IWC – formerly Industrial Water Cooling and headquartered in Johannesburg – said that by incorporating the flared-diffuser design, which has a slightly tapered exit cone and a well-rounded inlet bell, the fan stacks “reduce the amount of energy needed to power the 9.15m axial fan, resulting in significant energy savings when compared to conventional fan stacks”.
In 2012, Eskom awarded IWC the contract to supply two, four-cell mechanical induced draft concrete cooling towers for the Kusile plant. The latest fan stacks are for the second tower, with IWC having already completed installation of the fan stacks in the first tower. IWC has provided the same fan stacks on the auxiliary plant cooling towers for Eskom’s Medupi power station.
The cooling towers are part of Kusile’s auxiliary cooling system and supply cooling water primarily for the turbine and boiler plant auxiliaries as well as compressor cooling and other items of the plant. Each of the towers is designed for a flow rate of 16 000m³/h and has a heat rejection of 126 MW.
Kusile is scheduled to enter commercial operations in the second half of 2017. It will comprise six 800 MW units, with a total capacity of 4800 MW. Once completed, Kusile will be the fourth-largest coal-fired power plant in the world.