Lighting Cones can help make traditional and charcoal stoves light more efficiently and with less smoke than other lighting methods. For the best detail, download the Masters thesis pdf from Kathleen Lask

From Crispin Pemberton-Pigott's Description:

"The main principle is that there should be enough draft to light the fire rapidly. The lighting cone provides this if it is about 500mm tall."

"The second principle is that the bottom of the cone should sort of cover the lighting fuels so that most air is pulled from below, not from the side."

"The third principle is that if there is a secondary air supply at of just below the top of the fuel, the bottom of the cone should bypass it so that the heat inside the cone is not used to pull air through the secondary air ports. Very few stoves have a secondary air controller."

In the result with good fit: "You can just see on the left that it bypasses the secondary and draws all air from below, through the fuel – in this case charcoal. Peter Coughlin reports it reduces the charcoal ignition time by more than ½. We will quantify the smoke reduction and GERES way independently confirm it at some point – it is about 90%."

Lighting stoves can also be used with traditional fires. In tests lighting damp wood in Suba Island "The speed of ignition and reduction in smoke was dramatic. You can just see the hot air distortion of the picture above the cone – basically no smoke. It is quite a bit cleaner than the fire when lit and the cone removed."
The cone on the 3 stone fire is 125

The Stove in the top example is an Anglo Supra Nova.
"It was developed at YDD during the World Bank/Indonesian Clean Stove Initiative."

"It as an Anglo Supra with preheated secondary air. It can burn wood or charcoal, and it can burn wood pellets in TLUD mode. It can automatically switch from pellet burning TLUD pyrolyser mode to char-burning mode by using a disc of paper on top of the grate."

"The loose piece of clay is a door which can close the primary air without affect the secondary air. It provides a significant level of power control without adding or removing fuel. The heat transfer efficiency burning charcoal (it is nominally a charcoal stove) is about 50%. It Is portable with handles and sells retail for about $5.50."

Kathleen’s investigation is attached.

Regards
Crispin

(Thanks to Ben Sloan!) the presentations are posted on the ETHOS website: http://www.vrac.iastate.edu/ethos/proceedings2013.html

Save the Date!: ETHOS 2014, it will be at Northwest University in Kirkland, Washington on January 24 - 26, 2014.

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Dear Marc and Ron and All interested in air flows

This is a response to questions about air and Marc’s tube.

Here is an old photo of secondary air entering the combustion chamber of a Vesto pushing the flame to the centre. This accomplishes the following:

Keeps the fire away from the wall, reducing the temperature it has to survive (a lot)
Keeps the flame going
Not allowing it to spread to one side away from the smoke on the other side that might otherwise ‘get away’.
Provides turbulent mixing of flame, hot secondary air and smoke
Allows for preheating to a significant degree (250-500 C)

The fire is circular because it is spinning rapidly, though pushed to the side by the way the fuel happened to be sitting. The spin adds turbulence without a fan and assists in keeping the flame away from the combustion chamber wall.

Here is a Vesto burning switchgrass pellets operating as TLUD, showing that there is nothing special about a TLUD in the sense of it having to operate in a particular fashion. The air flow through the fuel is reduced by the fuel and it operates as a TLUD. The secondary air is send across the surface to keep a deck of flame going at the height of the holes. This obviates the need for adding a circular disk at the top to ’keep the flame going’. Adding a ‘concentrator’ as Paul calls it takes more material and moves the fire too far away from the heat of the pyrolysis bed leading to unwanted flame-outs from time to time. A major issue with all pyrolysing TLUD’s. It is simply not necessary. Just keep the fire near the fuel. This also provides additional vertical space for the flame to finish burning before getting to a cold pot surface.

Finally, here is a photo of a Vesto cutaway showing the inside parts in their correct positons.

The primary air controller is the ring with holes in it. When the handle is moved to the side the holes are closed.Air Max

EcoWorxx in Germany is selling a line of pellet makers that take materials from dry, chopped fuel to complete pellets that are suitable for use in stoves and other applications.

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