Sorry for the late reply. This is my first time working on any system, and I appreciate all of your input. I can see now that the ITAE formulas that I used were not applied properly.. however I'll have a go at using the tuning with a step input provided by @GrahamJ. I am also going to look at a cascaded system.. I've never actually thought of that, so thank you for the ideas.
The current PID settings (4, 4, 0) were probably set arbitrarily by the company that did the installation of the system (essentially whatever worked) but I'll have to call them to find out how they chose them. Our resident controls guy is more of an electrician.. all about PLCs as opposed to control theory.
Bottles are not apart of the heating system.. to clarify, 'to bottles' means release to the rest of the system, then to the filler.. that point is irrelevant. If the product has not reached the set point temperature in the hold loop, then it is recirculated. If it has, then it is sent out the 'to bottles' piping. Also note, the product spends approx. 50 seconds in the hold loop.
Below I have attached 2 notepad files that I used to create the red plot. Normalized is just TT-132 (triple tube heater temp.) divided by the set point of 200 degrees F.. and the timestamp is the temperature (TT-132) readings taken every 5 seconds over the course of a 3 hour start up period. I can pull other data values if it can provide more clarification.. once again I apologize, my week got taken up with other issues.
The current PID settings (4, 4, 0) were probably set arbitrarily by the company that did the installation of the system (essentially whatever worked) but I'll have to call them to find out how they chose them. Our resident controls guy is more of an electrician.. all about PLCs as opposed to control theory.
Bottles are not apart of the heating system.. to clarify, 'to bottles' means release to the rest of the system, then to the filler.. that point is irrelevant. If the product has not reached the set point temperature in the hold loop, then it is recirculated. If it has, then it is sent out the 'to bottles' piping. Also note, the product spends approx. 50 seconds in the hold loop.
Below I have attached 2 notepad files that I used to create the red plot. Normalized is just TT-132 (triple tube heater temp.) divided by the set point of 200 degrees F.. and the timestamp is the temperature (TT-132) readings taken every 5 seconds over the course of a 3 hour start up period. I can pull other data values if it can provide more clarification.. once again I apologize, my week got taken up with other issues.
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