RESIDUAL bagacillo and other suspended matter contamination of cane sugar factory
process streams contribute to processing difficulties and adversely affect marketability
of the raw and refined sugar products. Novel Sonic Self-Cleaning Filters (SSCF) were
tested over several months on process streams in Australian and South African factories
to assess their practicality and effectiveness for removing such contaminants. These
streams included clear juice, evaporator syrup and refinery melt. The results report
throughput rates up to 46 tonnes per hour for a single SSCF processing evaporator
syrup, and bagacillo removal efficiencies in the range 80%—100% for a variety of
process streams and conditions. Resistance to clogging of the screen by scaling was
shown to be good. The SSCF’s totally enclosed design was found to be readily
amenable to clean-in-place chemical cleaning which, when infrequently required, was
simple and effective in execution. One SSCF operated continuously on evaporator syrup
for 30 days, virtually unattended and under automatic control using an occasional
automated hot condensate wash regimen, and maintained a consistent throughput of 35
tonnes per hour without need for chemical cleaning. This SSCF employed a laser-drilled
filter screen (LaserScreen) with an area of only 0.32 m2 and apertures 60 µm wide. The
results are regarded as preliminary, but it is concluded that this technology holds
considerable promise as a simple, practical and efficient ‘in-line’ means for majority
bagacillo and insoluble solids removal from such streams, requiring neither manual
screen washing nor the installation of additional pumps or tanks.