Immersion pump flow rate through chiller

[Eric Tepe]

Hey everyone,
I was wondering from those who use the method of immersion chilling with a submersible pump in a bucket of ice water, what your flow rate through your chiller is. My chiller is a homemade "hydra" with 3x30ft coils of 1/4ID copper. My pump, which is rated at 550GPH (it puts out about 270GPH with the 1/2ID hose attached at pump level. The 550GPH is using the 3/4ID hose) has a flow rate through my chiller of 2GPM. Will that give fast and efficient chilling of my wort once I bring the wort down to 90ish degress with my 78 degree groundwater?

Thanks,
Eric

 

[IslandLizard]

Throttle the flow rate according to the temp of the water coming out of the chiller.

If the water coming out is ice cold, it's not chilling very well, and you're wasting it, unless you recirculate it back into your ice bucket. If it's warm/hot, it's doing its job, perhaps increase flow somewhat, and do not recirculate, just discard (single pass).

 

[cegan09]

Technically, the faster you can pump, the better. heat transfer works on heat differentials. Yes, the water will be colder coming out of the chiller the faster you pump, but it's actually working better. The closer the two liquids come to the same temp the slower the heat transfer. So if you're throttling the flow to make the water coming out hot, you're likely not chilling through the whole chiller, just part of it. If you're getting water out that's well below the beer them, the whole chiller is working.

Whether you try to collect and reuse or dump the water is up to you, but it will take the same amount of thermal energy either way.

 

[Eric Tepe]

Thanks for the replies. I understand the heat exchange dynamics of it. I plan on using ground water to get my wort to 80-90F then recirculate ice water from a cooler through the chiller and back. I was just wondering if anyone had calculated thier flow rate from the ice bucket throught the chiller and back to the bucket and what flow they found optimal for thier system. Most of the pumps I saw in the threads were rated at much lower GPM than the one I purchased. Mine doing 2GPM sounds like it should be plenty circulating through especially if my iced recirculation water is in the 40s.

 

[cegan09]

2GPM is plenty, especially if you're doing the last bit with ice water.

 

[balrog]

Dunno the flow rate. I use 25' 3/8" copper, 600gpm immersion pump in cooler with ice on floor so lifting ~4' vertical. I use groundwater to chill to 90-100 then recirculate in ice, total time 5g cool is roughly 15min.