jonasp
Junior Member
Posts: 102
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Post by jonasp on Dec 10, 2023 1:15:01 GMT -8
I did try quite a few variations to the theme, this one started off OK then went a bit wrong! I'm so happy I've never experienced a overfuel like that hehe, great experiment nonetheless trevThat's really interesting so we could conclude in your setup the resistance is crucial at the "fold over" exit and maybe also the second exit |
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Post by Vortex on Dec 10, 2023 6:05:45 GMT -8
trevThat's really interesting so we could conclude in your setup the resistance is crucial at the "fold over" exit and maybe also the second exit Well there may be other ways to achieve the same effect but so far all the best results have had a top chamber entry and exit port. My burn today overfueled a little at startup but was OK after, weather is still very windy though. I think next I will try it still with the new wider top chamber, but all at the maximum surface area to volume ratio. That would mean a depth of only about 45mm, I'd need to make the 'fold over' maximum width, and a sunken area around the exit again to help it transition into the ports. |
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jonasp
Junior Member
Posts: 102
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Post by jonasp on Dec 10, 2023 8:09:45 GMT -8
Not 100 sure what you mean by the depth bringing to 45mmm. But I'm interested in your conclusions by these changes.
How much CSA are your flow channels after the exit?
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Post by Vortex on Dec 11, 2023 1:55:51 GMT -8
Height would probably have been a better term. Before it was 65mm x 270mm (1 csa) but with the increased size, to get the same 1 csa and maximize the surface area it would be about 45mm x 400mm. I'm busy all day today but hopefully try it out tomorrow. The channels vary but are mostly around 200mm x 100mm, more around the bends and less where they go around the internal chimney.  |
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jonasp
Junior Member
Posts: 102
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Post by jonasp on Dec 12, 2023 1:00:37 GMT -8
Sorry if I was unclear, I was wondering about how the larger top chamber would fare in a bell, not the Vortex in general. If you get the chance attila , I'd love to know some dimensions or see a sketch of your heater- beautiful shape and proportions. It still feels like early days and all results help build the picture! Would love to see my details of the build too. What system size it is, how well it burns and if any overfueling. video seems to be very nice and stable vortex! |
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Post by Vortex on Dec 12, 2023 7:01:23 GMT -8
Latest experiment with the enlarged top chamber. This morning I added more layers of vermiculite to reduce the height of the enlarged top chamber and increase the surface area while maintaining the system cross sectional area at 1 csa. The opening from the afterburner into the top chamber is now 235mm x 75mm (1 csa). From the front edge of the shelf to the back of the top chamber is now 350mm x 50mm high (1 csa). The low height of the top chamber means there is no distortion of the vortex due to the draw being higher on one side, even though the afterburner exit goes straight into a 90 degree exit of the top chamber, the draw is evened out across the whole length of the exit by the low height. 1 CSA pipe (150mm) circumference = 471.3mm SA:V = 1 1 CSA chamber (272 x 65) perimeter = 674mm. SA:V = 1.43 (skp file) 1 CSA chamber (350 x 50) perimeter = 800mm. SA:V = 1.7 (this experiment) Exceptionally stable burn despite it being windy. The vortex was fast, perfectly formed and remained in the rear of the chamber the whole time. The stove temperature was also hotter than I would normally expect from the same load. I will do more runs with this setup but the initial impressions are excellent.     |
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jonasp
Junior Member
Posts: 102
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Post by jonasp on Dec 12, 2023 9:49:28 GMT -8
Great to hear such a good initial results! So it's definitely not only the 2 exits but the whole top chamber resistance which makes sense. (CSA and sa/v wise)
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Post by attila on Dec 13, 2023 1:39:00 GMT -8
Sorry if I was unclear, I was wondering about how the larger top chamber would fare in a bell, not the Vortex in general. If you get the chance attila , I'd love to know some dimensions or see a sketch of your heater- beautiful shape and proportions. It still feels like early days and all results help build the picture! Hello, Sorry for the late answer. The stove itself is a very smal stove. 49*49*184, but it is perfectly enough for a 19sqm room with 3 sides facing outside without insulation, when the temperatures winter time vary between -5 - -20. Sorry, I didn't make pictures while building and I dont have scetchup either. But here are the numbers. Down there is the ashbox with a door with an air regulator knob. The firebox is squere, 34cm deep, 27cm wide, 26cm high and there is a cast iron steel grill between the ashbox and the firebox. The firebox has double walls where the secondary air is traveling and gets heated and enters right below the ceiling of the firebox close to hte port. The Port is 15cm*4cm. Afterburner is 34cm deep, 22cm wide, 12cm high. The afterburner shelf is 10cm away from the front glass. The gasses from here are traveling directly in to the bell, which starts righ above the afterburner. The inside of the bell is 26cm*26cm*84cm. The bell is connected from the lowest point to the chimney with a ceramic squere tube with a regulator plate. the inside of the connection is 13*13cm, the chimney is an old brick chimney about 6m high and 15*15cm inside. I have realised that when I'm reloading the fire I also have to add more air. The window gets a little bit blurr but becomes clear again after about 5 min. If we add more fuel we need to add more air too. |
