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AIE were recently commissioned by BlueScope to refurbish their KOBM East Secondary Vent Fan Impeller and Suction Cones during their planned outage period.
The East Induced Draught Fan components were showing typical signs of wear after over 2 years in operation at BlueScope’s Glenbrook steel mill. BlueScope’s fully integrated steel mill produces a range of flat steel products for both domestic and export markets. Around 90% of New Zealand's annual steel requirements are produced at the Glenbrook Mill, with production of about 600,000 tonnes per year.
The purpose of the Induced Draught fans is to eliminate the fume laden air that is emitted during the charging of the KOBM and from the Iron and Steel making ladles during the steel manufacturing process.
The iron is delivered by a kress carrier from the melters in a steelmaking ladle weighing approximately 125 ton. The ladle of iron is then processed at the Vanadium recovery unit (The VRU) in preparation for charge. The 70 ton of molten iron is then charged with a percentage of scrap steel into the Oxygen Steelmaking furnace (The KOBM). After approximately 25 minutes the steel is then tapped from the KOBM furnace into a Casting Ladle and is transferred to the Ladle treatment station (The LTS). Here the steel is then refined inside the ladle before being lifted up onto the turret for casting through the Continuous slab casting machine.
AIE was the preferred choice for this work as our team had built a trusted relationship with BlueScope during previous projects at the Glenbrook Mill. Previously, AIE had manufactured the East and West ID Fans, as well as other components such as fan shafts and hub assemblies for the Steel Mill.
AIE manufactured a complete new impeller for the ID Fan. The impeller was manufactured using a proven design that was developed by AIE on a previous rebuild. The re-design that was carried out by the AIE design team included developing a 3D model for FEA analysis that was then verified by an external third party. The re-design gave better operating efficiencies and with the application of a wear resistant metal spray in high wear areas, it is hoped that an extend service life (beyond the current 24 month period) can be achieved.
The Suction Eye Cones were beyond repair and needed a full replacement. We manufactured the cones in our workshops and metal sprayed the high wear zones to ensure an extended service life is achieved.
On final assembly, the fan had wear resistant deflector plates installed around the hub and mounting flange with all of the high wear areas of the fan finally being metal sprayed to increase the life expectancy.
The fan runner was then balanced in our workshops to ISO 1940 G1 (980rpm), and departed our workshop on time, within budget and met our customers expectations.
Bruce Byrom from BlueScope Steel says "I was very impressed with the finished product we received from AIE and am quite confident that the metal spray will extend the life of the impellor well past the current 24 months". |
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