I started with a stainless steel trashcan that had seen better days. I
unrolled it and glued on ELSA stove blueprints from the web. Then I cut out
the shapes with a 24 tpi bimetal blade in a jigsaw.
I don't have an anvil, or the sheet-metal "curling" tool (is there a name
for it?) that is shown in the video. I bent the metal over some angle-iron,
and I made the tool from some stainless tubing I bought at the hardware
I couldn't get the stove to light until I used the lighting cylinder, which
is shown in the video, for some extra draft. I used brown packing paper as
tinder, and wood pellets as fuel.
Marc Ayats Plana has been working on TLUD stoves and improved low thermal mass ovens. This TLUD powered low thermal mass oven was inspired by the Anderson's Recho Rocket Oven, and uses a Champion style TLUD heating stove to power the low thermal mass earth oven.
Increased primary air draft, which can apport enough oxigen to burn the charcoal generated during the gasification process and continue giving heat to the oven. Now the primary air enters around the lower perimeter of the reactor, instead of having a single inlet tube like in the original model.
Increased the length of the riser, which also sustains the diffuser. This extra extension allows the complete combustion of gases gasification to completely remove the visible smoke in the oven.
TLUD Reactor. Diameter: 20cm. Total length: 30cm. Fuel Height: 20cm
TLUD Outskirt. Diameter: 22cm. Diameter central hole: 10cm. Total length: 25cm
TLUD Riser and diffuser. Diameter: 12 cm. Total length: 30cm. Diffuser: granite piece 2cm thick and 15cm diameter
In the Oven Temperature graph, you can see the complete temperature profile. Marc did a side by side comparison of both a 20cm reactor TLUD and a smaller TLUD, with 12,5cm reactor. "Note: the temperatures refers to the inside side of the wall oven, half way between the baking surface and the top hole. Note2: the temperatures were taken by a temperature datalogger and a type K probe."
Marc's Notes and TLUD size comparison are copied here: Notes about 20cm TLUD test
For those interested in using coconut husk (not shell)
Unprocessed coconut hulls make lousy fuel.
Coconut hull fiber are generally know as coir. http://en.wikipedia.org/wiki/Coir
It is a big business in India. http://msme.gov.in/Chapter%206-Eng_200708.pdf
The fibers are processed into mats, carpet backing, potting material, and geotextiles (for erosion control).
On a small scale, the hulls can be soaked in water for at least a month and beaten to break the pith and used as mulch.
The pith leftover from fiber production is known as cocopeat. http://en.wikipedia.org/wiki/Coco_peat
It is generally a coarse powder. It can apparently be made into fuel pellets for gasifier stoves. See attachments.
Bob Air Max
Here is some pictures of the Jiko Bomba casification cookstove.
The first shows the two part of the stove with pellet as fuel in the firebox before fire is lit.
Second show the stove burning.
The third the same, in the end of the gasification.
The forth shows the charcoal stage where the pellets remains as glowing carbon. A pot can be put on top of the bottom part of the stove, there are three supports for that.
Its a long winter, and old bones and cord wood and Crispin make me
Attached are two pictures which show my early steps towards
understanding the limitations of gravity with stoves.
One shows a wedge shaped door spacer "the Artful Dodger' which picks the stove's pocket for draft and connect it to any burner idea I can cobble together.
The other shows it operating with a burner that has a small unsealed
hopper for pellets. I use a loose lid/follower to ride down on the
pellets. So far there has been no fumes coming up and out, and the fire has not chased the air and fuel back into the hopper. The bottom throat on the hopper is about 5 cm diameter. It operates continuously at one speed with an input of 1.6 kg of wood pellet per hour.
From the Charcoal Project article:
"Mulcahy is the founder of WorldStove, a small Italy and U.S.-based company that manufactures a range of energy efficient, biomass-burning cookstoves. The company operates two business lines. One sells pricey cookstoves and barbeque grills for the outdoor/camping crowd in industrialized societies. The other line of stoves, the research of which is funded by the former, helps bring energy efficient cookstoves and locally owned businesses that produce them, to the oceans of energy poor people around the world who don’t have access to modern fuels like LPG and electricity.
"Mulcahy has recently returned from Haiti where he spent two months setting the foundations for a sustained long-term plan to alleviate the country’s heavy dependence on the inefficient combustion of the wood and charcoal. President Bill Clinton, the UN Special Envoy to Haiti, highlighted WorldStove’s remarkable and quick work in Haiti in a recent Earth Day address."