Hydrodynamics of gas-solid fluidization of a homogeneous ternary mixture in a conical bed:Prediction of bed expansion and bed fluctuation ratios

作     者：D.T.K.Dora S.R.Panda Y.K.Mohanty G.K.Roy 

作者机构：Department of Chemical EngineeringGandhi Institute of Engineering and Technology(GIET) Department of Chemical EngineeringNational Institute of Technology(NIT) 

出 版 物：《Particuology》 (颗粒学报（英文版）)

年 卷 期：2013年第11卷第6期

页      面：681-688页

核心收录：

学科分类：081704[工学-应用化学] 08[工学] 0817[工学-化学工程与技术] 081701[工学-化学工程] 

主　　题：Gas solid fluidization Conical bed Homogeneous ternary mixtures Bed fluctuation ratio Bed expansion ratio 

摘      要：Hydrodynamic characteristics of fluidization in a conical or tapered bed differ from those in a columnar bed because the superficial velocity in the bed varies in the axial direction. Fixed and fluidized regions could coexist and sharp variations in pressure drop could occur, thereby giving rise to a noticeable pressure drop-flow rate hysteresis loop under incipient fluidization conditions. To explore these unique properties, several experiments were carried out using homogeneous, well-mixed, ternary mixtures with three dif- ferent particle sizes at varying composition in gas-solid conical fluidized beds with varying cone angles. The hydrodynamic characteristics determined include the minimum fluidization velocity, bed fluctuation, and bed expansion ratios. The dependence of these quantities on average particle diameter, mass fraction of the fines in the mixture, initial static bed height, and cone angle is discussed. Based on dimensional analysis and factorial design, correlations are developed using the system parameters, i.e. geometry of the bed （cone angle）, particle diameter, initial static bed height, density of the solid, and superficial velocity of the fluidizing medium. Experimental values of minimum fluidization velocity, bed fluctuation, and bed expansion ratios were found to agree well with the developed correlations.