|
|
Post by peterberg on Mar 11, 2009 12:33:31 GMT -8
Canyon, last month I've been busy testing some different versions of the rocket/bell combination. The goal has been to find out the least complicated layout.
For that purpose, I've tested one extensively without a heat riser.
Conclusion so far: without a heat riser, the rocket siphon isn't heating up sufficiently to come to a clean burn. And most important: the bell won't warm up and flue gases are condensing inside the bell. After 10 to 15 minutes, the chimney got water on the inside and gave up draw altogether. My Testo analiser was giving readings of 99.4% efficiency at the height of the burn for 5 minutes only. Very spectacular!
I've changed the thing again to a little higher build with a heat riser inside and it went better almost instantly. Not as good as the last version on the forum, but I feel I am pretty close to it now.
During the coming two months I am going to make moulds for a siphon made of refractory castable with some modifications and an insulated heat riser. Most notable difference compared to the former incarnation: the siphon is on top of the fire box. In that way, the bottom of the rocket is heated up by the flames in the fire box, and a less complicated construction to add.
Interesting times!
|
|
Teach
Junior Member
Posts: 89
|
Post by Teach on Mar 15, 2009 15:20:59 GMT -8
That sounds like ur havin fun Peter!
Peter have you ever seen anyone or perhaps yourself ever build the body of a bell using stone masonry? How do you think it would hold up with cracks etc. from heat stress?
What about you other fellas? Any experience building fire stuff with rock?
Teach.....
|
|
|
|
Post by peterberg on Mar 16, 2009 13:12:17 GMT -8
I'm sorry, Teach.
I don't have any experience with a stove built of stone whatsoever. Here in the Netherlands there are very few rock deposits, silt in the rivers on the other hand is in abundance. The country is one large delta formed by two major rivers and two dozen smaller ones. So we are using bricks for building almost exclusively. But maybe concrete blocks are cheaper than clay bricks?
|
|
Teach
Junior Member
Posts: 89
|
Post by Teach on Mar 16, 2009 16:06:52 GMT -8
Thats alright Peter. Just figured I would ask. Must be nice to have such an abundance of clay for such purposes. Re the brick; red clay bricks were 79 cents each and 2x4x8 and the concrete bricks (solid) were 99 cents each and 4x4x8. So for 20 cents more I cover twice the area essentially.......I just don't know if they will take the heat(the concrete ones that is). Also, no one at the builders supply want to go out on a limb and recommend a type of mortar either. My building is on hold until I can gain the information. Once the weather warms up I can get out and start searching for clay again. If I can find some, most of my troubles will be over. I seem to remember reading somewhere that stone was not a good material but can't for the life of me remember where I read it. I think it had troubles with cracks in the stones but it would have to get extremely hot for that to happen. Maybe it was a warning not to use stones from certain sources such as road cuts/allowances where the rock has been blasted and is already full of invisible cracks from the blasting.? God I love getting older! Now, what was I saying? .........grin Donkey, ring ring, ring ring, LOL.  .........stop dreamin bout veggie oil and go back a little in this thread here and answer my question please ;D It was regarding the amount of vertical drop in a horizontal pipe run for a regular rocket setup. Thanks |
|
|
|
Post by Donkey on Mar 17, 2009 8:13:09 GMT -8
Vertical drop (or rise) matters not. Unless you plan to bleed heat till it condenses, in which case I'd go 2% drop minimum for drainage.
|
|
|
|
Post by canyon on Mar 17, 2009 19:33:35 GMT -8
I seem to remember reading somewhere that stone was not a good material but can't for the life of me remember where I read it. I think it had troubles with cracks in the stones but it would have to get extremely hot for that to happen. Maybe it was a warning not to use stones from certain sources such as road cuts/allowances where the rock has been blasted and is already full of invisible cracks from the blasting.? God I love getting older! Now, what was I saying? .........grin Thanks My swiss friend that has a few build it yourself masonry stove books (in German of course) says that the main issue is with rocks that aren't dry. It can take awhile to dry the rocks completely. Have you ever witnessed an exploding rock from a fire pit ring? Around here people go to the beach (our best local quarry) and build a big driftwood fire and pile on the rocks. The next day the rocks that didn't explode are harvested. Can be dangerous though. If you bike up here with a load of good rock (sidecar?) I'll trade you pound for pound for my good clay!  |
|
Teach
Junior Member
Posts: 89
|
Post by Teach on Mar 17, 2009 19:52:33 GMT -8
Canyon, interesting way to eliminate the rejects.......survival of the most dry!
