Dedicated Herms Guide, Problems And Solution Thread

[evoo4u]

Have a look on Google about self regulating and non-self regulating systems and decide for yourself what we have as brewers.

Wow - this brought up some excellent resources - thanks! Among others:
http://www.controleng.com/single-article/fundamentals-of-integrating-vs-self-regulating-processes/c4511ec71b114a19097c92b5e3276089.html

I can see why we don't NEED integral action, also why trialling it in a steady-state system (constant volume, flow, and SV temperature with constant heat loss to atmosphere) worked. The integral never got to a "windup" stage, but it wasn't doing anything that couldn't be done with just P (and D as reqd).

I guess I thought that because the Auber controller goes into 'hold' mode while ramping (if time is set to one) until PV is within one degree of SV (on my setup), that integral wouldn't accumulate much. But as I understand, it's simply not needed in this process.

So, back out to the shed, and do another trial with varying P gain, and observing the results, introducing D as necessary.

Thanks again. (Sure helps to brush out the cobwebs )

EDIT: I probably had a bit of the 'Window's Font' syndrome* and thought that because I had a PID controller, I just had to use all three to get my money's worth.

( *when the computing age advanced from pin printers, and Windows gave access to a gazillion TT fonts, some folk thought they just HAD to use them all!! )

 

[fraser_john]

After an earlier post about overshooting etc, found I had K-type thermocouples, so ordered a couple of these PT-100 bad boys and just added to the system, reconfigured the SYL-2362 and the SYL-2352P (ramp/soak) PIDs. One on SYL-2362 was accurate at 45c out of the box, SYL-2352P needed a 1.1c offset and it was spot on as well.

Brewing tomorrow morning.

 

[Nebes]

Hi all just wondering were everyone has put there temp senser on there HLT to control there element?
On the return flow or on the outlet of the pump?
Cheers in advance

 

[Stunts]

I have an old 50 litre keg I have converted, my temp sensor is situated half way up the keg

 

[Rosscoe]

If you mean you're running your HEX in your HLT, I'd measure at the return to the MLT. If it's just purely a HLT, midpoint would sound about right. Get it far enough away from your element.

 

[Nebes]

Yeh it's just a HLT I was thinking I would put a t piece as it returns back into the HLT or is there no point having it recurculating whilst it is heating up for the strike waster and the sparge?

 

[MastersBrewery]

Recirculating your HLT while heating is the best way to get uniform temps, just have the return same as your kettle whirlpool.

 

[Nebes]

Yeh thats what i thought just need to know were to put the temp senser to turn on and off the element was either thinking on the outlet of the pump or just before the return that goes back into the HLT

 

[fraser_john]

Yeh it's just a HLT I was thinking I would put a t piece as it returns back into the HLT or is there no point having it recurculating whilst it is heating up for the strike waster and the sparge?

Recirculating is an extra cost in terms of pump, plumbing etc. I just an old windshield wiper motor with a paint stirrer to agitate the HLT contents. Works fine and was less that $20 all up.

 

[TheWiggman]

I have convection currents on my side. I set the HLT to 78°C and my HERMS to 80°C. Any fluctuations in the feed temp are accounted for by loss between the HERMS and HLT which is then warmed up appropriately.
This applies to fly sparging.
However, I'd argue the temp of the sparge water is less relevant than other temps because as long as you're in the 75-80°C range, it shouldn't have any impact on the final product. I've never tasted a beer and gone "hmm... sparge temp was 2 degrees out, you can really tell."

 

[philistine]

Hey Beer Dudes,
I found a guy selling stainless steel coils to use as chillers - they're 10m long coils of 8.5mm internal diameter. I think they're meant for running kegged beer thru an esky or something to chill for serving (sorry, Im a very basic brewer with some pots and an esky mash tun - my familiarity with gear is very limited)

anyway, just wondering if they'd be suitable to use in an external HERMS HEX? Is the tubing too narrow? Too long?
They seem really cheap at $55 and come complete with compression fittings....

 

[CoxR]

Hi guys I have spent a good amount of time reading through various builds on various types of systems and am settled on a HERMS rig.
I have all the pots pods's and valves I think I need. 100l kettle 98l mash pot and s 78l pot for sparge water. I am looking to get 3 cubes per brew
My questions are regarding the herms element and coil. I was going to buy a Herm-it coil from online brewing supplies and use it in a kettle as I have seen on this forum, is this adequate for my needs? For the boil kettle is one 4800 watt element better and two 2400 w elements?
I assume that 4800 should be enough to boil 60-80 litres of wort.
Thanks guys.

 

[Moad]

Are there any HEX pre made that would be big enough for a 1 BBL batch?

I have made a HEX but haven't been able to test it out just yet. In case it just doesn't work is there anything out there? Not sure the herm-it coil will cut it...

 

[Mardoo]

Not that I've heard of or could find. The most pre-made bit I've seen is the coil. Hardest parts about making HEX's are wiring elements and stopping leaks, so I reckon with the help of a sparky your issues will be few. You look that HEX in the eye with a stainless steely gaze and tell it who's Daddy!

I mean, I, a complete novice and mechanical dimwit, managed to build one up in a few hours, so I'm guessing you'll be OK.

 

[CoxR]

Are there any HEX pre made that would be big enough for a 1 BBL batch?

I have made a HEX but haven't been able to test it out just yet. In case it just doesn't work is there anything out there? Not sure the herm-it coil will cut it...

What is a 1 BBL batch?
I think after looking through posts in this thread again I might be better to make a coil from copper I have rather than buying a HERM-IT. If I cram as much copper as I can into a tube with a volume of 5 liters the amount of water should be about 3 liters a 2400W element should be fine, Correct?

 

[Mardoo]

1 Barrel Batch. In brewing this usually refers to the US barrel, which is 119L.

I was going to say Moad that I've been thinking of making one in a corny keg for a 400L system.

Edit: I guess a plate chiller could be used as a pre-made HEX. I mean, it's a heat exchanger, not a chiller. Haven't heard of anyone doing that in brewing but it's dead-common in water heating and biodiesel production.

 

[Moad]

Mardoo I think it would then come down to flow rates, you'd need a big pump to ramp 400L!! I'll wait and see what the one I made can do...

 

[MastersBrewery]

Mardoo I think it would then come down to flow rates, you'd need a big pump to ramp 400L!! I'll wait and see what the one I made can do...

If your just short. I wouldn't risk clogging a plate chiller, but you could use one of those stainless convoluted cfc's with your hlt as a booster. I'm still thinking of going back to 3v 100L and I was thinking this with a 3600w hermit.
MB

 

[Moad]

Could hook something like this up to run just during ramping. Use the MT temp probe to control a separate brown pump circuit during ramp. Using BCS and I have a spare output. This could be a good option, could also be a simple coil in the HLT rather than CFC. I also happen to have a spare electric valve I could use for this! Cheers MB

 

[Mardoo]

Mardoo I think it would then come down to flow rates, you'd need a big pump to ramp 400L!! I'll wait and see what the one I made can do...

Yep, I'm thinking 5/8" and possibly 3/4". Even 5/8" is a hell of a lot faster than 1/2". We'd easily cut 2 hours out of the brew day. Not that it gets pulled out that often...