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Post by esbjornaneer on Dec 1, 2017 3:14:51 GMT -8
Great news Peter. Both name and that things are progressing. Have you already run all the tests on the heavy fire bricks? Are you planning to run tests on both versions (heavy & insulated) simultaneously? Only asking because of the ideas you had for how to get the oven function.
I thought to google 'DSR' as it seemed to ring a bell... some of the 'disambiguations' that Wikipedia came up with are:
Doubly special relativity, a proposed modification of Einstein's special relativity theory;
Design science research, a set of analytical techniques and perspectives for performing IS research;
Demand-side response, a form of energy system demand management.
some of them quite cool and somewhat related!
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Post by peterberg on Dec 1, 2017 8:23:18 GMT -8
Great news Peter. Both name and that things are progressing. Have you already run all the tests on the heavy fire bricks? Are you planning to run tests on both versions (heavy & insulated) simultaneously? Only asking because of the ideas you had for how to get the oven function. Tests have been run with hard fire bricks already. The Montana mockup build happened to be done using insulative fire bricks but no testing as such has been done other than running it, sniffing at it and crying out loud Ohhh! and Ahhh!  The attempt to run the Allerton Abbey build without a chimney failed miserably. But in the mean time Fred managed to get it running, see this short video. |
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Post by esbjornaneer on Dec 2, 2017 4:17:03 GMT -8
On a less frivolus note: Peter are you making measurements both with the original core in the first videos and the setup/design you did at Allerton? (That is does it make any difference in combustion if the 'chimney' comes directly following the top shoebox, or the switch-back of the cooler part of the hob?) Thoughts move on to what would happen if the core was used for a heater instead of a cooker and 'the third shoebox' was movend on top of the second instead of being next to it as in the Allerton hob. Would that affect the combustion? And would there be any improvements making a port between the 2nd & 3rd boxes like you have between the 1st (fire box) & 2nd box? Or am I just complicating things? Looking forward to when you publish some results and advice for replication  Esbjorn |
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Post by peterberg on Dec 3, 2017 1:59:19 GMT -8
On a less frivolus note: Peter are you making measurements both with the original core in the first videos and the setup/design you did at Allerton? (That is does it make any difference in combustion if the 'chimney' comes directly following the top shoebox, or the switch-back of the cooler part of the hob?) At this time, I don't have plans to build the AA kitchen at home. The setup like in the first videos is still in my garden and some measurements has been done on that one. But I fully intend to develop the heater variant further, where there's no switchback. Thoughts move on to what would happen if the core was used for a heater instead of a cooker and 'the third shoebox' was movend on top of the second instead of being next to it as in the Allerton hob. Would that affect the combustion? And would there be any improvements making a port between the 2nd & 3rd boxes like you have between the 1st (fire box) & 2nd box? Or am I just complicating things? The combustion core setup which is in my workshop now is the second, sporting a top exhaust from the second box like the first videos. I won't regard the switchback in the AA kitchen as a third shoebox. Probably it could be done but it'll complicate things and that's not the road I want to go. The only reason to introduce that switchback is to provide a larger cooking surface with different temperatures to choose from. And a second port between 3rd and 2nd shoebox? I don't see an advantage, mixing gases which are already violently mixed doesn't sound like a good idea to me. Interestingly though, Pablo Kulbaba came up with another idea already. By dividing the hot stream into two separate switchbacks, left and right of the top box, the two streams could be joined again at the back leading to a chimney or a bench, oven or whatever. |
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Post by esbjornaneer on Dec 4, 2017 4:18:21 GMT -8
Thanks for the answers, and from them more questions: At this time, I don't have plans to build the AA kitchen at home. The setup like in the first videos is still in my garden and some measurements has been done on that one. But I fully intend to develop the heater variant further, where there's no switchback. Not even the core of it, without the bench? Interesting as you have previously said: The goal was and still is a burn that's as clean as possible. Another goal was to create the possibility of cooking on top so it would be easier to create a kitchen range around it. Whether or not the temperature is lower and by how much is something to be found out. and this is a very practical design Does it support the same ISA as a normal batch box? To be frank, I don't have the foggiest idea. Didn't try yet, at this moment it isn't clear whether or not it will develop into a full heater. Why did you change direction? Is it due to tests or greater interest in heating than cooking? The combustion core setup which is in my workshop now is the second, sporting a top exhaust from the second box like the first videos. I won't regard the switchback in the AA kitchen as a third shoebox. In your opinion (without testing) does the switchback have any impact on the combustion? (Is everything combusted by the time the gases switch back?) Interestingly though, Pablo Kulbaba came up with another idea already. By dividing the hot stream into two separate switchbacks, left and right of the top box, the two streams could be joined again at the back leading to a chimney or a bench, oven or whatever. Have you got any links to this? And I thought there was talk at one point of running a rocket with two heat risers, which was thrown out as one riser would take presidence and the other not take any gases. This idea sounds similar would the effect not be the same? |
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Post by peterberg on Dec 5, 2017 2:27:42 GMT -8
