Wort Chiller Just Ain't Chillin

[Bribie G]

I had one of those moments as I woke up this morning and said "Ha".

When I get my immersion chiller in couple of weeks I intend, as suggested by an earlier poster, to use a $25 submersible pond pump dropped into around 70 L of water at 2 degrees in my 60L fermenter (will fit)

Then recirculate that through the coil immersed in 23L of wort at 100 degrees.

So when the heat exchange has been finally done, it's the equivalent of mixing 70 and 23 litres at different temperatures.

I used the handy tool Online Conversion of Liquids and it shows me that the final temperature would be a somewhat disappointing 26 degrees.
However subbing six kilos of ice for some of the coolant water (2 ice cream 3L containers) would bring me down to around 18 degrees that would be good... finish off to lager temps in the FV before pitching.

Then the 70 L of coolant can be run straight out to the veg garden that's just outside the door. This I expect would lead to a fairly rapid cooling initially, then diminishing returns as the system trends towards equilibrium. However minimal water usage and the plants get a drink, which I'd be doing anyway as it's the dry season here, supposedly.

I'll post results.

 

[Online Brewing Supplies]

I just so happened to be watching the BREWHA instructional video and they say it all @ 25.43.

https://www.youtube.com/watch?v=6ojtYKokOD8#t=437

Yes your right its a classic example of a very inefficient way to chill, just let the wort sit there with no motion and expect to chill it by throwing 5000L of chill water at it. :huh:
That expensive equipment just got a whole lot more expensive to use.
Nev

 

[Bribie G]

That's five tonnes of water :blink:

 

[Online Brewing Supplies]

Maybe a SLIGHT exaggeration on my behalf to make a point.

 

[pk.sax]

I had one of those moments as I woke up this morning and said "Ha".

When I get my immersion chiller in couple of weeks I intend, as suggested by an earlier poster, to use a $25 submersible pond pump dropped into around 70 L of water at 2 degrees in my 60L fermenter (will fit)

Then recirculate that through the coil immersed in 23L of wort at 100 degrees.

So when the heat exchange has been finally done, it's the equivalent of mixing 70 and 23 litres at different temperatures.

I used the handy tool Online Conversion of Liquids and it shows me that the final temperature would be a somewhat disappointing 26 degrees.
However subbing six kilos of ice for some of the coolant water (2 ice cream 3L containers) would bring me down to around 18 degrees that would be good... finish off to lager temps in the FV before pitching.

Then the 70 L of coolant can be run straight out to the veg garden that's just outside the door. This I expect would lead to a fairly rapid cooling initially, then diminishing returns as the system trends towards equilibrium. However minimal water usage and the plants get a drink, which I'd be doing anyway as it's the dry season here, supposedly.

I'll post results.

I know you are usually right, but, ice will also suck energy due to the act of melting and also, how below 0C it is when you chuck it in. Might get you to lager temps yet

 

[Burt de Ernie]

Yes your right its a classic example of a very inefficient way to chill, just let the wort sit there with no motion and expect to chill it by throwing 5000L of chill water at it. :huh:
That expensive equipment just got a whole lot more expensive to use.
Nev

5m3 of water?? WTF! Please...

 

[Goose]

So when the heat exchange has been finally done, it's the equivalent of mixing 70 and 23 litres at different temperatures.

I used the handy tool Online Conversion of Liquids and it shows me that the final temperature would be a somewhat disappointing 26 degrees.

Did somebody mention ice ?



Have posted this before but for good order;


1) it takes 4.18 KJ for every Kg of water, to raise or lower the temperature by 1 degree C

2) it takes 334 KJ for every Kg of water to phase change to ice at 0 deg C and visa versa

so you can see that a little bit of ice goes a long way in terms of cooling potential versus a water bath .... ie just 16 litres of melted ice warmed to 26 deg C has the same heat removal capability of 70 litres of your 2 degree C water moving up to 26 deg C...

a little bit of ice goes a long way... fwiw LOL

 

[itmechanic]

Its a bit hard to pump ice though.

 

[lael]

Is it cheaper to use 70L of cold water or pay for the electricity to freeze 20L?

 

[Goose]

Its a bit hard to pump ice though.

let me think about how you solve this one B)

 

[zarniwoop]

Did somebody mention ice ?



Have posted this before but for good order;


1) it takes 4.18 KJ for every Kg of water, to raise or lower the temperature by 1 degree C

2) it takes 334 KJ for every Kg of water to phase change to ice at 0 deg C and visa versa

so you can see that a little bit of ice goes a long way in terms of cooling potential versus a water bath .... ie just 16 litres of melted ice warmed to 26 deg C has the same heat removal capability of 70 litres of your 2 degree C water moving up to 26 deg C...

a little bit of ice goes a long way... fwiw LOL

I knew number 1 but didn't know 2, thanks.

 

[Not For Horses]

Yes your right its a classic example of a very inefficient way to chill, just let the wort sit there with no motion and expect to chill it by throwing 5000L of chill water at it. :huh:
That expensive equipment just got a whole lot more expensive to use.
Nev

5000L?! That's about $4 here in Tas. Can't get rid of the stuff fast enough

 

[Goose]

Its a bit hard to pump ice though.

Ok I'll remove the sarcasm.

The point I was trying to make is that a huge amount of heat is removed by process of the phase change from ice to water. So if Bribie still wants to use his 70 litre cold water reservoir AND achieve a lower equilibration temperature than 26, he can easily calculate how much ice he needs to throw in for his target temperature.

Thankyou, and goodnight.

 

[dago001]

5000L?! That's about $4 here in Tas. Can't get rid of the stuff fast enough

Might be at the moment, but the way the water authorities are being run you might have to add a few zeros to that in a couple of years.

 

[Parks]

Hrmz, you didn't mention what temperature the ice was...

 

[Goose]

Hrmz, you didn't mention what temperature the ice was...

I assumed zero degrees for sake of example.

Unless you are referring to the heat capacity of ice .. .

 

[Parks]

Well the ice coming from my freezer is -28deg C which would make a massive difference to the cooling capacity compare to 0.

 

[Goose]

Wouldn't say massive. A bit, and almost insignificant when compared to the phase change heat needed to melt ice. It is also worth noting that the heat capacity of ice is about half that of water (see below), though every bit helps.

Specific heat capacity, ice: 2.108 kJ/kg-K
Specific heat capacity, water: 4.187 kJ/kg-K
Latent heat of melting, ice to water: 334 kJ/kg-K

 

[Parks]

Wow, that's really interesting. So that means it takes roughly twice as much energy to increase water temp as ice temp?

 

[Goose]

Wow, that's really interesting. So that means it takes roughly twice as much energy to increase water temp as ice temp?

for the same weight, correct