The tests show that the secondary air injected tangentially creates strong vortexes, establishes particle suspension lay-ers and internal circulation, and suppresses elutriation of fine particles greatly. 试验表明,切向喷入的二次风在悬浮段内造成强烈旋涡现象,形成颗粒悬浮层和内循环运动,并大大抑制了细颗粒扬析。