Satamax Antone wrote:I can tell you the name is copyrighted "de facto" since the book has been published.
You do know that all of the text is in the public domain, right?
The text of the original Evans and Jackson book? Expressly waived? Surprising.
But, even thought, if it is in the public domain. What you plan might face a bigger opponent. The widespread use of the term rocket mass heater and rocket stove. Everywhere these are discussed. The other problem is confusion. People will know those as rocket stove and rocket mass heater, from other sources, "why do you call it something different? Is it different" will be the next question asked.
I forgot to say, iirc, for a good cyclonic burn chamber with not too much drag, you need at least 3x the riser size on big systems, on small ones, you can go up to 8x, this is to avoid as much drag as you can.
We all strive to have the fiercer, hotter burns possible, in order to achieve the best burn efficiency. And the idea of letting the fire out of the riser, which for most of us happens during the bad portions of a burn. You trod a somewhat beaten path with this single vortex. Peter has tried it, and some others too, nearly the way you have implemented it this time. You'll have to sniff in the old posts at Donkey's.
If you really want to make your fire turn one direction. I'd say, go the cyclonic route. A J tube entry, round if possible, finishing into a neutral vane into a big burn chamber, even better if it's conical, like a cyclone.
We already have plenty of tools, J tubes, Batch, DSR Radiators, accumulators cooking plates, ovens etc. To fit most of our needs.
I can see the appeal to à stove which wouldn't need to be stoked every now and then, and burn for a fair length of time, without needing attention.
But, this comes at a cost. The fact that the chances of it burning badly are far greater.
Plus, since the mass is recovering the heat which would be otherwise wasted, and redistributes it inside afterwards. The need for long burns is mitigated. Well, in the alps, at 1500m altitude, in a ski resort. I do mostly three loads a day, when it's cold. Two in October/November, and 2 End of march/ April. May be 3 in the evening, and one relit, in the morning on the embers, when it reaches around -20c° But i spend may be 1/2 an hour, between startup, and the three loads. May be if i pass nearby, i would stoke it once or twice an evening. The stove is downstairs, in the workshop. So, i don't see that much of a need for long burns. I startup around 6pm, and it burns full blast till 10ish. Usually, by midnight i can close the chimney flap (20% of airflow remaining)
Well, i would be afraid of the wood deprivation. I mean, if there is only one log in there, and it doesn't burn fast enough. And there is not enough embers underneath. This cools the fire. And kils efficiency, up to the point the fire stalls. Or stops.
You know, along the top load vertical batch. There is another solution, top load horizontal batch. Exactly a per the book batch. With a metal cookplate hinged on top. With a handle. You would load from the top. Instead of the front, but it is exactly the same. I think with a strong draft, may be the firebox could be extended upwards a smidge, over Peter's designs.
But the problem, is the full burn. In a batch, it starts somewhat tame, and then the full dragon breath comes in, where all the logs are on fire. And if you have too many logs, stacked in the top extension, this would overload.
What are you trying to achieve, being interested by the magazine rocket?
The air going through the wood is one of the principles of good rocketry.
Basically, you're reducing the free air circulation area, with burning wood, so the air velocity increases, augmenting turbulence and thus mixing. The port in a batch is there to increase the turbulence, but wood, either in batch or J tube is responsible for the turbulence too. Hot burning gases take some room to, so the air intake gets faster. Well you see what i mean?
Well, not having seen one in real life, i can't really comment.
I argued with F styles, that this wasn't a "rocket stove" I'm not that sure anymore. It can work with wrist size fuel, even smaller, i think. There might be an use for a stove like this. But this is not documented, over the course of several years, with measurements, follow ups on the mods etc. I would have loved to see "testo" graphs of this. And less bragging. I think there is a real risk of flashback. It could be interesting if someone with a few builds behind him, would make on of those, to see if it's worth pursuing. To get a more "sensible" evaluation of the thing.
Jura Rafal wrote:I do like the idea of both the 5 and 6 min risers but..
I'm pondering over fine particles emissions from the ceramic fibre .
As far as I know they are of the size of those from asbestos and thus being equally harmful.
If you're using superwool it has a very low bio persistence, as they say.
Gerry Parent wrote:Hey Satamax, When the wood is loaded vertically into the firebox, what is to keep it from leaning up against the glass or more importantly, up against the port and block the air flow?
Also, I guess the floor is flat with no angled bricks?
Fox, Its been a while since I last saw your cook stove. Could you post another picture of it when you send your sketches so we can compare them?
As for the heat from the barrel, couldn't you just put a heat shield of some sort around it or cover it with brick or cob?
Well, leaning against the glass, ney bother, it doesn't matter much. As only a small portion will touch at any given time. But a grid of some kind could be inserted there too.
