Process for Automation

[odtheta]

Hello everyone only posted a few times but looking to go big so I need some help.

I have been brewing for a few years extract. I have recently come across a few things to make an automated brewery and wanted to get some help in trying to write a program for it. I have broken the program down into top level description to see if my thought process it correct.


3 Vessell Allen Bradley PLC Big Picture
Background I am building up a system that is make out of 3 15g vessels.
I am going to use two pumps, RTDs in each vessell, Level sensors in each vessel. I am not fully automating the system as I want to start with the basics and add as I learn more.

I have a Allen Bradley PLC 5/05 and have started writing the program for this but I want to make sure that it makes sense how I am going through the process.

Step 1 Heating HLT
I simplified this down once I have manually filled the HLT I am going to set the temperature I want the HLT to heat to, I will then hit the start button and only heat to a temp. I will have a preprogrammed number for the heater to turn off that many degrees before the setpoint so that I will drift to the temperature. Thought process is this is just getting me to the temperature while the Mash process is what will be more precise. Once heater turns off alarm will go off until I hit reset button.

Step 2 Mash Process
I will use the manual controls on my PLC to pump set amount over to the MLT and add my grains. I will then set the temperature and the amount of time for the mash process. I will hit the start button. Using a PID in the program I will maintain the temp. I have set the timer to only count when I am within plus or minus 3 degrees from setpoint. I will obviously have the HLT set to recirculate with one pump and the MLT thru the Herms coil with the other. Once timer counts down alarm will sound until I hit reset button.

Step 3 Sparge
Once I am done with the Mash process and I am going to sparge. I am planning on using a sparge arm, a level sensor, and an automated valve on the infeed to the MLT to control the sparge process. So what I am planning on doing is toggling a button to set a level (dependent on the grain level) and then I will set a varience on what I will let the level dip before I open the valve and fill it back to the set level. All while I pump the MLT over to the Boil Kettle to a certain level. I will set that once the HLT gets to below 10% It will stay open to empty the HLT. Once the HLT level gets below 3% the pump will turn off so not to run dry. I have not figured out how to run down the MLT but I am figuring at a certain level sound the alarm and then I will manually run the rest down so I don’t run the pump dry.

Step 4 Boil
For Boil I have set the system so that I can run in either Manual or Auto either will run for a time I enter at the beginning of the process. Under Auto It will use a PID to go to a certain temperature 210ish I would presume or use manual which I set to run on a percentage of a 2 second interval.

 

[BrunDog]

Looks good. There are two elements to sparging as you know. Controlling temp and flowrate into the MLT and controlling flow rate out. I used to use a level sensor on my sight glass for MLT level but have recently switched to a hydrostatic pressure sensor. I pump water in at a controlled rate and run the second pump from the MLT to the BK. I use the level sensor to open and close a powered ball valve into the boil kettle. So when the level in the MLT increases, the sensor tells the valve to open and some of the liquid is drained off. The cycle repeats.

Once I am done adding sparge water, the valves continues to open and close every few seconds to continue to drain the MLT.

 

[odtheta]

So I need to maintain the temperature of the HLT. Never gave that much thought but I guess that makes sense as the sparge process does not a few minutes but a while.

Why is it that you put the automatic ball valve on the infeed into the brew kettle. I was thinking partially opening a manual valve into the brew kettle and using an automatic valve on the sparge arm I was going to use.

 

[rusty_tlc]

I am not familiar with the PLC you are using but the one I have used lets you program a PID loop between the temp sensor and heaters. Hope this helps.

What software are you using to write your program? I have been having a hard time getting my head around ladder logic. My programing background is with less linear style and more sub routine based.

 

[day_trippr]

fwiw, I added an Autosparge to my MLT, have done five brews with it, and am totally sold on it.



It simplifies the heck out of a long fly sparge as I just set the flow rate to the BK with the pump control valve and the Autosparge keeps the level at whatever depth above the grain bed desired (I use a couple of inches). I can literally walk away for the entire sparge.
The valve has no problem resisting the sparge pump pressure which is running wide open the whole time and there's zero channeling to boot.

A marvelous device, highly recommended...

Cheers!

 

[odtheta]

I use RSLogix 500, I am just learning how to do the ladder logic with this project as my training piece. There is PID logic in the PLC for controlling temperature which I am using. I just never put in my head that the sparge takes long enough that I need to use a PID.

I will add a PID loop to control while sparging.

I like the auto sparge you setup but I was planning on using a electric ball valve to control flow in a similiar fashion as what your autosparge is doing.
I am even debating using a ASCO valve as I have a couple of those readily available.

 

[odtheta]

Thanks for the suggestions on the auto sparge if I get there. I already have an automated Valve I am going to use to control the Sparge. If my idea fails I am sure to follow your idea as that is pretty simple.

I am hoping to post a picture of my panel and a list of components so that everyone can understand what I am building.

FYI I am piecing it together one part per paycheck so if you guys see something that is heading the wrong way please let me know so that you can stear me the right way.

 

[odtheta]

So here is what I have setup so far.

I have one keggle setup (Boil Kettle)

Electric Panel is a Allen Bradley PLC 5/05
One 24V Output Card
Output for Pump HLT
Output for Pump Wort
Output for HLT SSR
Output for Boil Kettle SSR
Output for Valve to control Sparge
Output for Alarm when timers are done or Something went wrong

One RTD card
One probe for HLT
One Probe for MLT
One Probe for Boil Kettle
One Probe for Counter Flow Chiller

One 24V Input Card
Available for future automation

One Analog Output Card
Planning to use it for SSVR in future for Boil Kettle


I should have some pictures of my panel up soon.
Please let me know if I am missing anything.

 

[BrunDog]

What HMI are you using?

 

[odtheta]

I got crazy and found a Panelview Plus for my HMI. Junk that was going to get thrown out because of a scratch.