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Post by peterberg on Feb 5, 2019 5:01:27 GMT -8
OK, I'll do that. None of the three pictured is the one I ordered, by the way.
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Post by DCish on Feb 5, 2019 6:36:33 GMT -8
As long as the fireball at the rear end of the box is transparent the Testo is extremely happy. I'd love to see a video of of this if you have one / get the chance. |
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Post by peterberg on Feb 5, 2019 10:49:08 GMT -8
I've uploaded two video's that shows how the top box looks like while the burn is going on. The first shows the flames coming through, the second shows the complete fireball when running full tilt.
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Post by independentenergy on Feb 5, 2019 11:52:50 GMT -8
very interesting!!
do you think it is possible to increase the width of the upper box in order to have a larger oven?
has it already been tried?
perhaps maintaining the original dimensions where the fireball is created.
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Post by peterberg on Feb 5, 2019 12:57:23 GMT -8
What you are looking at is a small heater core, just 120 mm system size. The first and probably also the only one so nothing else has been tried as yet. Scale the thing up and you'll get a larger oven.
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graham
Junior Member
Posts: 74
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Post by graham on Feb 5, 2019 13:03:39 GMT -8
Pizza in the top box of a DSR2 browns very quickly under those conditions!
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Post by independentenergy on Feb 5, 2019 13:13:46 GMT -8
Pizza in the top box of a DSR2 browns very quickly under those conditions! it is not necessary to introduce the pizza in full combustion, you can heat the oven and at the right temperature that in any case is around 350/400 degrees centigrade, introduce the pizza |
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Post by independentenergy on Feb 5, 2019 13:17:56 GMT -8
What you are looking at is a small heater core, just 120 mm system size. The first and probably also the only one so nothing else has been tried as yet. Scale the thing up and you'll get a larger oven. Peter in this period I did some design, the last if you would like to insert it because it is very similar to your concept, the system is 150 mm but the oven is larger. Tell me what you think. |
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Post by peterberg on Feb 5, 2019 13:23:18 GMT -8
It's nigh impossible to build a larger system in the setup I have at home. Would you care to start a new thread about that subject?
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Post by satamax on Feb 6, 2019 1:20:12 GMT -8
Peter, is it the quality of the video. Or my sight? I don't find the birick to glow much.
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Post by Vortex on Feb 6, 2019 5:43:56 GMT -8
It takes a surprising amount of heat to get those Insulating Firebricks glowing hot enough to make it obvious in daylight.
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Post by DCish on Feb 6, 2019 6:28:13 GMT -8
I've uploaded two video's that shows how the top box looks like while the burn is going on. The first shows the flames coming through, the second shows the complete fireball when running full tilt. Thanks for the videos. Impressive fireball indeed! |
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Post by peterberg on Feb 6, 2019 8:16:33 GMT -8
There are some unexpected effects with this DSR2 configuration. Please let me explain. Last Friday I loaded the firebox to maximum and lit it up. The exhaust port was restricted to 80% of system size, fuel 12% moisture, quite windy outside. And this was the result:  I wasn't pleased at all, blaming the windy situation. The opaque fireball is shown in the second video. I tried it again the next day, end port to system size this time, yielding even worse results. The moment the fireball went opaque, not transparent anymore, the CO rose within tens of seconds to something like 50000 ppm. Monday I tried half a load, same ash fuel, little bit less windy, end port as before. This was not bad, although the burn was quite short and the fireball didn't last longer than 5 minutes.  Since Ronyon asked about the possibility to have an object inside the top box, I placed two bricks on top of each other in the top box/oven. There's no point having an oven while there can't be anything in there, don't you think? I loaded it up to 2/3, same end port, same fuel, no wind and foggy outside. I started the computer and the Testo, rigged everything up and lit the fire. And I sat down to wait for the thermal runaway to appear. And it didn't, much to my surprise. Even the fireball wasn't as pronounced as I expected.  Development of the burn was slightly different, it took more time for the fireball to appear. Here are some pictures how the development looked like.     Through years of experimenting I got quite sceptical about excellent results: it need to be repeated to check whether it isn't a one-off. So today I ran the thing again with the bricks in place, a full load this time, everything else being the same as last run. The diagram happened to be even better, coupled to a low PM2.5 number it would pass an official test with flying colours.  Now what caused this effect? Not a restriction in itself, see the first run which had a pinched end port. It looks like the restriction need to be upstream from the end port, before the gases are rounding the bend to vertical. I am planning to build a restriction at the box ceiling and maybe placing also a brick on its floor. One thought: the bricks reached a temperature of 230 ºC (446 ºF), measured at the face that was protected by the other brick, an hour after the run ended. Another thought: during the experiments in my garden back in 2017 I had a meter of stove pipe on the top box of the prototype DSR1. The hole was a bit too wide so the stove pipe protuded inside, about 30 mm or 1 1/4 inch. The results in the garden couldn't be repeated in the workshop, perhaps because I left out that small feature... |
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Post by Vortex on Feb 6, 2019 9:48:17 GMT -8
Those last 2 graphs look great, Peter.
It's surprising what big effects small changes can have. It almost feels like changing one parameter changes the effect that changing any other parameter will have.
I wouldn't think you'd need much if any end restriction on that stove. I only found it helpful on outdoor setups with a straight up chimney, it seemed to help simulate a bit of back pressure in the system, like it would see with a mass, bell, bench, etc.
Only time I've seen that opaque type flame is if I try restricting the primary to early in a burn. On your graph the CO spike seems to correspond to a drop in O2.
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Post by peterberg on Feb 6, 2019 11:46:22 GMT -8
On your graph the CO spike seems to correspond to a drop in O2. Yes, it does. Actually, it's always like that, the CO is displacing the O² or it sure looks like that. |
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