EVALUATION OF SOLID BOWL JOHNSON SCREEN IN A WESTERN STATES CONTINUOUS LOW GRADE FUGAL

THE FILTERING screens in low grade centrifugals are expensive consumable items that are subject to substantial abrasion and wear. With increased openings of the slots increased sucrose losses to final molasses occur. The filtering screens also influence the massecuite throughput rate that can be achieved by the fugals for a target sugar purity. The selection of the filtering screens must take into account the processing performance, replacement cost and robustness. Johnson screens fitted to low grade centrifugals have previously been trialled in Australia. This paper reflects on the opportunity to trial an improved design of screen in search of reduced final molasses purity, with the benefits of increased screen service life and overall cost savings. A Johnson solid bowl wedge wire screen was installed on two different CC6 machines at Mulgrave Mill during the 2010 crushing season. The performance of the Johnson screen in terms of service life, throughput, final molasses purity and magma purity was evaluated against the two CC6 machines operating with stainless steel laser drilled screens (SSL screens).