How to avoid boiling/bubbling effect under vacuum?

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
Sign up Log in
6 replies · 3K views
Dr SAYEED
Messages
3
Reaction score
0
I have a process problem where my product is mixed with water and needs to be separated under low temperature range 5-10 deg C. I hope evaporation under vacuum is the only solution but the boiling effect is creating splash and want to avoid it. Prefreezing or lyophilization is not an option given the temperature range. If some body in the forum can help would be great.
 
Engineering news on Phys.org
Sounds like you need better control of your "vacuum" so that it is more like "low pressure". After all, you don't need to go to a hard vacuum to get evaporation but a hard vacuum would be more likely to cause rapid evaporation, thus "splash".
 
phinds said:
Sounds like you need better control of your "vacuum" so that it is more like "low pressure". After all, you don't need to go to a hard vacuum to get evaporation but a hard vacuum would be more likely to cause rapid evaporation, thus "splash".
Appreciate your reply also the concern is time and volume, for us 1 litre should evaporate with in 2-3 minutes or so then we transfer to sterile storage. Its a new challenge we came across and I am working on it.

rgds
Sayeed
 
phinds said:
how about floating a sterile, porous item on top of the liquid to quell the spalsh? Something like thin Styrofoam with lots of holes in it.
Thanks for the idea, will give it a try :)
 
I am with phinds second post. Limiting the effects of the splash (or the undesirable effects of it) rather than preventing it happening in the first place probably gives you an easier set of problems to solve.
 
The surface tension of the bubble as it forms must be building up energy prior to bursting and release. We do not know the form of the product or why the bubbles accumulate until they burst and splash.

What is it about the product that allows bubbles to form. Could some surface modifier like a drop of oil or a de-foamer be added to prevent the bubbles forming. https://en.wikipedia.org/wiki/Defoamer

Maybe a mechanical or ultrasonic vibration would help the bubbles escape from the material before they can accumulate to a size that becomes a problem.