Taking pulverized coal and dry air as the experimental materials

the flow properties of high-concentration gas-solids two-phase flow in an industrial scale horizontal stainless steel tube (I.D.39 mm) were studied.The main flow pattern was identified as stratified flow observed through a quartz glass tube.The test results indicated that the conveying characteristics were dependent on the relationship of the fluidizing gas and adjustment gas.Based on the comparison of test results of two conveying tubes (39 mm and 20 mm in diameter)

some empirical expressions relating the larger tube’s operating parameters

including system pressure

gas volume flow rate and solid mass flow rate

were presented.Comparisons of the two conveying tube’s phase-diagrams showed: the mass flow rate of pulverized coal in the larger tube was affected by the system pressure more strongly than that in the smaller one; the larger tube had a higher superficial gas velocity at the pressure drop minimum point and a lower pressure drop if the solids mass flux rate was constant; and the change of pressure drop was less remarkably triggered by the change of solids mass flux rate.