Why did you change direction? Is it due to tests or greater interest in heating than cooking? It is merely the point that I don't want to build something as permanent as a complete kitchen range out of brick inside my workshop. In Montana the idea to cook on top was tried and it worked, I didn't say it was my goal to develop and test a cook stove with bench, only to create the possibility. Plus the fact that I am more interested in heating than cooking and I have a half-baked heater consisting of two barrels in my home workshop already. That one is much easier to change and adapt in order to develop the concept further. Don't you forget I am a pensioner of 71 years old and have limited energy? In your opinion (without testing) does the switchback have any impact on the combustion? (Is everything combusted by the time the gases switch back?) I'm inclined to think he switchback doesn't have any impact on combustion, the burning seems to be confined to the back end of the fire tunnel. And I thought there was talk at one point of running a rocket with two heat risers, which was thrown out as one riser would take presidence and the other not take any gases. This idea sounds similar would the effect not be the same? It may sound similar to you but it isn't. A horizontal deviation when combustion is complete and split over two channels is something entirely different as compared to two risers where combustion should take place simultaniously. That double swithback is just part of the heat extraction back end of the heater, as opposed to the combustion front end. During the coming months I want to dedicate some time to developing the double shoebox front end while implementing the inevitable back end as simple as I can get away with. |
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Post by esbjornaneer on Dec 5, 2017 9:19:46 GMT -8
Thank you for all the answers and clarifications. Don't you forget I am a pensioner of 71 years old and have limited energy? I honour you for all the work you put in and your willingness to share it all. I did remember you being retired but not know your exact age. That was one of the reasons of my early offer of assistance in any way I may be able to. I do have spare time every now and then and now is such a time (hence all the posts ). During the coming months I want to dedicate some time to developing the double shoebox front end while implementing the inevitable back end as simple as I can get away with. Looking forward to the results when you share them! And even though it may not seem so I am attempting to be patient for you to share your developments when things are tested to the high standards that you have.  Thanks again, Esbjorn |
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Post by esbjornaneer on Dec 7, 2017 6:22:20 GMT -8
Re-reading and thinking things over... And also, glass won't warp and breaking it by overheating isn't a question. Proved by one of the participants who kept running this experiment untill 1:00 o'clock, an estimated constant firing time of 10 hours without destroying anything. How was the completeness of the burn with all these refuelings? As you light it from the top does it harm the combustion quality to refuel on top of the last embers? Would you push the embers to the back before refueling? Also, in the test core you are putting up for linking to your two barrels, will there be a 'chimney/heat riser' on the 2nd shoebox? It was not needed in the AA cooker so will it be needed in a heater? Assuming there is a chimney beyond the bell. |
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Post by peterberg on Dec 7, 2017 7:35:26 GMT -8
How was the completeness of the burn with all these refuelings? As far as we could see and smell, complete. If we waited until all was going down to coals there was a brief moment of smoke while refuelling. As you light it from the top does it harm the combustion quality to refuel on top of the last embers? No. I tried to refuel earlier while there was still fire in the top box. No smoke whatsoever while doing that. Would you push the embers to the back before refueling? No, minimal spreading using the first log and that was it. Also, in the test core you are putting up for linking to your two barrels, will there be a 'chimney/heat riser' on the 2nd shoebox? Test is already done, no chimney stub. Which was there in the mockup to keep the highest heat out of the operator's face. It was not needed in the AA cooker so will it be needed in a heater? Assuming there is a chimney beyond the bell. A chimney should provide the necessary pull, that's the whole idea. In most of my designs the riser is the afterburner area. In the DSR this is replaced by a tunnel. |
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Post by esbjornaneer on Dec 8, 2017 5:40:20 GMT -8
Does it matter where in the port the 2ndry air supply ends, height wise? And does it matter how thick, again height wise, the port is?
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Post by peterberg on Dec 8, 2017 7:34:22 GMT -8
Does it matter where in the port the 2ndry air supply ends, height wise? And does it matter how thick, again height wise, the port is? Yes, it matters. Halfway in the port seems to be best so far. To make answering easier: the length (or height) of the port is the largest measurement, the width is the second largest and the depth is the smallest. Since it could be oriented in different directions including 45 degrees, I prefer to talk about it seen in stream direction. I suppose you are talking about depth of the port, this seems to be best when it is about 80% of the width. Following that, a port of 50 mm width would be good with a depth of 40 mm. This isn't very stringent, although I tried a port depth of much less (12 mm) and it refused to behave itself. |
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Post by esbjornaneer on Dec 8, 2017 8:05:29 GMT -8
Great, exactly what I meant!
So as I am looking into doing a core out of insulated/ceramic fibre board 25mm thick should I then make the port smaller or build the port up in depth/thickness by doubling the board just around the opening?
(Or do you Peter have any reason the insulated fire brick would be much better than fibre board?)
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Post by peterberg on Dec 10, 2017 11:57:02 GMT -8
So as I am looking into doing a core out of insulated/ceramic fibre board 25mm thick should I then make the port smaller or build the port up in depth/thickness by doubling the board just around the opening? You want the same results as I reported about? Stay as close to the recommended design as possible. Proportions are crucial, double up the thickness of the whole area and don't alter the port's figures. |
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Post by esbjornaneer on Dec 11, 2017 6:12:06 GMT -8
Thank you for clarifications. Are you saying that a setup as the image here is OK? Or do I need to double up the whole of the divider between fire box and tunnel?  I guess it would make sense to have the 180mm height from the top of the port rather than from where it is in the image... Or would I fool it on both these points by putting the collar/ring underneath the divider, i.e. in the fire box? |
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Post by esbjornaneer on Dec 11, 2017 6:30:46 GMT -8
Working on both a fibre board core and a heavy brick core drawing made me remember something that you said: All of the early experiments were done outdoors, all made of hard fire bricks and cast refractory. In hindsight, heating up did take more time, in the order of 5 to 7 minutes. After that it ran as clean as the Montana setup which was built entirely out of insulating fire bricks and ceramic glass. Does that mean that the early experiments were done without any insulation around the core? And when you say 'in the order of 5 to 7 minutes' is that the total time it was unclean or 5-7 minutes + the time for an insulated core? How long is it taking for the insulated brick core to run clean? |
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