Statistical and frequency analysis of pressure fluctuation in an annular spouted bed of coarse particles

The pressure fluctuation characteristics of an annular spouted bed filled with coarse particles were studied by statistical and frequency analysis. The effects of spouting gas velocity, static bed height, and measuring point height on pressure fluctuation standard deviation and major frequency were systematically examined. The peak frequencies and the behavior of bubbles in the gas-solid spouted bed were observed. Experimental results show the unique features of the novel spouted bed filled with coarse particles: the pressure fluctuation standard deviation increases with the increasing of spouting gas velocity and static bed height; however, it decreases with the increasing of measuring point height For U-g < U-ms, two distinct peaks with one around 0.5 Hz and the other around 5.5 Hz are shown; while for U-g > U-ms, three peaks with the highest one at around 4 Hz can be observed in the spectra, and the major frequency decreases apparently with the increasing of spouting gas velocity, and also decreases with the increasing of static bed height or measuring point height The peaks in the power spectral density (PSD) of pressure fluctuation are in good agreement with the observed behavior of bubbles in the annular spouted bed. The results would be helpful for the identification of flow pattern in the annular spouted bed of coarse particles. (C) 2017 Elsevier B.V. All rights reserved.