My setup is kind of ghetto, but it works nice. Was doing 2 dimensional , buchnner style filtration for a while to remove sub 220 micron sediment after cold EtOH extraction. Was using the 5 gal refinement filter from BVV with a 5 micron sintered disc. That thing sucked (but not in the good way that it should). Very slow, clogged easily, etc. Tried that setup every which way - with a celite cake, without, with filter paper, without paper, etc. Either way it was just too slow. And the sintered disc clogged so much that I’d have to bake it in a 450C muffle furnace to make it usable again (never tried ultrasonic bath tho that probably would have worked too).
This works good for our scale. And was way cheaper than a larger set up from Rosedale or similar companies.
I use negative pressure (diaphragm pump) to suck solution to be filtered thru these staged filters (50-10-1 micron) and into a holding vessel. Works nice. Super fast. Takes under 1 minute to filter 5 gallons of cold (viscous) ethanol. I’ll probably keep the 5gal buchner around for filtering over carbon or clays, or whatever, but I am happy to be done with 2D filtration for removing sediment.
And yeah, I know I should probably ground those housings and get tubing that can be grounded. Got to do that and a few other modifications.
My only real problem with this method is the large holding volume in the housing. Have to flush a good bit of clean solvent thru to get everything out.
Some things I learned in the process of switching to this method that might help anyone that wants to do something similar. McMaster Carr has solvent compatible cold temperature tubing. However from what I understand, due to static electricity, tubing is probably not the best option. A braided stainless steel hose is probably the correct way to do this. Also, not all 2.5 x 10 filters are the same height. Tried a few different brands and some were a mm or 2 taller than others preventing them from fitting in the housing. It seems the typical Big Blue style houses have a greater tolerance for slightly different size (height) cartridges. I have the same staged filter assembly before the rotovap, but they are PP housings and every filter I’ve tried fits in them. Not the case with the stainless ones.
