[Stoves] Fwd: RE: Uganda Turns to Local Volcanic Rocks As Substitute for Charcoal

[Paul Anderson]

I am forwarding this to the Stoves Listserv that did not receive a copy 
of the two most recent messages below.

Interesting information.    I remember the earlier years of stove 
testing (2005 to about 2010?) when the only official testing at Stove 
Camp was with uniform cut kiln-dried fir.   It reeked havoc on the TLUD 
testing for several reasons.   Now at least pellets are included.

Paul


-------- Forwarded Message --------
Subject: 	RE: [Stoves] Uganda Turns to Local Volcanic Rocks As 
Substitute for Charcoal
Date: 	Wed, 13 Jun 2018 22:02:18 +0000
From: 	Crispin Pemberton-Pigott <crispinpigott at outlook.com>
To: 	ndesai at alum.mit.edu <ndesai at alum.mit.edu>
CC: 	Andrew Heggie <aj.heggie at gmail.com>, Cookswell Jikos 
<cookswelljikos at gmail.com>, Paul Anderson <psanders at ilstu.edu>, Cecil 
Cook <cec1863 at gmail.com>



Dear Nikhil

“I still don't understand why stovers would want to standardize fuel, 
pot, and power cycle in order to measure efficiencies for boiling water.”

They don’t and I am surprised you are repeatedly inferring that they do. 
The whole point of the HPT is to explore how stoves perform across a 
range of circumstances in order to communicate to potential users and 
buyers what to expect.

The threat to the WBT is exactly that: giving actual performance 
potential across a heterogeneous set of circumstances.

As for the stove below, the usefulness of the pumice is to delay the 
combustion of the powder. What probably looks to the novice as 
‘retaining heat’ is in fact the slow burning of carbon hiding in pores. 
In many cases people say a stove ‘holds a lot of heat’ at the end of a 
fire but in fact there is continuing combustion of the remnant fuel 
(char) within the ash. This is easily demonstrated in the case of 
burning dung.

This stove sounds like a similar case. The rocks hold very little heat 
as they have a very low mass. There is nothing special about the 
elemental composition of the ricks. They hold very little heat but they 
delay and extend the combustion of a carbonaceous fuel. Good for them. 
It is one way to burn a nearly useless fuel without making a briquette 
first.

The reason the fan helps is to circulate air near the pores to extract 
the carbon as CO and to maintain a hot enough burn (above 800 C) to get 
the carbon to react with the available oxygen and pull it out. The same 
process is involved in burning carbon out of ceramics like bricks.

It sounds like a good idea. The pumice is essentially a flame retardant. 
The function of moisture in wood is similar. The lower the moisture, the 
easier it is to burn clear, to about 12% by weight, Then it starts to be 
smokier until 0% is reached at which time it is difficult to burn 
cleanly in a conventional appliance.

The big error in the Indian IS1352 is that the fuel is 100% dry for all 
stoves and one has to tune the stove to the test method. Fail to do 
that, you fail the test, as Envirofit found to its chagrin.

Pass the emissions test, and you fail in the field, and that is the 
consequence of testing with a uniform fuel and pot, supported by the GIS 
For 27 years so far. Indians are inhaling the consequences.

Regards

Crispin

*From:*Nikhil Desai <pienergy2008 at gmail.com>
*Sent:* Thursday, June 14, 2018 4:01 AM
*To:* Crispin Pemberton-Pigott <crispinpigott at outlook.com>
*Cc:* Andrew Heggie <aj.heggie at gmail.com>; Cookswell Jikos 
<cookswelljikos at gmail.com>; Paul Anderson <psanders at ilstu.edu>; Cecil 
Cook <cec1863 at gmail.com>
*Subject:* Re: [Stoves] Uganda Turns to Local Volcanic Rocks As 
Substitute for Charcoal

Powder offers more surface and quicker burn, correct? Not always what is 
desired, whatever the damned computations. You sound just as 
número-nutty as IHME; parading penis as promise of performance.

The key here is heat storage and transfer. But not because it improves 
fuel efficiency. Rather, powder fuel and heat storage are combined in 
such a manner that is ideal to heat a cooking pan for, I imagine, 
grilling chicken.

We aren't told if it is grilling chicken or if it is only that. Maybe 
the story is fake. Maybe device is good for stews and rice as well.

Do you think it makes any difference that broiling or grilling a chicken 
allows the food item itself to retain heat and cook itself?

I am sure there are many variants of this idea of heat storage via rocks 
and pots. In particular, I remember large-scale cooking for festivities 
in my village. This was done on wood burnt in a hole in the ground, or 
some permanent structure with bricks. Large copper utensils were used 
and mud wrapped around the bottom and halfway to the sides. That was for 
heat storage.

Another variant was for baking on a charcoal stove. The pan was heavy 
and charcoal placed on both the stove as well as the lid. The pan and 
the lid stored heat and cooked.

Coming to think of it, all pots are for storing heat, aren't they?

