INNOVATⅣE FRP-CARBON PULTRUDED SHAFT FOR AXIAL FAN BLADES

摘要

Nowadays, large axial fans used on cooling towers and air cooled condensers are made using blades rigidly connected to the hub by means of hand laminated FRP or metal shafts. Cofimco's extensive research and laboratory tests have resulted in the development of a new innovative shaft to connect the blade airfoil to the hub, the new pultruded FRP shaft reinforced with carbon rovings. The innovative shaft material gives the blade a suitable elasticity, between a flexible and rigid connection. As a result, vibration introduced by the fan to the supporting structure is noticeably reduced. Simultaneously, high strength carbon rovings and an innovative dampening shaft design allow the fan blades to withstand severe duty points and limit blade deformation. Scope of the present study is to show how the new blade design can lead to a noticeable vibration reduction while maintaining high strength.