HLT Agitator

DrPaulsen · Post by **DrPaulsen** » Sun May 22, 2011 10:54 pm

Lately, I've been playing around with a few different ideas to reduce thermal gradients in my HLT. The one I tried tonight seems to work really well and is incredibly simple to install/implement.

http://www.flickr.com/photos/33275630@N ... 749054707/

I bought an aquarium pump and a length of silicone tubing from the pet store (this is the same pump all the homebrew shops will sell you for wort aeration). After cutting a few slits in the tubing and clamping off the end, I added a couple of weights and placed the tubing in my HLT.

I set the HLT to 180F, plugged in the pump, put on the lid, and then walked away. When I came back an hour later, the HLT was up to temp and the first couple of quarts from the drain were at the right temp and were the same as every gallon that followed. Normally, I have a couple of gallons of dead space below the electric heating element that need to be drained off before I get the good stuff.

I'm pretty surprised this works so well, but would recommend it to anyone currently using or thinking of building an electric HLT or else anyone running a HERMS system. The pumped air does a great job of moving the water around just enough to get rid of the thermal gradients and it is much easier to install than an electric motor with a fan/mixer. For a controlled electric HLT, this should mean more predictable temperatures. For a HERMS system, this should mean more efficient energy transfer and faster rise times.

Post by **JimPotts** » Mon May 23, 2011 9:50 am

What are the two copper tubes running down the inside of your HLT? Temperature probe and something?

-Jim

DrPaulsen · Post by **DrPaulsen** » Mon May 23, 2011 10:19 am

Temp Probe & Float Switch. The float switch is to protect the heating element from burning out in case something happens when I'm not around.

TappedOut · Post by **TappedOut** » Mon May 23, 2011 1:08 pm

I've been meaning to ask, anyway. What do you use for a float switch?

DrPaulsen · Post by **DrPaulsen** » Mon May 23, 2011 1:23 pm

http://www.mcmaster.com/#catalog/117/531/=cflbtb

Polypropylene Vert-Mount Liquid-Level Switch W/Slosh Guard, 1/8" NPT Male, 100 Max PSI, 1-1/2" Dia (PN 50195K94)

I've also got a stainless steel version, but that one is going to be used for an auto-sparge system I've been tinkering with. Since I dug it out of the trash at work, I don't have a PN.

Matt F · Post by **Matt F** » Tue Jan 17, 2012 1:58 pm

Hi Lee, bringing up an old post as I ran in to an issue while tinkering with my HLT. I cut the top off it and now can put my immersion chiller in the HLT. I used the pump and return tube to whirlpool the water, but with one pump can only do this prior to mash in. I can heat the deadspace with a gas burner I still have installed under the HLT. The problem I encountered is I installed a new sight tube with a thermowell as my old way won't work now. I mounted it low to maximize the use of the sight tube and it is at about the same level as the heating element. I say about because it is slightly below which as you know can be an issue.

I think your aeration system idea here will work well for what I need. Are you still using this and still like how it works for you? I think I have an aquarium pump already laying around and would just need to add some tubing and a piece of stainless I have laying around for weight. My other option is to make another hole and mount the thermowell in a better spot. I really like how the aeration could even out the temp in the HLT. Thoughts?

DrPaulsen · Post by **DrPaulsen** » Tue Jan 17, 2012 4:51 pm

I pretty much quit using the aeration system when I bought my second pump. Before that point it worked great. I played around with the number of holes to put in the silicone tubing and how many weights to put on it (i.e. to control the distribution of bubbles). None of those things really mattered. As long as I was pumping hard enough, the problem was solved.

Based on the description of your new setup, an aquarium-pump-based agitator should work just fine.