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Post by shahborn on Feb 10, 2011 13:07:57 GMT -8
Last night I did a little testing with the rocket. My setup was from the feed hole to the heat riser as follows 1 6" coupling then a 6-8 reducer then 2 8" elbows and another 6-8" reducer, another coupling and a 6-4" reducer with an insulated 4" pipe for a heat riser. I used a barrel made of some type of aluminum alloy with a 2" gap between the top of the riser and the top[ of the barrel. The whole "J" section of the stove was put in a box made of hardiboard and filled with a mix of perlite and wood ash for insulation. Also the 1st coupling in my feed tube was cut allowing a hole about 4 x 1" for an air intake and the i used a 6" cap as a cover. I hope you guys can picture this as I still dont have pics.
good results: After getting the fire started, and loading the stove with 4" round and 3"thick blocks of an small dead tree i had in the yard. I found that with a full load I could get burn times of about 4 hours per load. I could also heat the barrel to about 500+ and maintain that for the whole 4 hours. I had no bench but exit temps of the flue gas ran between 250-350. I did not melt the aluminum alloy barrel. Hardibacker, reinforced with 3/8" threaded rods makes and excellent container for anyone who might want to use something other than cob. this stuff takes heat very wall and seems not to break down. just fill with insulation an go!
Bad results: I melted everything from the second elbow to the bottom of the heat riser and the riser eventually collapsed. So Im in search of new materials.
Side note: I caught a mouse is one of those sticky traps during my testing so I dropped him into the rocket. He burst into flames after about 5 seconds. and was totally creamated in about 20 seconds.
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Post by machinemaker on Feb 10, 2011 19:08:23 GMT -8
Aluminum alloys have a fairly low melting points. It is pretty easy to melt aluminum in wood fire, let alone the temps seen in a rocket stove.
kent
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Post by shahborn on Feb 12, 2011 9:00:39 GMT -8
Yeah I know. I bought my barrel at a scrapyard. the guy who sold it to me said it was aluminum, but to me it looks like stainless steel so I bought it to see how it worked, it feels heavier than aluminum, and is just a lil over 1/4" thick. I actually think that it was once a trash can. You know the type with an ashtrey on top and a hole in the side that you drop trash in. I have been testing it for the past few days, and have heated it for 8+ hours per day. My thermometer only goes to 600 and I know I have been much higher than that, with no change to the barrel so im sure that this is either some type of alloy or a non magnetic stainless alloy. I have melted many a tin can over my rocket so Im sure its not aluminum, at least not pure aluminum.
I rebuilt my Rocket yesterday, spent all morning looking for new materials. I found an old prefab fire place an stripped out the fire tiles. I also picked up some cast Iron pipe for the riser, and another cast Iron "thing" to support it. Im am still using the hardiboard box reinforced and filled with a mix of perlite and wood ash 50/50.
I scored and broke the Tiles to make my burn tunnell, and they work great. Im not quiet sure what these things are made of but If I had to guess its a mix of perlite/vercumite , cement, styrofoam beads(burns out leaving lil air gaps) , Iron shaveings aprox 2" long, and cement. These thing work great, if anyone knows where to find them, please let me know.
Im building more of a space heater, and not a RMH, as I have very little mass. I would guess that my stove weighs about 100-120 lbs, as my 11 year old son helped me to move it yesterday. Also its a 4" system with a 7 1/2" tall x 8in wide and 16" long burn tunnel. I have read that it should be the same size all the way through but I have had no problems. My hear riser is cast Iron pipe with a 4"inner diameter, wraped in 6" stove pipe and insulated with the same 50/50 ash/perlite mix. Also it starts out as an 8", and the steps down to 4", due to the "thing the riser rest on ( looks like a part off the brakes of a bigrig with a 4"hole in the center.)
Good news is after a 12 hour burn, nothing melted! I burned for the first 2 hours without the barell. and there was one difference between this stove, and my last one that I melted, and that was there was never a flame. I stuffed it with wood, cardboard, twigs, pinestraw, and nothing caused it to throw flames out the top of the riser. the only thing that did work was lighter fluid. All I get out the top of the stove is smoke on startup, then a perfectly clear stream of very hot gasses. Is this normal? or should I expect flames?
