Project of FBCDZ type withdrawable counter-rotating axial flow ventilator fan in Zambia  Africa.  The power if 2*1000kw. The Blades are made of cast aluminum alloy ZL104 steel, The blade adopts orthogonal bending and sweeping combined three-dimensional twisted blade technology, the efficiency is increased by 5% -10%, and the noise is reduced by 10-20dB (A).