Would like to know if anyone has run new/used vacuum pump oil in their reactor heating circulator? Or in oil baths for max temps 140c.
I fucked up and accidentally mixed our purpose made silicone oil 47V350 ISO 350 high temp oil with some dimethicone. (dont even ask)
That is $600 worth of oil specifically made for the reactor.
So need to find an alternative oil for the heat bath and reactor heated recirculator that wont break the bank as money is tight in the lab game at the moment.
All of my old vac oil I was considering to run through Magnasol XL and then see if i can use it in the oil bath I use for CBD isolate. (max temps 130c on the oil)
We use JAVAC no.16 vacuum pump oil for the rotary vane pumps. Flash point of the Javac no.16 is > 262c, Viscosity 46cst @ 40c.
Javac no.16 vacuum pump oil $70 per 5 litres < Silicone oil 47v350 iso 350 $300 for 5 litres.
Im assuming it would come down to the viscosity and problem of potentially burning the pump out on the recirculating heater if viscosity were too low.
So anyone had experience and cautionary tales for running vacuum pump oil for general lab use outside of vacuum pumps?
As always cheers for the help and suggestions!
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This is basically it, will the new mixtures boiling point tolerate the process and will the mixture cause issues during heating like reacting or fouling while in use. Some materials, when mixed, will experience a boiling point decompression which could lead to boiling and thus pressure spikes.
If I had money id change the fluid because TCUs are investments. If I were broke, id still put it on the scheduled purchases.
Did the oil blend or white when it was added?
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Im hesitant to use the expensive dimethicone oil that had the dimethicone added anymore for that simple reason. I dont know the flash point or boiling point anymore. Currently have drained all oil out of the recirculating heater and am looking for a suitable replacement oil.
The oil homogenised when added together. Even though the pmx-200 silicone fluid 100cs that was added has a flash point of >320c. They are both (polydimethylsiloxane).
But as to how they would react together is out of my scope of understanding.
Ive got a cheap chinese recirculating heater i can dig up and run for a while with the mix and see how it goes.
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Well, i might get jumped for saying this but i wouldnt worry about that flash point at all. You shouldnt have any positive ignition sources anywhere near that bath. The auto ignition temp is the scary one.
I think youll be fine for the most part but always check what your wetted parts are compativle wth before buying fluids. For example, two chillers from the same brand may not allow the same fluids. Poly sil oils dont mix with hydrocarbon dont mix with water glycol etc. You could put fluid in and as soon as it gets hot it leaks everywhere.
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Aren’t those two fun facts to document?
Boiling point should be easily determined.
Flash point isn’t generally terrifying unless you decide to vaporize liters rather than milliliters.
I’ve heard of, and considered “use used vac pump oil as heat exchange fluid”…and not gone there, or even dared ask (Others have asked me). Seems like a it will work up to a point. How problematic it becomes probably depends on how you approach finding that point. Turning it to 300C and walking away for a hr or two vs starting 30-40C below your target. Real question is do you have better options?
You might. The fluid you added dimethicone to is compatible, it’s possible that the folks who formulated if for you can tell you exactly how badly you fucked up (assuming you know exactly what you did).
You might have only dropped your bp 10C for all you know…(yeah no, depending on how much you added that looks unlikely).
If it were me, I’d a) ask manufacturer how badly I fucked up, b) test it myself if they can’t quantify. c) evaluate achievable temps on available options (high flash point cooking oils?). There has been some exploration on the topic around here in the past. Digging around for that might be informative.
I’d usually vote for playing with the Chinese chiller first, but I’ve had a couple of those come really close to actual fire recently…
Eg this happened yesterday when I was out of the room. Fortunately a team mate caught it before it got too boisterous
True dat!!
~ 365C for both butane and ethanol
Accidentally hit the second of those in a CUP-30 asking it to do something stupid. Wasn’t but a ml or 12 of EtOH in there, but I pissed it off good and proper 
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Ouch that capacitor drank until it over flowith.
I hate to do this but no shame, if you need a new NRTL listed chiller or heater, I can get you hooked up with what you need. We dont use the exploding type capacitors haha
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Appreciated.
Nah, when I asked if I should track down the capacitor this morning, the response was “nope, firing up the polyscience we scored at auction last week…”.
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Cheers, well the cheap chinese one will be the test dummy for this situation. Fingers crossed!
Yep more likely to get a fire from that high quality chinese dog shit that has flooded every market. As im only heating to 94c with the heptane and 32c with the pentane I believe in the grand scheme of things its the ignition of either solvent that scares me a lot more in a reactor.
Will give it a go with the cheap chinese heater and see how it goes. I mean if it burns out ill probably throw the oil out and just buy new oil for the good recirc heater.
Cheers for the help!
