Tlud analog? Easy to make " reactive" furnace \ stove

I keep seeing these Russian videos on YouTube about a wood burning stove that is called a "reactive" stove or furnace:
   

One video says it is totally unique but it seems like an a analog of a tlud to me  but its a bit different.  Instead of the secondary air being delivered via holes around the top perimeter, it has a center opening  for secondary air. Its more similar to the tlud design made by Paul Olivier which also has a center pipe for secondary air. ( picture attached)

Here's more info on Paul Olivier's tlud design with center pipe secondary  written by "Tim Tinker " : https://tinkersblessing.com/tag/tlud/

Although in Paul Olivier's design,  the pipe air has holes only at the top.
But with the "reactive stove", the secondary " pipe" is mostly open along the whole length.. It is a cylinder made from spaced rods that supply air and also to keep out sticks.

This design seems really easy to make. Today I am going to make a prototype from a gal paint can . if it works good. I will make one from refractory material and insulate it.

I tried to find this design on this forum but I have not found it. The secondary air ( and flame intensity )can be controlled with a valve.  I'm just wondering if anyone here has tried these and if there are any drawbacks? Also wondering what ever happened to Paul Olivier's center pipe secondary tlud? Why is it not more popular? It seems much easier and simpler to make than the double walled tluds with secondary air holes around the perimeter.
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These stove remind me of sawdust stoves, in that they have a central chimney for combustion.
The flame front can proceed from the center out to the perimeter of the cylinder, instead of from the top down.
They also resemble the swedish torch in this way.

If there is an advantage over a typical tlud I think it would be due to less care needed to process and load the fuel.
Tluds do not need to be doubled walled , they work better with it but fine without  that feature.
If you feel like you need it, it's not hard to create.

The Paul Olivier design has primary air, secondary air and the central chimney.
It could be argued it uses less in the way of materials than a double walled tlud, but he seems to rely on  forced combustion air.

The "reactive" stove seems to tightly control the combustion air, and it's a "natural" draft stove.
The way the video built the central chimney seems unnecessarily fiddly.

A stainless steel stock pot with a NPT male threaded steel nipple would be a good start for a reactive stove.
Compatible with plumbing hardware, the npt threads would make adding a valve to control combustion air pretty straight forward.
For the central air "pipe" , a steel silverware holder is heat resistant and comes with perforations.
I think we can call this a vertical  tuyere, since it serves much the same purpose.
Inverted over the pipe nipple, it should keep the fuel from closing off the combustion air.
Cut a hole in the lid and your done.
I do think the stove in the video could benefit by a short length of flu pipe with some secondary air holes, so maybe add the that.

I bet this would work great with sawdust.....      Something I would be interested in seeing is if the air coming in would be at an angle if a vortex could be created.....

Would be useful for creating charcoal as turning off the air would be easy with this design...

Here is a "sawdust" stove that is burning leaves instead of sawdust:


It's in Russian, but if you skip ahead to 6:40 you will see it in action.
Total burn time is close to 4 hours.
Like most of these stoves the central chimney is formed when the fuel is packed around a pipe that is then removed.
If we used a vertical tuyere, the packing process could be less fiddly.
In particular, I think it could burn wood chips that are just poured into the fuel chamber.

I watched the video again......  ( from the first post )    and I do believe they are using a fan to push the flames....    The reason I say that is you see flames shooting out the cracks on the top of the stove....   this is not normal as it would normally just go out the chimney...    

I think a fan would be a good addition, but if they got the flames that big they should also show how they got them....

If using a fan, then these may basically be an "inside out" version of the T. B. Reed et al "Turbo Wood-gas Stove" TLUDs.

I've tinkered with natural draft TLUD stoves made from soup cans, but combustion wasn't particularly stable - they were either "up on plane" and burning cleanly, or were smokey and drafting poorly.  A small shift in the fuel load as it settled during combustion was enough to upset the apple cart, though I never tried fueling them with pellets, which would have a more consistent particle size and likely a more consistent draft and settling behavior.  The small branches and twigs I was using, cut up into short lengths, also probably had variable moisture content.  The small diameter burn chamber (and especially relative to the characteristic size of the fuel load) really was rather twitchy.

I suspect that a small forced draft fan (as I recall, Reed spec'd a 3 watt model) would probably help to ensure more stable combustion with a less consistent fuel.  I'd think the same would be true of small inside-out TLUD-ish stoves like these reactive stoves.

The bubafonya stoves are another Russian (Siberian) development, though not a gasifier, and so less clean-burning, as best I can tell.  But, they are pretty low tech, and long burning.

I'm currently working through the Alex Berberich online course (through Bosco di Ogigia) for constructing a pyrolyzing gasifier thermal mass heater.  Fancier burners than these reactive stoves, and definitely not a rocket, but still basically a TLUD, though relying on a chimney for draft.

Kevin, I love those stoves!
Home heating that produces charcoal is my jam!
This video introduced me to the product:

Mart Hale wrote:I watched the video again......  ( from the first post )    and I do believe they are using a fan to push the flames....    The reason I say that is you see flames shooting out the cracks on the top of the stove....   this is not normal as it would normally just go out the chimney...    

I think a fan would be a good addition, but if they got the flames that big they should also show how they got them....

I kept watching more of these reactive stove videos and I think we are just seeing natural draft.
Here's another one, it uses pellets but it's design is the same as the other one:


@5:59 onwards we see it in operation, it has a strong collum of flame with no forced air in use.
A well made natural draft tlud is pretty rockety, these stoves just might be the better version of a tlud.