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Old 26-04-2005, 01:03 AM   #12
BarraCuda™
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Join Date: Jul 2001
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Quote:
Originally Posted by monsterz1975
I was told to use a lower flow pump for my RR1.25hp by an expert who is making chiller for LFS. And i seen PR is using a low flow pump for their 1.25hp RR chiller too. So how should i go about?
I'm also aware of this low flow guideline, however I never managed to find out why the chiller need low flow. If the expert can explain the thermodynamics why having a low flow is better, maybe I can understand better.

All these are not theory only, I personally changed the hose size from 1/2" to 1" and I have seen the difference in reduction of chilling time. I would still say, dont take my words for it, go and try out!

Maybe I quote another example.

You drop 2 cubes of ice in 2 cups. 1 is 100C, 1 is 50C. After the ice have melted, which cup will have the greatest reduction in temperature? Of course cup 1.

Its because "coldness" is always referred to a reference pt. Ice is very cold to hot coffee but ice is very hot to liquid nitrogen. The greater the temperature difference between the water and Ti coil, the better the heat transfer.

If the flowrate is too slow, the actual temperature inside the heat exchanger is much lower than the tank water temperature thus narrowing down the temperature difference
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