Advice on solenoid valves and PIDs

[unclepumble]

Therefore my point is that if your using Herms you want to control the heat giving medium more accurately, rather than using a control valve or bypass loop, to ensure a consistent temperature in the mash and thus ensuring a more repeatable brew, that's why most people that go down the HERMS route, measure the temperature of the wort and hence control the PID using a PT100 on the outlet of the herms unit, as opposed to control from a PT100 in the mash.UP

I think I understand the point you're all driving at, and maybe getting 'crossed wires'. Please don't get offended folks. The intention was to use a PT100 in the outlet of the herms coil, before it enters the mash tun.

Can I just point out that several brewers I know who have gone down the HERMS route with the HEX in the HLT have abandoned the project. The issue is that the thermal mass of the liquor in the HLT the element cannot heat the liquor fast enough to compensate for the required temperature changes to the wort.

This is why people like Vossy, Seveneer and myself have gone for much smaller vessels as our HEX because the smaller amount of liquor responds much more quickly to the required heat demands.

I think Aleman has a point here, the limitation is the efficiency of heat transfer between the heating source and the circulating wort. My plan was to use a length of 10mm copper in the HLT at ?>77deg C. Perhaps as he says, this is not efficient enough a transfer to increase mash temperature in the timeframe required for a 'mashout', regardless of the flow-rate through it.
My plan was more for a maintenance of homegenous mash temperature, but would obviously like the flexibilty to try stuff out. Its till a 'pipe dream' pardon the pun.
Peace out.
PJ

PT100 on the outlet of the herms chamber :thumb:

Peace out:- No Worries :thumb: sorrry to all If my response sounds aggressive at all (one of my faults sometimes) it wasn't meant too if it is.

The Big boys aim for a temperature rise of 0.5deg C per minute, so if you can design a system that can deliver that you will be good to go.

UP

 

[drut]

Unclepumple, well yes, you have missed something - I covered denaturing in my second post in this thread.
And yes, using a PT100 in the return, as Pjbiker proposes, and I already use on both my systems, is obvious, the thermal inertia of the volume of the mash makes feedback loop control near impossible.

"Therefore my point is that if your using Herms you want to control the heat giving medium more accurately, rather than using a control valve or bypass loop, to ensure a consistent temperature in the mash.."

I am not proposing an uncontrolled valve or bypass loop. - this is why, with the greatest respect, I still think you are missing the point. There is no reason why we cannot control the flow/volume through the exchanger instead of the temperature - just as accurately.

There obviously need to be three modes of operation:
ramping from 50-66C with the exchanger output below say 69C (might need higher flow rate)
steady state, again with low delta T, higher flow might be needed
ramping from 66-77C where the exchanger output could reach 82C

I have already stated my doubts as to the use of on/off valves alone.
Maybe it will need linear control valves.
There may be a need to control flow to some extent as well.
Maybe it will need two exchangers of different lengths controlled by two valves.

Please do not assume that everyone else is an idiot - some of us might well be even better qualified and experienced than you and are willing to try new or different ideas, otherwise I would not have a several hands full of patents.

Following my first post of yesterday, and as a result of the somewhat hostile responses, I have ordered a number of Solenoid Valves, PIDs, SSRs, PT100s and a solar pump to build a "proof of concept".
It will take a couple of months for the things to arrive from China and for me to have time to build it up.
I will post back here, whatever the results, so that if it does not work it will save others trying.
And if it does not work, I will apologise profusely for wasting the time of forum members.

However, should this method be made to work, it will be less expensive, simpler and safer for the typical brewer - that is something worth aiming for.
Finally, I came to this forum because the members seemed to treat each other politely and with respect.

 

[drut]

This is my current idea and probable starting point:


The row across the middle are valves, the restrictors probably screwdriver adjusted, the others lever/ball.
Sparge and Underlet are shown for completeness.
Heated full flow would be open and Bypass stop flow closed for mashout.
The pump will start as a "solar 12W", but I might use a Speck MY2-8000.
The whole thing would be ripe for a bit of logic control, replacing the manual valves with solenoids.
If you have any constructive comments, please post, otherwise please wait until I have made a fool of myself (or not).

