As part of an expansion at its Marulan plant in New South Wales, Boral has installed a Lime Hydrator. The de-dusting of the saturated ventilation air from the lime slaking process is a challenging application for dry filtration. The process is difficult to de-dust with a dry dust collector since it operates very close to the dew point temperature and the dust is extremely cohesive.
The sizing of the filter, the type of cloth used and the bag design were critical to Luehr’s success in winning the contract. The Luehr DFR filter was chosen. It is an air pulse on-line cleaned filter using tubular filter elements (bags). The bags are mounted vertically in the collection chamber. Dust is collected on the outer surface of the bag and is periodically removed by pulsing with compressed air. The filter contains 4 meter long Aramid 550 g/m needle felt bags that are cleaned by monitoring the differential pressure across them and only initiating cleaning at a predetermined set point.
Another issue to overcome was the extremely difficult access to the area where the filter had to be installed. Luehr addressed this by supplying the unit in five sections. The clean air chamber incorporating the pulse cleaning system was supplied as a pre-assembled module while the casing itself was split into four separate sections for site assembly. The bags and bag frames were fitted on site, as was the casing insulation.
The system was installed on time and commissioned without any issues. The plant has since been reliably producing hydrated and is meeting all expectations.