Supposedly the thermocoupler came brand new with the setup and I have only been running it for two weeks and its already giving me tons of problems and shutting off randomly. I have a different one thats in the works to be ordered because I am working in the dark after the first 1-2 hours of the run.
@Schwarzite that is a mono-cow so i can close the top screw to seal the vacuum and swap flasks at any point. At least thats what I have been doing so far.
When I think āmonocowā I think a single distribution adapter. I usually call what you have a vacuum takeoff adapter ( VTA) or an isolation valve.
You can pick up an economy bullseye vac gauge from lab society for under $500. Not fancy but durable and very capable.
I just picked up a VTA. You can isolate the flask, vent it, switch out, then reopen to vacuum and keep collecting. Havenāt run it yet but I canāt wait.
Awesome. Iāll have to look into that
Check out Rocco Scientific on Instagram. They are excellent glass blowers and have very reasonable prices.
Plus one on the bullseye. I soaked mine in water when my dumbass thought itād be a good idea to run 92c water through vinyl hosing. Nearly had a heart attack thinking I broke a $500 tool, but still works like a champ today.
@TheLostBiologist Didnāt know that about acetone being a better thermal transfer fluid than iso. Iāll have to switch back to using that.
@Scientist42 Pick up some kimwipes or other lint-free wipes when you use the acetone to clean your joints. Fucking game changer when I finally switched to those rather than shop rags.
Kimwipes FTW! Lint free is a must.
So it sounds like you need to change pump oil at the very least, possibly a rebuild. that 1400 should pull down to 1micron with fresh oil, if itās not pulling down to sub 10 microns with fresh oil, she needs rebuilt. Though the Welch will work you should shoot for 4cfm per liter of boiling flask, especially with a full bore setup, that Welch wonāt be able to keep up. Heads fraction should be really small on a second pass if the first pass was done properly. Dry system vac is exactly what you expected, the assembled system without the crude. You should check the dry vac level every time before distilling to eliminate vac leaks. Helium is used to find leaks by releasing the gas next to your connections. Start at the connection closest to the vac pump and work your way toward the boiling flask, if there is a leak at a joint the vac level will shoot up quickly as it draws helium into the system, check all the joints for leaks.
One last thing Iāll add-it looks like youāve got an unused valve sitting on the table there. If you donāt already have one, put that between your pump and your cold trap. You can use it to warm up your vacuum for about 30 mins before opening it up to the system.
On mine I put a sensor between the valve and the pump too, so I can measure the blanked off vac when closed and the vacuum level at the pump throughout the run.
im getting those jackets looks great
Hi guys! took some of your tips and got some better results but still was only able to get my vacuum down to 350 microns during my run after getting it to around 50 in a dry system. I am wondering if you guys have any suggestions for vacuums. I was looking at this one
I am looking at the 9cfm as we will be setting up another 2L system in the coming weeks. My first question is will 9cfm be too strong for running just one of the 2L at a time? and also some other suggestions if that doesnt seem good.
Also can someone inform me what full bore means in distillation? I cant find a meaning on google or the forums for the life of me lol
someone correct me here if I am wrong, but a better choice would be a used alcatel 2021i off ebay. Full disclosure Iām still waiting on my equipment to all arrive, I have not yet distilled in real life, just read this forum a bit. so this may be a blind leading the blind situation, but this is what iāve read here, and what i have purchased
what is the blank off vacuum depth of your pump? How many cfm is your current pump? That 9cfm two stage pump would do just fine on a 2l but I would look into getting a used Alcatel 2021 as they can be picked up pretty cheap on eBay. Full bore just means that interior diameter of the glass from the head to the last cold trap are wide open to a kf fitting to bellows going directly to your pump. Full bore requires more cfm (either pump mentioned should be plenty) and a minimum of two cold traps to keep all the garbage out of your pump. It also wouldnāt hurt to use your old pump to pull volatiles and the newer higher cfm pump to pull mains, this will greatly increase your vacuum depth.
Sorry I forgot, your pump is .9cfm