HVAC furnace burner for forge?

[spareparts]

Would this set of burners work for building a dual freon can forge? Took them out of a scrap HVAC unit. I do have the propane manifold that mates up to these. Seems rather convenient for me.

 

[Stacy E. Apelt - Bladesmith]

Short answer - NO!


While you probably jury-rig them up and make some sort of a burner, it really wouldn't work well because of how a forge runs. Those are made to run in an open system, heating a heat exchanger tube that air passes through. The heated air is what gets circulated through the ducts to heat your house.
The gas jet is at a pre-set pressure and is aimed right down the venturi burner tube. The air is drawn in at an un-adjustable rate. Any change and the burner flames out. The burners just burn at full flame, and the exhaust gasses and excess heat are expelled out the vent duct.

In a forge, the burner has a nozzle that delivers the burning gas/air mix to the chamber, where the refractory heats up along with the knife blade in it. This is a closed burner system. The goal is to retain as much of the heat in the chamber as possible. Even if you could re-configure those HVAC burners to work, they would not last long in such an environment before they burned up that thin galvanized steel. (Before someone chimes in about poisoning himself with the galvanizing, lets all agree that the major issue is design, not materials.)

The only possible use in a forge would be building some sort of large half dome forge with a ribbon burner. Those might work for the burners ( for a while), but I think a proper ribbon burner would be far better.

The advantage of standard venturi forge burners is that they are very simple. They can be adjusted for varying gas pressures and volumes, and can be rebuilt as needed as the nozzle burns up. Blown burners are even more adjustable ... and simpler.

 

[spareparts]

Thanks for the info, I appreciate you taking the time for such a detailed explanation.