 

[unclepumble]

Drut,

Please don't take my comments as a personal attack they were not intended to be, and I have not questioned your academic abilities in any way shape or form.

I did miss the denaturing part of your post must have been speed reading or SWMBO or kids pestering me when I was read the post so please accept my appologies

You might have problems with the hydrodynamics - bang on/off of the two valves might shake things about a bit and possibly upset the pump.
I can see other possible problems with time constants but it would be a question of suck it and see - Good Luck!

You can remove a lot the problems of hydrodynamics (water hammer) if you fit a damper vessel on the wort circulation circuit between the pump and the valve, there are plenty about for potable water and are inexpensive, however i wouldn't like to use one for a mash to be honest.

Trying to be constructive:

The system you have planned should work just fine but will be a real pig to clean easily with all those valves and routes.

It would be far better but evidently more expensive you if utilise a two way proportional control valve and a flow meter, using the outlet temp and flow readings into an analogue card on a small PLC and programming a routine to control flow and temp, and don't bother with a PID (not my cup of tea though I am afraid, I would just ask someone I know to do It for me,)

However we are talking home brewing 5-10gallons of beer in a shed/garage or back yard, for fun not an 800 bbl/per brew set up, so why not just keep it simple.

However I will be interested with what ever you come up with, and applaud any new innovation in terms of home brewing, as long as it is within reach of the common man on the street. :clap:

Good Luck, with your endevours you obviously have a lot more time on your hands than me, :thumb:

UP

 

[drut]

Thanks Unclepumple, I hope I can call upon your experience if this thing is ever to be useful!
I am hoping that a damper would be unnecessary as it would add to cost and complexity, I am also hoping that some of the valves might be lost, but I fear there may be more, so cleaning will be an issue.
I do not want to use a PLC/PC/Microcontroller as this would escalate the project out of the hands of most users here. (Also my coding is so rusty as to be damn near useless...)
I propose a PID because (Pjbiker did! and) they are relatively cheap, easily available and many here have experience of them. It, and its sensor, will be used in a very similar way to the RIMS/HERMS systems shown here and elsewhere so examples can be followed.

I am absolutely confident that this could be made to work - if time, cost and complexity were no object.
It is clearly not the way either the "Big" boys or the "Micro" boys do things, but they do not batch sparge either!
Different scales often mean different techniques.
Whether it can be done so that others here might benefit remains to be seen!

I am only considering a brewlength of about 25 litres and my experiments will probably be using plastic vessels. My first trials with flow rate/heat transfer will be on one of my existing systems.
As you say, this is all academic if it is impractical for the brewers reading this forum.

I think you can see from my "output" that I have plenty of time. I am also used to spending a bit of money to try new ideas - we used to call it the development budget; I now call it fun!

 

[Springer]

I am watching with interest. :?
For me, the way I understand the HERMS idea is to control the temp of the mash tun, quite easily done by a heat exchanger controlled by a pid. simple cheap plumping plus a cheap pid and SSC. Not sure about Druts idea but I don't see that it will it be any better and looks far more complicated and expensive to build ?
i.e. build a simple heat exchanger and the job is nearly done, or is Druts idea more straight forward than it looks, certainly looks for the neck up to me :lol:

 

[Aleman]

Something else you have to be aware of is that you get stratification in the HLT. . . (Sort of aking to using an immersion chiller where if you don't stir the wort chilling takes forever) . . . So you will need some sort of recirculation/stirring device in the HLT.

 

[snail59]

I have been keeping track of this thread and it has re assured me that the 3 tire gravity system is the one for me. This may as well have been in a foreign language I probably would have understood more if it had :rofl:

 

[drut]

Thanks Aleman - I will be measuring the temperature differential in the HLT to find out if it is significant. As I said before, the actual temperature is not important as long as it stays hot enough to add heat to the exchanger coil. The action of the exchanger coil might reduce stratification anyway. (Cooler return from the tun in at the top where the HLT is hotter, carrying heat downward - maybe....). Also, the element will be coming on to compensate for the removed heat, and if that is below the exchanger coil...
I believe I saw a pdtnc post where he uses a solar pump to stir the HLT if necessary.

