Cole Parmer FSB-200 Series, Инструкция по эксплуатации

Страница: 21 / 36

20
Full fluidization is far from instantaneous and it takes several minutes to develop from a single vigorous ‘plume’
to a more distributed series of plumes and the level slowly rises even after the multiple plumes have formed.
OPERATION
The FSB-200-P-AC Fluidized Bath is capable of precise performance, but for reliable and consistent results it must
be used by personnel conversant with its operation.
For temperature stability, the heat input to the bath must exactly equal heat losses; the heat input from the
immersed heaters is varied by the controller which has a characteristic time constant for its response to a change
in demand. The heat losses from the bath are due to:
1. heating fluidizing air
2. radiation from the top of the bath
3. conduction through the insulation
4. conduction along loads inserted into the bath
5. heating the mass of cold objects placed in the bath.
Changing any of these will affect the temperature of the bath, but it will recover under the controller's influence;
this does mean, however, that after any parameter is changed or the load in the bath is changed, there is a delay
before the bath temperature re-stabilises.
START-UP
1. Check that the unit has been set up as described earlier and that required services are available.
2. Check that alumina level is correct and adjust if necessary. Never add new, cold alumina (which may contain
moisture) to a hot bath. Should the fluidized bath be stored for long periods of time under damp or humid
conditions, moisture may be absorbed by the alumina which is hydroscopic. To avoid violent fluidization
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.
3. Connect the bath to the electrical and compressed air supplies.
4. Turn on the mains power switch (10). The internal neon should illuminate. The bath will begin to fluidise.
The temperature controller will be illuminated and will indicate the actual temperature of the bath.
5. Turn on the dust extraction system switch (7); the green air extraction indicator lamp should illuminate.
6. Set the required operating temperature on the controller (6) by depressing the respective UP/DOWN button
until the desired value is obtained. The control parameters have been factory pre-set. For comprehensive
detailed information about the 2408 controller, refer to the operator’s manual.
7. As the bath heats up, check that the surface of the alumina is just at the top of the “hair pin” bend in the
heater assembly. Also check that the alumina is correctly fluidized; the surface of the alumina should be
flowing with the motion of violently boiling cream. Any fine alumina particles emitted from the surface of
the bath should be entrained by the extraction system when the probe plate is positioned above the bath.