XIE Kai, GUO Xiaolei, CONG Xingliang, et al. Minimum pressure drop velocity and stability analysis in pneumatic conveying of pulverized coal in commercial-scale horizontal pipe[J]. CIESC Journal, 2013, (6): 1969-1975.
Dense-phase pneumatic conveying of pulverized coal was investigated in an commercial-scale horizontal pipe (50 mm I.D.) by using compressed air as carrier gas.Minimum pressure drop velocity was obtained from the Zenz-type phase diagram
which was influenced by solids mass flux significantly.Based on electrical capacitance tomography (ECT) system
the flow in the experimental range was classified into four regimes:stratified flow
dune flow
moving bed flow and slug flow.Using probability density function (PDF) and power spectral density (PSD) function to analyze the pressure signals of typical cases
pressure fluctuations were well correlated with flow patterns.The relative stability characteristics of different operating conditions showed that the critical velocity between stable and unstable conveying was smaller than minimum pressure drop velocity due to the transitions of flow patterns.