Aussiedistiller, Home Distilling, Moonshine, Home Brew

Lately I've been thinking about the possibility and practicality of putting an agitator in a keg boiler. Anyone thought about this?

I was thinking you could use an SS paint mixer attachment for a drill, have a small hole in the top of the keg (the size of the shaft 1/4" or so), and run it with a small DC motor (or just a drill).

The issue I can see would be having a good seal, as even if you install an o-ring around the shaft, it still has to spin, so it may not be leak proof to rising vapours. There would be trickier ways like having the small part of the drill/motor protruding into the top of the boiler and sealed, so there's no spinning at the seal. Of course this would have to handle the heat and be safe for the product.

Ultimately, it's practicality that puts me off. At the moment when I have a corn-like mash, I leave the fill port open and stir it while it gently gets up to temperature. When close to boiling, shut it up and the violent movement of boiling should keep it from scorching. I do want to get to thicker full corn mashes though :think:

Food for thought, I'll probably never do it...just thought about it ;-)

You could think about using some kind of magnetic stirrer. :think: Kegs are not very magnetic and if you used rare earth magnets I reckon they would grip each other through the keg easily. The big problem I foresee is the friction on each side, you would need some sort of lubrication or a track of ball bearings etcetera. It would work a treat on the bottom of the keg, much earlier to set up, but I guess your on gas. Still maybe you could work something out. There are plenty of magnetic stirring options to take inspiration from, pumps, even them little rubber coated metal things they use in labs and on yeast starters. Good luck buddy, my smoke breaks over. :crying-blue:

sturdy mount, apropriate seal housing and material and you could build one, as long as no vapour leaks... they have them in commercial set ups so as long as you scale it down away you go...

res wrote:You could think about using some kind of magnetic stirrer. :think: Kegs are not very magnetic and if you used rare earth magnets I reckon they would grip each other through the keg easily. The big problem I foresee is the friction on each side, you would need some sort of lubrication or a track of ball bearings etcetera. It would work a treat on the bottom of the keg, much earlier to set up, but I guess your on gas. Still maybe you could work something out. There are plenty of magnetic stirring options to take inspiration from, pumps, even them little rubber coated metal things they use in labs and on yeast starters. Good luck buddy, my smoke breaks over. :crying-blue:

Thats the first thing I thought about but you would need revolving magnets around the boiler , to complex and expensive .

Or you could set it up like a stepper motor and have X amount of electromagnetic poles around the boiler . still to complex and expensive . I think the horrid seal .

What about having a ssteel ring near the bottom with heaps of 1mm holes in it and just blow air through it every 5 mins to mix up the grain . Just a thought

I would be avoiding the magnetic idea...but as JayD says, I think the key is the seal housing :think:

Also, the bubble idea would need to be constant and an issue would be the fact that the bubbles are pockets of air at room temperature, so you may have problems there...?

looks like silicon or ptfe lubed maybe .

Yeah, I think the key would be to have the shaft spinning in that seal material whilst maintaining a vapour seal. I guess if its under constant friction against the seal/o-ring wall, should be enough to seal from vapours...but unsure how it would handle once spinning :doh:

You could build a steam injection boiler. Be a lot easier and you won't have to worry about agitation

sent while napping in a cherry orchard

Hi all
There is a product that will do this job efficiently provided you have a reasonable bearing/bush set up and a top mount for the seal they are known as mechanical seals, I have built and or incorporated these on a large range of mechanical installations the most common being pumps. I'm not much good on computers or I would find a link for you, however a google search of mechanical seals will give you a fairly good idea. The only drawback may be getting a seal made from suitable materials, the seals are generally made of 3 materials which would come into contact with vapour. There is a stationary rubber seal which in this case would be mounted in a stainless stepped bush silver soldered into the top of the boiler inside this rubber is a ceramic ring which works as a thrust washer the sealing is done between faces not diameters hence the need for independent bearings. Then there is a rotating carbon ring rubber mounted on the shaft with a SS spring pushing the carbon down onto the ceramic. Sorry for the long winded shit just trying to explain. If anyone is interested do a search and let me know if you want pics and questions answered.
Cheers Mick.

