Outdoor Wood Furnace Info
Outdoor Furnaces - Manufacturers with NON EPA-Certified Models Only => Home Made => Topic started by: BFB Builder on November 10, 2010, 07:47:49 PM
-
I built my owb about 8 years ago from an 800 gal bulk dairy tank and a 400 gal air tank torpedoed into one end. This year I switched from green nasty whatever hard or soft wood was available to 1 1/2 year old dry slab wood. I have had problems smoked out the neighborhood BAD. I am using a 6" stack with a single pass through the water that only extends a couple of inches into the firebox then on the offending end goes up appx 15 feet. The smoke is especially bad just after I stoke up but I would love to reduce even "up to temp" output. I did also add a temp controller this year but it is cycled on during the periods of bad smoke. The gas off the stack is flammable (wood gas) about 15 min after a stoke but after about an hour it has settled down enough to not burn. I am looking for solutions to this smoke issue without a total rebuild, since the commies have come up with regulations that I am grandfathered from. I probably could call any next generation burner a "repair" as long as I used some of the same components. A couple more tidbits for what they are, the fire box is completely surrounded with water, I do not use a grate or ashpan but rake out a couple shovle fulls and pile wood onto the ashbed in the bottom. Any help would be great.
-
I have read a bunch more posts, what do you guys think about running my flue down into my coal bed to try and burn off the gas on the way out?
-
if you are creating gas that goes out the stack unburnt (smoke) just lowering your stack may help a bit but i think you will also need to add hot (as hot as you can get) combustion air to the unburnt gas to cause ignition. you need three things...fuel, heat and air
fuel you have (the smoke) heat, you may or may not have enough, and air you definately do not have enough or you wouldn't have the smoke problem
my thought on this anyway
good luck on your attempt to fix your problem..post back and let us know your results as we may all benifit from your work
-
I agree with Willie,you probably need more heat.I would think lowering your stack pipe would help.What diameter is the firebox?is this a natural draft?If you have a blower on it maybe you need more cfm's to get a hotter burn.
-
like me if you worried about smoking out the neighborhood....Raise that stack..The higher it is, its a world of difference..My stack is 20ft up...Yeah mine smokes the most when u first fill it up..Just like a reg wood stove..After that hardly know its there...Def I sug. a higher stack..Def will get a nice daft if not using fan
-
I am running a forced draft, the stack is appx 15' tall but only extends a few inches into the firebox. I am thinking of putting an extension inside the firebox to put the bottom of the flue into the coal bed. My thought is running the gasses through the coals will hopefully burn them up on the way up and out. The firebox is about 3' round and 6 feet deep. My fan is more powerful than in years past (they used to be outside unprotected so it ate them up once a year) but i am burning slabwood this year not log chunks..so i have much more surface area to burn at one time. I may need to run a fresh air pipe to the flue to give it enough air to light in the flur as opposed to smoking the neighbors out.
-
bfb...have you cleaned your blower and the pipe it blows in to ensure you are getting as good of forced draft as when you were not having problems? just a thought
-
I did some modifications last night into to early hours of this morning and some results are in, I lowered the flue pipe to about 2" off the bottom of the stove so the smoke now must pass through the hot coals laying in the bottom. I also split my combustion air and 1/2 goes to the fire and 1/2 blows up into that up piece. The smoke from opening the door is now pretty intense, but as soon as I close the door I have a nice red turbo flame in my horizontal and vertical sections of stack, the horizontal is passed through water and the vertical is up and out. The smoke was reduced but from a very cold fire to begin with and diffrent weather pattern I cannot pronounce this cured yet...but hope is high and looking good. I will post with more info when the results are in. Thanks to all that had input.
-
looking forward to the next post being a positive one BFB. hoping you see good results from your experiment. I am sure there are lots of folkls watching this post that may or may not be having similar problems and many will jot down your "fix' (if successfull) for future refrence.
I know i will!
good luck
-
Well more results are in and it seems that the smoke is redudced but my blower runs for longer cycles. This does not shock me since I stole 1/2 of te combustion air to burn in the pipe. My next step is going to be to increase the size of the fan, but I am in no hurry since all is running fine at the moment.