The course Process Control was an awesome course where I learned how to string together processes, see how they affect each other, and how to implement and tune control system to maintain the process setpoint.
A lot of what I learned in this class was the theory behind the things I was doing in Continuus (let’s just ignore that most of what I did there relied on educated gut instinct). It’s now too late, but now I know how the P, I, and D in PID work and the reason why I could not use it to control a valve. To slow the response time, you have to increase the I term. Decreasing it causes the system to respond more quickly, which was the opposite of my intuition or a website tuning method said. So my slow moving valve would constantly get a saturated signal because the I term was miniscule, when it should have been increased to give the valve time to respond and change position. You live and you learn.
My favorite lesson from this course was how to connect processes operating in unsteady state. Every other course analyzes one unit operation at a time, always at steady state. In Process Control, we were able to model the effect of a flow change on the concentration of a holding tank which then affected the exit concentration of a CSTR. Or a energy in a reactor and heat exchanger. Or a concentrations of a complex network of mixing tanks. That’s awesome, at this stage we actually know how to incorporate all of these systems together and see the effect one variable has on another. We also spent an appreciable amount of time on the safety of processes, learning about the layers of protection analysis. In other classes to this point, safety has been reading the SDS and checking the instrument operation range. But now we discussed how do you prevent and mitigate catastrophe. Also: chemical compatibility was mentioned! 3/4’s of my time at Continuus was spent checking to see if what I’m using is safe in our system. We also had to relearn so many topics in math. Synthetic division? Partial fraction expansion? Laplace transforms? What do you mean these are actually used past high school? The best (worst?) part is that my friends and I ended up using Laplace transforms to prove an equation for Chemical Kinetics and Reactor Design. I’ll look for what that was when I write up that course.
The final project was to create a control system for one of selection of processes and to model the process with control in MathWorks Simulink. Knowing a little bit about the process from Capstone 1 and personal interests, my group opted to go for a scotch distillery. Turns out that’s the hardest choice. Biggest challenge was figuring out all of the process transfer functions. We came up with so many possible disturbances and first trying to linearize the mass and energy balances was difficult but the group worked well together to complete them. Simulink is very nice and easy to use. I imagine you can get lost in the complexities, but for it was a 5 minute lesson before dragging and dropping things until they resembled the block diagram. Another challenge was the open-endedness of the project. Every decision had us second guessing whether it was the correct or best option. At the same time, we had a lot of fun with this project. My group has a great relationship with the professor: who (lovingly) calls us “the four idiots” which we ran with as our moniker. Also, one of our assignments had stick figures next to our names, where the professor commented “Why is Owen[‘s stick figure] so tall” (he is not much taller than the rest of us) leading to the company logo above that Matt made. Obviously we know when to joke or be serious, so in the report below you’ll see that after the title page everything is appropriate for the project.