Pemberton-Pigott

Lighting Cone on the Keren Stove no smoke 1 min after lighting
Anglo Supra Nova Stove
Loading the Anglo Supra Nova Stove
Good Fit for Cone Lighting
Lighting Cone on the Anglo Supra Nova
Handles get hot on lighting cones - make them large

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

OK, the focus is not the best but this is the require for submission of stove samples.

The potential order size is large -
Regards
Crispin

The document “Mechanisms for Evaluating and Achieving Efficacy of Household Energy interventions” from

http://community.cleancookstoves.org/user_content/files/002/955/2955562/...

is asking very pertinent questions that the CSI team in Indonesia has been grappling with, and I think making very good progress. I recommend everyone read and ponder the past portion, at least:

  1. The plan that is developed will have to be implementable, technically feasible, cost-effective, repeatable, and supported by multiple stakeholders. Will we have capacity to do conduct and enforce testing according to any requirements that are set?
  2. To implement any proposed plan, are there additional requirements beyond protocols, standards, indicators, tiers, and best practices? For example, do we need a serial numbering system? What are the data sharing needs?
  3. Stove usage and stacking is a particularly challenging issue to address. What aspects can be addressed through standards versus using feedback from customer purchase decisions? Does the mechanism change depending on whether stoves are subsidized or not?
  4. What are the short-term practical mechanisms, and what are the long-term implementable mechanisms? How can we plan to move from the short-term to a sustainable long-term solution?

They are correctly identified as ‘over-arching questions’. There are other questions in the rest of the text that will be of great interest to testers and developers.

Regards
Crispin

Dear Friends

This is very useful.

Save it!

y = 4-08x2 - 0.0036x + 99.996

X = your altitude in meters.
Y = the local boiling point (at standard air pressure)

If you know your altitude, it will give you the ‘standard’ boiling temperature.
If you know the local boiling point, you can work backwards to get the altitude where you are standing.

Excel cell contents:

=99.996-0.0036*Altitude+4*10^-8*Altitude

where ‘Altitude’ is the cell in which the altitude is located.

Regards
Crispin

Here is an example (hard to see of course because it is a still taken from a video) of the spinning of the flame caused by the shaped grate at the bottom.
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 really cool picture of a Vesto burning walnut shells in TLUD mode.
Finally, here is a photo of a Vesto cutaway showing the inside parts in their correct positons.

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.

Crispin Pemberton-Pigott

> It is a spreadsheet and a PDF with explanations and caveats. There could always be more. Testing stoves is a messy business.
So, don't read too much into any particular test, though they were chose to be representative of the technologies involved. It is expected that during the next three years we will make improvements on all of them. The ignition of the stoves involves 'technique' and as those skills are developed and transferred, we expect even better performance.

> You will see that two classes of stove, TLUD and Crossdraft, are consistently performing well no makes who makes it. I have not been making downdraft stoves for this market but will do so from July. That will bring in another strong contender into the 99% reduction class.
>
> It is not clearly stated that the stoves are developed for a particular fuel (lignite from Nalaikh Mine). They can be adapted to any fuel as far as I understand things. We are going to try goat dung during the coming year.
Dung burners: don't forget we are going to work out something for Central Asia!

Crispin Pemberton-Pigott April, 2011

International, DUE (Domestic Use of Energy) Conference
12 - 13 April 2011

Cape Peninsula University of Technology
Cape Town Campus, South Africa

See attached Brochure:

A sample of the conference presentations

Design Features of Solid Fuel Stoves: Workshop Discussion
Mr Crispin Pemberton-Pigott, New Dawn Engineering, Ontario

The Uncontrolled Cooking Test: Measuring Three-Stone Fire Performance in Northern Mozambique
Mr James Robinson, University of Johannesburg, Auckland Park,

A Preliminary Comparison between the Heterogeneous Protocols and the Water Boiling Test
Mr Tafadzwa Makonese, University of Johannesburg, Auckland Park,

The results of field testing the POCA/Maputo Ceramic Stove (MCS) and traditional metal stoves (TMS) using an uncontrolled cooking test (UCT) are attached. In a UCT people cook whatever they want and we watch carefully. The results have fuel-moisture compensated values. The charcoal was almost always hardwood lumps. Larger meals tend to be watery and small meals tend to be frying something in oil.

The comparison indicates a clear change in relative performance with meal size. The bigger the meal, the more the savings with the improved stove. There is also a chart attached showing the increase in thermal efficiency with meal size.

The meal size on one the X-axis.

The WBT locates one point on the line. Performing the test seven times locates that point very accurately but is it difficult to know where the line goes from that point.

No ‘outliers’ were removed in this analysis even when they were obvious. The meal size varies with the season so the question about consumption has more than one answer.

Regards
Crispin

Crispin Pemberton‐Pigott October, 2008
Sustainable Energy Technology and Research Centre University of Johannesbrg 
Programme for Basic Energy Conservation GTZ/ProBEC a SADC Regional Project 

See the attached pdf: CERAMIC DEVELOPMENT FOR DOMESTIC STOVES 

Also take a look at Crispin's very good ceramic stove image galleries.

It is intended that this brief report describe in an accessible manner the results of some basic research into the performance of ceramic materials suitable for use to make modern, low‐cost improved charcoal stoves. The 
theatre of investigation is the area around Maputo, Moçambique. 

 The information and ideas are assembled from a large number of tests and reports. If studied carefully an understanding can be gained of the 
principle ingredients found in typical clays. It is hoped enough can also
 be learned about what the tests show so as to interest the ‘stover’ in a 
deeper study of this vast subject.  

Some reasons why clay stoves and stove components typically have such a 
short life are described and to a certain extent, what can be done about 
it.   

There is a great deal of material available on how to find, identify and 
process clays such as pottery books and the internet. It is not repeated 
here.  Unfortunately very little of the material available is geared to 
the design of low cost ceramics stoves which have problems not encountered
 in many industrial applications with far higher temperatures.  

Ceramics are complex mixtures of many minerals so it is not possible to 
give comprehensive explanations in such a brief text, however the novice 
reader should learn enough to be able to deal with a laboratory and 
understand some common terminology and the test results.  There have been
 many technological advances in recent years making accessible tests and 
analyses that were previously unaffordable to the ordinary potter.

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