I still don't understand why stovers would want to standardize fuel, 
pot, and power cycle in order to measure efficiencies for boiling water. 
Except for the destitute, there is so much variety in cooking, such 
standardization in testing is the looniest exercise that could be imagined.

Just make a variety of stoves and produce charts of this kind or that, 
and sell to the cooks, not silly stove theorists.

Nikhil


On Jun 13, 2018, at 12:00 PM, Crispin Pemberton-Pigott 
<crispinpigott at outlook.com <mailto:crispinpigott at outlook.com>> wrote:

    I like the idea of being able to burn powder on a substrate. I will
    try it with coal dust.

    The calculation of thermal performance and fuel efficiency is
    straight forward.

    On with the masterpieces!

    Crispin

    <image001.jpg>

    *From:*Nikhil Desai <pienergy2008 at gmail.com
    <mailto:pienergy2008 at gmail.com>>
    *Sent:* Wednesday, June 13, 2018 10:54 PM
    *To:* Crispin Pemberton-Pigott <crispinpigott at outlook.com
    <mailto:crispinpigott at outlook.com>>; Andrew Heggie
    <aj.heggie at gmail.com <mailto:aj.heggie at gmail.com>>
    *Cc:* Cookswell Jikos <cookswelljikos at gmail.com
    <mailto:cookswelljikos at gmail.com>>; Paul Anderson
    <psanders at ilstu.edu <mailto:psanders at ilstu.edu>>; Cecil Cook
    <cec1863 at gmail.com <mailto:cec1863 at gmail.com>>
    *Subject:* Re: [Stoves] Uganda Turns to Local Volcanic Rocks As
    Substitute for Charcoal

    What it says is that thermal storage improves the efficiency of
    cooking chicken.

    "Like regular charcoal, these rocks are stacked in the stove and
    charcoal dust is spread liberally atop them.

    Twigs of pine or any highly flammable species are then inserted in
    the middle of the rocks and lit with a match."

    The dust and twigs are the primary combustibles. The way they are
    set, with the size and location of the rocks and the chicken, is all
    it takes to cook.

    So much for your theology of heating water and computation of
    efficiency.

    A stove is to cook something in the time required and at times
    desired. Nothing else. Get off your "performance standards". To hell
    with scientists.

    N


    ------------------------------------------------------------------------
    Nikhil Desai

    (US +1) 202 568 5831
    /Skype: nikhildesai888/

    On Wed, Jun 13, 2018 at 9:23 AM, Crispin Pemberton-Pigott
    <crispinpigott at outlook.com <mailto:crispinpigott at outlook.com>> wrote:

        It sounds like they are confusing the word 'heat' with 'burn.

        It is a solar thermal storage ‎cooker from the sound of it. Has
        anyone seen one?

        Crispin

        Hello everyone,

        Would anyone know more about exactly what type of rocks these area?

        /''Ms Twine said the rocks only work in the solar-powered Eco
        Stove, which comes with an internal air supply system that helps
        heat up the rocks./

        /The stove is also fitted with an on-off switch that enables the
        rocks to burn when turned on, and cool and return to their
        natural state when turned off. The stove comes with a radio,
        phone charger and has two lights./

        /Unlike charcoal which burns down to ash, these rocks can be
        used multiple times without losing their power or texture./

        /Domestic stoves retail at Ush200,000 ($53) together with the
        rocks while a "bag" of the rocks alone sells for Ush35,000 ($9)
        for domestic use and can last up to six months./

        /Ms Twine says since the stove does not emit smoke, those using
        it are protected from indoor pollution./

        /"They [rocks] do not produce smoke, burn for a long time and
        you do not need charcoal anymore," she adds/

          http://allafrica.com/stories/201806060869.html
        <https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fallafrica.com%2Fstories%2F201806060869.html&data=02%7C01%7C%7C8d26c5b5e33d4d3a222208d5d12ece3b%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636644921306201847&sdata=BIhVbdhlf8BuGjm%2FalzmCOOAwg7JmKBGo4Uk7DlANNQ%3D&reserved=0>



        Teddy Kinyanjui

        Sustainability Director

        for more Biomass Cooking Stoves,  News and Information see our
        web site:
        http://stoves.bioenergylists.org/
        <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Feur04.safelinks.protection.outlook.com%2F%3Furl%3Dhttp%253A%252F%252Fstoves.bioenergylists.org%252F%26data%3D02%257C01%257C%257C4bbe8e7f133b4162090908d5d13d7b11%257C84df9e7fe9f640afb435aaaaaaaaaaaa%257C1%257C0%257C636644984337425712%26sdata%3Da%252BwFXFFZxzAaRvko7YLZe18BLwxOAKY%252F6uOLldqGU78%253D%26reserved%3D0&data=02%7C01%7C%7C704ca169a02f43449dbf08d5d1686b5a%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636645168757818281&sdata=LrIJBaqcPZFu6pYKtUdjC6B%2BpSOv720pxTUWo115mbU%3D&reserved=0>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20180613/bc1c474c/attachment.html>