Colliery Dust Control adopts new manufacturing method for fan impellers
Dust Buster News

Colliery Dust Control (CDC), the Springs-based specialist manufacturers and suppliers of dust suppression equipment for continuous miners, has developed a new method of manufacturing the impeller blades on the fans for its wet-fan scrubber units.

The blades were previously made of VRN 690T and their shape was generated by rolling. However, inconsistencies in the steel and difficulties in controlling the rolling procedure made consistency in the shape of the blade hard to achieve. Furthermore the welding procedures carried out on the VRN 690T steel required very special welding techniques to prevent fatigue failure.

The decision was made to switch to mild steel blades, which would then be flash chromed to provide a better wear resistance than that achieved by use of the VRN 90T. The use of mild steel also allowed a change in the method of manufacture from rolling to die-pressing and since the mild steel is more easily worked and retains its press shape better, the consistency of the blades produced by this method is much higher. In addition the welding techniques are easier to control and fatigue strength is much improved.   

Because of the greater reliability in the shaping of the blades, fan performance has been increased, fan efficiency has improved and power requirements reduced, while the wear resistance of the impeller is much greater.

The development of the improved manufacturing technique for the impellers forms part of an ongoing development strategy by the company aimed at improving the efficiency and performance of all its products.

CDC is the largest supplier in South Africa of dust suppression systems for continuous miners. The company offers a three-fold integrated system comprising the unique CDC wet-fan scrubber box, air movers and a spray fan system operating in complementary fashion to achieve maximum dust suppression efficiency.