Prediction of minimum fluidization velocity of gas–solid fluidized beds by pressure fluctuation measurements — Analysis of the standard deviation methodology

• Published in: Powder technology Vol. 174; no. 3; pp. 104 - 113
• Main Authors: Felipe, C.A.S., Rocha, S.C.S.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25.05.2007; Elsevier
• Subjects: Applied sciences; Chemical engineering; Exact sciences and technology; Fluid-dynamic parameters; Fluidization; Gas fluidized beds; Hydrodynamics of contact apparatus; Incipient fluidization; Miscellaneous; Solid-solid systems; Gas fluidized beds; Fluid-dynamic parameters; Incipient fluidization; Pressure fluctuation; Prediction; Gas solid; Hydrodynamics; Fluidization; Pressure measurement; Fluidized bed
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2007.01.015

We analyze here an experimental method for the evaluation of U mf in gas fluidized beds, based on pressure fluctuation measurements in which U mf is determined by the relationship between the standard deviation of pressure measurements and fluid velocity [M. Puncochar, J. Drahos, J. Cermak, K. Selucky, Evaluation of minimum fluidizing velocity in gas fluidized bed from pressure fluctuations, Chem. Eng. Commun. 35 (1985) 81–87]. This was tested in four different particles: Sand, Microcrystalline Cellulose, FCC and Alumina using two circular plexiglass columns with internal diameters of 0.11 m and 0.14 m as the experimental apparatus. Validation of the method was made by comparing our U mf results with those obtained by the fluid-dynamic curve. The experimental data revealed that: (1) the valid range of fluid velocity in the method employed by us is broader than those observed by other authors; (2) the method is suitable for both Geldart A and B solids. Influence of probe location and type of pressure measurement (either absolute or differential) were also analyzed and discussed. It was analyzed in this work an experimental method for the evaluation of minimum fluidization velocity ( U mf) in gas fluidized beds, based on pressure fluctuation measurements in which U mf is determined by the relationship between the standard deviation of pressure measurements and fluid velocity. According to the conclusions of this article the valid range of fluid velocity in the method employed by us is broader than those observed by other authors and the method is suitable for both Geldart A and B solids. [Display omitted]