Conical Cooling Conundrum (Spike CF10)

[tdibratt]

Hi folks wondering if you all figured out the problem. I have my glycol at 26F and cannot get my CF10 below 44. Have 8 gallons in the conical doing a test run.. coils are not frozen and pump is running. Any ideas?

 

[mongoose33]

Hi folks wondering if you all figured out the problem. I have my glycol at 26F and cannot get my CF10 below 44. Have 8 gallons in the conical doing a test run.. coils are not frozen and pump is running. Any ideas?

What's your ambient temperature? What kind of glycol chiller are you using?

Do you have the neoprene jacket on it?

 

[jsharp4684]

I solved mine by following Spike’s suggestion. I swapped my input and output and now the system has no trouble cold crashing to 34F and keeping it there.

 

[tdibratt]

Ambient temps in basement are around 70 F. I have the complete T100 pkg from spike which includes the jacket and it is on. The chiller is made from a 5000 BTU AC. I have 2 gallons of Glycol and 6 gallons of water in an insulated cooler. It gets down to 28F no problem and I have it for 1 Deg variance. Morning after and Conical is 43.7F. Set for 38F. Pump is running gycol through. I had the input/output set and then realized I should have the input set on the length of SS that goes straight down to bottom then turns back up through spiral and then back to cooler. Still cannot get better that 43-44F. My solution works out to be 25% Glycol, but no signs of freezing or crystals in the mixture.. Further information, the chiller coil has frost on it above the water line, and glycol still moving through. The temp of the glycol is 28F as measured from a temp probe as well and the glycol returning to the cooler is about 29.1F.

 

[btcost]

Ambient temps in basement are around 70 F. I have the complete T100 pkg from spike which includes the jacket and it is on. The chiller is made from a 5000 BTU AC. I have 2 gallons of Glycol and 6 gallons of water in an insulated cooler. It gets down to 28F no problem and I have it for 1 Deg variance. Morning after and Conical is 43.7F. Set for 38F. Pump is running gycol through. I had the input/output set and then realized I should have the input set on the length of SS that goes straight down to bottom then turns back up through spiral and then back to cooler. Still cannot get better that 43-44F. My solution works out to be 25% Glycol, but no signs of freezing or crystals in the mixture.. Further information, the chiller coil has frost on it above the water line, and glycol still moving through. The temp of the glycol is 28F as measured from a temp probe as well and the glycol returning to the cooler is about 29.1F.

Can you try to slow down the glycol flow rate? If the chilled water (glycol) is moving too fast. You won’t exchange the heat.

Aim for 10 degree delta. So 28 in 38 out. You will get that slowing down the flow rate.

 

[mongoose33]

Can you try to slow down the glycol flow rate? If the chilled water (glycol) is moving too fast. You won’t exchange the heat.

Aim for 10 degree delta. So 28 in 38 out. You will get that slowing down the flow rate.

See, I don't get this. I have a Jaded Hydra immersion chiller. The thing is a beast. What Jaded says to do to get the best chilling performance is to run the water as fast as possible.

I don't understand how the glycol isn't going to chill the insides of the tubing worse if the glycol is moving fast than if it's moving slowly. All the stainless tubing knows is how cold is the material next to it, flowing fast or not.

I'm always willing to learn something new, and if I'm wrong on this, please correct, but I can't see how slowing it down improves the performance.

 

[SanPancho]

one problem with nice round coils like these is that you actually want a messy and turbulent flow inside the tubing. if you get laminar flow your cooling power goes to *****. higher speeds contribute to that.

 

[mongoose33]

one problem with nice round coils like these is that you actually want a messy and turbulent flow inside the tubing. if you get laminar flow your cooling power goes to poopyt. higher speeds contribute to that.

In theory I think I could test this. I have a Penguin chiller and two pumps; I can hook them in series, one pushing, one pulling, and I increase throughput about 50 percent when I do that.

