J Black

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since Mar 07, 2013
Central Portugal
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Recent posts by J Black

Thanks, Big Al! I will try to keep all that in mind

6 years ago
Thanks, Bob! I've just checked out the P-channel, on yr recommendation, over at the Donkey forums and it's something that I hadn't tried, but could easily get together. Especially, as it doesn't involve ripping any bricks off the existing unit! Wood-wise, I'm using sticks (straightish branches and small trees, with bark on), mostly, as that is the wood that I have most free and easy access too. Mostly, they are pretty dry. I could find better wood, I'm sure, but realistically, I will mostly be burning these sticks in my regular use. Oh, the ash pit, I can easily put a brick in, too.

My main confusion is that I don't know how high I should be expecting the flame to come up the heat riser. I've singed a fair bit of my hair trying to get a look down the tube at various configurations that I've been playing with over the last few days, so there's definitely heat coming up, just not visible flame any more than a maximum of 1/4 the way up the heat riser with any combination, thus far
6 years ago
I appreciate yr reply, Mr Dearborn, and yr absolutely right. I should really give more details.

Using the measuring points from the book, it is as follows:

Feed tube is 12.2cmx12.2cm and 23cm long (ash pit goes another 10cm down)

Burn tunnel is 11.9cmx12.2cm and 33cm long

Heat riser is 14cm in diameter and 80.6cm long

Thanks!
6 years ago
Simple and general question. Sorry if it's been spelled out elsewhere, but I haven't been fortunate enough to run across it, if it has.

When testing the combustion unit of J tube (in my case a 5.5" system) in a rmh/stove, how high should the visible flame be coming up the heat riser?

Is it a fail if the flame isn't shooting out the top. I've tried a few variations and the flame, at best, only just enters the heat riser.

Thanks!
6 years ago

Ernie Wisner wrote:Actually your rocket stove should be considered as a system. the J tube part is only a piece of the whole When the barrel/bell goes on things change then when the thermal mass goes on things change again.
you put drag on the exhaust you put back pressure on the J tube. your fire slows down, an essential thing to consider is time, temp and turbulence. this catches lots of folks who want to modify the stove. in order to burn up most of the smoke you need it to be in the flame path for a period of time you need the gasses to mix and you need to have ignition temp.

What this means is you build a core that roars and the flame path is near the top of the heat riser. put a barrel on it the flame path is a little further down the heat riser then put the ducting in the thermal mass with the general couple corners that lowers the flame path a bit further. the shape of the feed and burn tunnel and the texture of the brick act with the wood to provide a good mixing then the residue gasses get mixed a second time when the stream from the heat riser hits the inside of the bell this puts the little bit of O2 in contact with the little bit of pyrolitic gasses remaining and re-burns. consuming all the wasted fuel (smoke) what remains is CO2 and water with a couple gasses that wont burn unless you get a real high heat going. I am not for creating a super stove that wont work half the time I want my systems to be robust and work all the time. so I consider the system rather than a component. Something for the super rockety folks to think on, time temp turbulence.



Not sure whether I should be starting a new thread with this, but my questions seem directly relevant to this statement, by Mr Wisner, that I've quoted above.

The combustion unit for my RMH/stove is now mortared together, but I can't decide whether to rip some bricks off and shorten the horizontal burn tube or let it ride, because at this stage (as yet uninsulated and without the barrel/bell), the flame is only just about coming around the corner and up the heat riser, say 5" or 6" at most. This certainly doesn't conform to the idea of the flame being near the top of the heat riser.



The bricks are high spec refractory, as is the heat riser. The white bricks at the very bottom are high spec, very light and insulative. I was thinking that maybe when all the insulative material is in place around core and particularly the heat riser, and all the brick/ceramic material is up to temperature, that this might bring the flame up, but it seems that the words from the wise suggest the opposite. I don't want to increase the height (or diameter) of my heat riser, so I figure the only option is to shorten the horizontal burn tube.

The reason I went ahead with the mortaring even though the stacked bricks performed the same, was that I had assumed that the heavy leaking of air between the unmortared bricks were contributing to the poor performance, which I thought sealing would rectify. Anyone have any further words of advice, before I start de-constructing the core?

Thanks!
6 years ago
Thanks, Chris! That looks very interesting. We are certainly looking into options to take matters into our own hands, besides the petition, so this is a welcome perspective
6 years ago
English version:

https://secure.avaaz.org/en/petition/ANACOM_PT_OPTIMUS_VODAFONECCDRC_CM_Gois_DECO_ADXTURADIBER_Pedido_de_acesso_eficiente_a_Internet_nas_aldeias_do_interior_/?copy

Portuguese version:

https://secure.avaaz.org/po/petition/ANACOM_PT_OPTIMUS_VODAFONECCDRC_CM_Gois_DECO_ADXTURADIBER_Pedido_de_acesso_eficiente_a_Internet_nas_aldeias_do_interior_/?copy

Not only intended to help local people, lack of internet access is a barrier to outsiders coming in to start new projects in Permaculture, Homesteading, Self-Sufficiency, etc.

Initially, we focussed on Portuguese nationals in signing the petition, now we are hoping to boost the numbers with support from the international community. Might be a way forward for others in the same circumstance

Thanks!
6 years ago
I see, well, for such a short time, I'm sure you can mix them up something at home. The backyard chickens site is quite good for that sort of thing, too. Good luck with yr new arrivals
7 years ago
Ola Fernandinha! I'm raising non-exotic local breeds on a fairly small scale, at the moment (19 birds), but will want to up production once settled on new property in the new year (I hope!). Myself and other local, more alternative types, have looked into this question, too, and come up empty. My current strategy is to let them free range as much as possible, give them kitchen scraps (cut small, shredded or with some things, like potato peels, even cooked) and some things out of the vegetable garden. Our kindly, retired neighbours often give us their extra cabbage leaves that have been attacked by bugs, for our chickens to peck at. All this vastly reduces the store-bought grain they eat from the feeder. A friend in Benfeita has had some success with Fukuoka-style grain growing and has also fed the chickens home grown
amaranth, although he found that many new plants grew from the amaranth seeds in the chickens' droppings, in places he didn't particularly want them. I was recently impressed by a video that was going around from Geoff Lawton's site, about a farm doing fairly large-scale compost from restaurant waste, combined with their own, and raising chickens from that. Not only do they eat the parts of the waste food that appeals to them, but also the abundance of worms, larvae and bugs that the compost supports. Their own droppings add to the mix and the generated heat keeps the system going through the winter months. I believe they sell the finished, high-grade compost. I find the chickens' general health and the quality of the eggs is improved when they are eating little to none of the store-bought grain. Hope that helps
7 years ago