BCS 2 Vessel No Sparge Garage Brewery Build

[BrunDog]

I assume by looking back at your hardware and above, that the green trace is the probe down in the MLT next to the element? And that the blue trace is a probe somewhere on the feed back into the MLT? Which is the probe feeding the PID?

Also, one quick recommendation would be to insulate your MLT. Way too much heat getting lost there given your temps. Also you need to recirc as fast as your false bottom or bag will allow.

 

[poptarts]

Green is in the MLT below the false bottom. Blue is return. Blue feeds the PID. And yea I have some reflectix lying around I should probably hit both MLT and BK with it, no need not to. Fair point on recirc speed, ill try to pick up the pace with it next time, that would allow less time for it to cool while outside the tun.

 

[BrunDog]

First, confirm that you inserted some conductive gel at the tips of your thermowells and the thermistors are at the tip. They need to respond quickly... within a few seconds I would say. If you put your fingers at the tip of the thermowell... does the temp start to rise quickly?

Second, can you estimate your re-circulation rate? It needs be as least a 1.5 gals a minute... the more the better so long as you don't get a stuck mash. If your efficiency is good, consider opening up your mill a tad.

Blue seems correct as the driving probe but there is an awfully large temp drop between green and blue (3-4 degrees). This makes little sense as the element should be heating the liquid up hotter than green reads (assuming fast enough flow rate) and then a small decay as heast is lost through piping and pump, then read by blue. Unless green is sensing heat coming off the element (I assume its the probe pointed toward the element in the pics?). Would be better if green were further away from the element so it is not influenced by it, but I understand it is not in the PID loop.

I dunno... everything is pointing at recirc rate to me right now.

 

[BrunDog]

I just went back and looked... you are using a bag for your mash/false bottom? You are not using that snorkel gig in the MT, correct? That would pose a big problem there because the liquid would bypass the element. Can you post a pic of your MT inside?

 

[poptarts]

First, confirm that you inserted some conductive gel at the tips of your thermowells and the thermistors are at the tip. They need to respond quickly... within a few seconds I would say. If you put your fingers at the tip of the thermowell... does the temp start to rise quickly?

Second, can you estimate your re-circulation rate? It needs be as least a 1.5 gals a minute... the more the better so long as you don't get a stuck mash. If your efficiency is good, consider opening up your mill a tad.

Blue seems correct as the driving probe but there is an awfully large temp drop between green and blue (3-4 degrees). This makes little sense as the element should be heating the liquid up hotter than green reads (assuming fast enough flow rate) and then a small decay as heast is lost through piping and pump, then read by blue. Unless green is sensing heat coming off the element (I assume its the probe pointed toward the element in the pics?). Would be better if green were further away from the element so it is not influenced by it, but I understand it is not in the PID loop.

I dunno... everything is pointing at recirc rate to me right now.

there is thermal paste at the end of the probes. I will confirm they respond fast to the touch but I believe they do. The rate is about 1/4 open on the pump, I can measure but I would think its at least a gallon a minute, will double check and try to speed it up regardless. The green probe is about an inch from the element so it definitely could be reading hotter than the majority of the mash. I will hit it with some insulation as well when I'm out there installing the new chiller. And then we can see what happens from there I supose. I would assume faster recirc will tighten the difference in temp but not sure that it will do anything for the oscillation though. I think I probably need to drop D and or I more.

 

[poptarts]

I just went back and looked... you are using a bag for your mash/false bottom? You are not using that snorkel gig in the MT, correct? That would pose a big problem there because the liquid would bypass the element. Can you post a pic of your MT inside?

inside of MLT is just like BK, no snorkel. then there is a false bottom I made out of a lid that has lots of 1/4" holes in it that sits above the element. then I line everything with a bag. I should be able to recirc pretty fast without getting stuff stuck.

 

[poptarts]

MLT, probe well on left.

 

[thekraken]

The faster the better as far as the temp control goes, here is a shot of my controller running at about 3.5-4 gal/minute if I remember correctly:

(Useless data as far as practical use goes, flow too fast)

But @Brundog, at what flow rate do you need to worry about channeling? I personally aim for about 1 to 1.25 gpm on my system, maybe I should step it up.

 

[BrunDog]

OK. What voltage is that running at? 120VAC would be better (240VAC like putting a jet engine on a Cessna - **** gets out of hand quickly) but with the ambient temps it may not be enough.

