Counter rotating axial fan is a kind of down-hole long distance ventilated equipments that just applied in recent years;the in-depth research of it can ensure the safe production of the coalmine.

• 对旋轴流式通风机是一种近年才推广应用的井下长距离通风设备,对它的深入研究可以使煤矿的安全生产得到大大保证。