Propane Forge Blower

[HeavyHammer]

I have a propane forge that uses the Ron Reil style venturi blower. Its just not cranking out the heat id like it to. I was wondering if anyone knows if its safe to add a blower to it to beef up the heat. If yes then what would be the best way to do it:

[meco3hp]

Hello,
What temps are you wanting? I've got a gasser with the same exact setup and I'm doing ok with it. The only thing mine doesn't have a is a "choke" like yours has. Take that all the way off and see what happens.

http://www.blacksmithforum.com/viewtopic.php?t=401

This link is about the problems that I asked about. Ask more questions if you'd like. :mrgreen:

[HeavyHammer]

So do you think its is possible to use that pipe thing you put on top of yours with the elbow and such and attatch a blower to it? Im trying to start welding in it, right now i can get to a light orangish yellow. My coal forge is nice but i like the cleanliness of this thing:)

[meco3hp]

I don't know about the pipe with a blower on it. I'm assuming it is possible. You'd just have to figure out how much more propane you'd need to get it to work with the forced air. What are the dims on the inside of the forge? A Reil type burner should make enough BTU's to heat a 250 cu. in. forge to welding heat. What are the dims on the insulation? Does the outside of the forge get hot? As in any color to the outside? If it's showing color on the outside of the forge, your insulation isn't thick enough.

http://www.frontiernet.net/~gnreil/design1.shtml

If you haven't checked out Ron Reil's web site, you should. It has a fantastic amount of info about gassers, just like your's. I know they discussed setting this type of burner up using forced air and natural gas straight from the main line into the house.
If I may ask, why do you have a choke on it? I've not seen any designs that have that feature. Also make sure there isn't any burrs on the orfice in the feed tube and that it is orintaited so the orfice is centered in the burner tube, and that it is blowing straight down the center.

[Woody]

from the Anvilfire Guru Den Archives August 2001

EZ-Burner: Ricardo, That is an old Ron Reil plan hosted on his page. It has been built by thousands.

That burner is what is called an "Atmospheric Burner" because is runs on atmospheric pressure - there is no blower. They are used on many commercial forges.

They are very tricky to get everything balanced to run correctly. Any one burner will only work with one volume of forge. On commercial forges they add burners as the forge gets bigger. Make the forge twice as big and you need twice the number of burners. A single EZ-Burner will work on roughly a 1/3 of a cubic foot or about 10,000 cm3.

I quote from the Ron Reil site.
You will need at least 450 BTUs per cubic inch of forge chamber volume if your forge is going to be able to forge-weld. Some would argue for a figure as high as 540 BTUs per cubic inch.

The "Reil Burner" will deliver about 135,000 BTUs at medium to higher gas pressures, and can be cranked up to almost 200,000 BTUs by raising the pressure to 20 psi or more. In the lower pressure range of from 1-6 psi, where I do most of my work, it will produce about 60,000 BTUs, or even a little less. Use the middle figure in any design calculations.

Shoot for a burner to volume ratio of 1:300 or less. Some smiths who are very
knowledgeable would say a more conservative ratio of 1:250 would be safer and insure that your forge will be able to weld. To calculate how many 3/4" burners you will need just divide the total chamber volume of your forge, in cubic inches, by 250 or 300, and then round up. If you come out to a burner requirement of 2-1/3 burners, then you will need 3 burners for your planned forge volume. Always plan conservatively or you may end up with a forge that is too cold to forge-weld.
The above information is assuming that you will build a well insulated forge, having at least 2" of Kaowool lining coated with ITC-100, not Satinite, on the interior surface of the chamber. A 3" lining of Kaowool would be even better, and would probably pay for itself in fuel savings over the long run. If you elect to use a
rammable or pourable refractory, or bricks, you will have to address the lower insulation values associated with these materials. One option is a composite design, a pourable refractory shell for durability, inside a Kaowool shell for insulation value. These are more difficult to build but are long lasting and can work very well.

