Goose
0 Warning Points
- Joined
- 6/7/05
- Messages
- 634
- Reaction score
- 146
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 ?
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 ?