EverythingNice stove Mk II

So the initial burn of my EverythingNice stove went pretty well but it can still be improved. The main issue with it was the "cone" of uncharred fuel left in the bottom after the burn. From my (admittedly not perfect) understanding of TLODs¹, this shape makes sense due to the direction of flow of the hot gasses in the inner chamber.

My simple solution (I don't claim to have come up with the idea, others have done this before me) was to insert a cone-shaped piece of metal into the bottom to prevent any fuel from sitting where it wouldn't be burnt. The cone was made from the bottom of a tin of tomatoes (approx same diameter as the outer tin).

Circular piece of metal cut along a radius, and two holes drilled near the cut

The cone shape formed and secured with a bolt

The edges were snipped a bit so I could bend it to fit nicely inside the tin, and then it was simply placed at the bottom. I didn't really feel like watching it for an hour this time so I only filled it up maybe just over 1/2 way with 100g of pellets for the burn. I lit it the same way as before, soaking a couple of pellets in alcohol for a couple of minutes, putting them on top and lighting them.

Also played around with putting cans on top to try to increase the draw. Seemed to give a slightly stronger flame, but not much.

The results:

• Seemed to take a little longer to achieve a nice consistent flame cap. Not sure if this was the cone in the bottom, or because I only filled it halfway up. (What's that about only changing one variable at a time?)
• Once it was going, had a nice steady flame as before.
• The 100g of fuel burnt for ~32mins and produced 19g of nice biochar. (Okay, I couldn't resist throwing a couple of seeds and leaves in there to see what would happen, so I guess slightly over 100g of fuel)
• When the flame died down and went out, it smoked a little for maybe 5-10 seconds, but that was it.
• After it had stopped smoking I looked into the chamber and noticed that a little of the char was glowing red. Taking this as a sign that the charcoal was now combusting (which I didn't want, I wanted to keep it), I poured it out into a metal tin and put the lid on to deprive it of oxygen.
• After it had cooled down, the char left behind was much nicer than before. All fully pyrolised.

All fuel fully pyrolised. Yay!

So, in the end, very happy with Mk II of my EverythingNice stove at the moment. I'll do some water boil tests to get some idea of the heat output in the near future.

[1] : TLOD (Top-Lit Opposing Draft), the mechanism by which the EverythingNice and Lucia stoves (invented by Nat Mulcahy of Worldstove) operate. A lot of people out there claim that they are TLUDs, but they are a different beast altogether. I'll post about the differences and the airflow in TLODs in a future post.