- guru - Wednesday, 08/08/01 03:33:09 GMT

[HeavyHammer]

I have checked for burrs and i dont see any. The jet is straight . The outside of the forge gets warm but you can touch it for a second with little discomfort. Though i wouldnt go holding your hand on it. Its got 1 1/2" thick kaowool lining. Diminsions of inner chamber:9" long, 7" across:( i got the choke off of rons site: http://www.frontiernet.net/~gnreil/design2.shtml#axial

I think im going to see if the "improvements" i did today will help. I took it completly apart and reassembled it(pics tomorrow:))
Thank you for your help !

[ThomasPowers]

The choke is to try to adjust the atmosphere in the forge to get it more towards reducing. it's a common design---that was the type of burner we built at the SOFA gas forge workshop though out forges at 10-11" dia and appx 16-18" long used two burners; very handy as I can dial the back one way down and get a quite reducing fire in the forge.

Adding a blower to an aspirated burner shouldn't help. In fact adding extra cold air beyond what the burner can use will cool things down---as well as make it fiercly oxidizing---not helpful for welding.

If you want a blown burner build a blown burner---they are easier to build than an aspirated one as you don't have to be so very picky about alignment and orifice size as you can adjust the airflow to suit.

Thomas.

[Woody]

I ran the numbers on your forge chamber size, for that size chamber you will need a minimum of roughly 160,000 btu actually it comes out to 155,000 and change but 160,000 gives a very slight margin for error. Your current options are to either decrease the size of your forge chamber or add another burner. I would toss a fire brick in the bottom to take up some of the space and that may allow you to attain welding heat. You will have to crank the pressure on your propane way up, I run mine at 30 psi when welding. Also if you want a reducing atmosphere when welding toss in a chunk of charcoal, not a brickette, real wood charcoal, this will help burn the excess oxygen out of the atmosphere.

Hope this helps you

Woody

[frogvalley]

First, I agree withThomas Powers, if you want blown, build one from scratch. Simply put, you can't just add a blower to a burner of this type. Can't, shouldn't, it won't work.

So to try to fix the naturally aspirated burner that you have, first I ask a question. What is the orifice diameter? What pressure are you running? Where is the all important flare tip? It looks like your pipe from the burner is welded straight into the burn chamber.Without the proper taper or flared tip you will never get enough heat. You should also have the burner pipe isolated from the chamber wall, I use a larger pipe with the old three bolt pattern around to position the burner in the center. It helps to keep things cool and you can slide the burner in and out to adjust it.

About the choke. Open it or remove it. My choke is similar, but I just looked at it and its open about an inch at normal pressures. You can see a rough picture of it at http://www.frogvalley.com/forge.html

I have one of these types that I use daily and it will get to weld temp in 10 minutes. It s chamber is bigger than yours by a bit.

[HeavyHammer]

i need to post some new pics but i forgot(got a little busy to day) First my choke has a spring that keeps it up and i just put in a bigger spring to lengthen the opening. Im not sure the orifice size i think its a #60. im running at about 16-18 psi.There is no taper or flare or anything on the end. Its not welded to the chamber but it screws in. Im working on a thing like you said to get it up and outta there. im working on getting a flare from Zoeller Forge but i havent gotten that far yet.Thank you for the help you guys im gonna pretty much scrap the idea of the blower.i dont know much about this thing because i bought it from a friend of mines son(older than you think) Thanks,
pics later i promise.

[T-Gold]

Er. I beg to differ with Frog -- and I in fact have welded in forges without flares -- they are not that important, and simply provide flame stability when the forge is below cracking temps (red heat). Once the forge is up to temperature, the "burner" is just a mechanism for injecting a certain amount of gas with an appropriate amount of air accompanying it. Ron Reil is a very smart guy who provided a great resource for us all, but his focus on using burner flares to slow flame front velocity to the exclusion of just getting a dang burner working is a bit counterproductive.

Anyway, to shorten my yakking. If that were my burner, it would be drilled to #70, and the choke would be opened a bit. #60 would be the max for the jet size. Pressure at forging temp would be 6-10 PSI, initial heat would be 15-20PSI. Also, I can't quite tell how deep your forge is -- so the issue with forge size may be relevant as well. Since you built with Kaowool I would assume you have some left -- maybe stuff it into the back of the forge and see how it works. Also if possible you may want to neck down the front opening a bit -- stacked firebrick works well for this. Good luck!