January 27, 20188 yr Hi all.. I just made a two inch forced air burner.... I followed the plans of hans peot except that my gas comes into the tube slightly different ...... I have a 1/16 inch orifice.. .. all the metal tubes are two inch... I have a hair dry as a temporary air supply that blows warm air... I have welded rings that are three inch long at end of burner tube that are I had stainless steel wool at the top of the tube to aid the air gas mix.... the chamber is and I'm South African so it' in millimetres... . 300mm x 100mm x 70mm which I think is 210 cubic centimetres..... I run it at between 1psi and 5 psi with the blower adusting airflow according to gas pressure..... I think possibly the stainless wool might've melted a bit and blocked a bit of the flame holder as it was roaring and then I heard a sound and then it sounded different and when I took the burner out it looked like bits had been welded to the end... I shall attach pics and videos .... let me know if you need more info.... oh and the back door was closed with a cm gap a long the top and front door has a mouse hole..... thanks guys
January 27, 20188 yr It is not supposed to be burning inside the mixing tube. The flame holder rings in the one I built with Hans Peot looking over our shoulders were quite short. I read this as "I built it exactly like the plans but changed them so I didn't build it exactly like the plans, where did I go wrong?"
January 27, 20188 yr 29 minutes ago, Nic said: I'm South African We won't remember that after we leave the thread... https://www.iforgeiron.com/topic/53873-read-this-first/
January 27, 20188 yr Author The plan I have says 3 inch... Maybe I got confused as I work in millimetres... let me check
January 28, 20188 yr Can you show the part of the plan that mentions the stainless steel wool in the pipe?
January 28, 20188 yr Is that will not or cannot? a burn is a balance between the rate the flame will propagate up the tube and the speed the gas/air travels down the pipe. The typical flare on the end of many burners thus creates a gradient of speeds so hopefully one will be stable for the flame. If you are burning in the mixing tube the gas/air speed is too low. If it blows out off the end too high.
January 28, 20188 yr Author Hello.... Attached is the plan I'm working too (now).... my question is it says a 2 inch coupling which I have then a 2 inch nipple.... is that the length of the nipple when it is screwed betweeb the coupler and the 90 set bend .... coz i have a 3 inch nipple but a two inch gap.... I haven't seen 2 inch nipples.... my other question is doesbthe position of the orifice matter to much as in how far into the burner it should go.... and should I knock the flame holder out and cut it shorter as @thomas powers 'mentioned On 28/01/2018 at 12:41 AM, ThomasPowers said: The flame holder rings in the one I built with Hans Peot looking over our shoulders were quite short. Thank you
January 28, 20188 yr The size of your forge is nowhere near what the drawing is. It appears way to small for that size burner.
January 28, 20188 yr Author 4 minutes ago, jeremy k said: The size of your forge is nowhere near what the drawing is. It appears way to small for that size burner. I sha'll keep it for the next forge then Attached is the plan I'm working too (now).... my question is it says a 2 inch coupling which I have then a 2 inch nipple.... is that the length of the nipple when it is screwed betweeb the coupler and the 90 set bend .... coz i have a 3 inch nipple but a two inch gap.... I haven't seen 2 inch nipples.... my other question is the position of the orifice matter to much as in how far into the burner should it go.... and should I knock the flame holder out and cut it shorter as @thomas powers 'mentioned On 28/01/2018 at 12:41 AM, ThomasPowers said: The flame holder rings in the one I built with Hans Peot looking over our shoulders were quite short.
January 29, 20188 yr Looks to me like not enough air pressure and/or flowrate from the blower. A hair dryer may just not cut it for this type of burner (and steel wool certainly won't help). What did the designer specify?
January 29, 20188 yr Author The hair dryer is just a temporary thing... my actual blower I am collecting tommorrow.... it' is a jumping castle blower that I'll add a valve to to adjust the flow.... designer didn' specify the steel wool ... someone else suggested it....the designer specified a 150cfm blower.... but I think bottom line is ... it is to big for my forge.... which is fine as I am sure I'll be building another one at some stage... I did however today made some changes to it so now it is to the exact specs the designer specified .... I took the flame holder / rings out today and it actually melted the back end of the pipes ... this is with the adjustments.... needle valve and changed the entry positin of the gas... Will test in tommorrow morning
January 30, 20188 yr Author The steel wool was the 1st thing to go...i cleaned up the burner and gave it a try today.. .. the bottom of the burner tube heated up but not red.
January 30, 20188 yr Author I can' say for sure.... the steel wool is out.. . The gas is coming In at the 90deg bend.... i sand papered the tube to make it shine again now the bottom of the burner tube when I took it out from about 10 mins of burning....was hot but not red hot... and the steel for about 2 inches had gone that hot blue colour .... once it twice while I was adjusting things I would hear like a thump the flame would go out and then I'd hear a sort of hollow echoey sound. .. I'd swith off gas then switch on and light again.. .. is the only way to tell if it' burning in the tube is when the tube starts to glow?
January 30, 20188 yr No the sound is very distinctive. In my NA burners I can often back out the choke and give a big puff of air and push the burn out the end of the tube. With my blown burner I was always able to open the gate to the blower to accomplish that.
January 31, 20188 yr Author 7 hours ago, Mikey98118 said: Now you need to at least double the hight of your forge. I won' be changing that forge but maybe in a bit make a bigger one 6 hours ago, ThomasPowers said: No the sound is very distinctive. In my NA burners I can often back out the choke and give a big puff of air and push the burn out the end of the tube. With my blown burner I was always able to open the gate to the blower to accomplish that. It didn't happen when inside the forge but rather happened in the vise outside the forge....
April 30, 20206 yr Since the forge size is too small, I am wondering whether this design would be appropriate for a single burner with a 35° offset in a propane tank forge body?
April 30, 20206 yr Your flame nozzle needs to be a larger diameter than the mixing tube, if you want the stop the flame from backing up into it. You don't have to change the design of the flame nozzle, but you need to at least change its size.
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