The problem is that the temp of the mix coming out should be lower than if at a slower speed. But it's not clear what that would indicate--either that it's not picking up as much heat....or that it's actually chilling the coils to a lower temp than would otherwise be the case.

The only good test is the temp of the wort--and that I can do. I don't know if I'm brewing this weekend or not, but when I do, I'll try to do something with this.

BTW, yours is the first reasonable theory I've read about why faster would be less efficient. Not sure it's correct, but it's a nice approach grounded in some physics. BTW, what happens with the Jaded Chiller would seem to refute it, though w/ the jaded chiller it's copper, not SS, and it's water, not a water/glycol mix.

 

[SanPancho]

Jaded also has ridiculous amount of surface area vs your coil.

Surface area
Copper vs stainless
Contact time
Design efficiency
Temp differential

Lots of variables you can adjust. Jaded would be high conductivity high surface area which could make up for short contact time.

 

[btcost]

See, I don't get this. I have a Jaded Hydra immersion chiller. The thing is a beast. What Jaded says to do to get the best chilling performance is to run the water as fast as possible.

I don't understand how the glycol isn't going to chill the insides of the tubing worse if the glycol is moving fast than if it's moving slowly. All the stainless tubing knows is how cold is the material next to it, flowing fast or not.

I'm always willing to learn something new, and if I'm wrong on this, please correct, but I can't see how slowing it down improves the performance.[/QUOTE

All of my experience in this area have nothing to to with beer or home brewing but with commercial and industrial HVAC.

I am an air & hydronic systems balancer by trade. It’s my job to set the air and water flows to their correct numbers in order to achieve the engineers design. I live in Boston, so I work in a lot of hospitals and bio-labs. And of course all the schools (MIT, harvard, etc.)

Long story short I set up chilled water coils on large air handling units almost daily. And if the flow is not “right” you will not achieve design discharge air temp.

In your case, assuming you do indeed have 28 degree water (I trust you!)
The only other variable is flow rate. You are going too fast or too slow.

 

[augiedoggy]

See attached pic.

I have a 33% Glycol-67% Water mixture in a reservoir in my ferm chamber refrigerator. The system does well at moving temps down to the low 40s, but now, I can't complete a crash to 32 degrees.

Since last night, when the temp was 39.1, the temp this morning was 38.7. It simply isn't cooling, and I don't know why.

Five Gallon Batch (maybe 6 gallons in the fermenter).
Ambient in the garage: 64 degrees.
Conical wrapped in moving blanket down to floor.
Two towels on top cover the portion I can't reach w/ the moving blanket.
Condensation on both supply and return lines; they're cold.
Tilt Hydrometer in Conical confirms temp read on temp control.

Morrey does something similar with his SSBrewtech unitanks. He feeds his with a Penguin chiller which is much more responsive to temp than mine, but he keeps his at 28 degrees.

Mine is one degree lower--and the reservoir temp is more than low enough to take this down to 32 degrees.


Why? Is it possible I'm forming ice on the coils and that's limiting cooling? @Morrey suggested raising the temp of the coolant to 30 degrees. The only other thing I can think is that there's so much heat gain into the fermenter that it's offsetting the cooling. If so, how do any of the rest of you manage this?

To reiterate: it's not the temp of the reservoir. It's plenty cold, and recovers well.

View attachment 570130

from what I read from spike.. when using the stainless tubes you do NOT want to take the chiller down below 30-32 degrees since doing so causes ice to form on the outside of the cooling coils insulting it from cooling the wort. I know you show that theres no ice at the time you pulled the coil after draining so I would experiment with flow at this point.
Edit sorry just saw this is a old thread.

 

[tdibratt]

I suppose a valve after the pump and before the conical to slow down the rate would work

 

[Tartan1]

Found an old link with regards to temperature inversion. Interesting read.
https://cdn.shopify.com/s/files/1/0..._Product_Guide_FINAL.pdf?14033054371399362451

 

[laura2863]

Is it possible this is occurring? (From Spike's TC-100 pdf)