APPLICATION OF FRAME-TRAK® CLOTH FIXING TECHNOLOGY WITHIN THE PRODUCTION ENVIRONMENT: THE WORSLEY EXPERIENCE

An extended production trial of Frame-Trak® cloth fixing technology has been undertaken at Worsley Alumina. The Frame- Trak® system of fitting filter media has been designed by Clear Edge Filtration and Bokela GmbH, to replace existing caulking rope and retaining plate locking mechanisms on rotary vacuum filters. Frame-Trak® aims to eliminate Occupational Health and Safety (OH&S) issues associated with the existing methods of cloth affixation while promising filtration efficiency improvements by providing an improved vacuum seal. Frame-Trak® was retrofitted to a single 60m2 vacuum drum filter performing first stage fine seed filtration duty in late 2005.

Installation of Frame-Trak® was labour intensive and resulted in significant downtime. Design oversights contributed to poor filter performance and difficulties with drainage grid and cloth fit. The combination of these factors resulted in repeated failures, hydrate scale forming in the profiles and lengthy re-cloth times, contrary to design intent. Refinements to cloth design and fitting techniques, along with tooling modifications and education of personnel have since led to improved quality and ease of installation. Consequently, hydrate scale in profiles and failures in operation have been largely eliminated while cloth life has been extended.

Trial of Frame-Trak® at Worsley has delivered OH&S benefits by eliminating forceful re-cloth tool use. Re-cloth times are now comparable to the previous cloth fixing method and in terms of performance the technology offers extended cloth life, equivalent throughput, improved cake release and reduced cake recycle. Frame-Trak® is emerging as a convincing alternative to traditional cloth fitting technology.