Electric HLT stirrer?

[billvon]

I've been using a Minibrew electric HLT to heat water lately, but I'm having problems with temperature stratification. The first gallon or so I pull from the bottom tap is 20-30F below the temperature shown by the thermometer (about six inches above it, much closer to the element.) I assume that the cold water is just sitting at the bottom; the warmer water is rising to the top.

Anyone have a good idea on how to break this up? I've been thinking of using a stirrer but haven't found a good one; I would think it would have to be stainless steel (or some other inert material) to deal with sitting in 190F water for hours at a time.

How about a magnetic stirrer? Would the endless spinning eventually damage the plastic bottom of the HLT?

My last resort is just a pump that constantly recirculates the water, but I wanted to avoid another pump if I could.

 

[Catt22]

Someone recently posted that they used an aquarium air pump to keep the water moving and mixing. I think this might be an inexpensive solution. I have not tried it myself, but I see no reason why it would not work well. Find a way to inject the air near the bottom of the HLT. I could see making an "air wand" out of some copper tubing or CPVC with a properly sized barbed fitting at one end to accept the air line.

 

[P-J]

Build yourself one of these:
The article can be found Here

 

[wilserbrewer]

Hows a bout a long spoon and stir it?

 

[P-J]

Hows a bout a long spoon and stir it?

That absolutely will work. Just keep in mind that you will be standing there for about 12 to 20 minutes for that stir process to get the most efficient heat exchange. The temperature barrier layer will build within seconds (10 to 20) and then it will seriously inhibit heat exchange.. It is like adding a thin layer of insulation to the coil every couple of seconds during the process.

Just saying.