Post by marek on Jun 25, 2017 13:06:36 GMT -8
Hello all,
this is my first post on the forum, although I follow it for quite some time, around two years now.
I plan to build my batch box rocket stove this summer. Anyway, let's cut the background for now, I have something to ask you folks, or maybe a thing to propose?
Because of size limitations in the house, I am thinking about a sidewinder kind of stove, which takes less room in depth.
And this triggered a thought about the secondary air channel. Maybe you alreday tried it and you will tell me not to go there... or maybe, could it be something new to think through?
Here's the idea:
A secondary channel, build of a basic cast iron plate, standing inside the box (burning chamber) along one of the side walls. It leaves a small gap between the cast iron plate and the wall, where the air passes, starting at the front of the box, and up to the port, where it gets mixed with the burning gasses, sucked into the riser. The sidewinder has the port at the side wall, and the cast iron stands at the same wall, feeding secondary air to the port.
To explain what I mean, here's a sketchup: drive.google.com/file/d/0B6E4hMdeKTprZGxzN20tWHdlVVE/view?usp=sharing. Notes to the drawing:
- I tried to upload the file to the forum directly, but an error appeared, saying "Unable to upload file secondary-air-wall-channel.skp. Error: This forum has exceeded its attachment space limit. Your file cannot be uploaded.)
- To create this drawing, I just adapter one of the public domain drawings available, I hope you don't mind
- Please ignore the exact dimensions on the drawing, it's just to explain the general idea
Unfortunatelly I don't have any means to try the idea in advance and give you beautiful results. I don't have any measurement tool too, and no experience whatsoever, so even if I took a go and build something, I wouldn't know if I should be happy with what I see or not... Yet some of you guys have build tens of rocket stoves, and must have built this mental feeling about what could work or not. I hope to get you interested enough to share your dry opinion, or maybe some advice about it.
What I hope to discuss:
1. Is it something to discuss at all? Or is it covered already somewhere else, or maybe not worth mentioning?
2. A potential advantage - I guess the construction of this channel is quite easy to implement. You just need to have a cast iron plate, either the right dimentions you need from the start, or you it can be quite easily cut with a grinding machine, am I correct? Then you just put it in the box and lock it with some refractory bits. I may be wrong, but for a beginner the way the plate could be mounted inside the box easily, that's one of the factors I really like about it.
3. A potential advantage - iron cast plate is possibly more durable to burning temperatures than "pipe" steel, isn't it? If I'm correct, would it mean we could get a more durable solution for a secondary channel air, than ones made from steel pipes put inside the fire, which you say can hold a few seasons top?
4. A potential advantage - this plate has quite a surface contact with fire, so it can get hot. And the secondary air on the other side would probably flow relatively slow (as compared to a pipe), so it could get pretty hot before it gets to the port. The higher temperature of the secondary air, the better, am I correct?
5. A potential disadvantage - one of the side walls of the box gets cooled down by the secondary air. Do you think it could lower the effectiveness of wood gasification?
6. A beginner's question - do you think the shape of the channel at the port side would get the burning gasses mixed well with secondary air? It somehow resembles the original P-channel, yet it is stretched vertically. Then it resembles the vertical Mathew Walker pipe put in front of the port, yet the wall channel provides the air to the side of the port, not to its center.
7. If the way the secondary air is feed at the front of the box would be a problem, I can see an easy options to feed it from the bottom of the box. In fact, I was thinking about a small air chamber below the actual burning chamber, where I could feed the air, regulate it, and then split for primary and secondary air... but that's probably a different story.
To make a thing clear at the very beginning, if by any chance I am the first author of such solution and it would turn out to be some worthwhile idea, I would like it to be public domain, as most of this forum content is.
EDIT: I found this idea being mentioned already two years ago donkey32.proboards.com/thread/1556/why-side-window-door?page=2 - that thread did't get to any conclusion though... maybe some other thread went further on that?
this is my first post on the forum, although I follow it for quite some time, around two years now.
I plan to build my batch box rocket stove this summer. Anyway, let's cut the background for now, I have something to ask you folks, or maybe a thing to propose?
Because of size limitations in the house, I am thinking about a sidewinder kind of stove, which takes less room in depth.
And this triggered a thought about the secondary air channel. Maybe you alreday tried it and you will tell me not to go there... or maybe, could it be something new to think through?
Here's the idea:
A secondary channel, build of a basic cast iron plate, standing inside the box (burning chamber) along one of the side walls. It leaves a small gap between the cast iron plate and the wall, where the air passes, starting at the front of the box, and up to the port, where it gets mixed with the burning gasses, sucked into the riser. The sidewinder has the port at the side wall, and the cast iron stands at the same wall, feeding secondary air to the port.
To explain what I mean, here's a sketchup: drive.google.com/file/d/0B6E4hMdeKTprZGxzN20tWHdlVVE/view?usp=sharing. Notes to the drawing:
- I tried to upload the file to the forum directly, but an error appeared, saying "Unable to upload file secondary-air-wall-channel.skp. Error: This forum has exceeded its attachment space limit. Your file cannot be uploaded.)
- To create this drawing, I just adapter one of the public domain drawings available, I hope you don't mind
- Please ignore the exact dimensions on the drawing, it's just to explain the general idea
Unfortunatelly I don't have any means to try the idea in advance and give you beautiful results. I don't have any measurement tool too, and no experience whatsoever, so even if I took a go and build something, I wouldn't know if I should be happy with what I see or not... Yet some of you guys have build tens of rocket stoves, and must have built this mental feeling about what could work or not. I hope to get you interested enough to share your dry opinion, or maybe some advice about it.
What I hope to discuss:
1. Is it something to discuss at all? Or is it covered already somewhere else, or maybe not worth mentioning?
2. A potential advantage - I guess the construction of this channel is quite easy to implement. You just need to have a cast iron plate, either the right dimentions you need from the start, or you it can be quite easily cut with a grinding machine, am I correct? Then you just put it in the box and lock it with some refractory bits. I may be wrong, but for a beginner the way the plate could be mounted inside the box easily, that's one of the factors I really like about it.
3. A potential advantage - iron cast plate is possibly more durable to burning temperatures than "pipe" steel, isn't it? If I'm correct, would it mean we could get a more durable solution for a secondary channel air, than ones made from steel pipes put inside the fire, which you say can hold a few seasons top?
4. A potential advantage - this plate has quite a surface contact with fire, so it can get hot. And the secondary air on the other side would probably flow relatively slow (as compared to a pipe), so it could get pretty hot before it gets to the port. The higher temperature of the secondary air, the better, am I correct?
5. A potential disadvantage - one of the side walls of the box gets cooled down by the secondary air. Do you think it could lower the effectiveness of wood gasification?
6. A beginner's question - do you think the shape of the channel at the port side would get the burning gasses mixed well with secondary air? It somehow resembles the original P-channel, yet it is stretched vertically. Then it resembles the vertical Mathew Walker pipe put in front of the port, yet the wall channel provides the air to the side of the port, not to its center.
7. If the way the secondary air is feed at the front of the box would be a problem, I can see an easy options to feed it from the bottom of the box. In fact, I was thinking about a small air chamber below the actual burning chamber, where I could feed the air, regulate it, and then split for primary and secondary air... but that's probably a different story.
To make a thing clear at the very beginning, if by any chance I am the first author of such solution and it would turn out to be some worthwhile idea, I would like it to be public domain, as most of this forum content is.
EDIT: I found this idea being mentioned already two years ago donkey32.proboards.com/thread/1556/why-side-window-door?page=2 - that thread did't get to any conclusion though... maybe some other thread went further on that?