Maxi110 cooler meets Grainfather Conical Fermenter

[chris2012]

I'm thinking of having a play with my maxi again sometime for controlling fermentation temp, I was just reading
https://www.probrewer.com/library/refri ... ut-glycol/

I'm thinking using a pressure bypass valve you could then use the maxi's pump output directly and not need a water bath.

[Jef]

This is what I am doing, using the Maxi python pump to send chilled fluid round the fermenter, but you will need to replace the Maxi's built in ice bank thermostat. The supplied 'stat is very simple, it actually just measures water resistance - which increases when ice forms, so the suppled 'stat cannot be tweaked to different temperatures, it only switches the chiller off when solid ice forms.
The 2 caveats that you might want to think about are
1) volume, I used 3/8" line plus the volume in the fermenter cooling jacket, a total of something less than 1 Litre.The Maxi 110 takes 4 or 5ish Litres total, so when the python pump turns on the liquid level drops significantly in the Maxi. This has not caused problems for me, works effectively and when the pump turns off the coolant drains back into the Maxi. If you required longer python lines or larger fermenter jacket volumes then you might need to think about one way valves so you can keep a larger volume of coolant than the Maxi has and nothing drains back into the Maxi when the pump switches off.
2) agitator, the python pump has that little impeller on it which helps circulate and this chill the coolant more efficiently. The default Maxi setup has permanent power to the pump/agitator. In my setup the agitator & pump are only active when the fermenter is asking for cooling. Again this has not caused problems for me, if I set the target temp to 12ºC the chiller gets there, turns off, then the temp may drop 1 or 2 more degrees as the temps equilibrate.
pressure bypass valve? not sure where that may fit in?

[guypettigrew]

I remain completely confused! What's wrong with the way I do it? No modifications to the Maxi needed, ice cold water available all the time and a permanently filled and closed system.

Guy

[chris2012]

I don't think there is anything wrong with the way you do it, this is just a different idea, based on the diagram I found.

What I'm thinking of is leaving the maxi on all the time, and not adding a temp controller to it or modifying it.

Then taking the output of the pump on the maxi to the fermenter, with an electronic valve on the fermenter to control when the cold water can go through it and back to the maxi. And using a pressure bypass valve to return the cold water to the maxi, if the fermenter valve is closed.

[guypettigrew]

Ah, now I understand! Sounds like a really neat way of using the Maxi. The by pass valve is a good idea, as is not modifying the Maxi.

The only thing I'm not sure about is whether there will be enough water in the ice bath to fill the system. But I suppose it'll be easy enough to top up the Maxi when you first run it to make sure there's enough water.

Have fun with it!

Guy

[PeeBee]

… And using a pressure bypass valve to return the cold water to the maxi, if the fermenter valve is closed.

Not quite sure about the purpose of this? If it is to prevent over-pressure of the piping when a valve routing the outflow to the fermenter is closed, I do not worry 'cos the pressure those Maxi pumps will generate is pretty small. It is why my solution introduces additional pumps; to get a better flow to the cooling jackets. Although maybe the agitator function needs the return flow to be effective?

I use the "Blowtie Spunding Valves" for automated pressure relief. Such as here:

In this case the "pressure bypass valve" redirects the flow if the dispense pipes are not open for cleaning (the "bar's" CIP setup). But the pump in this case is a diaphragm pump and perfectly capable of reaching pressures that will burst pipes, disengage pushfit fitting, bust fittings, etc.. I know, because I used to get regular soakings! Note these "Blowties" can be used "wet" as can the "regulators" of a similar design. But used "wet" they exit the world of pneumatics and enter the world of hydraulics (e.g. a "regulator" becomes an automatic "flow control" - I'm using them with keg taps). Those devices were not designed for the brewing market, but have been repurposed from other, hydraulic, applications. Hence they work "wet".

[chris2012]

I was thinking of using the pressure bypass valve so that the return flow is effective for the maxi.

This is the valve i was looking at, at the mo' -

https://www.anchorpumps.com/1-2-13mm-br ... pass-valve

I do have one of those spunding valves, didn't think about using that, sounds an interesting idea.