Ports/Sensors for Automation

Lloyd

The logic is that monitoring the vapor above the dephlem builds in too much lag time.
By the time the vapor temp increases and the PID kicks in there will be quite a swing in vapor temp. The vapor temp climbs as the the PID begins to rush water into the dephlem then overshoots and the vapor temp plunges a few degrees. This causes the production at the parrot to be a tiny trickle or a full on rush and cycles back and fourth.
By placing the sensor in the dephlem the PID correction happens before the the vapor temp is affected and the product stream and vapor temp are more stable with a minimum of cycling.

With only a small amount of practice you can dial in the stabilization temperature where the column maintains full reflux. Then adjust the PID controller to the temp that extracts the fores. Then adjust again for heads collection and finally for the hearts (where you can, if you desire, add a touch more heat to the boiler to collect faster).
When production slows and/or the ABV drops then you are into tails. If you plan to wash out the column and condensers thoroughly then you can elect to collect them by setting the PID to a higher temperature, else they will stink up the equipment and deposit oily crap on everything. I don't collect tails anymore because after the hearts with a 4+ plated still there is precious little useable alcohol left. Certainly not enough to put up with the stench.

I don't and YOU don't NEED automation to get great booze from a plated still. I can get great results by tending a plated still that has NO sensors of any kind, or automation, and has only 2 simple, low cost needle valves. The key word here is tending.
You are tasked to feel your way a little at a time during the run (tending the still) or to learn the set points of the PID controller to give you the results that you are after (automation 'tends' the still for you).
I've done both many times now and I'm comfortable with either.

If I was making booze only for me and my family I would not spend the money on automation. If I was making booze to support my family (by selling booze) then I'd have automation and the biggest still I could afford so my time was spent mashing the next batch.

I ran the baby dragon with not a single thermometer or sensor, just an alcoholmeter in the parrot. I collected very fine sipping alcohol that anyone would be PROUD of.
I have next to the baby a 5" ProCap column with full PID automation that puts Baby in the dust but Baby can generate more whiskey than any average family could possibly consume.
The 5" is an extravagance for personal production. Automation is an extravagance for personal production. The 4" Dash is also an extravagance because anyone that one one can produce more booze than he can possibly consume.
And THAT'S probably why I have a 5" ProCap Crystal Dragon with automation, because I can. I have the room for it, I can afford it and this is really my only hobby.
If I had very limited income I would WITHOUT ANY DOUBT only own a baby dragon with no frills and I'd be quite happy because I'd get plenty of good booze for both me and friends.
If I was feeding my family by selling booze I doubt Baby would be adequate.

You can agree or not. Your personal wants and desires are going to be different than mine but the simple truth is THIS IS THE GREATEST HOBBY ON EARTH and I've seen folks spend thousands of dollars on their silly ass hobbies ($4,800 kayak for God's sake, $16,000 motor swap for their Corvette, $13,000 bathroom remodel that didn't need to be remodeled, $116,000 room addition to their $85,000 house, etc...) It makes us all look a little more normal!

Mickiboi

I agree with nearly everything you said Lloyd. Except for one thing. And I'm not having a go at you here. A properly tuned PID (Not to be confused with P or PI) loop will not overshoot. And this one doesn't overshoot. It works perfectly, yes it took some time to tune manually but that's my job. That's the idea of the Derivative, to predict future errors in the PV signal and corrects the output accordingly so the SV is never exceeded. If the controller overshoots the PV then it is under damped, if it undershoots or never achieves SV then its over damped. A properly tuned controller will take into account that time lag between the what the process temp is (vapour, water, acid) and what the thermocouple is reading until the change is so small that the two are equal without ever over shooting the SV. The control loop is then properly tuned. A 3 way modulating valve with the correct CV for the thermal load helps make this a lot easier.

Everything else you say I agree with 100%. After tuning this one up I think I can do it without the automation. And I have only done one run.

Lloyd

Please, please, please come tune my PID @Mickiboi!!!
PM me for my address.

grim

By the way, I'm still playing with the 2 and 3 way Johnson valves to find the appropriate sizing/cv. Taking a while to hunt down enough variants in the surplus/used market.

Just got the 1" 2-way with a cv of 11 - looks like it's going to be the winner for the pro setups with recirculating coolant reservoirs.

Still trying to find a cheap 3 way in 1". The valve bodies alone (no motors) are $100-150 a pop, makes for expensive trial-and-error.

