simple mash temperature control method

[stoutaholic]

I am designing a heat exchanger to control my mash temperature. This is the standard HERMS design where the mash is pumped through a copper coil in a heated stock pot. In this case, the stock pot that contains the heat exchanger is only about 2 gallons and is heated by a 1500 Watt 120 volt hot plate, as that was simpler than installing a water heater element in the pot.

Anyway, I want a simple method of controlling the temperature of the mash by controlling power to the hotplate. I know there are simple temperature controllers for refrigerators, such as this one Refrigerator Thermostat Control- Analog :: Midwest Supplies Homebrewing and Winemaking Supplies that come with a probe. I could probe the mash temperature with the thermostat probe, and then plug the hot-plate into the thermostat. So the hot-plate would turn on and off based upon the probed mash temperature.

The problem with this is that the thermostat linked above is not sensitive enough for controlling mash temps. It only adjusts to 3.5 degrees of the target temperature. Does anyone know of a similar type of thermostat that is more precise (i.e. that can keep the mash temp within 1 - 0.5 degrees of the target temp)? Has anyone used a similar setup for their HERMS? I dont want to mess around with a PID, SSR, pickaxe microprocessor, or anything like that. Trying to keep it simple.

 

[Boerderij_Kabouter]

This is an awesome idea. First you should find a way to incorporate a stir bar into the system for liquid movement within the HERMS vessel. If you haven't already bought it, you can get hot plate/stirrers pre-made that would work well.

Second, PID really isn't that difficult to use and would likely be the best option for this. Second best would be a LOVE controller like this:

Dwyer Instruments - Series TS2

 

[stoutaholic]

Oh yeah, I've heard people mention these Love TS controllers before, but I'm not completely clear about how they work. From reading the specs it sounds like they come with a probe and allow temperature control with in +-1 degree, so that is sensitive enough for me. I am just unclear about how one would hook this up to a hotplate or other heating device. I bet this has been discussed previously on this board, but I'm not coming across any helpful threads. Anyone have any good instructions about how to hook up a Love TS digital temperature controller to a hot-plate?

 

[Catt22]

This is an awesome idea. First you should find a way to incorporate a stir bar into the system for liquid movement within the HERMS vessel. If you haven't already bought it, you can get hot plate/stirrers pre-made that would work well.[/url]

I'm having trouble visualizing how a stir plate could work with a HERMS vessel. The metal kettle will likely prevent the stir plate magnets from coupling with the stir bar in the vessel and you would need a mighty big stir bar to make it effective.

 

[Boerderij_Kabouter]

https://www.homebrewtalk.com/f11/love-temp-controller-series-ts-wiring-diagram-2008-a-88369/

That thread should tell you all you need to know.

Also, this hot plate or similar would be perfect.
Discontinued Items And StableTemp Aluminum Hot Plate Stirrer - Cole-Parmer Catalog

 

[stoutaholic]

Boerderij, thanks for the link to the Love Controller.

Yeah, I'm not sure how I am going to stir the heat exchanger yet. My hot-plate was just going to be a simple single-burner portable stove top.

If a hot-plate/stir plate would work, that would be pretty cool.

Dennis Collins actually installed a bathroom vent fan moter in the top of his heat exchanger to handle the stirring separately from the heating: Heat Exchanger

 

[Catt22]

https://www.homebrewtalk.com/f11/love-temp-controller-series-ts-wiring-diagram-2008-a-88369/

That thread should tell you all you need to know.

Also, this hot plate or similar would be perfect.
Discontinued Items And StableTemp Aluminum Hot Plate Stirrer - Cole-Parmer Catalog

WTF!! You are somehow suggesting that he buy a Cole-Parmer stir plate for $510.00 plus shipping and use it to somehow stir his HLT? That's wild! I'm still having trouble figuring out how this might possibly work. Do they even make 6 inch stir bars? Can you elaborate?

 

[Boerderij_Kabouter]

Whoa Catt22. No need to get pissed...

I don't know what he is doing, I am just throwing around cool ideas. Maybe you like brewing with socks as filters and spending $2 to make hooch. Some people spend $$$$$ for crazy automated systems. All types are represented here and it is fun to throw out ideas from both ends.

A PID controlled hot/stir plate heat exchanger system would be totally awesome. Plain and simple. Maybe the OP isn't into that, or maybe he is. No need to get pissed at me for actually trying to help. Maybe you should contribute something before getting pissed.

Sorry stoutaholic, the interwebs get crazy from time to time.

 

[Bobby_M]

The key to controlling this system is to put the temperature sensing probe inline with the wort flow, just after leaving the HERMS coil. The stirring mechanism can be a simple paint stirring paddle attached to a small motor. You're not looking to make whipped cream, just provide some circulation.

 

[Catt22]

Whoa Catt22. No need to get pissed...

I don't know what he is doing, I am just throwing around cool ideas. Maybe you like brewing with socks as filters and spending $2 to make hooch. Some people spend $$$$$ for crazy automated systems. All types are represented here and it is fun to throw out ideas from both ends.

A PID controlled hot/stir plate heat exchanger system would be totally awesome. Plain and simple. Maybe the OP isn't into that, or maybe he is. No need to get pissed at me for actually trying to help. Maybe you should contribute something before getting pissed.

Sorry stoutaholic, the interwebs get crazy from time to time.

I'm not pissed at all. Amused would be a better description. Cool ideas? Yeah right! You should research some of your off the wall ideas before posting them here and making a fool of yourself. Just a friendly suggestion, nothing more. Have a nice day!

 

[stoutaholic]

Guys, do you know if the Love TS controller's probe can touch the wort directly, or would I have to put it in a thermowell? Is there any concern about the responsivity of the controller if the probe is in a copper thermowell?

I was planning on using one of these: http://www.rancoetc.com/wel11a601r-bulb-well-assembly-p-114.html