General Description - Cole Parmer FSB-200 Series Instruction Manual

GENERAL DESCRIPTION

The Cole-Parmer Industrial Fluidised Baths (IFB) FSB-200-5I and FSB-200-12I have been specially designed
for removing plastic residue from extruder tools, moulding machine tools and associated parts.
The fluidised bath employs the principle of fluidisation of a mass of finely divided inert particles by means
of an upward flow of gas. A state of fluidisation is achieved when the individual particles become
microscopically separated from each other by the moving gas. This "fluidised bed" of particles has unusual
properties which differ markedly from either those of the gas or of the solid particles. Instead, the fluidised
bed behaves remarkably like a liquid, exhibiting characteristics which generally attribute to a liquid state.
For example, the fluidised bed can be agitated and bubbled; it always seeks a common level; materials of
less density will float while those with densities greater than the equivalent fluidised bed density will sink;
and, most important, the heat transfer characteristics between the fluidised bed and a solid interface can
have an efficiency approaching that of an agitated liquid.
In addition, the fluidised solid phase has a most unusual physical behaviour, in that its basic characteristics
change only slightly over very large temperature ranges; it has no melting point and no boiling point. The
lowest temperature available is the liquefaction point of the gas used for fluidisation, while the highest
temperature level is the usable temperature of the inert solid. Various metal oxides with allowable
temperatures of over 1700°C are readily available. The metal oxide beds commonly used, (e.g. aluminium
oxide) are non-flammable, non-explosive and non-toxic.
The most commonly used fluidising gas is compressed air. It is important that it should be clean, dry, free
from oil and at a constant pressure. Any other inert gas, such as nitrogen, could be used for special
applications e.g. if a non-oxidising atmosphere is required, provided appropriate precautions are taken.
The unique characteristics of gas-fluidised particles is the relatively high rate of heat transfer which yields
highly isothermal conditions, as well as excellent heat transfer to solid surfaces. This characteristic is due to
the turbulent motion and rapid circulation rate of the solid particles in conjunction with the extremely high
solid-gas interface area. Therefore, even though gas-solid interfaces normally yield low heat transfer
coefficients and the solids normally have low thermal conductivities, the overall heat transfer characteristics
of fluidised particles approach those of a liquid.
The combination of excellent heat transfer characteristics and high heat capacity are ideal for attaining
rapid stabilisation at an isothermal condition.
Cole-Parmer Industrial Fluidised Baths use alundum - fused brown aluminium oxide - as the fluidising
medium. They have been designed to remove plastic residue from extruder and moulding machine tools,
paint build up from paint fixtures and carry out various heat treatment processes. When used for
burning plastic residues, the IFB's should be installed with an adequate fume extraction system. An
extraction fan and fume extraction collar can be supplied.
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