Vortex Stove

[yasin]

Hi Vortex , a few years ago, while I was buying insulating firebricks from our firebrick manufacturer, he warned me against using it if there is an oven afterward in the flue path : he explained to me that he had sold those insulating firebricks to a cookware (ceramic dishes and the like) manufacturer and that the manufacturer had it mounted directly as the inner lining of his ovens.

The problem was that the cookware products were corrupted with small deposits from the insulating firebricks. The problem was solved by putting the dense firebrick before the insulating firebricks, so that the insulating ones were not in direct contact with the hot gases.

I had also problems with using superwool around the risers of batchrocket cores : they melted away after just one year of use (surely because of the water content of the gases) and the clients complained about the bad taste of foods.

From then on I stopped completely to use those products..

Hi peterberg , with my experience with the batchblock V2, I have absolutely no doubts about the performances of your DSR2 without insulation ! The core we're making has a 200mm "riser" and can burn 14kg of wood in one batch.

My question was more about the Trevor's core. It is just that during the development I tried the Trevor's core and I didn't succeded to get it running correctly. I had not insulated it so I am still unsure if the problem was my experimental setup or the fact that the core wasn't insulated anywhere.

And I didn't know the the 2022 EU norm will not require to start measuring from a cold start ! That's fantastic news ! The EN15250 does require to start from a cold heater, which is different from what the other norms concerning iron stoves are requiring, making the tests harders for mass heaters.

Regards,

[peterberg]

OK, I did the complete retrofit today, fired it up this evening. It works, being a bit slow to come up showing the double vortex but kept going like that for 35 minutes. I housed all of the afterburner arrangement in the modified top box. Exit is at top rear now, 5% larger than the ceiling port. Due to the extra deep airframe the shelf is 18 cm away from the glass instead of 9 cm. All glass stayed clean, no soot to be seen anywhere. Those two barrels are a bit on the spacious side, highest chimney temperature a mere 80 ºC.

Tomorrow I'll install all gas analizing equipment into the workshop and start testing.

[Vortex]

Well done Peter, that was quick work. The double vortex can be slow to form properly if there is too much air, not enough wood-gas being produced (slow fire), fire too far from port, too strong a draft, or a cold afterburner. If you post a video I'd have a better idea of which one it is. I don't know how the larger gap infront the shelf will affect it as I have never run it that far back.

[Vortex]

Discussion of Peter's new core carries on here: donkey32.proboards.com/thread/3710/combi-dsr1-vortex-aspects

[Vortex]

Yesterday before lighting the stove I meant to clean the flyash off the afterburner glass, but forgot until I'd lit it, so I grabbed a damp cloth and took off the glass while it was running thinking if I did it quickly it wouldn't fill my house with fumes. To my surprise it ran away happily with the door open and no afterburner window, and no fumes came out of the door or afterburner.

That got me thinking about how it could be use as an outdoor stove, like a Chiminea or even BBQ stove if the top of the afterburner was a hotplate.

[Dan (Upstate NY, USA)]

But could you start it cold with the window open?

[Vortex]

No, not without a good strong wind. I tried it this evening and it smoked out the front of the firebox and most of that then got sucked up into the afterburner. You'd need some kind of door or cover for the afterburner at least for the first few minutes to warm it up and initiate the draw, then it'd be OK. Maybe a garden project for next summer.

[martyn]

I have made a start with a 5’’ system!
I cast four 32mm slabs, i use silicone to hold them together while i work and covered it all with 50mm ceramic board.
I hate working with ceramic fibre but i painted it all with water glass and covered it with foil so i feel a bit better about it now.
I used three coats of water glass on the roof piece including the port.
I used insulating fire brick for the top box with split fire brick for the shelf .
imgur.com/xTGUvCo
imgur.com/PjaIvnk
imgur.com/HyJNYqM
i.imgur.com/irCMIQ0.jpg

[Vortex]

Looking great Martyn Cant wait to see her running.

I'm the same about ceramic fibre stuff. Any reason you used a split for the shelf instead of CFB?

Here's the pics embedded, easier for people to see.

[martyn]

I was planning on using 25mm board for the shelf and top but I dont have any in stock until i make an order from the UK, I tend to buy the 50mm as it is much better value .
I want to keep the overall hight as low as possible but keep the vortex window at eye level when seated, so a 25mm shelf and top will help with this.
Unfortunately this is a bad time to dismantle my present stove so there may be a delay before the next instalment ....
I have a ceramic glass cook top ready but i have not given much thought to the finished design ... possibly a red brick bell with a steel front but where it will live is an outdoor garden room so radiant heat is more important, the whole room is ‘steampunk inspired’ as is my rocket stove so I may come up with something to blend in!

PS thanks for the photos i was having issues getting anything to show!

[Jura]

Is the content from VITCAS container "ceramic fiber rigidiser " a mere water glass? (if so: sodium or potassium?)

I haven't kept abreast with the development of the vortex core for past 4 month so won't you be looking at me with askance when I ask what are those 2 wholes down the rear firebox wall for?

Do you use any fiber or mesh in your castings?

At Trev: Thanks for placing the photos (I'm still using the embedding method advised by you)

[martyn]

Ha well spotted ! I formed two holes at it allows me to experiment with pre heated air flowing under the slopping floor pieces.
I am told the Vitcas ridgidiser Is a special blend but it smells like water glass although it is quite thick, it works very well and forms a hard shell that is quite tough once heated. (I should read the label one day!)
I find that if you build up 3-4 coats it really does to seem to form a hard glass like surface but i use it to mainly seal the board and stop them dusting.
I have used it to form heat risers in conjunction with ceramic weave and ceramic matt.
I use stainless steel needles and burn out fibres,In my cement mix, i have considered using chopped carbon fibre strands but never actually have!
I build quite large single refractory pieces up to 60kg that are heated to 500c and rarely crack with the mix i use, we will have to see how these 30mm thick pieces stand up.

[cork]

Hi Trev,
I have been running my stove a couple of weeks now. My bench as I was thought when building is too big. Originally the flue temps were only 50 C. At these temps the stove would form a rams horn vortex but after a short time the air control needed careful management. Still it was testament to your design that it worked at all in these conditions when sometimes the outside temps were in the high teens. It seemed to run best with no exit port then. Since I have blocked off nearly 2/3 of the bench and flue temps now peak at around 75 C it now runs with the exit port. I shall block off a little more of the bench to boost the temps further and was also thinking of making a couple of hinged insulated covers for the hot plate. I have noticed on windy days the flames in the afterburner flux or corkscrew in and out, maybe an anti-downdraft cowl will help? There is no room for a draught regulator. One of my best runs was on a calm dry day where with my umbrella cowl was taken off ( highest flue temp). Delighted with it and thanks. James.

[Jura]

Oct 15, 2020 13:15:24 GMT -8 cork said:

Hi Trev,
I have been running my stove a couple of weeks now. My bench as I was thought when building is too big. .

HI James,

Do You have some thread where you showed your set up ? I wonder what is the length of your bench and firebox size.

I am planning to give it a try to connect vortex firebox placed in cook top range to a 2 m long piped bench.

[Vortex]

Rafał, James's posts are in this thread, just go to his user profile page and look under the activity tab and you can see them all from there:
donkey32.proboards.com/user/4825/activity