Operator Maintenance - Cole Parmer FSB-200 Series Instruction Manual

Figure 4: Full extraction system required for burn-off of toxic fumes and PVC. *Items not supplied
by Antylia Scientific Ltd.

OPERATOR MAINTENANCE

The aluminium oxide fluidising medium, not being degradable, will only require replacement when losses
occur due to attrition, spillage or contamination with inert pigments, filler or acidic by-products from the
burn-off process. Note that the aluminium oxide pulled out of the bath through the exhaust duct can be
captured for reuse by the cyclone trap.
Should the fluidised bath be stored for long periods of time under damp or humid conditions, moisture
may be absorbed by the aluminium oxide which is hydroscopic. To avoid violent fluidisation which occurs
when damp aluminium oxide is heated above 100°C, operate the bath for a period of approximately 8
hours at 90°C prior to operation at elevated temperatures.
On at least daily intervals, the bed should be cleaned of floating residues by means of a wire mesh hand
scoop. This procedure removes carbon char which impairs fluidization and acts as an absorbent. More
importantly, it can also remove uncharred plastic and so reduce the quantity of fumes produced and the
time of processing.
The optional air-line filter into the bed is self-draining. However, it should be kept in good condition by
inspection at two-week intervals and by cleaning the bowl and washing or replacing the filter element as
necessary. With exceptionally dirty or wet air supplies, this frequency may have to be increased. Free water
or water vapour in the air supply acts as a solvent to produce hydrochloric acid in the bed when PVC is
burned off. In addition, oil vapours in the air supply which reach the fluidising plate are carbonized within
the pores of the plate, quickly causing blockage and consequent poor fluidization, local overheating,
premature heater failure and possible distortion of the inner container.
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