Springer - no second heater, no SSR on the PID (only one on the HLT if you use one there already). No danger of scorched wort if something stops (that's really a RIMS thing rather than HERMS).
You can get away with a cheapo digital thermostat (eBay £11.90+ £4.90 carriage) for the HLT as long as your element is 10A or less - no SSR or relay there either.
If you are concerned with longer morning warm up times, add a plug in timer. I use these:
http://cgi.ebay.co.uk/7-DAY-PLUG-DIGITA ... 3a5a701063
but mechanicals cost less than £4 inc carriage. On at 05:00, mashing by about 07:30.
No mixing of water and electricity in a separate HERMS vessel, so safer. (Still got water and electricity at the HLT and Boiler, so still plenty of opportunities to kill yourself).
No extra plumbing between the mash tun and HERMS coil, but extra complexity of some valves etc. - a small price to pay?

So in answer to your last line - No building of a heat exchanger, just drop a coil into your existing HTL.
I think it is more straight forward than it looks, I should have left off the sparge and underlet lines and drawn the restrictors smaller!

In summary:
No SSR/relay on the controller PID
No separate HERMS vessel
Similar heat exchanger coil assembly
Same pump, PID controller, sensor
Added complexity of flow control valves
You would be using one valve to control the flow through the HERMS anyway, so if the simplest solution should work (wishful thinking?!) you might need two restrictors, a £6 solenoid valve, a 12V 250mA power supply for the valve and one more ball valve.

Now waiting for a few more LM35CAZ temperature sensors (0.2C) so I can drop a couple of coils into one of my existing HLTs and try some flow rate tests with a data logger. If anyone is interested I can put those results up while I wait for the Chinese bits.

Sorry Snail59 - your post has come in while I was waffling! - I still propose using the HLT higher than the mash tun, so still 3 or 4 tier - it makes mashing in, sparging and tun draining much easier - and when the pumps fail etc etc - you can still make beer!

 

[Springer]

3 tire gravity system is the one for me.

I hope your kit is not like my early gravity system, Snail.
I used this gravity system in various forms for 5 years and produced some very good beer, before getting "sophisticated". I still use the kit shown, slightly modified, for pilot brews. I particularity like the boiler high visibility thermal lagging :lol:

Things needed improving :lol:

 

[unclepumble]

3 tire gravity system is the one for me.

I hope your kit is not like my early gravity system, Snail.
I used this gravity system in various forms for 5 years and produced some very good beer, before getting "sophisticated". I still use the kit shown, slightly modified, for pilot brews. I particularity like the boiler high visibility thermal lagging :lol:

Things needed improving :lol:

I think the engineered brick brewstand beats the high Viz thermal shock restrictor :thumb: :rofl:

As long as it makes good beer who gives a monkeys!
:clap:

UP

 

[snail59]

Springer It's not that far off. Home made FV based HLT. Coolbox Mash Tun and a Burco boiler.

Or is that a 4 tier system as it goes from boiler to FV???.

 

[Springer]

Wouldn't like to judge this one Snail, but one of the systems is a dam close second, for me my coat, UP used the correct term , clinches it, but then again I have to admit you have a full blown singing and dancing, 4 tier set up there. :hmm: :lol:
Once again, UP has the important comment, "as long as they make good beer" I might add "and doesn't fall on anyone" :)

 

[pjbiker]

Hello all,

I told you I'd nicked the idea from somewhere , well here's the link to the american guy's site that it came from. It seems that he doesn't actually leave the valves to look after temperature regulation via PID, 'on the fly' rather a simple temp controller. He's also using 55gal (presumably US so 44UK gal) vessels and 50ft of ?1/2"? copper coil as the heat exchanger.

"I started by hunting on ebay for a temp controller and 2 solenoid valves. After finding them I hooked the valves onto the HLT manifold and put the temp probe into the MLT and the valves click back n forth in order to maintain the temp in the MLT. Worked like a charm right off the bat!"

