I’m looking for a little info on my filter setup. I just purchased a tank of Nitrogen and a regulator so I can start using super cold solvent instead of doing a hot path with a second tank like I was before. Anyways, I bought a 2nd filter plate and was wondering if this is an adequate setup for filtration:
From top to bottom I am going to have - 50um Buna gasket, then a filter plate with 20um ashless filter paper from BVV, followed by a 2nd filter plate with 10um filter paper. Will I have any issues with flow rate with this setup or should the nitrogen pass through this with ease? I was thinking of pushing at like 20psi or so.
Also would the bottom filter plate with the 10 um paper be enough to stop filter media if I were to pack the 2nd filter plate with some Celite and B80. OR should I just stick to the filter papers.
Sorry I’m using 100% n-butane at cyro temps and pushing with N2. I was thinking of adding some filter media like celite and b80 in the 2nd filter plate hoping it may help with clarity / filtration speed.
Even if the screen were to brake on the buna gaskets would it not still be holding a seal, since the actual gasket part would still be in tact ?
But if I were to ditch them, do you think 2 filter plates would be enough? Going from 20um paper filters on the first filter plate and 10 um papers on the 2nd filter plate. Both doubled up
Those screen gaskets are only likely to bust when your sending a large volume of liquid through them at too high a pressure, high pressures alone won’t make them deform or break. If you spread the pressure load across the entire gasket and build pressure slowly those screen gaskets are a cheap alternative to sintered discs.
Flow rate is the thing to keep in mind when you’re worried about blowing out a filter. For example if at your capacity you plan to push 5 gal/min of solvent at 100 psi thru your CRC column then you’re going to want a sintered disc. If you’re at 100 psi in the headspace of your crc column and you have a properly packed column, your filter gasket on the bottom of the column isn’t going to see 100 psi of pressure.
But if you do use a screen gasket to stop your powders you need to use a triclamp filter plate thats been welded flush to the ferrule on one end to act as a backing for the screen gasket. I like to add a circle of stainless mesh on top of the welded filter plate to cover the holes and keep pressure from being localized in those spots in case of a failure so my screen gasket doesn’t get deformed. I also add a shit ton of clean sand on top of screen filters before creating my powder stack and also top top of my powder stack to help hold it all in place when I flood the column to wet the powders.
Thanks for the reply, so if I keep my flow rate and psi down with the nitrogen I shouldn’t have to worry about the first buna gasket that is 50um? After that 50um gasket I have two filter plates from quality stainless parts: first filter plate has 2 layers of 20um ashless paper plus the mesh sceen held down by a SS ring, the second filer plate has 2 layers of 10um ashless paper plus the mesh screen held down by a SS ring. Would this be good enough filtration, going down from 50um-20um-10um?
Thanks again
Probably not, I wasnt talking about ashless paper filters. Those are very likely to rip and you will want to go lower than 10um.
That being said if you have your crc column separate from the material column, a 10um ashless paper filter would be sufficient if you slurry packed the b80 when you made your CRC column.
Thing with paper filters tho is that you need to make sure that the filter paper never sees any back pressure from the collection vessel, the paper can’t shift or deform whatsoever or else your 10 micron filter rating means nothing. If your plan is to use filter papers for final filtration then your pretty much going to need a sintered disc to lay it on. Theyr just really delicate.
Theyr pretty expensive when u get that low, you would be better off finishing with a .02 um Pall filter cartridge as a final polish.
I think they call them virus filters or something. You can speak to Pall directly, the cartridges are polypropylene housing and they offer units with triclamp connections.
If you need any depth filter media, filter paper, filter cloth, or filter aids like diatomaceous earth or activated carbon, feel free to reach out to me at ErtelAlsop. I am the market manager for all things cannabis and CBD. We can assist you with any and all aspects of your filtration - plate and frame filters, lenticular filters, recessed chamber filters, bag filters, cartridge filters, filter media, pumps, etc.
Thanks!
Dave