Using Compressed Air for Temp Control

[cdrein88]

I did a search but couldn’t find anything on the subject. I’m also not sure if I’m posting this in the correct section...

Has anyone used compressed air to regulate temperature on a charcoal smoker? I have my hands on a pressure transducer (turns a 0-10 volt signal into PSI), volume booster, and a PLC that I would do this with. I would need to feed the temperature back into the PLC with thermocouples. I would use an oil less compressor. I am aware you could also use a fan.

Just curious if this is uncharted territory.

 

[crazzycajun]

So your using the plc to open a solenoid of compressed air to essentially fan the flames a nitro boost so to speak? If so I would think it would be fairly unstable what kind of deadband would you try to prevent short cycling and since your using an analog signal would you require a pid loop or would this be a on or off with basic deadband? Either way I don’t think it would be consistent temps, but in theory it would kind of work. Good luck

 

[Steve H]

With charcoal I would imagine dialing in a PID that would be stable would be quite a challenge. There is a lot of variables to consider. Or, are you considering another program to control this?

 

[cdrein88]

No to the deadband, the valve accepts an analog command and can output a scaled pressure (let’s say 0-20 psi) to the volume booster which sends the pressure (...volume, sort of) to the firebox. This would need to be PID controlled and with a system that responds this slow I would assume the control would need to predominately be a slow acting but large integral term. I guess you could add a deadband but the more you do that you might as well have a thermostat and a fan. Which you could, but that’s not the point here...