It is found that the solids backmixing rate between stages is mostly influenced by gas velocity, baffle free area and baffle spacing, but it hardly influenced by solids feed rate and the diameter of the holes in the perforated baffle. 结果表明,影响级间固体返混速率的主要因素是气速、挡板开孔率和板间距,固体净流率和挡板孔径的影响不明显。