PID valve control is common enough - what are you looking for? It shouldn't need any genius ideas, just some basic design. What have you already got in place for the PID loop?
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If we learn from our mistakes I'm getting a great education!
Hey. I am just not too familiar with the PID controller in the software. We had a schiele S-400 in an industrial clothes dryer Die on us, and instead of trying to monkey with it we thought we'd replace it with a PLC we could program. The PID is just for modulating the gas valve based on the outlet temperature actual vs. an arbitrary setpoint.
I concur. Burner Management Systems are designed for this task, not PLCs.
xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
the purge, pilot solenoid, uv scanner, block & bleed and the like are all managed externally by a flame safeguard controller. All the safeties are kosher. I read up on the PID controller as soon as I got a hold of the rockwell manual though and it seems pretty straight forward. It may just be a matter of calibrating it with the RTD to 0-10V converter that is in the unit.
haha thanks dV8r ! we are using a PLC because we also need to allow operators to control the dryer functions for loading/unloading the dryer ie. open/close front and read doors, tilt dryer, rotate basket cw and ccw, and selectable dryer program parameters depending on the laundry type.
We are still confused by your question..
How can you directly modulate the gas valve if there is a "burner system" involved? Burner systems are generally part of the burner control.
I can almost imagine what this installation will be like!
We have a small steam-raising boiler on plant which is primarily designed to establish low grade steam for fuel pre-heating. Its automation is a loosely integrated hybrid of a PLC for sequencing, three Moore loop controllers, a couple of flame scanners and a trio of hardwired sequence supervisory units. It is a nightmare to fault-find and is difficult to assess for functional safety. It is screaming out for a modern burner management system, possibly based around one of the new safety-qualified PLCs, and I suspect that your application has some parallels with this.
We should have taken the opportunity when the old TI-505 packed in, but for various reasons it was replaced with an SLC500 performing the same role. At the time I wanted to ditch the Moore controllers and at least have the PLC doing the majority of the control, but that was in the days when a safety-qualified controller meant Triconex, which is an abbreviation for "holy sh*t, that is expensive!". Now there are some alternatives.
Save yourself the pain and contract this out to an automation company with BMS experience who can add the other functions to their package.
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If we learn from our mistakes I'm getting a great education!
