Reflux Control

Can anyone recommend a good quality controller that can run a variable ball valve?

I would prefer something that has good auto tune as I can’t program a PID to save my life. Would love to hear what valve/controller combos others have used with success. Not overly concerned with price.

Comments

  • edited June 13

    I doubt that a controller will solve your requirement for your existing ball valve. This is because for it to work properly it would have to be tied into an input i.e. PLC with temperature, atmospheric air pressure etc. Further the device would have to receive multiple settings for positions as it goes through and interrogates the process.

    I have reflux control with my automated PLC controlled LM still. However instead of a ball valve, I have effected control using a motorised needle valve. I was of the opinion that the likes of a ball valve would be too rough in flow control .... I am controlling distillate output / reflux...... not sure if you are looking to do same or control water flow to dephleg.

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  • I’m looking to control water flow in the Dephleg. I do this currently with a solenoid but clicking drives me crazy. Would love to swap this out for a silent option

  • Okay but then here's the issue .... so you are going to control it around temperature then for the water flow. For a simplistic setup, this is okay. So what happens when you want to increase or decrease water flow based on for example heads, hearts and tails and or change in atmospheric temperature and pressure which then requires a change in flow for changing cut points etc.

  • edited June 13

    We do this very effectively with dephleg coolant temp control.

    The trick is sizing your valve - too big and you'll never get it working right. The other part of this - mains water vs. recirculation - that also impacts the sizing.

    You need to measure your range of flow rates through the solenoid - then we can probably recommend an option.

    Getting the conditions right for auto-tuning is very tricky.

  • @grim @Richard at full speed its about 4.1L a minute through the solenoid, its currently driven by mains but I am happy to change to recirculating if it helps me use a more silent system. I want to keep things as simple as possible and mainly aim to automate the control of the dephleg to hold a set temp. My system is a 5" bubbler with 6 plates and a 120L boiler, it has 7200w of elements. I had mentioned a ball valve because I saw a few years back cotherman posted a build but I am open to other types of valves if they are more viable.

  • edited June 13

    At those low flow rates I'd actually suggest a small proportional solenoid valve (aka Burkert).

    https://www.youtube.com/watch?v=ec82V2uzE9c

    I'd use a small pressure regulator on the front-end of this, to ensure mains pressure variations (toilet flushes, sprinklers, showers), it'll also let you tweak the overall flow rates such that you have some more flexibility in valve sizing.

    They don't chatter like typical big on/off solenoids, they are far faster to respond (full close to full open in milliseconds), and they are more forgiving of valve sizing mismatches.

    They do require both the Burkert 8605 pwm controller and a PID.

  • I showed my setup here on the forum back in 2014, and it is still valid and works great..

    Automating Reflux Condenser Water Flow

  • @richard said: Okay but then here's the issue .... so you are going to control it around temperature then for the water flow. For a simplistic setup, this is okay. So what happens when you want to increase or decrease water flow based on for example heads, hearts and tails and or change in atmospheric temperature and pressure which then requires a change in flow for changing cut points etc.

    no issues at all if you are going based on RC internal temperature, as it will increase flow as the boiler temp rises to keep the setpoint... pressure and temp have a minute effect compared to the temperature inside the RC... been working for 7 years in production to keep my 190 at >190 without wasting energy taking it to 192... and without much user input other than tasting..

  • @CothermanDistilling You make some great points and I followed your previous post I will give your method a try. Would a Johnson VG1245AE+906GGA 1/2" two way ball valve with actuator be suitable? More than happy to buy a different one if it isn’t!

  • edited June 14

    So long as it's a proportionate control valve, almost all proportionate control valves could be used.

  • @richard Ok thanks I believe I’m good then! I’ll put it together and see if I can get some peace and quiet from this click clack noise!

  • @vooharmy said: CothermanDistilling You make some great points and I followed your previous post I will give your method a try. Would a Johnson VG1245AE+906GGA 1/2" two way ball valve with actuator be suitable? More than happy to buy a different one if it isn’t!

    I think it is, but you should read the datasheet to understand each number of the part number works.... the AE part is the cv of the valve, based on the plastic inserts. However, how we are using them, there is not much difference. GGA is proportional and AGA is not... there are also ones with terminals and owns with wires.

    also, I used these because they were cheap and readily available back then, and had proven ruggedness, but now if you want a 5/12/24VDC one, you can get one... maybe even 120/240vac...

  • edited June 14

    I’d lean towards AD for a small rig dephleg on mains water. That’s the smallest they make I believe.

    You absolutely need to match the valve to the flow range. Too large and it’s almost impossible to control. The oscillation of temps will drive you crazy.

  • on a 1/2" valve, AE is pretty good, it has a very small slit, maybe 2mm wide, for the initial opening.. page 3 has the letters and cv numbers:

    Johnson Controls VG1000 Series Ball Valve Selection Guide (PDF)

  • edited June 14

    The other important consideration is that what works fine on moderate pressure mains water - is going to be way too small for recirculating. Suppose you could run a huge pressure pump to compensate…

  • I am using a march MD5 size pump, and I can get 0.1-5.0 gpm through my RC and HX setup yes, city water would be a huge increase to that, but a "DN15 NPT 1/2'' Adjustable Water Pressure Regulator Reducer w/ Gauge" from eBay for $30 would be the best way to deal with that... I used a similar device before my carbon filter to stabilize city water pressure so the drinking fountain in the gift shop did not go from a trickle to overshooting the whole fountain.

  • @vooharmy - Here is the smallest, AD:

    johnson controls actuator va9104-gga-3s 1/2" brass valve electric HVAC for $18 @ eBay

    I messaged the seller about what the brass tag had on it, and got back: "part number is VG1241AD+9T4GGA CV:1.2 T203F RY11608"

    *note - the GGA-3S has a 3-position terminal block and the GGA-2S has a long 4 conductor wire. The difference is in the 4th wire, as the orange wire is the 0-10v feedback that can tell you the actual position of the valve. I like this and use it on my BruControl based system.

  • I wish we had Ebay as close on hand this side as you have it that side. They want $65 to ship it.

  • Johnson VG1245AE+906GGA 1/2" I have this one on hand might try this first. Ordered on omcron E5CC will see how it goes and reassess from there!

  • That $18 Johnson is a crazy good deal.

  • @grim said: That $18 Johnson is a crazy good deal.

    That's what she said.....

    StillDragon North America - Your StillDragon® Distributor for North America

  • Shipping & taxes where over $100 USD…

  • @vooharmy said: Shipping & taxes where over $100 USD…

    eeeek! here is one, if nothing else, provides voltage options and some new keywords to use..

    1/4''-1'' DN8-25 2-Way Modulating Valve Electric Stainless Steel Ball Valve DC9-24V Motorized Proportional Modulating Valve @ AliExpress

  • A bit of an update, I purchased an omron E5CC and hooked it up to the Johnson Valve and everything works flawlessly. Omron auto tune nailed it first go. Happy and silent!

  • Shocked that autotune worked so easily.

  • On cheaper units that I have used in the past its been pretty bad, the Rex 700 unit I used previously was comically bad. The Omron algorithm was remarkable for a first attempt, I believe a little bit of hand tuning will make it better buts its definitely on the money.

  • In the past I have read it takes an hour or more for PID controllers to Auto Tune.

    How long did it take for yours to dial itself in ?

  • @captndiet not long the time for 3 up and down cycles 5minutes? Holds within .2 of a degree

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