meco3hp Posted August 31, 2005 Share Posted August 31, 2005 Hello, I got my gas forge put together and I'm having a problem with keeping the flame stable. It "huffs", but when it is stable it is a nice neutral flame. it looks nice then, but it goes to a orange flame that is soft and bellowy (is that a word?), then it reignites to a nice blue neutral flame back in the opening of the burner. It is a 8" Reid burner with a #58 orfice and I'm running it at 15 psi with an adjustable regulator. I've tried to change the pressure, but I'm not seeing any change, other than in the sound of it. What am I doing wrong. I've got it out in front of the shop with a little breeze, could that be a problem. I've checked it for leaks and such but everything looks good. This is too simple of a design to have too much wrong with it. What have I missed? Thanks Richard Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted August 31, 2005 Share Posted August 31, 2005 I think "billowy" is what you wanted but bellowy is a nice double entendre for a blacksmithing board... 8) Questions: Is it unstable when the forge is cold or hot or both? Can you post a pic of it burning? I think what is happening is the burner is running rich and starving for air so it starts to lose stability, but the fuel pressure stays the same and overwhelms it - that's when it "huffs". The explosion pulls in air and starts it burning blue again. They usually work fine but the problem with naturally aspirated burners is that they do take some fiddling to burn right - a blower helps even out the hiccups. However, I would try a smaller orifice first and see if that helps with the mix. I ran a #68 on my home made single burner and it burned well except on hot dry days when it could have been a bit leaner. In general, it's better to start very lean and open the orifice as needed. Try something in the range of a #63 and see how that works but keep the pressure around 15 lbs. Please note that a properly adjusted burner will often sputter and huff when you first start a cold forge but will even out and burn correctly when it gets warm. Quote Link to comment Share on other sites More sharing options...
meco3hp Posted August 31, 2005 Author Share Posted August 31, 2005 Hello, I might just have too much gas. The orfice size was a suggestion from most of the forge web sites. Start with a #60 and most likely go to a # 58 or 57 later on. I figured on a #58 to split the differnce. It "huffs" wether it's cold or hot. I'll get a couple of nipples tommarrow and try differnt sizes, starting with a #63 and see what I get. Here is a picture of it running. Kinda fuzzy, and it is "huffing" about once a second in that picture. I was going by the pictures on the following web site as to the shape and color of the flame.http://metalcast.boorman.us/reil_1.html I noticed that he says you might need to "adjust" the "flare tip". I might try that if after I get some new nipples I still have problems. I need to get this going as I need to get to forging! Thanks RichardEdit: photo resized Quote Link to comment Share on other sites More sharing options...
Ralph Posted August 31, 2005 Share Posted August 31, 2005 Do you have a nozzle tip on the burner? ( a flared one?) If so you might need to 'tune' it. Take burner out and light it. see how flame is. turn off and slip nozzle up or down till it huffs. The go other direction till it burns poorly. slide it back till it burns smooth. At least that is what I remeber. I got that info from Ron Reils web site. But I am not sure if he still has that info posted. Good luck Quote Link to comment Share on other sites More sharing options...
meco3hp Posted August 31, 2005 Author Share Posted August 31, 2005 Hello, Yes I've got a flared tip. I didn't relise that it would make much differnce. I'll take it out and try it. I'll also look at Ron's site some more. I might have got info-overload and missed that part. He has so much info on that site that you can get lost real easy. Quote Link to comment Share on other sites More sharing options...
Marc Posted August 31, 2005 Share Posted August 31, 2005 I'm guessing it's not the nozzle. Adjusting that is usually for very low or very high operation. A #58 at 15-lbs, and inside a forge, is usually not that sensitive to the nozzle. A couple things that make a big difference with naturally aspirated burners is aiming the propane down the mixing tube, a badly drilled orifice, and any obstructions in the tube itself. Chances are, if you're using a standard black pipe nipple for the mixing tube, you're all set. Make sure you have no burrs in the orifice. I used a MIG tip for my orifices when I had a Reil burner. And you could use a MIG tip cleaner to clean out the orifice and remove burrs. Ron's site has a real neat trick to aim the propane jet. You hook up a water source to the gas tube and adjust until the water goes straight down the mixing tube. It's interesting that this very subject was just brought up on the forgemagic forum. So anyway, those are a couple more things to try. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted August 31, 2005 Share Posted August 31, 2005 You did say there was a breeze right? Aspirated burners are very breeze sensitive, I can even get an effect from one when it's in the shop. Thomas Quote Link to comment Share on other sites More sharing options...
Ralph Posted August 31, 2005 Share Posted August 31, 2005 I still think it is the nozzle. Made a world of difference :?: Questione in my forge. And I have talked with Ron in person. It is his contention that it is more important than most think. Takes only a few mins and costs nothing. Ralph Quote Link to comment Share on other sites More sharing options...
