Forced air burner design

[sr peters]

I am looking to build a gas forge and I want to use a forced air burner. Anyone have a good design? I have a copy of the BAM design they used on their forge projects a few years back. Just looking to see if there is any newer or improved versions.

Thanks

[Dodge]

I am looking to build a gas forge and I want to use a forced air burner. Anyone have a good design? I have a copy of the BAM design they used on their forge projects a few years back. Just looking to see if there is any newer or improved versions.

Thanks

I used this design and scaled it down to fit my needs. Working well for me.

[sr peters]

Thanks,
I had forgot about that one. I had seen it a few years ago when I was thinking about building a gas forge then. It appears easier to construct than the one I was looking at.

I used this design and scaled it down to fit my needs. Working well for me.

[Dodge]

My shell is 10" x 15" but I'm using 2" of wool giving me a 6" chamber instead of 8" like the drawing. Also, I used 1.25" pipe for my burner instead of 2". I used the same orifice; .0625" but its really too large for this size burner and forge comb and plan to change it for a .05" or smaller.

[maddog]

I like to use an 035 mig tip on my forced air burners just so that I can get a pressure reading on a 0-30 psi gauge.

Looking at the plans Dodge posted, thats a very large burner tube for a forge that size. A wide burner means the gas/air mix is moving comparatively slower and limits the amount you can turn down the flame even with the grill as a flame holder. I would go for a 1" or similar or I would flatten the end of the tube like Jymm Hoffman does.

[ornametalsmith]

I used this design and scaled it down to fit my needs. Working well for me.

I've built a few of these burners. One for a Pipe forge and the other for a "Beer Keg" foundry furnace. They are big burners. Work great,IMO.

[Dodge]

I thought the original design was a large one as well which is why I scaled mine down. I wasn't sure if one 1.25" burner would provide even enough heating in a 6" x 15" forge chamber but I'm able to get 1/2" bar fairly evenly heated for most of a length passed all the way through. Once I put a smaller jet in I think it will be even better. Also, I will be able to enjoy a wider range of pressure.

[Jymm Hoffman]

I guess you did not see my version in the "Hammer's Blow." It is so simple combustion engineers can't believe it, till they try it. Now they like it. If you want complicated, don't look here.

Starting with the manifold, it is made from 1 1/2 inch black pipe parts. The burner tips are 10 inch nipples cut in 1/2. I heat them up and flatten to a 1/8 inch sheet to act as a gauge. I no longer us elbows and street ells as it requires more adjusting or tuning of the burners tips. By only using T's, there is less need to adjust the burner tips (open one that is not burning as well as the other by using a long chisel while it is running.) The T's do not necessarily have to be welded together as I do, you can use short nipples to connect everything. I recommend one of this size burner tips for every 6 inches in length of shell. I used to recommend 1/8 inch hole for the gas, but the newer method of connecting a 1/4 nipple to a ball valve into the 1 1/2" to 1/1/2 inch T works fine.Or the 1/4" reducer can be plugged with 1/2' threaded rod, cut flush. Then drill a 5/32" hole in the center of the plug and counter sink (so the counter sink bevel is the outlet of the gas into the 1 1/2" pipe.) VERY IMPORTANT: This system works on household gas pressure, here in the United States, that is 11 inches of water column, about 1/2 pound of pressure. A common regulator that is already set for this pressure is used on outdoor gas barbecue grills. Do not try this system on high pressure gas with this large of an orifice. I normally run 3/8 to 1/2 inch rubber propane hose from the regulator to the ball valve. NEXT IMPORTANT PART: The blower must be a high speed blower that can produce not only enough CFM, but also enough pressure. I do not know what the minimums are, I use blowers readily available from Kayne & Son/Blacksmiths Depot: http://www.blacksmithsdepot.com/Templates/cart_templates/cart_browse.php?theLocation=/Resources/Products/Forges_and_Parts/blowers. The small blower they sell works great, it is listed at 112 CFM at 36 ounces of pressure. I run my smaller 2 burner and large 3 burner systems with the same blower (not at the same time of course.)

[sr peters]

What type of forge body do you use? Round square? Also how is it mounted to the forge? Guess it boils down to do you have pictures and details of the forge used for this burner? Sounds very promising.

I guess you did not see my version in the "Hammer's Blow." It is so simple combustion engineers can't believe it, till they try it. Now they like it. If you want complicated, don't look here.

Starting with the manifold, it is made from 1 1/2 inch black pipe parts. The burner tips are 10 inch nipples cut in 1/2. I heat them up and flatten to a 1/8 inch sheet to act as a gauge. I no longer us elbows and street ells as it requires more adjusting or tuning of the burners tips. By only using T's, there is less need to adjust the burner tips (open one that is not burning as well as the other by using a long chisel while it is running.) The T's do not necessarily have to be welded together as I do, you can use short nipples to connect everything. I recommend one of this size burner tips for every 6 inches in length of shell. I used to recommend 1/8 inch hole for the gas, but the newer method of connecting a 1/4 nipple to a ball valve into the 1 1/2" to 1/1/2 inch T works fine.Or the 1/4" reducer can be plugged with 1/2' threaded rod, cut flush. Then drill a 5/32" hole in the center of the plug and counter sink (so the counter sink bevel is the outlet of the gas into the 1 1/2" pipe.) VERY IMPORTANT: This system works on household gas pressure, here in the United States, that is 11 inches of water column, about 1/2 pound of pressure. A common regulator that is already set for this pressure is used on outdoor gas barbecue grills. Do not try this system on high pressure gas with this large of an orifice. I normally run 3/8 to 1/2 inch rubber propane hose from the regulator to the ball valve. NEXT IMPORTANT PART: The blower must be a high speed blower that can produce not only enough CFM, but also enough pressure. I do not know what the minimums are, I use blowers readily available from Kayne & Son/Blacksmiths Depot: http://www.blacksmithsdepot.com/Templates/cart_templates/cart_browse.php?theLocation=/Resources/Products/Forges_and_Parts/blowers. The small blower they sell works great, it is listed at 112 CFM at 36 ounces of pressure. I run my smaller 2 burner and large 3 burner systems with the same blower (not at the same time of course.)

[Jymm Hoffman]

What type of forge body do you use? Round square? Also how is it mounted to the forge? Guess it boils down to do you have pictures and details of the forge used for this burner? Sounds very promising.

Take a look at this thread of first gas forge. I prefer round. send me an email and I will forward more photos and information:
http://www.iforgeiro...ge/page__st__20

[sr peters]

Thanks Jymm. Think I have it figured out but will probably ask more questions once I get started.

Take a look at this thread of first gas forge. I prefer round. send me an email and I will forward more photos and information:
http://www.iforgeiro...ge/page__st__20