There is convenient impeller adjusting device . the clearance between housing and end of powder concentrator ' s blade also effects fineness . this patent technology is convenient to adjust the clearance 方便快捷的叶轮调整装置。选粉机叶片端部与壳体的间隙大小也影响成品细度,本项专利技术使得调整该间隙大小方便快捷。