It was discovered also that it fishtails when the gas in the separating column rotates at a high speed, the axial line of the vortex core fishtails along the geometrical axle center, and that results in unstable flow field which brings down the separating efficiency. 2. 同时发现,分离柱内的气体在做高速旋转时出现摆尾现象,涡核的轴线沿几何轴心左右摆动,从而导致了流场的不稳定,使分离效率下降。