^^^ Looks like a reasonable setup. Double check the shaft and coupler dimensions, and plan on something (perhaps 2 x 4's and some pipe clamps) to mount the motor. And of course drill holes in your lid or whatever... But seems off to a good start.
Exactly what I'm planning, except I will use a stainless mash paddle cut to length. I know the mash paddle is completely food safe and should provide plenty of movement at 100 RPM. My plan is to use this at flameout to keep wort moving over my immersion chiller. None of my kettles are ported, so using a pump to recirculate is more difficult.
Here's the parts. I'll likely need to reduce the diameter of the mash paddle handle to fit the coupler. I also plan to build a mount that will slide over the side of the kettle so I can use it on all of my kettles.
https://www.amazon.com/gp/product/B072R57C56/ref=ox_sc_saved_title_2?smid=A18IHNL4DD28Y&psc=1https://www.amazon.com/gp/product/B07TTH283Z/ref=ox_sc_saved_title_3?smid=AGOSLUO29ZUJ2&psc=1https://www.amazon.com/gp/product/B01N25GA98/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I think I have a 12v power supply in stock, but if not, this is the one I'll get. It can lower the voltage, which will lower the RPM. It also has an adapter to make connecting it to the motor simple.
https://www.amazon.com/gp/product/B01N7RS0NG/ref=ox_sc_saved_title_1?smid=A2WETDVOSZN7JY&psc=1
~HopSing.
I'd use the aquarium air pump output through some stainless tubing to the bottom of the HLT. I considered doing this for years, but I have an excess of pumps so no need.
This is a really interesting idea. Surely worth a test. The cooling from the air would be beneficial in my use case and the additional O2 would help aerate for the yeast. I would definitely add some kind of in-line filter as I've seen oil slicks on aquariums from the air pumps. It's usually food safe lube, so it won't hurt the fish, but it would likely kill any head retention for a batch.
Thanks for the idea.
~HopSing.
For an aquarium pump though, I think you'd want to also put it into the tun valve, any tee relating to a sight glass would just have that air going into the sight glass and not into the tun, unless you had yet another couple valves setup. Maybe I'm just not picturing the idea correctly.
What I was thinking about running the aquarium pump through the sight glass was, putting the air line in the top of the clear sight glass tube. No T involved. If done this way and only in the HLT, You would use the sight glass as normal for measuring your water but, once you start heating, you would send the air down the sight glass tube into the bottom of the tank. Simple! And, no need to pay and wait for a stainless T, either! To me, it just has my affore mentioned drawbacks such as the cooling effect it would give. No "biggie" really, for the right guy. The heating element and controller would compensate. The little pump is still the way to go though, IMO.
I think I see what you are saying but, why not just disconnect the air tube from the sight glass? Or, just let the pump run the whole time until the HLT is drained?
I'm probably missing something here.