T-Gold Posted August 31, 2005 Share Posted August 31, 2005 This kind of problem is typically caused by the burner "rebreathing" forge exhaust, in my experience. I've seen it on a variety of forges, in a variety of situations. My suggestion is to aim a desk fan so that it will blow the dragon's breath away from the burner intake. Good luck! Quote Link to comment Share on other sites More sharing options...
frogvalley Posted September 1, 2005 Share Posted September 1, 2005 I too had problems adjusting my modified "reil" burner to work well inside the forge I designed. The flare tip adjustment is the first thing I had to get right, it is critical and difficult to do outside the forge as everything changes once you install it in the forge , but the next thing was the actual shape of the forge and the way the flame entered the chamber. Backpressure from the forge is a big factor in adjustment of the burner. I like the vortex created by a tangentally mounted burner. The burner I have is mounted as a sidearm and not a top down burner and has less backpressure than my early experiments. My experiences led me to change the angle that the burner comes into the chamber several times. I use a mig tip as well, the difficulty of aligning the hole in the pipe of the original design was just too great, I switched to the mig tips and visually its much easier. Quote Link to comment Share on other sites More sharing options...
Ralph Posted September 1, 2005 Share Posted September 1, 2005 I got around the hole alignment issue by scribing a straight line down the pipe before drilling. Helps a load when lining up down the tube. :) Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted September 1, 2005 Share Posted September 1, 2005 First off - I am not knocking anybody's design and I don't know if any of you fellers ever built one of the old Sandia forges designed by Robb Gunter but the burners were pretty simple after a few bugs were worked out. I eventually made a little single burner that was no more than a short piece of 2" pipe necked to 3/4" pipe size. A factory 2" to 3/4" reducer weld fitting will work just as well. I drilled a cross hole in the two inch just back of the neck to hold 1/4" pipe for the feed tube. The jet was drilled directly in the small pipe - #68 drill. A file mark on the cap end shows approximate orientation so it could be both rotated and drifted right or left to get the flame right. The 2" pipe was only about 3" long including the necked area and was welded to a 3/4 pipe nipple, which was screwed into a 90 el, then another 6" nipple went down into the forge. The whole burn tube length was therefore about 14 inches from jet to forge. No special flaring or other tip treatment was required on the pipe. If all the stock was in the shop, you could make one of these in an hour or two. Everything can be black iron EXCEPT the small cross pipe for feeding the gas should be stainless because the thermal cycles make black or galvanized pipe drop scale and the debris will clog the small jet. This burner will make a blue flame about 3-4 inches long at 12-15 lbs of propane in the shell of your choice. With all this said, I eventually changed to a 60 cfm squirrel cage blower and no jet. I just dump gas thru a needle valve into the air stream at 4 lbs of pressure and get welding heat in about 20-30 minutes. The combination of needle valve and blower cover to choke the air flow gives me infinite adjustment for the flame. Quote Link to comment Share on other sites More sharing options...
meco3hp Posted September 2, 2005 Author Share Posted September 2, 2005 Hello, Ok I've been messing with my forge and it burns just fine when its out of the forge. When I put it in the forge I have to "adjust" the pipe in the flared tip until it burns steady. When I do that I get a nice steady, neutral flame. But when I close the door it starts to do long "huffs". I open the door and I get a nice steady flame, agian. When I put the elbow and the pipe nipple on the top, it gets a little better. Do I need to open the "exhaust" hole in the back more? Where my flare tip goes though the I have some gap, could that be a problem? Here are some pictures. Now don't laugh too hard at my setup. Once I get the bugs worked out I'm planning to build a bigger and better one. I got 4700lbs of refractory to work with! :mrgreen: Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted September 2, 2005 Share Posted September 2, 2005 Sounds like a back pressure problem and having a larger exhaust vent would help. Is that elbow above the burner to allow the use of a blower? Because it will hurt the draw of the burner as well. Thomas Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted September 2, 2005 Share Posted September 2, 2005 I suggest removing all the pipe from the nipple up. In other words, the top most piece should be the reducer that holds the gas fitting. That is easy to try and should make some difference. You also need a hole to let it exhaust - like a car, plugging the tail pipe will make it quit running - but you already have that back hole, which should be enough. That is a good flame but the color looks rich - maybe too much gas, so I would also reduce the orifice. Quote Link to comment Share on other sites More sharing options...
meco3hp Posted September 3, 2005 Author Share Posted September 3, 2005 Hello, I'm planning to go to a #60 orfice and see what happens. I'm also thinking of opening the rear hole more, I'll have to see what happens. The "extra" pipe was a experiment. It kinda helped. I thought it might be pulling exaust into the "mix" and giving me fits. I'm thinking I need to force the exhaust away from the forge. The door seals up pretty good, but could use some more "fitting". I might get some stove door seals and see if I can get the door completely sealed. Do you guys think this would help? Thanks for all of the suggestions. I'll get this thing figured out one way or another. Quote Link to comment Share on other sites More sharing options...
