Hello, I am looking for a new chiller. We have a 3 Phase 220v Dual Condenser 50L Roto (link below).
We are currently using Two Polyscience 1.5hp 6860 chillers. They simply can’t keep up with the heat load. We are evaporating heptane and can’t push it past 85c without losing temps quickly. We’d like to move to one chiller and upgrade. Not opposed to rolling a home grown solution.
Ideally where do we want to be with temps on the chiller? -10, -20, -40? What chiller would be best?
Thanks!
The general rule for rotovaps is a 40f difference between bath and condenser. The higher you can run it, the more you shift the load to heating (which is generally cheaper than cooling). So if you want to stay under 85f bath temp you’ll want a chiller that can keep up around 45f. Decreasing that temp will improve your rates but not as substantially as you’d think. Do you plans on having more cooling load in the future? It might be worthwhile to install a bigger unit now and use it for all your needs (this was the best decision we ever made)
Edit: something like this would run your cooling needs forever:
I only looked for a minute, you can probably find a 30 ton unit for about the same price that won’t demand so much to install
No other cooling needs at the moment. Also, we are leasing our unit, it would need to be a mobile indoor unit. At 85C (bath) the chiller doesn’t get higher than 0 - 3C. It was my understanding if we can get down the temps even further, we can recover faster. We are having to roto 80-150gal at a time, even a minor bump in efficiency will help over the long run.
Thx
I didn’t realize that was 85c (learn to read dummy). I would suggest just using a regular 3-5hp r410 split system condenser running to a big brazed plate. It’ll be a lot cheaper for the capacity than those little packaged chillers are.
What I meant about the lower temp is that once you start exceeding those temps, you are probably better off throwing money at more surface area on your condenser than lower temp fluid.
Last thing I’ll mention is that a cooling tower might be a good option for you depending on your location. It’s also super cheap to rig up a DIY one and cheaper to run as well
What about pump?
Yes you’d in any setup you’ll need a reservoir (read: insulated bucket) and pump. I find the Grundfos UPS-16 circulating pumps to be robust and quite effective for this application. Simply elevate the bucket above the pump to prime it, route your piping from bucket>pump>heat exchanger>condenser>bucket. If you use a tower, you can substitute the bucket for the tower and ditch the HX.
Also, don’t run the compressor if you’re not running the rotovap or you won’t keep it loaded and it’ll cause early wear on the compressor/oil. It’ll still last longer than your average “cannabis industry” chiller anyways lol
Dude, someone is selling an iso reactor AND a BIG ASS CHILLER for $37K in the classifieds!
Edit: Might not be what you need sorry… ^You’re in good hands^
Grab a solvent tank and a coil, keep coil filled with dry ice.
Vac pump> solvent tank> coil> roto vac port
What you need is. -10 5 hp polyscience. These import chillers you’re looking at don’t even compare…
Ideal number is -10 or 0. Any lower you aren’t going to really get the best benefits. You want hp at temp to suck heat away. The colder you go the least you’ll see a huge jump. But more kw power will remove more.
I don’t think this needs to be done. If you use correct chiller you won’t need any auxilary buckets.
Yeah you are going to need about 5Hp. The colder it goes the better but it usually cost a lot more and is harder to find the colder temp range. A standard industrial glycol chiller is about 15k (with a 5-25°C range) and a Huber CS100 (-10 to 25°C range) is about 28k.
We can get both options for you, and we have a 3 phase industrial chiller (5-25°C) that had some minor damage to the panel in shipping and we can get you a really good deal on it. Shoot me a pm if interested.