Neal L Posted April 5, 2008 Share Posted April 5, 2008 :o I had a suprise today as i was working. I got a very big bang the blew the air pipe off where it is joined. I haven't been using this blower very long but this is the first time this has happened. I put my blower outside to reduce the noise in the shop. I ran metal pipe from the forge and then went through the wall with PVC pipe. It's a good thing i didn't glue all the joints and gave it a place to come apart other wize i might have had a busted pipe. I'm guessing some hot gasses went back up the pip and when fresh air hit the hot gas...BANG:o. After that happened i close the blast gate each time i turned off the air. Anyone ever had this experience or know how to keep it from happening. I have some pictures i will see if i can get them linked from the gallery Quote Link to comment Share on other sites More sharing options...
agsolder Posted April 5, 2008 Share Posted April 5, 2008 It's just coal gas, methane, that accumulated down in the tuyere and a spark got in there and ignited it is all, the pressure from the blast went back into the pipe. Like the pop you can get on a propane forge after you've shut the feed off, and then bleed the line into the hot forge. Scary but not life-threatening-- as far as I know, anyway. Sure gets your attention, though, doesn't it? Quote Link to comment Share on other sites More sharing options...
Neal L Posted April 5, 2008 Author Share Posted April 5, 2008 Yea it was a loud enough I was wondering what blew up. I had just added more green coal to the forge also. That might have help with the build up of gas. Quote Link to comment Share on other sites More sharing options...
steponmebbbboom Posted April 5, 2008 Share Posted April 5, 2008 my tuyere is designed with a counterweighted ash dump, that is to say it has no latch but rather a weighted handle and a pivot that allows you to dump ash by raising the handle. the advantage to having no latch is that in the event of a backfire, the easiest path for the expanding gases is through the ash dump. it simply forces the dump open and blows downward, that way the fire doesnt explode upward. Quote Link to comment Share on other sites More sharing options...
Neal L Posted April 5, 2008 Author Share Posted April 5, 2008 My ash dump is the same this shows my setup.... it blew the pipe off where it goes through th wall. Quote Link to comment Share on other sites More sharing options...
steponmebbbboom Posted April 5, 2008 Share Posted April 5, 2008 sweeet. well neal, in my experience backfires are most common on startup, when im really pouring the air to it and the smoke is barking out the top, it tends to backfire if i let off and go back on again. what i do to prevent this is ease down on the air until the smoke ignites. if you have some coke in the firebox and you see a lot of smoke, it doesnt hurt to cut back on the air feed and let the fire build. Quote Link to comment Share on other sites More sharing options...
dablacksmith Posted April 5, 2008 Share Posted April 5, 2008 I remember the first time i had that happen ... I had a kid tryin to learn blacksmithing and he had started to shut the forge down .. i told him not to so he added a bunch of green coal and cranked hard.. the intake for the blower (champion 400) was above the forge and sucked a bunch of the coal smoke ...BANG I hollerd at him WHAT DID YOU DO!! i finally figured it out nuthing hurt but scared the ..... out of me and the kid .. never had it happen again but now I know why so I dont let the same condition happen... Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted April 7, 2008 Share Posted April 7, 2008 Pouring water on the fire can generate gas too---used to make gas for gas lights in cities by running steam over hot coke. Quote Link to comment Share on other sites More sharing options...
pete46 Posted April 7, 2008 Share Posted April 7, 2008 . Lower The Hole At The Wall; And Make The Air Feed Blow Up Into The Forge. The Way It Is Sucks Air Back Into The Pipe ,hot Air Rises. I Hope This Makes Sense ! Quote Link to comment Share on other sites More sharing options...
Neal L Posted April 8, 2008 Author Share Posted April 8, 2008 Pete that does make sense. Plus the blower is outside is mounted even higher. Thanks Quote Link to comment Share on other sites More sharing options...
chyancarrek Posted April 9, 2008 Share Posted April 9, 2008 I used to be an interpretive blacksmith at a National Historic site and we used ceiling mounted double chamber bellows - We'd get gas rising into the chambers if we let the fire idle while we were giving a talk - if we forgot to pull slowly to expel the gas - BAM! It blew one bellows completely free of it's mounts and shattered the frame - we then installed openings in the pipe with a taped on can lid - this gave the pipe of point of least resistance so the lid would blow first. It'll wake you up that's for sure . . . Quote Link to comment Share on other sites More sharing options...
pete46 Posted April 9, 2008 Share Posted April 9, 2008 I Have Justified My Existance ,& Helped Someone ! If Only My Ex- Wife New!;) Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 9, 2008 Share Posted April 9, 2008 I Have Justified My Existance ,& Helped Someone ! If Only My Ex- Wife New! You want her back? Frosty Quote Link to comment Share on other sites More sharing options...
Ice Czar Posted April 9, 2008 Share Posted April 9, 2008 It's just coal gas, methane, mostly carbon monoxide, possibly some hydrogen, possibly some methanePouring water on the fire can generate gas too---used to make gas for gas lights in cities by running steam over hot coke.Coal gas Producer gasWater gasWater gas shift reactionFuel gas for industrial use was made using producer gas technology. Producer gas is made by blowing air through an incandescent fuel bed (commonly coke or coal) in a gas producer. The reaction of fuel with insufficient air for total combustion produces carbon monoxide (CO); this reaction is exothermic and self sustaining. It was discovered that adding steam to the input air of a gas producer would increase the CV of the fuel gas by enriching it with CO and hydrogen (H2) produced by water gas reactions. Producer gas has a very low CV of 3.7 to 5.6 MJ/m Quote Link to comment Share on other sites More sharing options...
Gary Posted April 9, 2008 Share Posted April 9, 2008 chyancarrek, was that the one that blew at Ft. Vancouver a few years back? Quote Link to comment Share on other sites More sharing options...
chyancarrek Posted April 9, 2008 Share Posted April 9, 2008 That it was Gary! I had a number of those "poppers" that really got my attention. Luckily none did any damage. It was just so darn easy to forget to purge the bellows if you had a fairly green fire running . . . You're being familiar with that incident I'm thinking you put in some forge time down there. If so, still there? Quote Link to comment Share on other sites More sharing options...
pete46 Posted April 9, 2008 Share Posted April 9, 2008 Frosty: R.u. Nuts! I Get All The Adult Supervision I Need At Work! Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 9, 2008 Share Posted April 9, 2008 Frosty: R.u. Nuts! I Get All The Adult Supervision I Need At Work! Well. . . Yes, yes I am, but it was you made the "if ONLY" statement. Frosty Quote Link to comment Share on other sites More sharing options...
pete46 Posted April 9, 2008 Share Posted April 9, 2008 Frosty you have a point and I stand corrected! MAYBE DEEP DOWN IN MY SUBCONCIOUS I WANT TO BE BEAT DOWN , HAVE MY MONEY WASTED ON CAT FOOD,[cats feed themselves] & BE TALKED TO LIKE A RENTED MULE! AGAIN I 'M SORRY. I'M THE ONE WHO'S NUTTER THAN A SQUIRREL! Quote Link to comment Share on other sites More sharing options...
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