CothermanDistilling

I agree with @mickiboi

if you have the D at a sufficient level, the PID sees a .1 degree temp increase in the vapor temp above the dephlegmator or in the outlet cooling water and says 'whoa, what is going on here, let me cut back on the power'. The cooling water in the condenser is a ballast for the time needed for the vapor pressure to decrease...

if you want a PID you can play with every day to learn the P, I, and D, get/make a PID'd espresso maker such as a Rancillio Silvia... Rancilio Silvia PID @ instructables

Wallybox

@Mickiboi said: I agree with nearly everything you said Lloyd. Except for one thing. And I'm not having a go at you here. A properly tuned PID (Not to be confused with P or PI) loop will not overshoot. And this one doesn't overshoot. It works perfectly, yes it took some time to tune manually but that's my job. That's the idea of the Derivative, to predict future errors in the PV signal and corrects the output accordingly so the SV is never exceeded. If the controller overshoots the PV then it is under damped, if it undershoots or never achieves SV then its over damped. A properly tuned controller will take into account that time lag between the what the process temp is (vapour, water, acid) and what the thermocouple is reading until the change is so small that the two are equal without ever over shooting the SV. The control loop is then properly tuned. A 3 way modulating valve with the correct CV for the thermal load helps make this a lot easier.

Everything else you say I agree with 100%. After tuning this one up I think I can do it without the automation. And I have only done one run.

Aggree completely @Mickiboi. This is why I go straight at the vapor temp as well. Also the type of valve you are using will play a role. I use a proportional valve with constant flow so the vapor temp does not deviate much at all. I would imagine a on/off solenoid valve would be harder to control temps if you were chasing the vapor directly. But as long as YOUR setup works for you then to each their own.

punkin

That looks great Mickey. Very professional. I have those reducers in stock next time you need one with the TC port already in there. If it's 4mm or over you need you'd only have to cut the well off, drill and tap it.

olddog

As per the instruction manual. Quote Derivative. D Derivative action can be used to minimize the temperature over shoot by responding to its rate of change. The larger the number the faster the action.

vooharmy

This is a hobby for everyone, we all have different needs & wants and there is no one size fits all solution. I think in many ways pro caps have changed the game a bit in terms of production speed and this will undoubtedly make it easier to accept a smaller setup. I am drawn to a larger setup because I still infrequently in large batches, and I would like to cut down on the time I spend doing it. As Lloyd pointed as far as hobbies go this one is cheap, I have gotten more back in booze than I have ever spent on my equipment. I don't regret a dime, extravagance and all!

Mickiboi

@punkin said: That looks great Mickey. Very professional. I have those reducers in stock next time you need one with the TC port already in there. If it's 4mm or over you need you'd only have to cut the well off, drill and tap it.

Thanks mate. I appreciate the positive feedback. We didn't have time to order one from you so we went with the do it yourself approach. Have TIG.......will weld. :)

olddog

Nice job on the panel Mike

Mickiboi

@olddog said: Nice job on the panel Mike

Thanks OD. Much appreciated.

Lloyd

Great tread. Thanks for the tips on the D of the PID. I was adjusting it the wrong way.

grim

Yeah, but no matter how you slice or dice it, variable dead time or variable lag time is still a pain in the a88 to tune. Anything you can do do take variable dead time out of the physical design will make things easier for you in the long run. Anything you can do to improve the overall responsiveness and consistency of process heating or cooling temp will make tuning easier.

Mickiboi

@grim said: Yeah, but no matter how you slice or dice it, variable dead time or variable lag time is still a pain in the a88 to tune. Anything you can do do take variable dead time out of the physical design will make things easier for you in the long run. Anything you can do to improve the overall responsiveness and consistency of process heating or cooling temp will make tuning easier.

Totally agree @grim. Which is why I use thin wall sensors exposed directly to the vapour. Stainless steel is a really shit conductor of heat. The ones I use have a wall thickness of 0.1mm, very thin. They have a thermal response/time lag of about 1 second for every 50 degC rate of change. Putting any temperature sensor in a well should be avoided if you can and we are not dealing with any pressure or volatile/corrosive substances when distilling so pockets are really not necessary. I only put the boiler sensor in a pocket because it could be easily damaged being so thin. And they cost $95 each, not cheap ebay or alibaba sensors.

There is more to making a control system work than just gathering parts and chucking them in an enclosure. The most important part of any system is the sensing. If you don't sense correctly then you have no hope of ever getting any sort of decent control. The REX C100 controllers cost 13 bucks, the 2 sensors cost 180. Now you might say that's ridiculous spending ten times the amount on the sensor than what you do on a controller, but if your sensor has a time lag of 10 seconds per 10 degC rate of change then you may as well not have any control at all, you will never tune the controller loop to be consistent and repeatable. Some of those ebay/alibaba sensors can take 30 seconds to totally respond to a naked flame which is rubbish.

I use Allan Bradley PLC's that cost about $600 each, the pressure sensors that I attach to it can cost $6000 plus. If you want decent control then you have to be prepared to shell out some bucks to get the right sensing otherwise save your money.

