PID controlled coal forge?

Sam Salvati

Sam Salvati

Joined
Aug 6, 2007
Messages
5,060
I am thinking, would it be possible to wire a PID control into the plug wire for a blower, to regulate the amountof electricty and in turn air going into the fire so that you could maintain a sort of more even temperature? I understand of course it would not be EXACT due to the difference in combining fuel and air all over in the firepot, but would it ba able to help atleast alittle? Would save a bit of trouble, if it were possible to keep the coal burning at a somewhat regulated temperature.
 
It will help, a variable speed blower and a valve in the piping to adjust airflow helps keep the temperature where you want it. With my old blower I would use 1/2 valve then once the metal hit 1800 3/4 then at 2000 1/1 for forge welding. It really helped prevent the burning/melting of the thinner spot where the metal was cut and folded. I use charcoal so it might work a bit differently for coal.

I don't know much about PID controls but variable air flow is great.
 
It could be done with an SCR drive and variable speed motor. In real life air is controlled with a damper valve, not usually by speed of the motor.

Frankly, I question whether it is practical or not. Good thought though.

Craig
 
Yeah i guess it would be impractical. Make more sense to just put a valve in, and use a temperature gauge and fine tune until you get the temperature you want.
 
probably cheaper and better control to just build or buy a propane can like mine and get a thermocouple and learn how to regulate it

-Page
 
I am just wondering if it would be plausible, to have the little temperature reader control the airflow, so you can set it to not go above or below certain temperatures, and do so aoutmatically.
 
You would need a thermocouple in the right part of the fire, but it would work and the PIDs I have have an auto tune function that causes the PID to adjust its operation to the equipment to get the correct effect. The PID can actually learn how to control the fire. How fine it could tune itself to a coal forge via running the blower would be interesting. But, I bet you might be suprized at how well it works. At the site mentioned in the HT oven thread you could get a pid for $40, a thermocouple for $27 and a 25 amp ssr for $15 so for $83 and shipping you could give it a whirl. I would spend $19 and get a 40 amp ssr so if you didn't like it you could sell it to all to someone building an oven. Although with those components and a propane forge you could add a electric valve to the propane supply and use it to control the forge. Just use the ssr to turn on the fan and the propane at the same time. You would need a bypass valve to get the thing going and built up some heat or run a small flame for a pilot to cause the forge to ignite when it kicked on the propane and fan
 
You must log in or register to reply here.
Back
Top