After the first 2 hrs I put on the barrel and it worked like a charm, the new riser is shorter than the last one so the barrell sits about 4-5" inches over the riser. It heated like I wanted it to and all I think I need now are a few safety features. My barrell is only about 10" in diameter, so I plan to attach a fan to it and put a cage around it like a kerosine heater, anyone see a problem with what im describing? The whole stove is 1' wide x 2'deep x 48 in tall. I also plan to plaster/stucco the outside of the hardi board to make it pretty. I let my kids use my camera, so when they find it I will have pics. I plan to break this stove down one more time before I bring it in the house so that I can see all the parts and see how they are holding up, but I dont expect any problems. maybe ill take pics when I finaly put it back together so everyone can see what I did and give suggestions on what could be better.
Peace
Shah
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Post by zoidberg on Feb 12, 2011 9:43:44 GMT -8
My barrell is only about 10" in diameter, so I plan to attach a fan to it and put a cage around it like a kerosine heater, anyone see a problem with what im describing? If my grasp of the theory is firm, the better you cool the outside of the barrel the better draft you should have. You seem to have achieved a pretty compact space heater. I am eager to see those pics! |
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Post by Donkey on Feb 13, 2011 10:42:07 GMT -8
Yeah, I'd like to see pics as well!
Especially of the heat riser..
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Post by shahborn on Feb 16, 2011 23:02:53 GMT -8
This is my lil stove. I hope im posting my pics right. I talked the ol'lady into letting me bring it in the house, promising her a warm night. I put it in my shower, as its tiled and has water right there in case shit!
Last night in NC, it was about 36f, my bedroom was 84 f and that was after the ol'lady opened the window a crack. She is happy about the free heat, but pissed about the mess its making in the shower. Guys, ashes and perlite floating around in the floor of the shower aint the best v-day gift.
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Post by shahborn on Feb 16, 2011 23:10:47 GMT -8
I gotta finish the top.its just another piece of hardiboard that screws down with those bolts. Then I think im gonna plaster the outside of the base.
Please dont mind the mess, I aint usually that dirty.
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Post by shahborn on Feb 16, 2011 23:18:48 GMT -8
This thermometer has be shoved up the ass end of quite a few of my experiments, so its a bit hard to read. The temp at the center of the barrel is about 425 f. There is a large box fan blowing into the bathroom, to move the cold air form the bedroom into the bathroom, and force the warmer air into the bedroom. Without the fan that temp would read off the thermometer which tops out at 550 f.
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Post by shahborn on Feb 16, 2011 23:34:07 GMT -8
This is the reason I bought this barrel. That is a perfectly round 6" hole. I just stuffed some venting into it and piped it out the bathroom window, then vertical for 2 ft and bent an elbow away from the house. exit temps are around 200- 250 f.
Can anyone give me a guess as to what my barrel could be made of? The scratch test says aluminum around the sides and a steel or something similar at the top. Am i going to develop problems with the seal, I see no rubber?
Oh yeah there is a carbon monoxide detector on top of my toilet. It has not sounded the alarm, as of yet.
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Post by shahborn on Feb 16, 2011 23:51:00 GMT -8
Donkey, Ill snap a pic of the riser tomorrow. Its kinda hot right now.
Its just a iron pipe which stands on a 30 lb chunk of steel thats shaped like a brake part. with a 8"round 3" deep lip on the bottom and a 4" hole in the center top. Ill try and get you a pic of that too. This piece stays hot for hours and I find that there is still a steady stream of hot air coming out the exit 3-4 hours after the fire goes out. Its usually about 100 f.
My feed tube is a odd cinder block I had lying around in the yard. The feed hole is slightly larger than 4x4". So far I have not had any problems with fire trying to climb the feed, it usually stops at the bottom of the block, which is where the fire tile starts.
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Post by shahborn on Feb 16, 2011 23:53:49 GMT -8
Another of the feed hole with a better view of the fire.
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Post by shahborn on Feb 17, 2011 0:03:22 GMT -8
This is a piece of the fire tile I used to build the burn tunnel. the bottom and both sides are identical to this one. The front and back are the same except cut in half. Each piece measures aprox 8" x 16". the top of the fire box is another piece of tile chipped out to accept the steel part of the riser. All the pieces are dry fit into the hardiboard box and stuffed all around and over the top with the perlite ash mix. the outside of the hardiboard gets warm to touch but not hot.
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Post by shahborn on Feb 17, 2011 0:31:11 GMT -8
My bedroom is usually 55-60 f, so I sleep with electric sheets I picked up from walmart. Its 85 f in here right now and I can run around in here in my draws without feeling the chill on my ass. I can get yall a pic of that too! Aint no shame in my game.
the electric sheets are off.
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