Optimizing your RotoVap

#102

I will probably be ok I think. No exposure to UV light or metals to react with it.

Dowtherm 400l sds below along with comstar frost free that’s identical minus the 5 percent water that’s only 18 bucks a gallon on amazon

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#103

Got the Aldrich super condenser operating with the cryocool it appeared to be faster than the previous Dewar condenser.

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#104

Sorry I meant 10liters.Just a out of box across intl, their vacu pump and chiller, just upgraded to a 50liter with julabo but havent clocked speed yet

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#105

Epoxy gleu on the outside can make decent fixes

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#106

We use Rice Bran Oil at my work.

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#107

I often use oils from the kitchen
Rice bran or avocado are My favorits

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#108

are you just pumping water through the condenser?

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#109

Use duratherm then you xan decarb and syrip volitales saves me rons of time. Ifs thwn ready to go steight to the wiper

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#110

Has anyone figured out a solution for continuously pumping solvent out of a rotavap without breaking vacuum? (Basically, replacing the solvent flask).

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#111

Get one with a feed tube to fill the main flask, the recieving flask should also have a valve in it to drain. My re-501 has exactly that. Im down about 1min or less when i have to drain my recieving flask. About 20 seconds when im filling up the main flask.
I banged out 20 gallons this go, lost .5 gallons

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#112

That is good but i’m still wondering about a truly continuous solution (IE, I could run it for five hours without needing any intervention on my part). Some kind of pump. I know it’s possible because the distimatic does it, but my efforts at using a peristaltic pump didn’t go anywhere. The tubes were either too small and couldn’t gravity feed effectively, or too large and caved from the vacuum.

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#113

From what I’ve experimented with you need more rollers to pump under vacuum without running into problems with fluid moving backwards. Most of the larger off the shelf peristaltic pumps only have 3 rollers and aren’t intended for use with vacuum. If your tubes are collapsing then you need ones with thicker sidewalls, from experience silicone tubing from a brewing store works pretty well in 1/4 & 3/8" ID but runs into collapsing problems above 1/2" ID

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#114

OK, that is good to know. So you’ve gotten a peristaltic pump to work as a replacement for collection flask?

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#115

When I tried it was with a collection flask with the bottom valve left open and a piece of silicone tubing connecting the collection flask valve to my peristaltic pump. As I said with a 3 rotor peristaltic it was slow going because of the flow reversal due to vacuum, would love to try out a descent size (3/4" or 1" hose) peristaltic pump with 6 or 8 rotors, my initial hope was that I could empty multiple recovery flasks teed together simultaneously with a single pump but the max flow I was able to achieve makes me think I need different equipment to do so.

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#116

I got a 15 gallon stainless keg, with a feeding straw and air vent ports. I simply connect my recieving flask with a silicone tube into the vent side of the keg and its good for 55L which is about 24 hours for me. I have another 15 gallon keg that feeds into the boiling flask with a peralstatic pump, the masterflex l/s.
After the peralstatic pump is a heating wire that wraps around the tube and heats the liquid up from room temp to 45C and my roto is set to 50C.
I also have a wide scale that i use to check how much is left in each keg. I run the roto continously and check it every 12 hours
My setttings are 50 mbar, 50C bath and 70 RPM.

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#117

That seems like a good solution as well.

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#118

What are you guys setting your preheated inlet temp to?

Said in another way, if your bath is at 70c what do you want the fluid entering into the boiling flask to be pre heated to ?

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#119

A few posts up

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#120

Use a “suck tank” and pfa hose. Those should get you what you want.

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#121

Does this suck tank just become another vessel that needs emptying?

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