|
Post by peterberg on Nov 8, 2017 12:09:15 GMT -8
I'll say it again. Peter, this is verry intetesting. I haven't paid real attention. How's the secondary air implémented? A simple floor channel duct that goes to vertical against the back wall and ends halfway in the port. As uncomplicated as a duct with a 90 degree bend in it.
|
|
|
Post by satamax on Nov 8, 2017 19:57:58 GMT -8
Thanks Peter.
I see the simplicity in it. Tho, i'm not totally sure about the mixing. I don't have time to play with this. But, may be just another elbow at the very end in the port could solve the erratic behavior. Or add some O² to the burn in a more spread manner.
Pretty much like you did the first batch P channel. You said, iirc, that the stream of gases, in the original batch, was squashed down, somewhat, by the incoming secondary air. My, gut feeling, tells me that it is also, forcing the mix with o² too. My idea of increasing mixing, which is yours originally; might not be necessary in this case. Tho, if i was doing it myself, i think i would try that last elbow. Just to be sure.
This idea comes from the carburetor main jet. Sending the petrol perpendicular to the main stream. Here, it would be air, sent perpendicular to the, already made mix.
Just an idea.
|
|
|
Post by peterberg on Nov 9, 2017 2:28:17 GMT -8
At the moment I'm inclined to think that erratic behaviour of the flames is a good thing. In fact, I tried about six different combinations of that tube and another elbow at the top. Much like the floor channel in the straight batch box, only horizontal this time. Here's a snapshot of the drawing. None of the combinations was as good as the straight tube without the horizontal stub. Also, the chaotic looking fire fountain is performing consistently better than the more "neat" and rapid spinning double vortex. That is to say, in the double shoebox configuration. Interesting times, aren't it?
|
|
|
Post by satamax on Nov 9, 2017 7:45:34 GMT -8
They are Peter. I will test that one i think.
|
|
|
Post by Vortex on Nov 12, 2017 1:53:02 GMT -8
|
|
|
Post by peterberg on Nov 12, 2017 4:00:23 GMT -8
Finally, I got time to amend the drawing of the Allerton Abbey kitchen. It's a real world example, I'm convinced it should work given a proper chimney and bypass. A door is needed, although this isn't drawn. The air inlet should be around 35 cm² (5.43"²), placed low in the door. The bricks sizes are what was at hand in Montana, used in such a way minimal cutting was in order. The drawing can be downloaded using this link.It's in SketchUp 8 format, so most of the older versions should be capable to load it. Regarding videos and sketches that show similar concepts: of course they are around, some of them quite ancient I'd guess. I won't claim it is an unique invention, literally everything has been done before when you look back far enough. The point is that I took the time and equipment to work out what seems to be the best and simple layout so far. The combustion in that last video in particular can't be very clean, the low and wide tunnel I tried showed a nice double vortex but ran dirty most of the burn. There's a fine line between running remarkably clean and not at all, believe me. So please, stop looking and pointing to other examples and promote progress of this concept instead.
|
|
|
Post by pinhead on Nov 14, 2017 8:31:59 GMT -8
I have a question with regards to the top shoebox.
Did you try a round upper burn chamber? I ask because it is real easy to make ceramic fiber blanket hold its shape in a round/tube form, but the material needs support when laying flat.
I assume the CSA would need to stay the same - and volume should be close. Or, perhaps, it should be treated much the same as a square vs round riser - the diameter being the same as the length of a side.
Which is correct?
|
|
|
Post by peterberg on Nov 14, 2017 12:16:15 GMT -8
I didn't try a round upper burn chamber, simply because I don't have a box of superwool laying around, just some scraps.
I'm convinced it should be treated the same as the round vs square riser. I ran a test during September with a top box of the same csa as the square one and it didn't produce the same results.
|
|
|
Post by pinhead on Nov 15, 2017 10:59:01 GMT -8
The top shoebox is 6-9/16x7-1/16. Would 7-inch diameter be close enough?
|
|
|
Post by peterberg on Nov 15, 2017 12:00:12 GMT -8
Given all the other dimensions stay the same, yes. I suspect the burn would be quite different as compared to the experimental model. I think there will be a really nice double vortex but the Testo did prefer the chaotic fire fountain.
|
|
|
Post by Orange on Nov 17, 2017 3:32:22 GMT -8
this is a very practical design Does it support the same ISA as a normal batch box?
|
|
|
Post by peterberg on Nov 17, 2017 3:42:01 GMT -8
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.
|
|
manU
New Member
Posts: 41
|
Post by manU on Nov 17, 2017 5:31:12 GMT -8
Hello. I like this design specially for its simplicity and compact size. Reminds me a lot to Vortex stove and Matthew Walker Riserles Core, that I like too. My concern would be too much heat hitting the cooktop right over the Port. Metal there would probably get cherry red. I have had that experience with 5 and 6 inch L rockets. My suggestion is to try a flame deflector (rafractory slate). This will give more even distribution of the flame and help reducing the temp difference in the cooktop, and therefore warping or deformation. But more important, I have the "feeling" (because I don`t "have a testo") that it can also make combustion cleaner: the deflector could provide a "very hot crash surface" for the hot gases and create at the same time a violent turbulence (chaotic fountain?). Just a thought cheers. This is what I would try (green slate): Cheers, and thanks for sharing your good work.
|
|
|
Post by rakettimuurari on Nov 19, 2017 22:33:43 GMT -8
Great stuff!
Can't wait to see how this will end up... Having this kind of "riser" just below the baking oven floor and finally shooting the jet through the oven could add quite a bit to the oven temps after the burn!
I wonder if the riser top plate/ oven floor was made of - lets say 5cm/2" refractory (or hard fire bricks); would it let the riser/ burn tunnel hot enough without any insulation? It would definitely give the oven solid floor heat!
Thanks for sharing!
|
|
|
Post by peterberg on Nov 20, 2017 1:42:38 GMT -8
My concern would be too much heat hitting the cooktop right over the Port. Metal there would probably get cherry red. I have had that experience with 5 and 6 inch L rockets. My suggestion is to try a flame deflector (rafractory slate). This will give more even distribution of the flame and help reducing the temp difference in the cooktop, and therefore warping or deformation. But more important, I have the "feeling" (because I don`t "have a testo") that it can also make combustion cleaner: the deflector could provide a "very hot crash surface" for the hot gases and create at the same time a violent turbulence (chaotic fountain?). There's no such thing as heating the cooktop too much, provided it's made of ceramic glass. Glass isn't a very good conductor, much less as compared to steel. A fair amount of heat will be kept inside the combustion area by using glass. I'd suspect a deflector plate would disturb the fire fountain, thereby killing off the clean combustion. Of course you've seen the videos, the glass is very clean, no soot to be seen anywhere once it's hot. Even the front window of the upper shoebox is clear. The fire fountain and the ceramic glass (Neoceram or Robax) are together a very good combination, much better than a cast iron cooktop would be. 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.
|
|