Energy efficient ventilation for aluminium plant in India

Fläkt Woods has supplied a specialist-cooling system to an aluminium smelting plant in India, which has helped to reduce the working temperatures for the operatives and increase machinery efficiency. The Hindalco aluminium plant at Renukut has a number of pot rooms. Here, machines treat the alumina ore to extract melted aluminium metal in a crude state. The high temperatures of between 55°C to 60°C have had a detrimental effect on working conditions and the efficiency levels of electrical drives fitted to each pot. Fläkt Woods' technicians were asked to create a way of keeping the temperature of the pot rooms within 35°C to 37°C. The result was two evaporative cooling based ventilation systems. Up to 340,000m3/hr of air is passed through each of the units and is distributed to the hot points through ducts. Internally, water is forced via a high pressure pump, through tubing and 3000 mist nozzles that have an orifice of about 5 micrometres, thereby producing a micro-fine mist. The water droplets that create the mist are so small that they instantly flash evaporate. Flash evaporation can reduce the surrounding air temperature by as much as 20°C in just seconds. Fläkt Woods India manufactured the blower, which features a double-inlet-double-width centrifugal fan of 170,000m3/hr capacity, belt-driven by a 55 kW motor. The complete unit is thermal-insulated with aluminium sheet. The treated supply-air distribution system consists of galvanized steel sheet metal ducting, (of about 4000 m²) and the delivery ends are equipped with supply-air grills with adjustable dampers.