Angled bricks could be used at the bottom, but it would be a pain for loading wood, which would need to be far shorter than firebox length. Mind you, it could prove interesting to light the stove.
The port doesn't go all the way down, so it doesn't get blocked by embers. On top, a wide "P channel" out of thick steel could be implemented. Onto which the lid could hinge.
But i need proper materials, not salvaged heat riser and ultra thick bread oven bricks.
Aaron, try to check what is the legislation about kachelofens, where you are. A "batch box" is a kachelofen, more or less. I can see houses facing yours. And i'm dubious you would get away without trouble. Exhaust against a wall can be done, if you are absolutely sure that there won't be a wind gust which will put your fire out, and smoke the whole house. Remember, this could kill.
What i see, is the right hand corner of the room doesn't seem busy. You could fit a bell there. And a U turn bench, in place of the radiator. But, since the wall is not insulated, this is not the best place. Better heat inside walls. Which retain heat inside. And spread the heat to other rooms.
I am partial to batch boxes. J tubes are too finicky for my liking.
Well, i used some reclaimed IFB, that sat outside for a while, wet and all, no problem.
Mind you, i don't see much use for IFB. They're no good in a firebox. As a backer for splits, they're ok. But air entrained concrete can also be used. Ok, it cracks, but it's cheap. In this case, ok, the 1.5 dolls for wetted IFB, might be a game changer. You can use these bare in a heat riser, ok. Tho, may be not at the bottom. where the ashes rake might hit these. And a five minute riser works as well.
These don't work for mass.
I like dry fit, not mortared fireboxes. And yes, these are handy as a backer and insulation in that case too.
For a forge or a kiln, thought, i could buy more.
That's where they would be the most useful for me.
thomas rubino wrote:
This same bell with an 8" J tube and 1 barrel ran flue gas temps of 250 + After it was warmed up.
I would hope a 7" batch can support one extra barrel over a J tube?
A 9" stove eh! Wow that's a big one. Peter suggested to me that an 8" might be to large.
Thomas, The nine incher is my workshop thing. I heat 635 cubic meters approximately with it. Barely no insulation in the roof, 12cm of cork panels. Which is an euro R of 3, R17 in the us. Hollow brick walls, R1 theoretically that's us R6, and loose strawbales leaned on the walls, that if these were stuck and plastered would give a US R of 34. But this is bare straw, for the moment.
If your 8 J was doing 250, the 7 incher batch should do the same at least. I have a fair bit more primary air than recommended, due to the altitude, 5000ft elevation.
Your seven incher should be able to cope with that extra barrel. I think, with a well running 7", you should be able to cope with a 8 m² or 9 m² total ISA. ( barrel and mass)
There is one thing i have noticed. I find your secondary port a smidge close to the port.
thomas rubino wrote:Hi All ;
Took the dragon out for a long flight this morning! Five loads of fuel later... We were cruising!
My shop was warmer than it has ever been! Admittedly it was in the 40's outside.
Barrel temps of 320 on the lower and 465 on the upper.
Brick bell temps were 120 near the barrel and 90's down at the floor. Those numbers would have continued to rise had I kept burning.
Exhaust stack, gas temperature , checked with a T & G dragon breath monitor, reached 145 F at the end of the last load.That is significantly lower than I was getting before with a single barrel.
That temperature would also have continued to rise.
After the last load went out. I fabricated a ceramic board plug to seal my primary air off when not burning. The secondary air just got a piece of cf board propped in front.
Both will help keep all that generated heat right there in my mass and not being sucked up the chimney.
Thomas, sorry to say, but i find your temps a smidge low. 145 F, that's really really low. That's the kind of temp i get after five minute burn, on a warm stove. Ok, mine is a 9 incher or so.
End of the load, i am at 240 F / 250 F, mid stream of the 8"x 8" chimney.
This is with 1.9 m² of radiating metal, and about 11 m² approximately of mass ISA (or is it total ISA? can't remember)
Usual temp for me just above the riser, 8" above and may be 8" off to the side is 370 C°, 5 cm inside the barrel. So that's 700 F more or less at 6' above the workshop floor.
I think i could extract a bit more. But i don't think i will ever go down to 145 F too close to stalling temp imho. I already get smoke filled workshop every now and then, with what i have. Usually in the spring or summer, on a cold and rainy day, when the outside temp is rather close to inside temp, atmospheric pressure is low. and a stone cold stove.
My feeling, is that you have too much primary heat extraction with those two barrels.
Joshua A Smith wrote:Hi, new here...
Has anyone tried the "brick lattice" idea? Does it allow the barrel to shed heat or does it act as an insulator? If it insulates too much, I wonder if spacing them out and allowing for air to pass through would help. Just curious.
I would try it, if i had to. But i'm not building much for others. And i have a system i'm happy with.