Dear Lawrence,
these days process air volume control is done by the
outlet flap only, which is fully sufficient.
Inlet air flaps were in the past used for very wet granules
which did not like to fluidize in the beginning, so that
playing around with the inlet air flap did create some impact
on the wet mass by creating some higher negative pressure inside
the FBD, the fans of which usually had quite low differential pressures.
As FBD's have all powerful fans these days, the inlet air flap has
become superficial. It would also not measure up to existing validation
standards.
Hence, first choice should be to keep the inlet air flap fully open
and modulate the air flow with the exhaust flap
-----Ursprüngliche Nachricht-----
Von: Lawrence Young [mailto:yaku_98@yahoo.com]
Gesendet: Dienstag, 8. April 2003 15:39
An: Process Technology
Betreff: Flap control to in FBD
Dear Forum;
When we apply FBD dryer to dry granuales, we hope to minimize the
fluctuation of granuales to prevent granules from deforming.
Naturally we should reduce the inlet/outlet air flap. But in the end
this way also affect the granuale by increase the fluctuation time.
Would you please advise me what is optimium flap setting, I assume
inlet should be high enough to reduce air flow rate, but increase air
volume and outlat flap should be lower enough. Right? Would you
please share your exprience with me.
Thank you very much.
Best
Lawrence Young
yaku_98@yahoo.com
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Lawrence Young
yaku_98@yahoo.com
Pfizer
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