REDUCTION OF BOILER STACK DUST EMISSIONS AT PLANE CREEK MILL

PLANE CREEK sugar mill in 1999 embarked on a program of significantly reducing its boiler stack dust emissions through the installation of wet collectors on its 100 tph boiler, and upgrading the dry collectors on its 200 tph boiler. The collection systems’ performance, process design and operational problems were investigated, and new equipment and plant modifications introduced. Dust emission levels were reduced from above 1500, to below current licence limits, wet –250, and dry –700, mg/Nm3 (at 12% v/v carbon dioxide). The key factors contributing to these results were the installation of efficient cyclone-type wet scrubbers, the repair of faulty forced draught air dampers, grate and multicyclones, the improvement of combustion efficiencies and the blocking off of excess multi-cyclone capacity. It was concluded that the careful selection of available new equipment, the systematic analysis of key criteria and the attention to detail with respect to inspection and repair has enabled Plane Creek Mill to meet its environmental requirements for stack particulate emissions for all its boilers in a cost effective manner.