[mahesh]

Hi all!
I am looking for a dryer design that involes complete recovery of the evaporated liquid. The reason is, the solvent that I am losing while drying the solid is too expensive and killing my process economics. Can someone help?
Thanks,
Mahesh

[technologist]

Mahesh
I can provide you the complete solution if you can let me know more details.

[mahesh]

Hi! I am working on a system where I am using solvents like acetone, diethylamine etc., which are highly volatile. The solids are crystallized, and are sent for drying. Now, the LOD of the solids is appreciable (4-6%), where the solvents will be lost. The process till now has been using centrifuges, hence the economics was bad. I want to make it much better by the use of an appropriate dryer or a similar equipment, where I can recover the solvents. Can you help in this? In upcoming cases, I will have to suggest much costlier solvents, where I may not have the liberty of 0.5% LOD..

[technologist]

Providing a complete sketch of existing system with parameters and then your objective will make it more clear.

Currently I could understand that you are separating solids using centrifuge which is having 5-6% LOD and while you dry these solids - the 5-6% solvent is lost. You want to reduce this to 0.5% so loss is minimum.

Is this your objective?
If yes I need to understand your system upstream of centrifuge & solvents / solids involved so that I can suggest a method.

[DrCMS]

If that understanding is correct you are saying the loss of ~60kg of acetone per T of dried finished product is too expensive?
Acetone is a very cheap solvent and 60kg cost ~ $30. 
The kind of solvent recovery system that you could add to your drier would cost >$100K
Therefore given a 5 year lifespan you'd need to be drying > 700T/year to even consider it.

[mahesh]

Dear Technologist,
there are confidentiality issues, so I can not provide all the details even though I would have liked to do so.. The solvents are presently acetone and DEA, as I have already said.. from what you have asked, I understand you need to know the composition of the LOD.. The LOD (which is in the range of 4-7%) consists of nearly 60-80% wt/wt organic solvent and balance water.. the solids are common inorganics having bulk densities in the range of 1-1.6 g/cc. Is this information sufficient?
I appreciate your help.

Dear DrCMS, the ROI is not an issue, I'll be happy if I can reduce the solvent losses. As I have mentioned, there are some other similar cases, where I will be using much more expensive solvents too.

[technologist]

Right I can understand confidentiality part but it is sufficient that they are in organics but even then I need to know / understand the following. May be you can discuss on my mail separately.

1. Nature of solids - abrasive etc.
2. Type of solids - crystalline, amorphous
3. Behavior of solid mass - sticky, free flowing
4. Nature of slurry - newtonian, thixotropic etc.
5. Heat sensitivity
6. Process - Batch or continuous
& probably finally the quantities which are very important to design & select a good system.

So as I said I need to understand your upstream step also where from you are getting this slurry which is centrifuged & then you are getting 5-6% LOD from centrifuge.

See without complete understanding of the system you will not get the best solution. I can say any process or separator & dryer but that may not be the best unless I understand it completely.

I am an expert in providing MOST cost effective solution, so you need to share some part of your process without disclosing proprietary information.

I think being in India you can call me on my mobile in the evening time. I can share that on mail only.

[mahesh]

Dear Technologist,
thanks for your generocity. It will be great to have a mail as well as telephonic communication with you. I will be thankful if you can give me your telephone number and mail ID, so that I will be able to provide moe details.