Experimental investigation on vertical plug formation of coarse particles by a non-mechanical feeder

Pressure fluctuation instability in vertical plug formation of coarse particles with a non-mechanical feeder

“…Power spectral density (PSD) analysis by using the Fast Fourier Transform (FFT) has been used to characterize the dominant frequency (F d ) of the pressure fluctuations for plug formation in the previous work (Zhang et al, 2016a;Li et al, 2018). The Welch method (Welch, 1967;Johnsson et al, 2000) of power spectrum density estimation is used to characterize frequency distribution of the pressure fluctuations in this study.…”

“…Plug conveying receives continuous interests in recent years, due to the advantages of low particle attrition, low pipeline wear, and low energy consumption (Konrad, 1986;Rawat and Kalman, 2017). As summarized in our previous work (Li et al, 2018), previous studies on plug conveying mainly focused on pressure drop (e.g., Tsuji and Asano, 1990;Pan and Wypych, 1997;Shaul and Kalman, 2015;Kofu, 2016), stress and friction force (e.g., Tsuji et al, 1992;Mi and Wypych, 1995;Pahk et al, 2013;Shaul and Kalman, 2014;Nied et al, 2017), plug motion behavior (e.g., Strauβ et al, 2006;Sturm et al, 2010;Lecreps et al, 2014;Rawat and Kalman, 2017), and transport boundaries (e.g., Wypych and Yi, 2003;Setia et al, 2015), with little attention paid to the process of plug formation.…”

“…Detailed particle motion behaviors and plug formation mechanisms in a DTF with dp = 6 mm glass beads were investigated by CFD-DEM (Computational Fluid Dynamics-Discrete Element Method) coupling simulation (Zhang et al, 2018). The influence of particle diameter (d p = 6, 4, and 2 mm, glass beads) and relative entrainment height on the gas-solid flow behavior during plug formation were investigated by experiments (Li et al, 2018). It should be pointed out that the pressure fluctuation instabilities in the vertical plug formation of coarse particles were only preliminarily introduced in our previous work (Zhang et al, 2016a;Li et al, 2018).…”

“…The influence of particle diameter (d p = 6, 4, and 2 mm, glass beads) and relative entrainment height on the gas-solid flow behavior during plug formation were investigated by experiments (Li et al, 2018). It should be pointed out that the pressure fluctuation instabilities in the vertical plug formation of coarse particles were only preliminarily introduced in our previous work (Zhang et al, 2016a;Li et al, 2018). In this study, we further analyze the detailed characteristics and the origin of the pressure fluctuation instabilities, with an emphasis on the microscale instabilities.…”

“…Figure 2 shows the schematic diagram of the experimental setup. It has been used to investigate vertical plug formation of coarse particles in our previous work (Li et al, 2018). Detailed introduction of the experimental system can be found in that work.…”