Super efficient Gas Forge

V

Van Zanten

Joined
Sep 20, 2011
Messages
104
Hey folks,

I wonder at what pressure your gas forges run? My old gas forge with a homemade venturi burner needed 2,2 bar (32PSI) for a welding heat. The burner had a 1mm MIG contact tip. My bottle's were always empty in no time.

Fortunately Achim Wirtz has designed a way more efficient venturi burner. With this burner and new oven design I can weld at 0,7 bar (10PSI). General forging can be done at 0,4 bar (5,8PSI). Also, the flame is burning inside the oven, and not at the end of the burners nozzle. With this method the nozzle doesn't get eaten away by the flames and heat, zero wear on the burner.

[video=youtube;oL-9f6Az-t0]https://www.youtube.com/watch?v=oL-9f6Az-t0&list=UUKXyVqXWEYv5W8quZrSgaaw[/video]

Bye,

Johan van Zanten
 
In my venturi forge, I HT at 3PSI, forge at 5PSI, and weld at 10PSI. Blown forge is around 1PSI for HT, 2-3 for forging, and 5 for welding.
 
My forge HTs at 1.5PSI, forges at 5PSI and welds at 10PSI. Pretty much the same as Stacy. I choke the air flow at 1.5PSI and it gently hisses away at 1500F with a muffle pipe.

A blown forge is my next build. They sound pretty efficient.
 
While we are on the subject maybe someone can give me some advise. My blown forge ran on a 100lb propane tank at about 2psi for forging. I just built a shop and had a propane line run in. The gas guy said he installed a 2psi 11 water column(whatever that means) line. I havent found my box with my blower yet so havent fired up the forge, but I am concerned about it not being enough and asked if he could do a 5psi line in. He was rather reluctant to do that due to concerns of hooking up a heater. My suggestion was a tag stating not to use the line for anything except a forge or something. Not that I plan on moving again, but he was concerned about liability if we sold the place and someone used the line.
 
Keep in mind that volume usage (q or flow) is not a direct function of pressure. Running a venturi at 10psi could very well be more efficient than a blown burner at 5 psi depending on design (orifice sizes, etc.).
 
Cory, if you have an lp tank (big tank) then chances are you have a 2 regulator system. A regulator at the tank and a second regulator at the house or building. Tank regulator will lower pressure from the tank and deliver propane to the second regulator but at too high of a pressure for the standard appliances to use. Our area is common to have up to 10psi to 2nd regulator. 2nd regulator adjusts pressure down to 11" water column which is about .4 psi. (Four tenths of a pound) So no it would not be enough to run your forge from the second regulator.
 
Thanks for the replies, the PSI's are interesting, but what are your MIG tip diameters?

I'll read the other posts tomorrow, first I got to take some sleep
 
Ok, that is also 1mm (1,12mm)... Leads me to believe that my forge fuel consumption isn't so special after all :p My previous one was just very thirsty...
 
I have three blown verticals.
I heat treat at 2 psi line pressure, then adjust air and needle volume at the forge.
I forge around 3-4 and weld at 4 1/2.

Line pressure is one thing, but how it is controlled at the forge - and you had damn well better have air and fuel volume control AT the forge - will make all these pressure numbers a little ambiguous from one person to the next.
 
Matthew Lomas said:
Keep in mind that volume usage (q or flow) is not a direct function of pressure. Running a venturi at 10psi could very well be more efficient than a blown burner at 5 psi depending on design (orifice sizes, etc.).
Click to expand...


Mat is absolutely right. I've had blown forges that would weld with 2-3 psi unrestricted but still eat propane like it was going out of style.

My current damascus forge is 24" long with a ribbon burner, that I run 5psi at the regulator but through a needle valve that's no where near half open. Blower is choked with a gate valve and about 1/4 open at 2300ish.

This forge is very efficient, for long welding sessions. But it's got huge thermal mass (weighs a few hundred pounds) and takes 45 mins to get to heat. For 8-10 hours straight making steel its near ideal and uses very little propane once its up with super even heat and lightening fast temp bounce back.

For general forging where you're running for an hour or so, it's useless and wasteful.
 
Rick Marchand said:
My forge HTs at 1.5PSI, forges at 5PSI and welds at 10PSI. Pretty much the same as Stacy. I choke the air flow at 1.5PSI and it gently hisses away at 1500F with a muffle pipe.

A blown forge is my next build. They sound pretty efficient.
Click to expand...
What Venturi burner do you run?
 
I Have a couple forges. One uses Lary Zoeller's "Z-Burner" and the others use 100K burners from Atlas. Both work great!
 
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