chiller capacity

[fullmoonwinery]

hi, does anyone know what cooling capacity i need to cool beer from 10degC to about 1 or 2degC if the flow rate is 10 liters/minute?

we are using a heat exchanger to cool the beer in line as it goes to the filling machine (1200bottle/hr). i need to buy a chiller to drive the heat exchanger and need to know the capacity for it.

thanks, steve

[sbradt]

Chiller load

You will be dropping about 2,300 lbs of beer by 16°F in 1 hour which requires about 37,000 BTU/h of cooling assuming the heat exchanger is sized appropriately.

BTU/h= lbs of beer x (starting temp °F - ending temp °F)/hours allowed for cooling

[fullmoonwinery]

thanks, so about 12kw chiller should do it then, that's pretty much what i guessed.

anyhow it turns out a chiller and heat exchanger is a bit outside of my budget right now, basically like here to the moon outside my budget so i have another idea.

i have a plastic ice chest, i plan to fill it with ice and water, so water temp about 1-2degC.

i will make a stainless steel box (heat exchanger) , 40cm high, 80cm long, 2-3mm wide (inside). i will drill many 1/2" holes between the two walls and weld 1/2" stainless tube through. so this is my heat exchanger, surface area about 0.5m2, liquid thickness 2mm.

beer comes in at the bottom corner and out the top diagonally opposite corner. flow rate is the same as my original post, 20L/min and beer temp going in is about 8degC.

what temperature drop can i expect to get in this setup? I am aiming to get down to about 3-4 degrees so i wonder, will one of these heat exchangers do it or will i need a few?

by the way, i know i will need to replace the ice a lot as it melts. that's ok, large ice blocks here are quite cheap and i can use the melt water for something else in the bottle filling process (bottle washer/chiller).

thanks again, steve

[sbradt]

ice box cooling

Steve,

You're getting a little beyond my specific knowledge. My thought is that you may have a hard time getting enough heat transfer fast enough. You'd need to have good contact between the ice and the heat exchange surface and find a way to maintain that as it melts and changes. Maybe some sort of recirculating pump to encourage speedy melting and good circulation of the chilled water from the melt. Good luck, I admire the resourceful spirit of the effort.

[Scott M]

Can't give you any specifics, but if you add water and salt to the ice, you can lower the temperature of the mixture you're using as a cooling media.

http://antoine.frostburg.edu/chem/senese/101/solutions/faq/zero-fahrenheit.shtml

[fullmoonwinery]

i did some calculation and it looks like one heat exchanger should work, but i'll build it this week and post the results if anyone is interested