 

[poptarts]

OK. What voltage is that running at? 120VAC would be better (240VAC like putting a jet engine on a Cessna - **** gets out of hand quickly) but with the ambient temps it may not be enough.

yea it runs on 240, thats why the max pulse down to 25% appears to have helped a lot.
@thekraken yea those are a lot tighter temps than mine.

 

[BrunDog]

But @Brundog, at what flow rate do you need to worry about channeling? I personally aim for about 1 to 1.25 gpm on my system, maybe I should step it up.

I think that's good. Probably can't get to 2 GPM unless its a big FB. As long as your temps are consistent, it's tuned and running well. No need to chase silly ideals.

 

[thekraken]

@thekraken yea those are a lot tighter temps than mine.

That's only because of the really fast flow rate, I was just illustrating that the faster the better for the controller. But you have to balance flow rate with avoiding a stuck mash or channeling.

 

[BrunDog]

I love me a bottom drain but I think an issue is probe is located above the drain. The liquid flows down along the sides of the MT and flows along the dome and out the drain without getting heated by the element. In addition, with a slow enough flow rate, the liquid that is heated by the element actually rises, setting up a current, in theory, like this side view:



One way to test this would be to run with just water, at the recirc rate you use, and without disturbing the water too much, drop in some food coloring drops with a long pipette. Try from about element height along side. Also try from about element height about halfway between side and center. See where the drops go. Another test would be to run with just water, as you did with the mash (same recirc rate), and see if you get the same temp variation/oscillation. Then, max out your flow to maximum, and see what you get (shorter peaks/faster oscillation). Yet another test would be to run with just water, as you did with the mash, and use an accurate temp probe and snoop around to see what are the different temps throughout the vessel.

This make sense?

 

[poptarts]

I love me a bottom drain but I think an issue is probe is located above the drain. The liquid flows down along the sides of the MT and flows along the dome and out the drain without getting heated by the element. In addition, with a slow enough flow rate, the liquid that is heated by the element actually rises, setting up a current, in theory, like this side view:

View attachment 327572

One way to test this would be to run with just water, at the recirc rate you use, and without disturbing the water too much, drop in some food coloring drops with a long pipette. Try from about element height along side. Also try from about element height about halfway between side and center. See where the drops go. Another test would be to run with just water, as you did with the mash (same recirc rate), and see if you get the same temp variation/oscillation. Then, max out your flow to maximum, and see what you get (shorter peaks/faster oscillation). Yet another test would be to run with just water, as you did with the mash, and use an accurate temp probe and snoop around to see what are the different temps throughout the vessel.

This make sense?

Yea I can definitely believe that some channeling is happening. These are some good ideas although it will be hard to test the dye ones with the false bottom in place. Sounds like I have to plan some water play time this weekend. I need to tune the PID anyway so might as well right. Good to know why stuff is happening the way it is. But like you said earlier, it all comes down to how fast i can recirc.

 

[BrunDog]

I think if you insulate the heck out of the MT (including bottom if possible) and recirc as fast as possible, your problem will be mitigated. If you installed a dip tube that raised the drain up near/into the element, the problem would be solved even more. Maybe a design like your snorkel but a rubber stopper instead of the scrubbie and put the parallel portion inline with the element with maybe a couple of tees inline pulling liquid from above it.

 

[poptarts]

I think if you insulate the heck out of the MT (including bottom if possible) and recirc as fast as possible, your problem will be mitigated. If you installed a dip tube that raised the drain up near/into the element, the problem would be solved even more. Maybe a design like your snorkel but a rubber stopper instead of the scrubbie and put the parallel portion inline with the element with maybe a couple of tees inline pulling liquid from above it.

I could get down with some chimney thing to help it pull from the element. Ill see what I can slap together.

 

[crane]

Mash from last brew day; setpoint 154, blue is return, green is MLT. Still has oscillation but nowhere near last time.

