Air bubbles in crystallization solution ??
Air bubbles in crystallization solution ??
(OP)
Dear all,
I'm doing a experiment with cooling crystalization in a small baffled vessel (stirred). From my probe i notice air bubbles (trap) in my solution which is not desired. How can i easily remove these bubbles.Cooling from 55 to 50deg.C.
Any suggestion /advice is welcome!
Thanks
wati
I'm doing a experiment with cooling crystalization in a small baffled vessel (stirred). From my probe i notice air bubbles (trap) in my solution which is not desired. How can i easily remove these bubbles.Cooling from 55 to 50deg.C.
Any suggestion /advice is welcome!
Thanks
wati





RE: Air bubbles in crystallization solution ??
When you trap bubbles it won't be easy to get rid of them-by slow aggitation your cristalls will settle down and they will agglomerate, recrystallize and change their original form.
m777182
RE: Air bubbles in crystallization solution ??
But its a vessel with about 5L saturated solution. First I tried diffent speed on agitating, hovewer without any specific results of reducing bubbles.Then I tried to insert the probe after I filled the vessel with sat. solution and adjust the for probe about 40-45 degrees, while shaking off the bubbles trapped in the probe.This relief the problem a little bit. However as you mentioned is not easy to get rid of all bubbles, since these bubbles may effect the CSD measurments.
Another problem is that I have less concentration(sample)for CSD measurement after cooling. Any idea how to optimize this?
Thanks
RE: Air bubbles in crystallization solution ??
m777182
RE: Air bubbles in crystallization solution ??
Results: large CSD and width -> not desired
thanks.
RE: Air bubbles in crystallization solution ??
Some particle size analyzers do use ultra sonic pretreatment of the suspension to get rid of the bubbles; however it wil destroy the agglomerates as well and it may change your CSD. You may try a short vacuum treatment with the same purpose.
To concentrate the solids you can use a small hidrocyclon (difficult to make in such a small scale and CSD bias again) or maybe filtrate the solids and redisperse it in a small amount of mother liquor. It will give you a lot of work and a nasty mass ballance.
m777182
RE: Air bubbles in crystallization solution ??