In 2004 Hlsmelt commenced construction of a commercial scale process plant in Kwinana using a new technology for the direct smelting of iron ore. As part of the process pig iron was continuously tapped through a fore hearth and underwent desulphurisation before being cast in the pig casting facility. As a result of this process a great deal of fume was generated that required capture.
Hlsmelt selected Luehr Filter Pty Ltd to supply one of the largest fabric filters installed on a metallurgical process in Western Australia. To meet the stringent emissions required, Luehr's unique "off-line" cleaning design feature was selected. This method of filter bag cleaning greatly decreases filter emissions during pulse cleaning by reducing the energy required to clean the bags.
This results in less particle penetration during the cleaning cycle, reduced compressed air (in this case nitrogen), less energy required to run the plant and also greatly increased bag life due to reduced material fatigue. These features along with the compact oval bag plant configuration influenced Hlsmelt's decision to award Luehr the fume control contract.
The contract included an extensive duct system to collect the fume and convey it to the filter. The filter unit itself was compartmentalised to allow for on-line maintenance. Servicing is done from the weatherproof clean side of the filter offering rapid, safe and efficient removal of the filter bags. There is no need for maintenance personnel to enter the dirty side of the filter during bag removal or fitting.
The unit was delivered on time and has operated exceptionally well. It achieved extremely low emission levels (8mg/m3), well within the EPA requirement.