Lloyd

I'm sure that's true of high end equipment but personal (artisan) and small pro distilleries seek a balance between price and quality. Somewhere in the middle is where the value is hiding and it takes a lot of effort to find it.
As a still tends to change vapor temps slowly its not like we're going from 30C to 80C in a few minutes, more like 80.0C to 80.1C over a minute or so. That's the range I'd like to sample every 0.5 seconds (more or less, but certainly faster would be better unless the costs get crazy).
Can you recommend a reasonably priced sensor with that in mind?

And your panel looks amazing @Mickiboi.

Mickiboi

@Lloyd thanks for the comment about the panel mate, very much appreciated. Leave it with me and I will find a sensor around $30 or so that will do the job. I did notice on the still I commissioned that as soon as that top plate started loading the temperature above the dephleg really took off. This is the temperature change I was referring to. Exposing the TC to the vapour and not in a pocket and having a sensor that responds reasonably quickly.

I think what I was trying to say in the post above is this, if you spend $3000 + on your still and you want a little bit of automation, don't buy a 4 buck sensor. It makes no sense to buy the best bit of kit going around and then spend $80 on a complete control system hoping it will do the same thing as a something that would cost say $500. It just doesn't make sense, and then when it doesn't work they blame everything else except the fact they are a cheap arse and wouldn't buy a component that was fit for purpose. I seen a thread on that other idiots website/forum where one guy in particular was trying to find cheaper sensors than $4 delivered. He was also complaining about the $13 cost of the controller and was asking if anyone else had found them cheaper. I simply don't understand the logic in it. But that's just me. Not calling anyone one here a cheap arse either, just trying to get my point across.

olddog

Although price is an indication, it does not always mean more is better. I noticed on other sites folks were raving that Auber were the only PID worth looking at. To find out more I ordered one of their PIDs from USA which cost around four times the price when shipping is taken into account, in a side by side comparison I can honestly say that they are no better in performance than the ones I source from Asia. In fact there is a very small sticker which needs a magnifying glass to red saying "Made in China" BTW the RTD sensors I supplied to Lloyd and my other customers are around the $30 mark, not the cheap $5 ones

Mickiboi

I wasn't having a go at you @olddog. It was a general comment about people trying to get the cheapest stuff possible on that other idiots website/forum and then it doesn't do what they want. I have the same Made in China controllers you do, both kinds and there is nothing wrong with them as you can see from the panel I made.

olddog

No worries, I did not intend to stir. Just pointing out that paying a big price is not always necessary.

Lloyd

Since I know precious little about electronic wizardry I tend to ask really silly questions and my comments are far from either knowledge or logic.

I've said it before and I'm sure to say it many times again, I could not be more pleased with the control panel that @olddog built for me. But it was built custom and has more features than most folks would want or need. I wanted something on the higher end and got that.
Now I'm exploring the lowest end possible, like your guy...

one guy in particular was trying to find cheaper sensors than $4 delivered. He was also complaining about the $13 cost of the controller and was asking if anyone else had found them cheaper.

The logic is simply to try to find a low cost middle ground for only one purpose - to control the dephlegmator and if I can find that sweet spot then I'm sure we'd vend a fair few of them. No frills but universal enough to ship to any country so the PID needs to be able to accept 110 to 250v and 50 or 60 Htz. But mostly it has to be simple.
Til then I refer anyone in Australia to OD because of the great service I received.

I bought a very low end controller box that has been around for years here and its normal purpose is to keep chicken eggs warm enough to hatch. Its in a slick little metal housing but the instructions are, naturally, in Chinese. It comes with a POS temp sensor but except for that it could be OK. Tan laughed when she saw it because it was the exact model that she used in her biology class at university. A sensor upgrade and it could actually do a decent job. The SSR inside the housing (which says it can accept 85 to 250v) passes through supply voltage so some might have issue with 110v or 240v attached to a valve that's connected to their still. I have 3 elements on the boiler so I don't see much difference by adding another hot wire.

And as long as I'm dreaming and wishing, if the sensor simply screwed into a 1/2" (or better yet, a 3/8") NPT coupling and was waterproof it would be perfect. That's pretty much the sensors that OD supplied to me.
I have one spare sensor that he sent and I'm too afraid to cut the end off and use it.

fadge

@Mickiboi panel looks spot on, neat & tidy just great. Would look good hanging on my wall ^:)^

I like your logic with not buying too cheap to then expect a perfect controller system. For most of us small hobby back yard guys we tend to sometimes forget the bigger picture and look to save a few bucks, then work out its " buy cheap, pay twice" most times. I doubt anyone regrets spending the $$ on stilldragon parts?

I've been following the various discussions on semi auto controllers and I simply cannot get past the idea that we need to use proportional valves as you have done, for more precise, smoother water flow, 3 way being the preferred option.

