Blown forge qustion

bikermikearchery

bikermikearchery

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Jan 18, 2007
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All of the blown forges I have seen are single burner. Venturi forges of the same size have as many as 3 burners. I have finely assembled most of what I need for my next forge. I was wondering if I could improve the heat distribution in a round horizontal forge by putting in 2 burners. This would have a inside dimension of 6" diameter x 18" long. 2 burners plumed to a single blower.

Thanks Mike BMA
 
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I may be wrong so take this with a grain of salt.

I would think that, multiple smaller venturi burners give better control for a forge, where as a blown forge has much more control from a single larger more controllable burner. I could and probably am wrong, but this makes sense to me.
 
I have built two forges, the first with a venturi burner and the second with a blown burner similar the the one Indian George has on his website. My current forge is blown and about the same size as yours except maybe 2-3 inches longer. I have my burner about halfway back am able to reach welding temperature in it no problem with just the single burner. Personally I wouldn't mess around trying to add a second burner as with that size forge you wouldn't really need it.
 
A 6" vertical is pretty small.
No need for more than one burner in a vertical forge.
But a long horizontal needs multiples to even out the heat.
 
The biggest issue you will face with multiple "blown" burners is adjusting them so that they run equally. In a multi burner setup, venturi burners are almost self-regulating, however, when you add a blower/blowers, everything changes, and they can be a major pain to adjust so everything runs smoothly. In many cases I have seen instances where one burner will continually blow out the other.......just more trouble than its worth.

I agree with Don, a 6" ID is very small, and will likely weld with a single venturi burner. My welding forge is an oval shape, where I took a 12" ID X 18" long pipe, split it down both sides, and added 6" into each side. With the refractory installed, the inside dimesions are 10" wide X 16" deep (front door to back door) 15" tall...... and it runs on a single blown burner. At 6psi, it easily reaches 2400F and higher (don't know just how much because my pyrometer tops out at 2400F.)
 
my new forge is about 13-14 inches long and 8" in diameter. which gives me a chamber size of about 12" x 5.5" - 5". i use one forced air burner with a burner tube of 1". has more power then i will ever need. i placed the burner inlet at one third (1/3) of the way from the back and its canted forward to intice the flame to swirl twords the fount. when the flame gets to the door opening it does not come straight out but shoots out on an angle to the right so i can get my hands closer to the door and not get burnt. the forced air burner pusses heat arount the forge so fast that it heats quite evenly.
 
I find a blown forge with individual needle valves on each burner give you a better burn overall.

I run three burners on a horizontal forge and each has its own needle valve.

This set up gives you more options; unless you only want to work at welding temps.

Just another way to skin the cat.

Fred
 
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