Fermentor Crashing Problems

[biglakebrewing]

Hello,

I've had some fermentor issues with my glycol system this week. My wort goes in at ~72F, my JCI419s are set to 68F (1degree dif). The glycol is set to 26F. I've come in the following morning to a fermentor at 55F and crashing on my last two batches. The last batch came back up after I manually turned off the glycol to the tank. The beer came up to 68 and I turned it back on. Everything was fine after that.

Any ideas why this may be happening? The glycol is plumbed with PEX, and I can't recall the relay unit we are using, but I will check that shortly, and edit the post.

Thanks in advance,

Travis
Big Lake Brewing

[krichard]

Hello,

I've had some fermentor issues with my glycol system this week. My wort goes in at ~72F, my JCI419s are set to 68F (1degree dif). The glycol is set to 26F. I've come in the following morning to a fermentor at 55F and crashing on my last two batches. The last batch came back up after I manually turned off the glycol to the tank. The beer came up to 68 and I turned it back on. Everything was fine after that.

Any ideas why this may be happening? The glycol is plumbed with PEX, and I can't recall the relay unit we are using, but I will check that shortly, and edit the post.

Thanks in advance,

Travis
Big Lake Brewing

I had the exact same problem last week and it ended up being the solenoid valve not closing all the way and allowing glycol to flow through the jacket. I replaced the valve and all is good now.

[biglakebrewing]

I had the exact same problem last week and it ended up being the solenoid valve not closing all the way and allowing glycol to flow through the jacket. I replaced the valve and all is good now.

The valves are only 2 months old, and it's happened to two different fermentors now. I don't understand how we could be damaging them. We are using the valves in the link below (Model @W-200-2N)

http://www.dudadiesel.com/choose_item.php?id=2W20020N

[Luch15]

I have read similar threads here about this happening. Knock on wood I have never experienced this issue but from reading the other threads it seems that many of the instances were due to foreign matter such as plastic or metal shavings from pipe cutting or other debris holding the solenoid valve slightly open when the plunger came down on top of it. If you don't have a good strainer on your system maybe check for this kind of debris in your glycol.

[TiminOz]

solenoids

Often with a new system there are small particle in the glycol jackets and glycol piping leftover from manufacturing and installation. These bits can get trapped in the diaphragm of the solenoid. All you need to do is take apart the solenoid and rinse the parts with water. You will most likely see the little chunk that has caused the problem. There are only a couple parts in the solenoid so it is really hard for them to actually break.

The valves are only 2 months old, and it's happened to two different fermentors now. I don't understand how we could be damaging them. We are using the valves in the link below (Model @W-200-2N)

http://www.dudadiesel.com/choose_item.php?id=2W20020N

[gbrower]

We have had similar issues. We had some old valves go bad and then we had some new ones not installed correctly. The ones that were not installed correctly were over torqued on by the plumber. They were ball valves so I don't know if you would have this problem.

[biglakebrewing]

We may have this figured out. The thermowells aren't packed with transfer grease. There is a differential between the 419, and the analog thermometer on the tank when we initially cool our wort to 68.

We think it's just a lag in the 419 temp probe reading the actual temperature because of the air gap. So the 419 keeps the valve open until it's thermometer hits 68.

Thanks for your help with this.

[Gunrunner]

I would check the flow of glycol your solenoid control valves as many have stated may have some debris in them (could be as small as a piece of sand). You should have a secondary vale that you can close to see if you still have flow when your control vales are closed. Once you determine that then you can test other ideas.

[dick murton]

You haven't used vehicle coolant glycol have you? One of the breweries I am in contact with did as it was cheaper than "proper" refrigerant glycol and had awful trouble with bits, thought to be the reaction of the copper piing with the glycol. They drained, flushed out and replaced with refrigerant glycol, and have had no problems since.

Failing that as already noted - bits of grit. If your takeoff point is right at the bottom, try moving it to a few inches (ahem - see my comment about metric in another thread) above the absolute bottom of the tank to allow some sludge settlement space.

[eskreen]

If your having a delta issue between temps get a cord cinching 1/2" adapter and put tension on the cord as you tighten it down on the RTD cable. Make sure it squeezes tight on the cable! An RTD should be "bottomed out" if you will. I've never used grease and have never ran into a problem.
Also diaphragm solinoids if anybody uses them are uni-directional. Installed backwards they will not be able to shut flow off.
I run expansion PEX as well and Wirsbo engineers said their product would hold up at a 1:1 glycol mix. The only difficult part is getting it insulated well.


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[kugeman]

Do your solenoid valves require a zero pressure differential? If not you could be getting fluctuations in your pressure causing them to not close all the way. It can be very inconsistent and it may only effect certain tanks depending on where they are located in your glycol loop. I used to have this problem all the time and ended up swapping out all of my solenoids for the proper ones.

[TGTimm]

J419s

I use several J419s in our HL system. It is normal to see several degrees of difference between the readouts, with the probes located within inches of each other, and bedded in conducting compound in the thermowells. The J419s are great little thermostats, but I wouldn't rely on them for fine temperature control for a fermenter. We use the Fuji PXZ series PID thermocontrollers, which use a three-wire RTD sensor. The advantages of the 3-wire RTD are many, but of these, comparability and self-correction of wire length are perhaps the most important for us. The RTD element itself is accurate to something like 0.01%, making readings from one sensor very comparable to any other. The three-wire rig self-compensates for wire length and changes in conductivity due to temperature of the wire (check out Wheatstone bridge for the reason this works--one of the three wires is a compensating leg of the bridge). J419 sensors are not as accurate, nor do they self-compensate for wire length or wire temperature.

We try to control our fermenter temps to within 1 degree F at times during the ferment. I wouldn't count on anything but a three-wire RTD sensor linked to a PID controller for this.

Oh, yeah--as mentioned above, it is very important that the temperature sensors, whatever kind, are fully seated in the thermowells. The RTD probes we use have a spring-mounting that keeps them fully seated, and are each fitted to the length of the individual thermowell, as well as being bedded in thermoconductive compound. These probes are not exotic, and most controls distributors can source them for you. Prices are higher than simple thermostats, but not ridiculous.

I'm not knocking the J419--we have a half dozen or more in use--but I wouldn't use it for a professional-sized fermentation system. The risks and consequences are just too great.

[patbrewer]

Yeah, what it seems to come down to is "get to know your system". We use Johnson 419 controllers on our FV and BBT and make beer, at least, free from fermentation flaws. We have chosen to avoid solenoids and invest money in what seems to be a better choice; actuated ball-valves. As is, what means one chooses to measure is less important than consistency in how one measures as well as your ability to taste the results and make adjustments; beer is organoleptic after all.

[TGTimm]

.... We have chosen to avoid solenoids and invest money in what seems to be a better choice; actuated ball-valves....

Our older fermenters use Red Hat solenoid valves, which work, but... our new fermenter hall uses pneumatically-actuated poppet valves, which, like your actuated ball valves, are full-port and resistant to fine debris, which tends to cause the diaphragm-type solenoid valves to stick open.

[patbrewer]

Yeah, we looked at the poppet valves too but have no air to work with. As you were saying it is the full port that matters. We have friends who put in a glycol system several months before we did. They went with GW Kent solenoids and warned us about theirs sticking already. The Red Hats are supposed to be better and capable of rebuild but end up being similar in price as most full port options.