Soaking in iso wont remove fine particles. It will only dissolve any remaining oil
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Im going to bake the media and see if that helps with the flow as I have gone through 2kg+ of each powder with the same procedure and no issues ,no stall. This is the first time Iâve actually had any issue at all. What do you recommend? I usually have acetone around but only iso today plus I clean every run columns,base,crc column so itâs hard to point the finger towards particles in the filters idk could be though.
I use an ultrasonic cleaner. Alcohol first followed by distilled water
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I also keep collection on dry ice to avoid vapor lock
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Baking wonât have any effect on what your experiencing. You either have a clog or a vapor lock. Your collection base wasnât hot was it?
Vapor lock as in vapor pressure not allowing the gas to come through to the collection base ? My collection base stayed in negative pressure so I donât see how that is even possible. And yes the collection base was kept cold as why it stayed in negative pressure.
You can have a hot collection base under vacuumâŚ
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Filter blowout and your trying to filter the powders out?
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Im very aware of hot collection in vac, I know its something with the crc column because when I remove the feed line from the material column to crc and put it to the collection base it all started flowing like normal so thatâs why I donât see how its vapor lock from the collection base.
Your sintered disc is clogged with media
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No filter blowout in fact I would rather that happen then what im experiencing now. Its just not coming through the crc like usual
Clog.
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20um ss screen holding back celite seems like a major oversite on your part.
I pack celite onto an 11um filter paper in a stack, 6um paper in a stack then a 5um sintered filter stack and another stack with 2.5um filter paper. Never seen a single blow by, clog, or even reduced flow
Are you packing the celite?
I pack mine with a wooden puck cut to fit inside the 3â stack. Then I press a 1â thick puck of celite with all my body weight. Then the rest of the media is tossed in loose above that
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I guess itâs a matter of doing a process of elimination. Media is being baked if that doesnât work then I will change the filters. Its just crazy that iâve done numerous runs with same micron screens and same procedures with no issues then I run into to this problem I donât see what changed⌠anyhow I appreciate the responses will take all advice in to consideration
here is some pics of successful runs with the same micron screens and media
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Yea I have been wanting to change to a smaller size um to hold the celite also using a paper filter. Being that I used a bigger size um one could assume that it would flow faster. yes im packing it for sure same as you using all body weight. I even considered I was packing to tight which may have caused it to clog but people are using mechanical presses with success so iâm not sure if that is even the issue.
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get a bigger crc
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Have you tried running less No2 pressure ?
I had filters blow constantly. Was able to stop it by switching the 1u with 5u. ( some people will prob disagree as some particulate May find way through 5u)
I would leave No2 pressure very low. Gradually increasing and checking honeypot for action.
Every time I pressurized and tried to open valve on reducer to honeypot the paper would blow. My taxtractor Depot ball valves are shitty but Iâve started to throttle them. I usually start reclaim slightly open then gradually increase as column drains.
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Just realized youâre using a coil in between your solvent tank and column. You probably didnât have enough head pressure to keep the flow going. You state you could only get 8# of solvent in⌠Your problem ( if not a clog ) is you donât have sufficient pressure in your tank to flow properly/dry ice coil stalled you. Try it without cooling your injection. Majority of people will need n2 to push through a media bed, which I absolutely donât recommend considering youâre using single pin hinge clamps on your collection base. Change those out ASAP.
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God this is silly. You clogged it.
One would not assume that a higher um is going to help you with flow. The higher the um the easier all the powder can slip by. Thus clogging your sintered filter.
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Sorry if it sounds silly or if I came off condescending just trying to narrow down the issue, I based it off the earlier readings and recommendation for micron sizes 20,8 , then 1 even Bvv crc filter recommends 20,8,2.5. Im doing a 20 , 20, 5 sintered ,1.5 and then 50 mesh gasket. I will adjust the micron sizes and see it that works just thought it was a matter of excess moisture in the filter medias more then the micron filter sizes. Thanks for the input ill try the 11,6,5 like you suggested