Unpowered natural draft prevents bird ware

The utility model relates to an unpowered natural draft prevents bird ware. Its characteristics are: including vertical scroll (4), overlap respectively in the top and the centre of this vertical scroll (4) and be equipped with upper bearing and middle (center) bearing, install the turbine head on this upper bearing and middle (center) bearing, there is hollow hemisphere (1) at the top of this turbine head fixed mounting, be equipped with ring (3) bottom this turbine head, the equipartition has a plurality of curved blades (2) on this ring (3) to the top of all blades (2) is together fixed. It is proved in experiments tha, the utility model discloses prevent the bird ware and can install in shaft tower insulator chain top cross arm department that rotation through the ventilator and self shared space of preventing the bird ware have been solved the bird and has been stopped and the problem of nesting in shaft tower insulator chain top cross arm department to bird to stopping on the shaft tower plays the frigh