3 replies to this topic

[atc]

Background:


I am currently working with a fluoro-based ester. There is a reaction where in ,NaCl salt is formed after passing HCl . To remove the salt i am currently using a ANF (Agitated nutsche filter).

Problem:

1) The NaCl do not form cake inside the filter instead it comes out with mother liquor ,which is slimy
2) The cake is formed after rigorous recirculation of slimy mother liquid.
3)The rate of filtration is very slow.i.e 50 Kg/hr
4)The salt passes cloth which is above 20 microns.

Actions Taken :

1) Filtration aid (HighFlow) was added - No improvement


Pl suggest me how to proceed as iam struck with this problem.

Edited by atc, 03 October 2010 - 04:56 PM.

[riven]

1) not sure; is enough time being allowed for the cake to form or area for this to occur or is the batch too big?
3) rate of filtration primarily will depend on membrane type and driving force. The former seems to be discounted so can you increase driving force

The real question is how much solvent are you recovering and is the volume of the remaining mother liquor still too large to be treated. For one particular solid it was preferred to have it very wet (slurry) after filtration.

Have a look at the particle size of the salt and the filter medium.

[pawan]

I know your problem as I have handled the similar situation.
Now first you should list out your complete process with operating conditions so that I can properly guide you.