An Experimental Study on Pressure Fluctuations of Gas-Solid Two-Phase Flow in a Fast Fluidized Bed
1. Shanghai Research Institute of Petrochemical Technology, SINOPEC, Shanghai 201208, China;2. State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
Abstract：Pressure fluctuations along the vertical direction of the gas-solid fluidized bed in the different conditions have been measured. Standard deviation analysis of pressure fluctuations revealed that the intensity of the pressure fluctuations decreased along the column upwards, and there’s an obvious turning point of the standard deviations curve between the bottom and upper area. The measurement was also extensively analyzed by using power spectral density and wavelet decomposition in addition to the standard deviation analysis. The dominant frequency of the pressure signal went up as the particle mass flux increased, and its corresponding power peak (fluctuation intensity) was also increased. With decoupling of the pressure signal based on multi-resolution analysis of wavelet transform, the pressure signal was separated into three scale sub-signals. It was found that the meso-scale sub-signal mainly captured the large fluctuations caused by clusters passing by, the micro-scale captured the small fluctuations interweaving in the dominant fluctuations which is probably produced by the particle-turbulence interaction, formation and breakup of the clusters, gas turbulence, or the slight oscillations of fast fluidized bed. And macro-scale signals with low frequency and amplitude of demonstrate macro-stability of the fluidizing system was a macroscopic overall unit. Therefore, with the microscope analysis on the dynamic pressure, instantaneous parameters characteristics of gas-solid flow and interaction between gas and solids in the fluidized bed could be well investigated.
Xu Jun 1,2,Gu Songyuan 1 et al. An Experimental Study on Pressure Fluctuations of Gas-Solid Two-Phase Flow in a Fast Fluidized Bed[J]. 化学反应工程与工艺, 2014, 30(5): 391-397.