I understand @olddog has excellent success with the standard on/off valves and his sensing methods have plenty of praise and support, hell the big boss uses one!

The proportional valves appear to be up to 10 times the price of normal valves, finding these types of valves is not as easy however, some are only rated to 50 degrees or seem to have long open/shut times.

Any chance you can point us in the right direction for the valves as well as the request for decent sensors ?

I'm already starting collecting parts for a build but a long way off just yet, as cabinet/case depends on build design, pid depends on valves, and fittings depend on sensors..etc etc.

The supplied and trusty old quick connect needle valve will have a lot more runs before I'm done.

Cheers

Fadge

olddog

One of the reasons I go with solenoid valves is that the reaction is virtually instant whereas the motorised valve I have in my workshop has a delay between fully open and fully closed. This may not be the case with the ones that Mickiboi uses though.

Lloyd

Is the proportional valve something you'd use with a recirculating system?
I'm forced to use mains water and the diverted water would simply go to waste?

It would not be a problem for me to attach a push tee and needle valve to slowly bleed a bit of hot water from the dephlem and that just might be a good thing with my on/off valves as it would keep the water moving and should help to add even more stability.

And @Manofconstantsorrow who did a run with me recently using the OD controller could have pointed out a few hints like that and to increase the D value in the PID, after all he programs nuclear reactors for gripes sake! (poke, poke)

Mickiboi

"Buy once buy right" has been my motto since I smashed all my knuckles using a cheap socket set to remove spark plugs from my drag car (Which my new wife made me sell when we got married and then decided she wanted a divorce, I'm not the least bit f%#$ing bitter about it though). I only buy quality tools now, bugger the expense. I learnt my lesson.

I'm looking into the proportional valves a bit more now I know people are interested, $350 is out of the question for the one I used on this. There are a couple of Chinese ones I have been looking at. Daikin use them on their air conditioners so I don't think they can be too bad. You are right about the actuator travel time. They need to go from fully closed to fully open in about 15 seconds, olddogs open/close solenoid valves win hands down here. But with a fast actuator and the correct PID settings the 3 way valve works a treat. I will get my supplier to send me some samples and prices of his other sensors and let you know the outcome. I have to test them before I can recommend them.

There is another way and that is to forget about the valves completely and use a VFD to drive the pump. Now there's an idea. A VFD cost $112 delivered and you already have a pump. Now that is fully variable control, no lag, no delay, no open/close times, no pulsing through an opening closing solenoid valve. And it will run from the standard 0-10VDC PID controller.

Mickiboi

Hows this? Sorry the drive is $139 delivered. Still works out great value and the PID will run this with a minimum of tuning.

Mickiboi

@Lloyd said: Is the proportional valve something you'd use with a recirculating system?
I'm forced to use mains water and the diverted water would simply go to waste?

It would not be a problem for me to attach a push tee and needle valve to slowly bleed a bit of hot water from the dephlem and that just might be a good thing with my on/off valves as it would keep the water moving and should help to add even more stability.

And Manofconstantsorrow who did a run with me recently using the OD controller could have pointed out a few hints like that and to increase the D value in the PID, after all he programs nuclear reactors for gripes sake! (poke, poke)

Didn't know @Manofconstantsorrow worked in nuke plants, I used to calibrate instruments for nuke plants in Germany. Wish him Happy Neutron day for me.

A 2-way proportional valve would be used for a mains water setup. A 3 way for a recirc, constant pump flow for a tank.

So clearly there are a lot of situations and different configurations and set ups. There is no one simple solution to every ones set up. I guess that's the idea of all this head banging that goes on behind each and every one of these posts from all of us. From all of this hopefully you will say, "That's my answer right there".

fadge

@Mickiboi said: Hows this? Sorry the drive is $139 delivered. Still works out great value and the PID will run this with a minimum of tuning.

Thanks, never even thought of controlling the pump directly.

I assume a decent sized tank with fairly constant temp variation and a second pump for product condenser perhaps?

Yep bit of head banging required to sort out what will work with what setup.

fadge

Mickiboi

Constant pump for the PC and a VFD for the dehpleg. And that really is the beauty of the VFD drive, you can oversize the pump to the max and push a shite load of water through the dephleg as the temp rises in the condenser water storage tank. No flow to full flow in 1 second with variable control in between on start up. I have just ordered one to test and see what happens, there is no reason why this shouldn't work better than nearly everything else on a recirc system.

Mickiboi

@olddog said: One of the reasons I go with solenoid valves is that the reaction is virtually instant whereas the motorised valve I have in my workshop has a delay between fully open and fully closed. This may not be the case with the ones that Mickiboi uses though.

Fully open in 15 seconds. For an electronic valve this is quick. To get one that opens in about 2 seconds costs lots and lots, made by Keystone Valve Company.