Stirring Water

[nabs478]

Howdy,

I am getting to the tale end of my brewery build, and I have bought a couple of MashMasters HLT temp controllers. One for the heat exchanger for the HERMS, and one for the HLT. I am told that without stirring the water can stratify in the vessels and that in turn makes sensing the temperature unreliable, not to mention the water coming out of the HLT flucuationg in temperature through out the sparge.

I plan to use windscreen wiper motors for stirring (I have a couple of rusting car hulks available). I am hoping to mount the one for the HLT outside the tank, but having a shaft that goes through the wall of the tank and stirs the inside liquid. Has anyone done something like this? Or does anyone know how you would go about making the hole the shaft goes through watertight, but still free to rotate the stirrer?

Or has anyone found a better solution to this problem, that is easier to set-up?

Any comments and thoughts welcome.

Thanks

Pip

 

[hockadays]

I think there is something in here under equipment that describes what your after...

www.brewingtechniques.com

it's under mash mixing but it has the hole going through the lid of the tun not the side

may help...

 

[poppa joe]

Google..."cd's old electric wort boiler"
Has Info that you maybe can use...
Cheers
PJ

 

[nabs478]

I think there is something in here under equipment that describes what your after...

www.brewingtechniques.com

it's under mash mixing but it has the hole going through the lid of the tun not the side

may help...

Google..."cd's old electric wort boiler"
Has Info that you maybe can use...
Cheers
PJ

Both these are examples are of using stirring through the lid, which is one way I can do it. I am hoping to attach the stirrer through the wall on my setup because I am using a 200L drum, which is about a meter tall. I will have to mount it at the top, and I think having a shaft a meter long might cause it to wobble around a bt and vibrate. This woudnt be a big deal, but I would prefer to do it in a more professional manor.

Thanks for your interest anyway fellas.

 

[razz]

Good morning Pip. I think that stirring from the top is the way to go, I say this because I'm thinking about the machinery that's out there in the industrial world and most or all of it probably stirs from the top down. With you 200lt drum why can't you mount a support in the bottom half of the drum so the shaft is supported? That may be an easier fix than trying to make/purchase a water tight seal for a side mount stirrer. Food for thought.

 

[Hogan]

Howdy,

I am getting to the tale end of my brewery build, and I have bought a couple of MashMasters HLT temp controllers. One for the heat exchanger for the HERMS, and one for the HLT. I am told that without stirring the water can stratify in the vessels and that in turn makes sensing the temperature unreliable, not to mention the water coming out of the HLT flucuationg in temperature through out the sparge.


Pip

Hi Pip - before you go down the 'stir' road do some test runs on your rig. I don't have a HERMS but my element in my HLT sits about 5 inches above the bottom of the pot. The outlet and MM probe are combined at the same level. I used to stir to mix the lower layer below the element but I found that if I left it alone, the water at and above the element heated and came out the outlet constantly at the right temp. I don't stir anymore and strike temps were reliable and right on target.

Edit: I might add that my MM is a temp gauge and not a temp controller but they both sense the temperature so there should not be a difference - I think.



Cheers, Hoges.

 

[Tony M]

If you go thru the lid and weld a drilled boss on the bottom of the tank to recieve the shaft end, it will be quite stable and the engineering can be dog rough. If you go thru the side you are looking at at least a good bronze bush in a housing with a couple of oil seals. Its a much bigger deal.

edit; I have found from experience that only the liquid below the heat source is at a lower temp. and it is only 3 or 4 degrees C so perhaps you can take off your fluids from a higher position------or maybe you are using gas and dont have a problem.

 

[ant]

Hey Pip - 200L drum sounds almost professional in itself! Strewth! I'm with you on having a shorter or fixed shaft if you were talking about a mash stirrer, but if it's just going to be for a HLT, I don't think there will be sufficient resistance at the very low speeds you will be using the wiper motor to cause significant wobbling/vibration. It really doesn't have to mix the water very quickly to avoid stratification.

 

[MHB]

Stratification of the water would only be a problem when you arent heating, while the power/gas is on there will be plenty of convection to keep the water fairly well mixed.

If you are heating and then leaving the HLT to rest for any length of time (say 10-15 minutes) then a stir/stirrer would be a good idea, just a quick whisk around with a brew spoon or paddle would be fine if you dont want to go to the trouble of fitting a stirrer, or a recirculation pump.

A magnetic follower bar and one of the "cheap ass stir plate" arrangements would be worth looking at, the magnetic field should work though stainless just fine.

Someone was asking about side entry - what you need is a stuffing box, you can make a simple one with a socket and a couple of plugs drilled to take the shaft, the inside is filled with a type of self lubricating rope (stuffing), you tighten up the plugs to get a seal. PM me and I will e-mail you a doodle if you need it.

MHB

 

[Zizzle]

If you go thru the lid and weld a drilled boss on the bottom of the tank to recieve the shaft end, it will be quite stable and the engineering can be dog rough.

+1

What is the drum made of? Can you get away with a magnetic coupling with the stirrer? Like a big stir plate.