Interpreting Differential Pressure Signals for Particle Properties and Operating Conditions in a Pilot-Scale Circulating Fluidized Bed Riser

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• 作者：Aditya Anantharaman ; S. B. Reddy Karri ; John G. Findlay ; Christine M. Hrenya ; Ray A. Cocco ; Jia Wei Chew
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2016
• 出版时间：August 10, 2016
• 年：2016
• 卷：55
• 期：31
• 页码：8659-8670
• 全文大小：676K
• 年卷期：0
• ISSN：1520-5045

文摘

Pressure taps are ubiquitous in fluidized bed reactors. Unfortunately, attention is typically paid only to the mean or standard deviation of the fluctuations in practical operations, which leads to a loss in the wealth of information contained therein. This effort is targeted at assessing the hydrodynamic characteristics that can be understood from a comprehensive data set of pressure signals via wavelet decomposition. Differential pressure (ΔP) signals were recorded at 11 axial positions along a pilot-scale CFB riser for five particle systems (namely, three monodisperse materials and two binary mixtures) and four operating conditions. The effects of material property, operating condition, and riser axial position on the differential pressure (ΔP) signals were evaluated by comparing the energy contained in the wavelet-decomposed signals (E_Dj). Results indicate the following: (i) whereas the averaged ΔP values and power spectra of the signals were largely invariant, E_Dj values tended to be sensitive to material property and operating conditions throughout the riser; (ii) under conditions of lower solid loading, higher E_Dj values were obtained and E_Dj was more sensitive to material properties; (iii) among monodisperse particles, the larger and denser particles tended to be most sensitive to operating conditions; (iv) among the five particle systems, monodisperse small glass and monodisperse large glass systems gave, respectively, the lowest and highest E_Dj values; (v) particle density exerts a more dominant influence than particle diameter on E_Dj; and (vi) the effect of axial position on E_Dj was secondary compared to that of operating condition and material property. The observations provide insights into ΔP signals from CFB risers, which find value spanning a mechanistic understanding of the relationship between the gas phase and particles and process monitoring in practical operations.