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Post by fruitbat on Dec 13, 2023 2:21:25 GMT -8
Thank you attila for taking the time to add the information, it seems close to a 5" system size wise. Sounds like it works really well! It would be interesting to know what materials you used too. I've yet to build a Vortex and am very excited to! I really love the tall, slender bell. Beautiful work! |
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Post by attila on Dec 14, 2023 1:01:14 GMT -8
Thank you attila for taking the time to add the information, it seems close to a 5" system size wise. Sounds like it works really well! It would be interesting to know what materials you used too. I've yet to build a Vortex and am very excited to! I really love the tall, slender bell. Beautiful work! Thank you fruitbat, indeed it came out really good. Anwering your question, the stove is built by regular clay bricks 23*11,5cm and then at the and it is plastered and painted white. This paint is a lime base paint, but it also has some other ingridients and because of this I believe it discolored at hotter spots, it became yellowish. At the level of firebox the bricks are placed on the sides and after leaving a small gap another layer of fire brick came in 4cm thicknes. The ceiling of the firebox is a 6cm thick fire resistant ceramic plate in which I've cut the 4*15cm port. On top of this plate I have placed the afterburner, which is made of vermiculite board. On the side of the bell I placed 4-4 pieces of ceramic tubes so the heat can start coming in the room quicker, otherwise it needs 2 hrs for the stove to get hot. |
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Post by Vortex on Dec 14, 2023 5:57:00 GMT -8
Yesterdays burn was with the exact same setup as the previous, but the weather had changed from very strong wind to dead still, so a great time for a comparison of the two extreme. This burn was very different to the last one, fire felt very sluggish and overfueled for about 10 minutes over the peak of the burn. Opening the primary air more had no effect, as the level of restriction in the system was so high that it was unable to draw in any more primary air. I remember that same effect when I tried the vertical vanes in the afterburner a few years back ( donkey32.proboards.com/post/36721/thread ). This morning I increased the height of the top chamber to 56mm and shortened it by 40mm to keep the csa at 1.0. The SA:V was 1.577. The weather was very still again. Beautiful vortex, perfect burn, no overfueling. Vortex slightly more pronounced now on the left side of the afterburner due to the higher draw on that side with the higher afterburner. Will do some more runs with this setup and see how it goes.  Trev |
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Post by fruitbat on Dec 14, 2023 6:40:27 GMT -8
Thank you very much for the details! And to Trev for developing this core, which in action turns and heater into an art form! On the side of the bell I placed 4-4 pieces of ceramic tubes so the heat can start coming in the room quicker, otherwise it needs 2 hrs for the stove to get hot. Aha, I wondered what they were. Very clever! |
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Post by hof on Dec 16, 2023 8:05:45 GMT -8
Reduced afterburners exit from 1.32 CSA to 1 CSA. Now it burns with less overload.
Enlarged topchambers entrance from 0.6 CSA to 0.75 CSA. Now it burns clearer and much more powerful. Glass do not have soot on it. Almost do not have. Just a little glare.
Happy.
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ollie
New Member
Posts: 2
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Post by ollie on Dec 18, 2023 3:27:52 GMT -8
Hi Martyn,
I have been following your videos on Youtube they are great and have inspired me!
I am currently trying to design a stove that will work as a patio heater and achieve the following objectives: smokeless, provide dispersive heat, have a cooking surface and provide ambience (flickering flame).
So far I have been following Peter van den Berg Batch rocket designs and over the weekend we built a 5'' stove. We found although it was smokeless and the firebox got extremely hot (at least over 500 degrees C as my gun said error) temperatures out of the flue were quite low so probably not hot enough to cook on or heat. Additionally due to the long flue we have no visual affect.
Then I stumbled on the Vortex and thought well that looks perfect! In a very long winded way I am asking could you adapt one of these vortex stoves to achieve the above objectives, and if so could you kindly share the plans so I could build one.
The price of vermiculite is eye watering so I may do a test run with bricks if possible.
Appreciate any and all advice. Best wishes and Merry Christmas.
Ollie
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Post by Vortex on Dec 18, 2023 7:09:25 GMT -8
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