Fume Ignition - Techne IFB-201 Bedienungsanleitung

Fume Ignition

Spontaneous ignition may occur above the surface of the fluidised bath or within the exhaust ductwork
if the concentration exceeds the lower explosive limit.
The fume concentration is dependent upon the rate of fume production in the fluidised bath and the
level of dilution achieved by entraining air from above the bath or through the dilution tee.
The rate of fume production is dependent upon the type and amount of material being treated and the
temperature of the bath.
To ensure that the concentration of inflammable fumes is below the lower explosive limit, ensure that
the amount of combustible material immersed in the bath at any one time is within the design capacity
of the extraction system. Ensure that the temperature of the bath is at the minimum level at which
satisfactory results can be achieved. Increased working temperatures result in increased fume
concentration. By way of example, an extraction rate of 2m 3 /min is required to ensure that the fume
concentration is below 25% of the lower explosive limit when thermally decomposing 1kg/hr of
polythene at 450°C.
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