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Direct Glycol Cooling Solution

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Goose

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I've long been envious at how fast some of the craftbreweries I have visited can crash cool freshly boiled wort down to pitching temperatures so I thought I'd share some number crunching I did to look at the feasibility of a direct cooling system for crashing wort down to lager temperatures.

My dream was a machine that I could plug into a wall socket, pump in 100 deg c wort and have it come out at 12 dec C. Right now I am using a shedload of ice in a water bath that I recirculate though a plate chiller, it works, but I do need literally a shedload of ice to cool 50 litres of wort down which is a right pain.

So I figured surely a glycol chiller could do the trick. have seen these on the Morebeer site. The question is, could it work asuming I could spend the kind of cash they want for one of these units.

So lets say I have 50 litres of wort I need to cool to 12 deg C. Amount of heat I have to remove is Cv*W*Dt where:

Cv = heat capacity of wort (water is 4.18 Kj/Kg.K , close enough)
W = weight of wort (use 1.0 Kg/Kg, or 50 Kg close enough)
Dt = change in temperature (looking at 100 to 12 ie 88 deg C)

so this equates to 4.18*50*88 =18392 KJ of heat I need to pull out.

say I want to do this in 1/2 hour, or 1800 s, rate of heat removal I need is 18392/1800 = 10.2 Kj/s or 10 KW.

now, my single phase electricity supply is fused at 13A and is 240V, maximum power draw from our trusty P=V*I equation is 3.12 KW. ! OMG, nowhere near enough, even at 100% efficiency could I cool down 50 litres of wort in 1/2 hour.

So, again if I assume 100% efficiencey and 3 KW rate of hear extraction, it would take me 18392/3/3600 or 1.7 hours to cool.... which is madness.

So conclusion is, it cant be done unless I want to spend a bomb on a glycol chiller and wait nearly 2 hours for wort to cool.... :wacko:

What rapid cooling solutions do you guys have ?
 

Phoney

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Have you considered hiring a cylinder of liquid nitrogen and pumping that through your plate chiller?

We have one at work approx 2m in diameter, and 6m high. I've watched folks pour it into smaller cylinders, the shit is freakin cold! It can't be that expensive given plumbers use it to freeze pipes and block water flow while they carry out repairs.
 

GalBrew

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Liquid nitrogen can be reasonably dangerous though, I work with it quite a bit. Not sure how well your plate chiller would survive the rapid freeze-thaw cycles also. I would consider using dry ice before liquid N2 (outside of course). I have heard that using a whirlpool immersion chiller first and then pumping the beer through a plate chiller can work quite well also. I plan to implement this on my new build, but can't comment on its effectiveness ATM.
 

Truman42

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Im envious of a lot of things that craft breweries have that I dont, stainless conical fermenters, 1000 litre bright beer tanks, hot chicks working their bars..etc...But they are spending money to make money

Whats the hurry anyway? With a craft brewery time is money. With a homebrewer its not.

I run the wort through my chiller and in summer its chilled to around 32-35C. So I put it in my fermentation fridge and pitch the next day. In winter it chills to 25C so i usually pitch after transfer. i certainly wouldnt want to spend shit loads of money on a glycol system just so I can pitch 12 hours earlier.
 

GalBrew

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That being said, you could just cross over to the dark side and no-chill........ :beerbang:
 

donburke

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liquid nitrogen can snap metal and fittings, I don't think its practical for a homebrewer

I use my glycol chiller to cool my wort down

I chill approx. 85 litres of wort using tap water, takes approx. an hour to chill to 25 - 30 degrees

I then divert the tap water through the product lines of the glycol chiller, which prechills the water before it enters my immersion chiller, takes another 15 min or so to get to 18 deg and say another 15 - 30 mins to get to 12'ish deg

my glycol chiller has a 20 litre tank and usually sits at around -2 to -3 deg

when i start to pump tap water through, it starts to rise, and I try to regulate flow to that the glycol bath doesn't exceed 7 or 8 degrees, that way the compressor can keep up

i'm keen to hear of any other methods in rapid chilling as at times the 1.5 hour wait can be tedious
 

Goose

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Truman said:
Im envious of a lot of things that craft breweries have that I dont, stainless conical fermenters, 1000 litre bright beer tanks, hot chicks working their bars..etc...But they are spending money to make money

Whats the hurry anyway? With a craft brewery time is money. With a homebrewer its not.