I knew it was going to be a bad day when my bcs was reading 2 degrees in the garage. The short version, everything was frozen, so frozen one of the ball valves broke. was able to take it apart and mend it during the mash. Lines apparently didn't drain fully so they had sections of solid ice in them. Ended up doing an hour or so whirlpool because I couldn't thaw the chiller for the life of me. Decided to just rack to carboy and chill in icy water. After cleaning up and taking the chiller inside and thawing it fully sad news was found. There was water left in the outer coil of the chiller that froze and appears to have collapsed the inner tube the wort runs through. Pretty sure its ruined beyond repair. I will cut it open to make sure but sadly I think its dead. I cant blow air through either end, its sealed shut. Here is a pic of the fallen trooper. Loved this chiller, it always worked perfect, 1 pass and done.

Good news though, Austinhomebrew has a pretty sick deal on counterflows so I picked one of those up. Should be a lot easier to mount and drain. And I learned I think in the winter I need to take the hoses off and let them fully drain, and store the ball valves in open position when not in use. So yea any tips on how to tighten up the PID more or is this about as good as I should expect when its about 150 degreese colder ambient temp.

You really don't need the derivative for how slow our systems respond. I would suspect that this is causing your oscillations. I would set it to 0.1 to disable it.

 

[JonW]

Mash from last brew day; setpoint 154, blue is return, green is MLT. Still has oscillation but nowhere near last time.

There's actually not much oscillation going on there. Your blue graph runs from 153.5 to 154 for the first half and then from 153.5 to 155 for the second half. A little overshoot there, but that's still not bad at all. Anything different going on in the second half of the mash over the first?

 

[poptarts]

There's actually not much oscillation going on there. Your blue graph runs from 153.5 to 154 for the first half and then from 153.5 to 155 for the second half. A little overshoot there, but that's still not bad at all. Anything different going on in the second half of the mash over the first?

Yea I bumped up the D value at 30 minute mark to see if it would help, but it appears to have done the opposite and made the wave length a bit longer.

 

[JonW]

I don't think .5 degree swing is bad at all. Is your setpoint is on the MLT return (blue line) or the MLT (green line)? Have you calibrated the temp probes?

Both (initially) only exhibit a .5 degree swing, so for me, the next goal would be to bring the two measurements inline with each other (as close as possible). That might be hard given that your plumbing is sitting in extreme cold temperatures right now.

 

[BrunDog]

For a large scale system, the temp should not vary that much IMO. Also, what is the actual mash temp... 153.5, or 158? Makes a big difference, especially if you have lots of stratification in both planes. Properly tuned, this should be holding dead nuts at the desired temp. The instability is also concerning to me, though he did say he changed D, as is the difference between those probes. I think a few tests as noted above and he will have the answers. No doubt this system would be responding very differently at 80 degrees ambient.

 

[poptarts]

Help is on the way

View attachment 1452132302491.jpg

 

[TrickyDick]

I have one of those. Works great. I use for cooling. What are you planning to use it for?

By the way, how are you making your brewing calculations with no sparge? In effort to achieve dream of possible weeknight all-grain brew session, as well as to shorten overall brewing time, I am wondering how you calculate everything. I use BeerSmith and I'm not very adept at the mash design section.

TD

 

[poptarts]

It's my new chiller. A couple posts up I explain how mine broke. I use beersmith to calculate everything recipe wise.

 

[TrickyDick]

It's my new chiller. A couple posts up I explain how mine broke. I use beersmith to calculate everything recipe wise.

Ah, I see it now. You'll love this one just as much if not more. In FL, one pass cooling isn't a practical reality for most. I recirculate with my chiller during whirlpool, and seems to work quite well on the one and only batch I've dont with my new setup.

TD

 

[poptarts]

Good to here. Hopefully it's the last chiller I buy. I like that it's alot smaller than mine that's for sure.

 

[poptarts]

Insulation in place, turned out pretty decent I think.

Started ventilation system, hole drilled, still waiting on a few pieces before I can assemble and permanent mount.

Chiller fitted and sudo mounted, seems like its going to work good.

Did more tuning with PID, here is graph as I dialed it in more, set temp to 155 then 157, pretty decent all things considered. same flow rate, just with insulation and better numbers.

 

[30Bones]

How do you like that sight glass? I plan to get one once I get back to recirculating my mash.

 

[TrickyDick]

I love it when a plan comes together! Great job. How is first batch coming along??

TD

 

[poptarts]

How do you like that sight glass? I plan to get one once I get back to recirculating my mash.

Its awesome, I have some pics of it on my first brew day a few posts back. Really cool to watch the wort convert.