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Dephlegmator Control


indyspirits

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Omega CNI16D53-EI Proportional control PID (With Ethernet for remote control/logging), RTD in the dephlegmator itself (through the wall).  Using a Johnson 4-20ma proportional actuator with a 3 way ball valve to provide dephlegmator flow control.  We use a reservoir, and the dephlegmator is on it's own loop, so the water either passes through the deplegmator or bypasses back to the tank (easier than dealing with pump control or pressure bypass).  We are using a Grundfos Alpha circulator valve - it uses a ridiculously small amount of power, about 5 or 6 watts.  The dephleg loop only runs about 4-5 gallons a minute.

Nice thing is the PID compensates for the reservoir temperature as it heats up through the run.  We can adjust the dephleg to any temp we need on demand, and I think that the run-to-run repeatability is solid.  Makes it very easy to do things like run heads compression, slowly back off to take off fores/heads, adjust the hearts proof, and then compress tails  if necessary.  The only upgrade pending is to swap to a much faster acting proportional valve.

Went with PID as it was easier to control on the fly than something like a PLC - especially considering the cost of an HMI.  To go through all that trouble and the PLC would really just be "simulating" a PID?  We use the same exact setup for product condenser temp control.

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That 3 way valve sounds expensive. 

 

I use 2 solenoids to shunt water coming from condenser to dephleg, operated by a relay attached to a PID. The Auber SYL15xx series works well, and is inexpensive. They can supply RTD temp probes as well. 

Not sure what's in your current control box, but if you have space for an extra 1/16 DIN and a relay, then you can run this AC or low voltage DC if you already have a power supply. Total cost depends on what solenoid valves you use, but it's not expensive. 

Using preheated water from condenser means that sudden shocks to the dephleg are less likely, so if your setup is on the small side, less likely to stall your column. PID lets you set ramp/soak, gives you <1 F granularity, and has alarms for temperature presets.

 

I've used the setup with pneumatic-actuated proportional valves as well. Works a treat!

 

Email me dan@dododistilleries.com and I can set you up with schematics. 

 

 

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If you can build something like this, eBay and industrial surplus are your friends.  For example, the PID I list, you can find on eBay for $100.  From Omega directly?  It's like $350-400.  At $100 it's a better deal than a standard off-the-shelf PID for $50.  Same goes for valves, decent proportional control models are relatively easy to find on the surplus market.  Sure, theres some risk involved, but like I said, this endeavor requires a certain amount of technical and mechanical skill, if you have those, you should be pretty comfortable spec'ing the right parts, sizing valves, pumps, plumbing, etc.  Do solenoids work too?  Yeah, totally, plenty of ways to skin this cat.  On a municipal or well water based system, solenoids are really the only way to go.

@indyspirits mentioned software, so I thought I'd share the details around the Omega, since it's a pretty cost effective way to put a PID in place that has the ability to be connected.  Omega has some very good documentation online for how to interface over Ethernet, and there are plenty of options in place if you are interested in hacking around.  You can data log to Excel, build simple VB programs with their ActiveX control.  They've got some dashboard software too.

http://www.newportinc.com/software/iseries.htm

http://www.newportus.com/PDFspecs/Dashboard.pdf

 

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2 hours ago, Natrat said:

I've used the setup with pneumatic-actuated proportional valves as well. Works a treat!

When I looked at the Auber site I didn't see any PID that had proportional output, only time based / PWM output. Can you explain?

 

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21 hours ago, indyspirits said:

When I looked at the Auber site I didn't see any PID that had proportional output, only time based / PWM output. Can you explain?

 

Sorry, the particular system I was thinking of didn't use an Auber SYL, I think it was a Siemens PID with an amplifier and signal converter. 

Having said that, there are a variety of proportional valves, both electric and pneumatic, that operate with PWM outputs. Omega and AASFOL both have electric prop valves that work directly off PWM. And I think KPI has an amplifier that translates pwm signals for their valves

The thing is, the valve that opens and closes the AIR for a pneumatic proportional valve is a solenoid, which works great with pulse width. I admit, setting up dither and line amplification takes some learning, but it's well within the capabilities of most guys or girls that have constructed their own distillery!

another approach is using cyclic open-close valves, and adjusting the modulation to a lower-speed cycle. I find that the autoune feature on good low-cost temp PIDs can cope with that setup. The main thing there is to keep the valve exhaust clean, as the PID takes a while to learn/detect faster or slower valve cycles. 