I run the wort through my chiller and in summer its chilled to around 32-35C. So I put it in my fermentation fridge and pitch the next day. In winter it chills to 25C so i usually pitch after transfer. i certainly wouldnt want to spend shit loads of money on a glycol system just so I can pitch 12 hours earlier.
Are you not concerned about wort oxidation ? I understand its ok for the no-chillers because they have zero airspace in their cubes while they wait for them to cool ?
 

donburke

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did have a thought for a somewhat inexpensive method, providing you have the room, which I don't otherwise I would have tried it

chest freezer set to 1 degree filled with 300 or 400L of water can be turned on a couple of days before brewing and pumped through the chiller, there is a fair bit of cooling power in that volume,

or better still, 30-40% glycol solution will let you get the temp down to -18 which is what a deep freeze can sit at

might need a few days to get there
 

donburke

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Goose said:
Are you not concerned about wort oxidation ? I understand its ok for the no-chillers because they have zero airspace in their cubes while they wait for them to cool ?
also the risk of your non inoculated wort sitting at temperatures ideal wild yeast and bacterial growth
 

Goose

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I like the chest freezer idea ... good one...



donburke said:
did have a thought for a somewhat inexpensive method, providing you have the room, which I don't otherwise I would have tried it

chest freezer set to 1 degree filled with 300 or 400L of water can be turned on a couple of days before brewing and pumped through the chiller, there is a fair bit of cooling power in that volume,
 

Phoney

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Truman said:
I run the wort through my chiller and in summer its chilled to around 32-35C. So I put it in my fermentation fridge and pitch the next day. In winter it chills to 25C so i usually pitch after transfer. i certainly wouldnt want to spend shit loads of money on a glycol system just so I can pitch 12 hours earlier.
The first and last time I did that my wort was infected when I went to pitch the next day.

What sort of a chiller do you have? Do you run your water tap on full blast?

I have a mashmaster chillout mkIII and im able to chill to 25 - 27C in summer and 18 - 21C in winter and I'm 1000km north of you. I discovered sitting the chiller in a mop bucket & putting in half a dozen giant ice blocks and pour in around an inch of water keeps the chiller cold and that helped knock off a few degrees.
 

Nodrog

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Even In nz summer my ic gets it down to 30ish deg c pretty quick. Tap water around 18 c. I have Eski with 4 x ice cream containers frozen water, and filed up with water, done when mashing, so have 40l of iced water by time ready. Running this through ic gets last bit of wort down to sub 20s.

Think your turbo charged glycol chiller maths would get more realistic answer if you used 'conventional' means to get the wort down to 30 or 40, then throw some technology at it??
 

mikk

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2 wort chillers, inline with each other. The first chiller uses tap water to get the wort down to 25-30, the second chiller uses iced water or glycol to get the temp down to 10-15 deg.
 

treefiddy

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mikk said:
2 wort chillers, inline with each other. The first chiller uses tap water to get the wort down to 25-30, the second chiller uses iced water or glycol to get the temp down to 10-15 deg.
I think most people just slapped themselves on the forehead for not thinking of this before.
 

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i hate single stage wort chillers and ones that run off a cold liquor.

Make a stand if you have too, search for something like an alfa laval 2 stage online if you need to see one. The good thing is to divert the hot water back to your hlt for batch #2, comes out in the high 60's on the systems i use.
 

woodwormm

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treefiddy said:
I think most people just slapped themselves on the forehead for not thinking of this before.
hold on a minute... i'm getting in first... rainwater tank and pump in first chiller to save the precious planet :)
 

Goose

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mikk said:
2 wort chillers, inline with each other. The first chiller uses tap water to get the wort down to 25-30, the second chiller uses iced water or glycol to get the temp down to 10-15 deg.
Although the same could be achieved by recirculating back to the boiler... first using tapwater as the coolant then iced water... thugh not as elegant of course.
 

Goose

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Nodrog said:
Even In nz summer my ic gets it down to 30ish deg c pretty quick. Tap water around 18 c. I have Eski with 4 x ice cream containers frozen water, and filed up with water, done when mashing, so have 40l of iced water by time ready. Running this through ic gets last bit of wort down to sub 20s.

Think your turbo charged glycol chiller maths would get more realistic answer if you used 'conventional' means to get the wort down to 30 or 40, then throw some technology at it??

Can I add some more turbo maths to your turbo sarcasm :p

I reckon a frozen eski is a good idea, but by allowing the ice to melt first you are wasting most of the heat extraction potential. The latent heat of melting is the amount of heat it takes to melt 1 kg of ice at 0 degrees C. This is 334 KJ for every Kg of ice. By comparison, it takes only 4.18 KJ for every Kg of water, to raise it by each 1 degree from 0 thereafter. Its a huge difference.

I realise you cant pump ice through your exhanger, but add just a bit of chilled water atop the ice level to prime the pump, you may save yourself a bit of electricity next time ;)
 

markymoo

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hi Goose,

their Glycol system works on a refrigeration circuit, so the Coefficient of Performance is above 3:1, therefore your 3kW power in would result in over 9kW of cooling capacity.

at the temperatures we are talking (100degree wort down to 12degC) and on a mild day that efficiency would be much higher, say 6:1 plus.

This is why the refrigeration circuit is such a popular way of heating and cooling :)
 

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