"As long as the HLT is always hotter then what I'm shooting for in the MLT, all is good,"

Theres a simple narrative of how a brew goes. Worth a look. :thumb:

http://www.lamabrewery.com/System.htm

 

[drut]

Spot on Pjbiker!

It is good to know that there is a system working somewhere.

I am surprised the coil is as long as that, and I suspect that if he left the pump running he might kill all the enzymes eventually - however it does not matter if you kill a few.
Now to see if it can be made to ramp from 50 to 66C in a decent time without killing the enzymes, and then sit there constantly pumping to give the control we expect from HERMS. Then finally getting it up to 77C (he quotes 74C).

As for your original requirement - just maintaining the mash - I am sure we can manage that with a much shorter coil.

 

[Talon_Ted]

what a very interesting thread!

it is always fascinating to see two men at the top of their game arguing over a highly technical subject. it reminded me of the last time i was in court listening to two barristers! though that was a lot less fun as i was having to pay a king's ransom for one of the combatants!

i must say that the level of discussion on this forum is far above the level i have found on another forum (nothing to do with beer or brewing) of which i am also a member. it's therefore considerably more informative and enjoyable.

i am very tempted to build a RIMS in the near future. however as i have only recently progressd to cornies + co2 cylinder, a temp controlled fermentation cabinet (as recommended by aleman) and a brand new 'igloo' type mashing tub from malt miller, i may have to wait a little while to save up.

mark

 

[unclepumble]

Spot on Pjbiker!

It is good to know that there is a system working somewhere.

I am surprised the coil is as long as that, and I suspect that if he left the pump running he might kill all the enzymes eventually - however it does not matter if you kill a few.
Now to see if it can be made to ramp from 50 to 66C in a decent time without killing the enzymes, and then sit there constantly pumping to give the control we expect from HERMS. Then finally getting it up to 77C (he quotes 74C).

As for your original requirement - just maintaining the mash - I am sure we can manage that with a much shorter coil.

I don't see a problem with him leaving the pump running as his bypass valve takes care of the temp control, the enzymes in the wort sitting dormant in the HLT coil will suffer though, when on bypass.
I would have been tempted to put another valve on the outlet of the coil myself to work in conjunction with the inlet valve to the coil.

The system should work ok but I would assume the control is pretty crude it looks like he is using Ktype thermocouple's as opposed to PT100's.

Each to their own though K Types are better suited to heating elements and ovens where a few degrees don't make a lot of difference, therefore I prefer the use of PT100's and PID's.

Correct me if I am wrong (don't think I am) the point of having very accurate control on a herms or rims is,
:-The enzymes are mainly soluble in the wort, and therefore I think that is why the thick porridge is heated in a decoction mash, as opposed to heating the liquid and adding it back to the mash, if the liquid is kept to a minimum less damage to the enzymes. (I'm no expert on decoction mashing though its an art/craft on its own, Aleman appears to be the forum expert, on this technique, and will I'm sure, put me right should the last paragraph be incorrect)

Therefore if you are pumping the liquid in the mash and using that as the medium to retain mash temp, you want to maintain a homogeneous temp in the liquid, rather than heat it higher than the mash temp, and allow the pipework and mash to dissipate the added heat to the liquid wort, to attain a homogeneous mash, hence for the best results on a herms It is advisable to have a very well insulated tun, well insulated pipework, (or silicone hose) small heat exchanger chamber and very accurate PID control.

Any how this subject is getting a little too much like work for me, so will not be adding a great deal more :nono:

Good luck with your builds, whatever method you choose to control your mash, Time for a beer for me :drink:

UP

 

[timbim]

From what I can tell of this system, not that I fully understand how HERMS works, these are my observations. Please do correct me if I'm wrong on any of this, I would like to understand it all a bit more fully.

By passing the mash through the HLT, you will necessarily heat that small portion of mash above the target temperature, which is bad. The ideal system would raise the temperature of all the mash carefully, without heating any parts more than others. Leaving any sat in the coil would obviously be disastrous as it would heat to the temperature of the HLT, well above the target mash temp. Not a good situation. The other potential problem is that the mash has to be passed through the inside of a coil and through the pump. Sterilising before and cleaning afterwards will therefore be problematic, but not massively so. Would this disturbance of the mash be bad news?

