Hi all, does any one have a simple schematic with values of components for a high temperature control circuit, say around 2600 degrees F? I am building a kiln for melting metal and need to accurately control temperature to activate and deactivate a relay connected to a gas valve.

 

Hi all, does any one have a simple schematic with values of components for a high temperature control circuit, say around 2600 degrees F? I am building a kiln for melting metal and need to accurately control temperature to activate and deactivate a relay connected to a gas valve.

It's not going to be simple, as most thermocouples either won't go that high, or that is their absolute limit.

Also, it sounds like you are planning on using either natural gas or other type of flammable gas in a kiln.

There are definite safety hazards involved in such a project, and as such it would have to be made fail-safe.

I don't believe that we can design such a thing via here, as the Terms of Service prohibit discussion on projects that may result in property damage or injuries/death - and a gas explosion would certainly be capable of causing either/both/all of those things.

 

It's not going to be simple, as most thermocouples either won't go that high, or that is their absolute limit.

Also, it sounds like you are planning on using either natural gas or other type of flammable gas in a kiln.

There are definite safety hazards involved in such a project, and as such it would have to be made fail-safe.

I don't believe that we can design such a thing via here, as the Terms of Service prohibit discussion on projects that may result in property damage or injuries/death - and a gas explosion would certainly be capable of causing either/both/all of those things.

Well I guess I could go electric, did not want to use LP much anyway, I have not built the fire brick layout yet so it would be easy to go with flexible heating elements [like a heat strip], high heat wire and two contactors [if one contactor were to stick in closed position the other would still open so as not to cause a runaway condition in temperature]. Also would need a electronic high limit. I was wondering if there was some type of IR sensor to sense temp instead of a T couple, if not then the max temp would be 2300 degrees F. I think this would be relatively safe, what do you think, I can also get heating elements from a kiln manufacturer. I need to build all else myself though to save money, thanks.

 

Steel mills routinely measure 2000-3000 degree temps day in and day out. Leeco made sacrificial probes for measuring BOP heat temperatures, 2900-3000 +/- a few degrees. IR sensors read plate and finish temps in the rolling mill and T/C's read slab temperatures in the slab reheaters.

 

So, back to my original question, does any one have a schematic with values of components for a high temperature control circuit, to control an electric kiln?