Why not just use a small pump something like you'd use when mashing drawing from the bottom and have the outlet entering back on such an angle that it would promote a whirlpool swirl type action. Would keep things moving and you could also use it with the addition of a ball or 2 to pump the dunder out when ya done.

I have never done a grain mash but couldn't you strain out the grains before you distill it or do you need them in there for flavour or something

Cheers sponge

You could drain the mash, though some do argue the flavour issue. It's a massive pain and you never get all the wash out. So much easier to mash it, ferment it then still it all without the need to strain.

kickarum wrote:Hi all
There is a product that will do this job efficiently provided you have a reasonable bearing/bush set up and a top mount for the seal they are known as mechanical seals, I have built and or incorporated these on a large range of mechanical installations the most common being pumps. I'm not much good on computers or I would find a link for you, however a google search of mechanical seals will give you a fairly good idea. The only drawback may be getting a seal made from suitable materials, the seals are generally made of 3 materials which would come into contact with vapour. There is a stationary rubber seal which in this case would be mounted in a stainless stepped bush silver soldered into the top of the boiler inside this rubber is a ceramic ring which works as a thrust washer the sealing is done between faces not diameters hence the need for independent bearings. Then there is a rotating carbon ring rubber mounted on the shaft with a SS spring pushing the carbon down onto the ceramic. Sorry for the long winded shit just trying to explain. If anyone is interested do a search and let me know if you want pics and questions answered.
Cheers Mick.

:text-+1:
have overhauled dozens of pumps with these and machined housings to convert from gland packing to mechanical seals.
great seals
Ben

Brendan,

Have you considered simplifying the situation by using a recirc pump instead?
It will do 9/10th of of the job an agitator will do in reality, without the expense and hassle.

Cheers,

Mech.

TheMechwarrior wrote:Brendan,

Have you considered simplifying the situation by using a recirc pump instead?
It will do 9/10th of of the job an agitator will do in reality, without the expense and hassle.

Cheers,

Mech.

Hi TMW
Certainly a recirc pump has a lot of merit, but perhaps not as simple as it may first seem. Allow me to state I have very little knowledge of distilling and none at all of grain mash, however this thread was started with Brendon's question of seals, which to the best of my ability I have tried to be helpful.
Now lets look at a recirc pump. You would need to have an inlet and outlet port in your boiler, the pump would need to be capable of pushing (please excuses my ignorance) I would imagine quite a thick pulpy mash, it would need to handle the temp, it would need to be made of alco friendly materials, it would need to have a fairly sturdy sealing system and it would wear. No doubt there is equipment on the market that could fill these requirements but I would imagine it wouldn't be cheap. Of coarse that is just my view.
Cheers Mick.

Hi Brendan,
I have just sent an email off to my china contact for 16x13mm round neo magents which I intend to use for 3 phase motor conversions for wind turbines. Now I can machine up a weld in casing out of SS for a magnetic drive if you want, if you are interested I can do a cad drawing in the morning and talk with my contact about seals used in an alcoholic nature. I do remember viton seals are high temp but as far as leaching into vapor well that needs research. Anyway if your interested let me know and I will design that block for what you need.

Cheers Bryan

Of course I thought the boiler we were talking about was a still boiler and not a boiler for doing AG. Hence no mess, no fuss.

Hey guys,

All good discussion. Mech, I was referring to a still boiler which would be loaded with think all grain mash (as the pros do it). Bryan, I can't say it's something I'm actually going to do now, but just a point of interest...I'm. Ore than hay with my straining method now; it gets the job done. Your wind turbine motor sounds interesting though, I just finished writing my thesis on 3 phase induction machines in certain applications :-B

put the shaft up through the bottom, then you only need to worry about a liquid seal.