Installation - Techne IFB-121 Operator's Manual

Mount the fluidised bath in the position where it is to be used. It is important to ensure that the bath is
level, otherwise it will fluidise incorrectly. This will lead to the formation of large temperature gradients
across the bath which results in premature heater failure and possible damage to the porous plate and
inner container assemblies.
Connect any associated fume treatment equipment to the fluidised bath effluent gas extract duct. See
section which follows on Fume Cleaning.
Check that the heater isolation resistance (measured from the load side of the solid state relay, to earth)
is at least 2.5M ohm before connecting the electrical circuit to the electrical supply. See attached circuit
diagram for connection details and the unit rating plate for details of the electrical supply required.
The compressed air supply to the fluidised bath must be clean, dry, and free from oil.
If a manual control option is fitted, close the air flow adjusting valve which is situated on the front of the
control console, and connect the air inlet port at the rear of the control console to a suitable dry, clean
air supply. Make sure that the pressure delivered to the fluidised bath is between 204kPa (30psi) and
1030kPa (150psi), and that the compressed air line is capable of supplying sufficient air to fluidise the
bath (see specification details).
Fill the fluidised bath with a sufficient quantity of aluminium oxide so that, when fluidised, the distance
between the top of the aluminium oxide and the top of the bath is 390mm.
Should the fluidised bath be stored for long periods of time under damp or humid conditions, moisture
maybe absorbed by the alumina which is hydroscopic. To avoid violent fluidisation which occurs when
damp alumina is heated above 100°C, operate the bath for a period of approximately 8 hours at 90°C
prior to operation at elevated temperatures.
NEVER ADD COLD OR DAMP ALUMINA TO A HOT BATH AS THIS WILL ALSO CAUSE VIOLENT
FLUIDISATION WHICH CAN BE DANGEROUS. Allow the bath to cool then add the fresh alumina. If this
fresh alumina is a large proportion of the charge then dry the whole charge as above.
Set the air pressure regulator, which is situated within the pneumatic section of the control console to
204kPa (30 psi).
Units fitted with the automatic fluidising air control system require no further adjustment. Other systems
require adjustment of the air flow adjustment valve which is situated on the fascia of the control console.
Adjust the air flow so that the fluidised bed lifts and fluidises evenly across with bubbles of approximately
50mm diameter. It is important to ensure that the bath is correctly fluidised.
If the air flow is too small, uneven fluidisation will result in poor heat transfer and large temperature
gradients across the bed. If the air flow is too large the fluidisation will become violent and an excessive
amount of fluidising medium will be lost from the bed.
The following table shows the recommended fluidising air flow rates which should be used to achieve
the correct level of fluidisation.
Ambient to 200°C
200°C to 400°C
400°C to 600°C

INSTALLATION

320 l/min
260 l/min
180 l/min
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