Recirculating Chiller / Heater Fluids

#1

Hey guys,
I’m trying to compare the capacities of different heat transfer fluids to see if there is something that would be suitable to use for both low temp chilling and high temp heating. I don’t know if there is anything that would meet this need.

I would like to be able to go from -40c to 150c with a open bath system. This way I could use one chiller/heater for different purposes, running one fluid, instead of having to drain one out to put another in. Anyone find something that works for this?

Ethylene / propylene glycol + h2o
mixtures will work for low temp chillers, but not good for higher temps

Dynalene hc-50
-51C (-60F) to 110C (230F) in a open system

Pure Silicone Oil, 100 cst Super Lube
-50C to 200C
Would it still flow through chiller lines at a low temp?

Dynalene 600
70°C to 288°C in open system
@Breakingdabs recommends this for running a hot condenser
Sounds like it would be really thick when cooled.

Dynalene SF
20°C to 150°C in open system
Much cheaper ($250 for 5 gal) than Dynalene 600, doesn’t go as high but might be easier to drain out if I wanted to switch to a chiller fluid

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#2

I’ve used HC-50 for this trick, so I could both chill and heat my receiver and my jacketed column on a PX-1.

It worked, but I don’t like HC-50. It is really corrosive.

I actually tried firing up a chiller last week that had been emptied but not flushed about 24 months back.

At first nothing came through the pump, them the insides of the pump came through…

It doesn’t swing as widely as you’ve requested, but it may still be your best bet

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#3

Thanks, that’s good to know. I will definitely flush it if I go that route.

Dynalene HC-50 will do -50°C to 218°C in a closed system. Would a standard recirculating chiller/heater pumping through a condenser or jacket be considered a closed system, or would it be considered a open system because of the bath/reservoir?

The other option is draining the reservoir between uses and using a silicone oil based oil for heating. However, I would imagine the silicone oil is not miscible with the chiller fluids, so it might cause issues if it was not properly flushed before using the chiller function.

Anyone know what type of hoses to use for silicone based fluids? I read that silicone hoses are no good.

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#4

Doesn’t pure propylene glycol freeze at -59c and boil at 188c? Sounds like that would fit the bill unless I’m missing something.

#5

I believe it. That really sucks. Looked at the MSDS and is just water with potassium formate with an “inhibitor solution”. I guess the inhibitor solution only does so much for corrosion…

#6

Propylene glycol gets pretty visocous at those temperatures. When you mix it with water it tends to have a slush effect when you get close to freezing point. I second the HC-50 but don’t like it being in my chiller. I’m open to an alternative!

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#7

Thanks for that. Figured I must be missing something.

On that topic though, does anyone use a methanol water mixture for ultra low temps? 90/10.

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#8

I was going to, but methanol can destroy seals on pumps so i went with isopropyl instead

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#9

Whats the benefit in using isopropyl vs glycol? Does it transfer heat better or less corrosive?

I talked to a Dynalene sales rep about my question of open system vs. closed system. He said a closed system is air tight and holds pressure. A recirculating chiller with reservoir and lid would be considered open because it doesn’t hold pressure. That’s what I figured, but wasn’t quite sure.

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#10

Isopropyl doesnt freeze up on you when going cold

#11

We’ll be running our PX1 for the first time here soon. We were going to get a chiller and heater to accompany the extractor. Did having only 1 device to heat and chill your columns slow your production down significantly?

#12

No. I was using one of each. Because they were both running the same fluid (HC-50), I could switch between them (with a little effort to keep them balanced).

It still meant a slug of hot or cold into the other system, but allowed (for instance) me to chill the receiver until after all my solvent was through the biomass, then switch to heating it for recovery.

a more capable chiller and heater would have made the strategy more effective.

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