Installation - Techne IFB-101 Operator's Manual

I F B - 1 0 1 O P E R A T O R ' S

INSTALLATION

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
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M A N U A L
160 l/min
110 l/min
70 l/min