The way I was wanting to use the rock was in similar manors to bells and large heat sinks and even in a bell I highly doubt the temps would get anywhere near what rocks in a bon fire would be subjected to. Especially when you consider the gasses are cooling from the time they would have left the riser tube. Would they get good and hot? Probably. Hot enough to crack or explode? I doubt it. I suspect there is far more to worry about in problems arrising from the mortar in trying to find a mortar with expansion and contraction properties similar to the stones being used so as not to run into stress cracking. But not being a pro, I am only speculating here. Stone masons are a dying breed now. Not many around to queerie on the subject.
Teach....
P.S. I'm thinking granite weighs about 50 lbs a cubic foot so Im thinking trading for your beer instead of clay pound for pound. Nah, that would not be fair to you. Beer is far lighter per cubic foot........great trade for me though........hickup! grin...
|
|
|
|
Post by Donkey on Mar 18, 2009 7:17:29 GMT -8
Soapstone is used in those ultra fancy and expensive European mass stoves. A good friend of mine got one for around $20,000! It's pretty sweet.. I could do it just about as well with cob and scavenged leavings. I gotta say though that the thing is impossible to leave alone, you just wanna fiddle with it and hug it.. But, uhh... Teach.. Could you start a separate thread for your stove?? Peterberg's here is getting quite long and getting to the meat of it is harder by the moment.. Thanks. |
|
|
|
Post by satamax on Jun 22, 2012 12:54:18 GMT -8
Hi vrybody!
Peter, if ever you read this. Would you think a "rocket stove" as per the book more or less, i mean an insulated J tube with no barrel with a bell'ish thing right on top could work? I've just done this extremely insulated J tube out of bricks and castable and refractory clay chimney tubing, surounded by something like ten cm of vermiculite. then the first layer of a water tank, then 3cm of cork, and the outside layer of the water boiler. Riser is about 50cm long, a smidge more may be, the idea of putting a 300liter water tank on top of all this cooking rocket, as a bell, with exhaust at the lowest point of the bell, as usual. Would you think this might work? Or it's just a brain fart?
|
|
|
|
Post by peterberg on Jun 23, 2012 2:15:15 GMT -8
Hi vrybody! Peter, if ever you read this. Would you think a "rocket stove" as per the book more or less, i mean an insulated J tube with no barrel with a bell'ish thing right on top could work? I've just done this extremely insulated J tube out of bricks and castable and refractory clay chimney tubing, surounded by something like ten cm of vermiculite. then the first layer of a water tank, then 3cm of cork, and the outside layer of the water boiler. Riser is about 50cm long, a smidge more may be, the idea of putting a 300liter water tank on top of all this cooking rocket, as a bell, with exhaust at the lowest point of the bell, as usual. Would you think this might work? Or it's just a brain fart? Yes, it will work, it's not a brain fart. ;D But, the 300 liter tank could be too large for the stove to manage. What's the system size of this J-tube? I would think it has to be at least a 6" inch version, a smaller one might just do it. But I'm not sure about that, it could work using a proper chimney stack. Don't forget: when placed on top of the riser, there has to be a 1 foot pipe inside the tank as lengthening of the riser. Just to get the entrance of the gases above the level of the tank exhaust. |
|
|
|
Post by satamax on Jun 23, 2012 6:17:38 GMT -8
Thanks Peter. So, it's a 6ish incher. 160mm for the heat riser. I've used landini's "refrattorio" clay tubing, i went to the other side of the border yesterday to buy some! Cool, i have a supply of not extremely expensive refractory clay tubing tees etc, just 34km away! And they have 8 inch id tube, and even 10 inch. Nicee! They also have some 14X14 squareish, and 18x18. All in 50cm lenghts. The burn tunel was cast for 18cm, but i'll just pour some stuff at the bottom to reduce the size if need be. Well, originaly it's meant to be a BBQ. Lava rocks on a "grate" heated by the rocket. But what do i do with a barbie in the winter?  Cool, i have another clay tube which i've got spare. I might give it a try then at some point. |
|
|
|
Post by woodworm on Jun 24, 2012 0:49:47 GMT -8
Please let us know what softwaer you use to produce your excellent sketches. Free, I hope !
|
|
|
|
Post by peterberg on Jun 24, 2012 1:04:13 GMT -8
Please let us know what softwaer you use to produce your excellent sketches. Free, I hope ! Google SketchUp Pro 8. I've paid for a licensed version because of the exporting facilities. The download page is here: the normal version 8 (not Pro) is free. |
|
|
|
Post by woodworm on Jun 26, 2012 0:17:50 GMT -8
Thanks Peter, I will now start climbing that SketchUp learning hill ! Regards Erol
|
|
|
|
Post by satamax on Jun 26, 2012 10:11:21 GMT -8
Plenty of sketchup tutorials on youtube.
|
|
.........stop dreamin bout veggie oil and go back a little in this thread here and answer my question please ;D It was regarding the amount of vertical drop in a horizontal pipe run for a regular rocket setup. Thanks
Cool, i have another clay tube which i've got spare. I might give it a try then at some point.