Charcoal Stove

Manually-operated biomass pelletizer - clay as a binder?
Charlie Sellers, May 10, 2008
Honeycomb CoalHoneycomb Coal

First test of the Maputo Ceramic Stove
Crispin Pemberton-Pigott, New Dawn Engineering, August 20, 2006

MCS200MCS200

Note: click image to enlarge.

Dear Friends

I have completed a test of the first fully formed Maputo Ceramic Stove (MCS) with 3 litres of water and initially a bit more than 300 gm of charcoal. The unit in the pictures is the final version.

The test was done without any skirt or under-tray to improve efficiency, just a pot and lid sitting on a simple stove.

The water boiled in exactly 30 minutes even though the stove body was wet from being washed (oops).

The specific fuel consumption calculated on the basis of water remaining at the time of boiling (good idea) and water remaining at the end of the simmer (something I think is weird) is:

48 gm per litre of water boiled
16.5 gm per litre simmered at 1 degree below the local boiling point for 45 minutes.

This translates into about 324 gm to boil and simmer 5 litres of water, depending on how you calculate it.

The stove was easy to use. I closed the air hole when it boiled and otherwise did not touch anything at any time.

There was more than 140 gm of charcoal left in the stove at the end of the test. This means it had too much in it to begin with. I was unable to get the temperature to drop below almost the boiling point so I think if it was done again with perhaps 200 or 250 gm of fuel it would come out with a better figure.

The stove in the photos will cost about $3 to manufacture profitably. The material is very low thermal expansion PK11 clay mix fired at 1150 degrees. The whole stove weighs 2230 grammes. The material cost about US$0.40. The grate is removable. The two parts can be formed in a manual press like the Ring Maker.

160 grams of charcoal boils and simmers 5 liters/CF04 Stove
Lanny Henson www.lanny.us July 2, 2006

The CF04 Stove boiled and simmered 5 liters using only 160gr of charcoal and wood.

After several modifications to 4 different prototypes, it only took 150 gr of lump charcoal with 11% moisture and 10gr of wood to boil 5 liters of 83 degF/28.3 degC water in 45 min. That is 32 grams per liter to boil and simmer. At 1 hour after boiling the water was still simmering at 100 degC and after 2 hours the water was 205degF/96 degC. At this point I shut the air control and capped the pot module to stop the airflow and retain heat.

At 3 hours the water temp was 190 degF/87.8 degC and was 178 degF/ 81 degC at 4 hours.

CO/CO2 Ratio in the Charcoal Stoves Tested at Aprovecho (pdf)
Dean Still, Aprovecho Research Center, June 23, 2006

The following graph plots the levels of CO and CO2 during one test each of the charcoal burning rocket stove and Jiko-type charcoal stove from Ghana. A higher level of CO2 suggests a higher burn rate of fuel.

It can be seen that even though the CO level for the rocket drops below 10 ppm, the CO2 level remains high suggesting a high firepower continues. The Ghana charcoal stove has a lower level of CO2 with a considerably higher level of CO.

Comparing the Charcoal Burning Rocket and Jiko Stoves (pdf)
Dean Still and Nordica MacCarty, Aprovecho Research Center, June 22nd, 2006

The charcoal Rocket Stove was compared to the Jiko-type charcoal stove sent from Ghana. 600 grams of Kingsford charcoal was placed in the stoves under the Aprovecho emissions hood. One test was performed on each stove for preliminary studies. The stoves are compared in the following graph for carbon monoxide emissions during a cooking task (to boil 5L of water and simmer 30 minutes).

CO Emissions from a Charcoal Rocket Stove
Dean Still, Aprovecho Research Center, June 12, 2006

CO Emissions From a Charcoal Rocket StoveCO Emissions From a Charcoal Rocket Stove

Initial Improvement of a Charcoal Burning Rocket Stove (pdf)
Dean Still, Nordica MacCarty Aprovecho Research Center June 5 2006, Rev June 14

Fuel Entrance ClosedFuel Entrance Closed

New Lao Bucket charcoal stove by GERES and the Cambodia Fuel Savings Program (CFSP)

GERES/CFSP Cambodia New Lao Bucket StoveGERES/CFSP Cambodia New Lao Bucket Stove

Average efficiency 29% compared with traditional Lao Bucket 10%.



See:
CFSP Stove Designs
Charcoal Savings Using the New Lao Bucket Stove, Stove Molds and Other CFSP tasks to improve production and dissemination
and Improving Wood Charcoal Manufacture

Brochure on Cambodia Fuel Savings Program

Monitoring Table

Dread & Works Enterprises Improved Cookstove Producers
Chewe Lazarus, Lusaka, Zambia April 2006
Dread & Works Enterprises, Chewe Lazarus, Biomass Cookstoves Producer, Lusaka, Zambia April 2006

Ten top tips for successful scaling up
Alan Brewis, Enterprise Works 2005

Practical Action Boilng Point Issue 50 2005

Please read the whole article for the details. Every tips has great detail that will save you hours of work.

The premise: in creating a successful stoves scale up - you need to create a supply chain of successful stoves manufacturers and retail businesses, as well as people who will be able to maintain and fix the stoves (even when they are imported from elsewhere).

the tips:

  • Don't tell the customer that you are from an NGO
  • Know your customers and their habits
  • Copy good ideas from the private sector - e.g. manufacturing, branding and marketing tips
  • Give the stove status and style
  • Balance demand creation with supply
  • Pay attention to quality control
  • Treat your retailers well
  • Pay your sales agents on a commission basis
  • Beware of projects bearing your stoves as gifts. This undercuts your hardworking retail outlets
  • Use your stove on a regular basis, using your stove to cook on will help you educate your customers and improve your stoves

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