The place where I have had trouble is using proportional pilot steam valves. That requires a specific solution, although a good workaround is a pair of high speed solenoids and a digital needle valve (if you can't reach a manual valve) to fine tune things. 

But in this application (dephleg temp control) the relatively low volumes of water required can be handled fine by solenoids. Which means on-off control signals. Unless your dephleg is the size of a pickup truck and the piping in is over 3" dia!

 

hope that helps :-)

 

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The PID I mentioned above Omega CNI16D53 - has both Proportional (0-10v and 4-20ma) Outputs and Relay Outputs w/ Cycle time (Basic PWM - in seconds)  - The "5" in the model number stands for proportional output, and the "3" stands for relay.

If you are going to use solenoids, make sure you use relays between the controller and the solenoids to provide additional level of safety for the controller.

If you do have only proportional analog output, but want to use solenoids, as mentioned in the Stilldragon thread posted above, the Burkert 8605 and 8611 controls are a nice way of converting a 4-20ma proportional signal from a controller into a solenoid-friendly PWM.  They also provide much more flexibility in solenoid control than you will find in a straight PID.  

Burkert makes proportional solenoid units that are comfortable with faster duty cycles, with the integral controllers, but they are just as expensive as actuated proportional valves.

If you are using municipal water with solenoids, and have a high water pressure, make sure you account for water hammer, as it can be severe depending on your solenoids, flowrate, duty cycle, and plumbing.  For safety sake, use normally open solenoids on your condenser loops, so that when your control system fails, loses power, solenoid burns out, relay burns out, etc - your condensers will go to full flow and shut down the still.  This will require manual shutoff valves.  Same goes for proportional valves, just be sure you understand and consider what the behavior is when the system fails, and someone else is operating the still.

 

 

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these guys make a relatively inexpensive proportioning valve....will operate with low pressure steam and water (must check specification!!)...spring closing could present issues for running over temperature condenser if you buy the normally spring closed variant and loose power.....seems like jumper would allow 0-10VDC or 4-20ma control.....little tricky sorting out the valve body (from 1/2" on up) and the control specs.....be sure of your specification.  (me4840)

http://pdf.directindustry.com/pdf/spartan-peripheral-devices/me4640-me4740-me4840-me4940/16884-496545.html

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  • 1 month later...
  • 1 month later...

Hi all,

I would like to build a basic dephlemator control system, and am wondering if a simple temp controller + solenoid combo could work, or if any of you have experience with this approach?

I'm thinking:

https://www.freshwatersystems.com/p-1991-2-way-solenoid-valve-normally-closed-34-fpt-120v.aspx

https://www.morebeer.com/products/ranco-digital-temperature-controller-wired.html?gclid=Cj0KEQjwqtjGBRD8yfi9h42H9YUBEiQAmki5Op_YDKsr_vB0BeIwB0GQnaMpm7u0vzRfWbON5h4PqEMaAmSJ8P8HAQ

I use the Ranco to control mash temps and it seems that it'd be the same principle concept.

Alternatively, do you know of any complete over-the-counter packages that solve the dephlemator control problem?

Thanks, Josh

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  • 9 months later...

 

On 1/18/2017 at 10:16 AM, Southernhighlander said:

Thermostatic valves work great.  All that you need is the valve and probe.  No controller necessary and it does not work off electricity so it is explosion proof.  I have used them on stills with up to 3 columns and they do the job really well.

I was about to buy a valve, probe and controller but this seems like a great idea.  Any tips on manufacturers or suppliers? Thanks!

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  • 4 weeks later...

For maintaining a constant temperature, I use a Honeywell T775M2006 controller with a Danfoss.  Danfoss are not the cheapest to buy. I now need a controller that has a proportional output that I can program to do a fixed ramp.  Anyone know of a reasonably priced controller that you can do ramps on?

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We are a Danfoss dealer. We have danfoss thermostatic valves at a better price than our competitors.  No controller or power supply is needed.  We also have the thermowells that go with them and we can show you how to set them up so that they work correctly.  paul@distillery-equipment.com

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  • 1 year later...

Thanks for all that started and contributed to this thread already. We're now looking to add a control system to our dephlegmator, and just want to revive this thread to see if anyone else has done this with a PID. If so, would you mind posting specs/pics of your setup?

We plan to go the 4-20ma proportional valve route. 

Thanks in advance.

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