The other obvious solution would be to pump liquid from the HLT through a coil in the mash tun. This would avoid any problems with what happens when the flow stops, as the small amount of hot liquid this time in a large amount of cooler, so minimal additional heating of the mash. Of course with a PID rather than a simple thermostat, you shouldn't get any overshoot anyway.

Obviously the best solution is a sealed heat exchanger, with a coil in both vessels, but that's probably taking things a little too far.

One advantage I can see of pumping the mash is that it will agitate the mash more than the convective effects of a heating coil would, and the principle of a heating coil is a homogenous solution around it, which won't be the case given no additional agitation. It would be interesting to see what could be done to keep it homogenous, I doubt a magnetic stirrer would do much good, and running some form of mechanical fixing through the bottom of the vessel might be challenging. I'm sure there is a way though.

Have I gone wrong in any of my thinking there, or am I just about on target?

Tim

 

[Aleman]

Except they are not passing the mash though the coil . . . just the mash liquor . . . Still bad for the reasons you mention though

 

[unclepumble]

From what I can tell of this system, not that I fully understand how HERMS works, these are my observations. Please do correct me if I'm wrong on any of this, I would like to understand it all a bit more fully.





Obviously the best solution is a sealed heat exchanger, with a coil in both vessels, but that's probably taking things a little too far.

One advantage I can see of pumping the mash is that it will agitate the mash more than the convective effects of a heating coil would, and the principle of a heating coil is a homogenous solution around it, which won't be the case given no additional agitation. It would be interesting to see what could be done to keep it homogenous, I doubt a magnetic stirrer would do much good, and running some form of mechanical fixing through the bottom of the vessel might be challenging. I'm sure there is a way though.

Have I gone wrong in any of my thinking there, or am I just about on target?

Tim

By passing the mash through the HLT, you will necessarily heat that small portion of mash above the target temperature, which is bad. The ideal system would raise the temperature of all the mash carefully, without heating any parts more than others. Leaving any sat in the coil would obviously be disastrous as it would heat to the temperature of the HLT, well above the target mash temp. Not a good situation. The other potential problem is that the mash has to be passed through the inside of a coil and through the pump. Sterilising before and cleaning afterwards will therefore be problematic, but not massively so. Would this disturbance of the mash be bad news?

You only pump the liquid part of the mash not the grains.
Not need to sanitise as the wort will be boiled for a min of an hour later.
leaving a little in the coil is not disastorous but you should avoid overheating the wort to avoid deactivation of enzymes in the liquid part of the mash.
Best method is to use an underback & level switches so the mash drains by gravity, rather than being sucked by a pump.

The other obvious solution would be to pump liquid from the HLT through a coil in the mash tun. This would avoid any problems with what happens when the flow stops, as the small amount of hot liquid this time in a large amount of cooler, so minimal additional heating of the mash. Of course with a PID rather than a simple thermostat, you shouldn't get any overshoot anyway.

Possible but the coil would get in the way when emptying the tun if permenant. also you would need to measure the HLT liquor and the mash temp and control the valves via the two values so could be a more complicated way of controling mash temp, you would also be more likely to experience hot spots in the mash. The thing with herms/rims is if all is insulated well you should only need to acurately control the liquor temp as the main mash will follow this trend.

One advantage I can see of pumping the mash is that it will agitate the mash more than the convective effects of a heating coil would, and the principle of a heating coil is a homogenous solution around it, which won't be the case given no additional agitation. It would be interesting to see what could be done to keep it homogenous, I doubt a magnetic stirrer would do much good, and running some form of mechanical fixing through the bottom of the vessel might be challenging. I'm sure there is a way though.

Not ideal to agitate the mash with this method as you would need a large aperture pump and pipework to deal with the porridge like mash, best to use a good false bottom and just recirc the wort.

Hope this clarifies things a bit more, typed very quickly with 2 year old using me as a climbing frame, so there could be some errors.

UP