Instability Analysis on Gas-Solid Two-phase Flow in the Standpipe under Negative Pressure Gradient
负压差立管气固流动的不稳定性实验分析

The paper presents an experimental study on the instability behaviors of gas-solid two-phase flow in a f150 mm11500 mm standpipe under negative pressure gradient. The gassolid two-phase flow in the standpipe is characteristic of the flowing against negative pressure and slip velocity upward, which made flow instability of the gassolid two-phase flow. There are two kinds of instability, one is the flowrate shift resulting from non-fluidization, the other is flowrate fluctuation resulting from compressed gas. Flowrate shift happened at the entrance or the exit of standpipe and the flowrate fluctuation occurred in any part of standpipe. The instability of gassolid two-phase flow in the standpipe has potential harm to the operation of circulating fluidized beds.