T-Gold Posted September 3, 2005 Share Posted September 3, 2005 I third what Thomas and Woolridge said. As I said, use a fan to blow the exhaust away -- don't mess with sealing the door, waste of time... and in general, it's best to bring burners in from the side, so that A) they don't huff their own exhaust (kinky!) and they don't get super super hot when you shut off the forge (chimney effect). Quote Link to comment Share on other sites More sharing options...
frogvalley Posted September 8, 2005 Share Posted September 8, 2005 I too would change the burner from top down to a side burner. And I agree about not sealing the door. I just have an opening in front and back, the back has a loose brick for a plug and the front stays open almost all the time, ocassionally I put a brick in it partially blocking it. You can see mine sitting in my shop at www.frogvalleyforge.com. It ain't pretty, but I've run a dozen tanks of propane through the pig(that's her nickname) with no trouble. Naturally aspirated or non-blown burners should never be closed tight. They must have at least as much flow out as they do going in. That is a lot more volume than you think. Quote Link to comment Share on other sites More sharing options...
Ralph Posted September 8, 2005 Share Posted September 8, 2005 How does a burner huff its own exhaust if you are using a cylinder? Side or top it will be the same distance from the edge of the forge. The few forges I have built all had the orignial issue and tuning the flare fixed it. Ralph Quote Link to comment Share on other sites More sharing options...
meco3hp Posted September 8, 2005 Author Share Posted September 8, 2005 Hello, I think I got the problem hammered out. I changed the orfice size to a #60. As you guys said the forge had to be warmed up for a while for the flame to stableize. When I was adjusting and testing it I was only letting it get about 10 minutes of warm up time. That was just starting to get a good orange color to the surface of the refractory. When I let it run for about 30 minutes and the refractory was a bright orange almost all the way through and I shut the door, it'd run fine, with no "huffing". I'm going to run it for a few days and see what happens. Thanks For the help! Quote Link to comment Share on other sites More sharing options...
T-Gold Posted September 8, 2005 Share Posted September 8, 2005 Ralph, heat rising. Top mounted burner means as hot exhaust flows up and out of the mouseholes it gets sucked into the burner -- side mounted it would have to flow down and around Meco, glad you got it working! Now you can pound some iron :) Quote Link to comment Share on other sites More sharing options...
Ralph Posted September 8, 2005 Share Posted September 8, 2005 Tyler, I understand about heat rising. But unless thte burner was placed close to the edge I do not think that is a problem. But that is my two cents worth based on my forge. The burners are on top but they do have about a 30 degree angle ( I think) Either way I do not have exhaust recirc issues. So far Ralph Quote Link to comment Share on other sites More sharing options...
bellman1 Posted March 8, 2009 Share Posted March 8, 2009 I built the "Reil" burner as per specs. Got a 30# adjustable regulator, put it all together and can't get t to stay lit. Tried increasing and decreasing the pressure with no joy. The closest I came was reducing the pressure to 3.5 lbs. and that was still unstable. So I'm thinking "too much air". Started off with a #60 orifice and decided to open it up a bit. I went to a #50 opening, to get more fuel, and still it won't stay lit, although it sounds like a FA/18 taching up! Anyhoo, as an old school person as far as carburetion goes, my thinking is that if the flame is burning out or won't light then there is not enough fuel. Should I keep opening up the oriface till I get the proper burn, or ? Thanks in advance for all the help. Mark Quote Link to comment Share on other sites More sharing options...
Frosty Posted March 8, 2009 Share Posted March 8, 2009 Try partially choking the intake with your hand while you light it. This will richen the mix. If it lights and stays lit (you can adjust available intake air by moving your hand.) then you need to enlarge the orifice. However, the #1 problem getting a burner working is proper alignment, if the jet isn't aimed straight down the bore it won't work well if at all. Symptoms are the same as you describe. You can try hooking it up to water so you can see where the gas is aimed. Point the burner straight down when you check so gravity doesn't throw it off. Frosty Quote Link to comment Share on other sites More sharing options...
bellman1 Posted March 14, 2009 Share Posted March 14, 2009 Hey Frosty, Thanks for the tech tip about using water to check alignment. I learned alot about following through when building something just from doing the water check (which if you have burner problems you should do this to check the alignment of the oriface into the burner tube). It turns out I had left a burr in the oriface tube after drilling. I replaced the tube with one that has a #60 hole, alignment is perfect with the water test and it still won't stay lit at 15 lbs. psi. As suggested, started to close off low pressure side of venturi with my hand. I got a stable flame after closing off about 1/3 of intake. I don't have a problem with trying to make some kind of aperature to control the air flow, but I'm more interested in knowing if it would make more sense to keep opening up the oriface size to get a proper burn? I know that at some point you would have a four foot long flame coming out of your burner, and be wondering why it won't work in your 10" forge. I'm sure that you'll be able to steer me in the right direction. TIA. Mark Quote Link to comment Share on other sites More sharing options...
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