RotoVap brand comparison/experiences?


#21

But can you automate that? A dosing pump could just be set to a specific value to constantly feed and/or drain


#22

pumps can regulate both. have your receiving pump run constantly, feed in intrevals. If you feed constantly you will have the feed work its way up the vapor duct.


#23

I could possibly automate with some sort of level controller and peristaltic pump but that may be overkill for my needs. then again my tubing layout may cause feed vs drain inconsistencies and one will overtake the other.


#24

Ive been getting mixed feedback from operators, as low as 1L an hour. Based off what you said the 5L should get about .75 gal/h. Where does AI claim their recovery rate?


#25

@Trichomie

The recovery rates are in the manual for all the ai rotos. What vac and temp are you running at? I’m at 55.9c water bath and vac 20-50 torr with the flask spinning at 130 rpm.


#26

Yeah, I had the same issues trying to continuously feed. Now I just fill it once every 30 min and have a larger collection pot connected to the drain valve. When I want to empty that I just close the drain valve and empty the collection put while the system is still running. Then pull a vac on the collection chamber and open it back up again. I can do 20 gal in a day. Maybe more.


#27

From my experience with 6x Chinese 50L rotos:

  • Ditch the water bath vacuum, if you’re using the roto for more than an hour the water gets hot and vacuum level fades. A well worn Welch or cheap Harbor Freight vacuum pump will pull deeper vacuum than the water bath will
  • When you get sick of the water bath and use a real pump, put a good vacuum trap in line and size your pump for more demand than you think you will. If you pick up a second roto (or more) you can run them all off a single vacuum source.
  • They don’t like to be run on the low end of the voltage spectrum. If it says its rated for 220 volt operation it will run great on 240, if you try and run on 208 you will have random electrical hiccups on the roto itself and the chillers will overheat and not keep up
  • The Chinese chillers are hot garbage on their best day. If you don’t have the electrical service you could always set up an IBC tote and an aquarium powerhead style pump and recirculate, or set up a garden hose adapter and do a “total loss” coolant where the outgoing water goes into the drain or waters your lawn. If I had a do-over I’d just buy the roto bodies and glass and use a Chill-King with a multiple tap manifold or individual higher quality chillers (like Neslab).
  • If you’re buying new, the glass will come internally packed with sawdust. If you don’t have a good sized air compressor to blow the sawdust out, make friends with someone who does. Wear a respirator doing this lord only knows what kind of toxic shit is in that sawdust.
  • If you extract cold you won’t have a bunch of nastiness cooking to the inside of your evaporation flask. Handling glass frequently and cleaning it sucks. I haven’t broken any glass but I’m sure its a nightmare to get a replacement flask if yours gets cracked.
  • Figure out a slurp tank and hose to empty your roto globes without pulling the glass, you can thank me later.

#28

Thanks for the reply. I’m just looking at some kits. Looking at the 5l rotovap. Any suggestions on pump?


#29

If you use a diaphragm pump you don’t have to worry about etho getting in and fucking it up. But that’s about as much as I can say about that. I keep pulling some amounts of etho through cause I’m overclocking the rotos vac and temps.


#30

Where and what size ate tou finding them fir 1k, im in rhe market for wither anither 10 or20 with chillert match and before the tarruffs take effect. I stay away from ai m, since evry oiece of equipment ive eve bough, wirh serious hesitation even whenit used m. I only use my 5l ai dor decarb be ause it keaks like a sieve and its simply mail bix letter on chinesywbite labels. Any good chineysuppliwr orher rhan @touch science which i have and they have work like a dream and easily have 100k miles on rhem . So unless someone can give me a better alternative rhey have acguallt used I’ll probably just call ben rbis week. Rhanks guys


#31

Good God man I had a hard time reading that post. Sorry are you using some form of speech to text app that’s not translating correctly? I pieced together my own used equipment from eBay. There’s no secrets to finding the deals, you just gotta search. Also my unit is a 114 that is really for .5l to 3l flasks that I was just so able to fit a 5l flask onto. If youre looking for a Chinese 10 or 20 liter try lanphan industries. I haven’t heard anything bad on them yet but I haven’t been following them long.


#33

Hi buddy,

i am China manufacturer and my main products are rotovap, chiller, spd, vacuum pump and so on.
If you need the quotation, just DM me and tell me your inquiry content, then i could send the quotation to you.

some people on this forum has purchased rotovap from me, like @tare @asher and so on;

welcome your inquiry.