Recomended flow rate?

[Rbeckett]

Does any one have the optimum or recomended flow rates for immersion chillers? Mine is 3/8ths stainless and I have a plan to use the reject water from my RO set up to operate it. I think I read 2.5 Gall a minute, but cannot remember where I read or found that spec. If the recomended rate is higher than my reject water flow I can add a bit from the tap since it is not in contact with anything that could get contaminated. Thanks for the info.
Wheelchair Bob

 

[bja]

How much waste water does your RO make? Mine is less than a quart a minute.

 

[duckredbeard]

The flow should be so the water comes out hot. If it comes out cool, you aren't exchanging heat. It will cool as the wort cools, of course. Keep adjusting it to optimize the exchange of heat.

 

[Paul07293]

I don't think there is a "recommended" flow rate. I have 3/8" X 50' copper chiller with a Jamil whirlpool attachment. I gauge my flow by the temp of the water coming out. Generally speaking you can go with a pretty fast flow initially because the heat differential is greater. Once you get below 100 degrees you can slow it down considerably so the incoming water has more time to suck up the heat. I don't measure the flow but I reclaim the water in a 6 gallon bucket and I'm sure I'm going slower than 2.5 gal per minute, even at the start.

 

[Rbeckett]

Paul,
Do you re-use the water during the chill or just collect it in the pail? I have never used a chiller before and cooled the only batch I have ever made in the sink with ice so I am trying to get a grip on the parameters so I can automate it to assist me in my wheelchair. I cant lift so I have to depend on hydraulics and gravity to do as much as possible. I was thinking since I am using a surge tank for the RO I could also divert the outflow of reject water into another surge tank and use the mixed water to chill the coil. I figure since I added a boost pump to the RO it would still be at a higher pressure than the well water and could be collected to prevent wet spots on the floor and wasting water. Technically I am still a noob to brewing but have been studying the engineering thats required to integrate a bunch of differing systems into a solution that will assist me. My spinal disease is progressive so I am trying to figure this out while I can still stand to tinker and adjust. Oh yeah I am also trying to do this as cheaply as possible on a disibility income, so I love to repurpose and reuse as much a possible to save a few coin of the realm. Thanks for the help and input.
Wheelchair Bob