).
Fan, L. T., Kang, Y., Neogi, D. and Yashima, M.,“Fractal Analysis of Fluidized Particle Behavior in Liquid-Solid Fluidized Beds”,AIChE J.,39, 513 (1993).
Fan, L. T., Kang, Y., Yashima, M. and Neogi, D.,“Stochastic Behavior of Fluidized Particles in a Liquid-Solid Fluidized Bed”,Chem. Eng. Commun.,135, 147 (1995).
Fan, L. T., Neogi, D., Yashima, M. and Nassar, R.,“Stochastic Analysis of a Three-phase Fluidized Bed: Fractal Approach”,AIChE J.,36, 1529 (1990).
Feder, J.,“Fractals”, Plenum Press, N.Y. (1988).
Kang, Y., Min, B. T., Nah, J. B. and Kim, S. D.,“Mass Transfer in Continuous Bubble Columns with Floating Bubble Breakers”,AIChE J.,36, 1255 (1990).
Kang, Y., Min, B. T., Ko, M. H. and Kim, S.D.,“Fractal Analysis of Pressure Fluctuations in a Gas-Liquid-Solid Fluidized Bed”,HWAHAK KONGHAK,32, 65 (1994).
Kang, Y., Shim, J. S., Cho, S. H., Choi, M. J. and Lee, K. W., “Dehydration of Ortho-Boric Acid in a Three-Phase Bubble Column Reactor Operating at Low Pressure”,J. Chem. Tech. Biotechnol.,63, 313 (1995a).
Kang, Y., Ko, M. H., Kim, S. D., Yashima, M. and Fan, L. T., “Pressure Fluctuations and Particle Dispersion in Liquid Fluidized Beds”,AIChE J., in print (1995b).
Kim, S. D. and Kang, Y.,“Dispersed Phase Characteristics in Three-phase Fluidized Beds”, Encyclopedia of Fluid Mechanics, Cheremisinoff, N. P. ed., Gulf Pub. Co., 845 (1995).
Kodo, M., Kaneko, S. and Kurata, N., The Development of the Process for Manufacturing sec-Alcohols and Their Ethoxylates via n-Paraffin Oxidation”,Oil Chemistry,25, 427 (1975).
Kwon, H. W., Kang, Y., Kim, S. D., Yashima, M. and Fan, L. T., Bubble-Chord Length and Pressure Fluctuations in Three-phase Fluidized Beds”,I &EC Research,33, 1852 (1994).
Idogawa, K., Ikeda, K., Fukuda, T. and Morooka, S.,“Behavior of Bubbles of the Air-Water System in a Column under High Pressure”,Int. Chem. Eng.,26, 468 (1986).
Luewisuthichat, W., Tsutsumi, A. and Yoshida, K., Fractal Analysis of Particle Trajectories in Three-phase System”,Trans. IChem E.,73, 222 (1995).
Prince, M. J. and Blanch, H. W.,“Bubble Coalescence and Break-up in Air-Sparged Bubble Columns ”,AlChE J.,36, 1485 (1990).
Shah, Y. T., Kelkar, B. G., Godbole, S. P. and Deckwer, W. D., ”Design Parameters Estimations for Bubble Column Reactors”,AlChE J.,28, 353 (1982).
Shim, J. S., Kang, Y., Choi, M. J. and Lee, K. W.,“Applicability of the Bubble Column Reactor Operating at Low Pressure , Proc. 7th Symp. on Chem. Eng., Kitakyushu, Japan, December 15–16, 193 (1994).
Suh, I. S., Schumpe, A., Deckwer, W. D. and Kulicke, W. H., “Gas-Liquid Mass Transfer in the Bubble Column with Viscoelastic Liquid”,Can. J. Chem. Eng.,69, 506 (1991).
Yashima, M., Nassar, R., Fan, L. T. and Kang, Y., Stochastic Modeling of Pressure Fluctuations in a Three-phase Fluidized Bed”,AlChE J.,38, 629 (1992).
Yoon, S. H., Kim S. D., Kang, Y., Kim, Y. J. and Cho, S. H., “Effective Comminution of Diatomaceous Earth in a Vertical Type Jet Mill”,Korean J. Chem. Eng.,12, 436 (1995).
Yu, Y. H. and Kim, S. D., “Bubble Properties and Local Liquid Velocity in the Radial Direction of Cocurrent Gas-Liquid Flow”,Chem. Eng. Sci.,46, 313 (1991).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kang, Y., Shim, J.S., Kim, S.D. et al. Fractal analysis of pressure fluctuations in a three phase bubble column reactor operating at low pressure. Korean J. Chem. Eng. 13, 317–323 (1996). https://doi.org/10.1007/BF02705956
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02705956