Heat/Cool – First Experience
Although we have extensive PID heating experience for thermoplastic injection molding, today we are faced with a welcome, new, challenge of alternate media injection.
The media is staged in a vertical tank that is staged in vertical temperature zones where the top zones are at a higher liquid temperature, and the lower zones are cooler.
We have NO empirical data collected yet.
We are confident with PID set-up for electric heating of the zones, but do not have any COOLING PID experience.
We speculate that the heat/cool would not be a balanced slope, therefore, we speculated that two separate PID loops would be required. One loop tuned for the HEATING gains, and a secondary LOOP set up for cooling.
We will have thermocouples in the process media, we have electric resistance heating for the the heating PID, and we have digital on/off solenoid valve for cooling of the same zone.
Again, embarrassed that we have been around thermoplastic extruders with this heat/cool scenario, this is our first actual implementation.
Questions:
Should we use a single, bi-polar PID for heat/cool…
OR
Should we use two separate PID controllers, one for heating, and another for cooling.
Thank You for your input.
Plastic
Although we have extensive PID heating experience for thermoplastic injection molding, today we are faced with a welcome, new, challenge of alternate media injection.
The media is staged in a vertical tank that is staged in vertical temperature zones where the top zones are at a higher liquid temperature, and the lower zones are cooler.
We have NO empirical data collected yet.
We are confident with PID set-up for electric heating of the zones, but do not have any COOLING PID experience.
We speculate that the heat/cool would not be a balanced slope, therefore, we speculated that two separate PID loops would be required. One loop tuned for the HEATING gains, and a secondary LOOP set up for cooling.
We will have thermocouples in the process media, we have electric resistance heating for the the heating PID, and we have digital on/off solenoid valve for cooling of the same zone.
Again, embarrassed that we have been around thermoplastic extruders with this heat/cool scenario, this is our first actual implementation.
Questions:
Should we use a single, bi-polar PID for heat/cool…
OR
Should we use two separate PID controllers, one for heating, and another for cooling.
Thank You for your input.
Plastic