[Stoves] Jatropha fruit as fuel?

[Bjarne Laustsen]

Dear Ronald
No we have not seen any tar deposit in any part of our stove.
Yours
Bjarne Laustsen

On 1/25/2013 1:12 PM, Ronald Hongsermeier wrote:
> Dear Bjarne,
>
> Do you notice any tar deposits in the hollow part of the upper stove 
> part; i.e., between the outer wall and the wall of the gas-combustion 
> area?
>
> regards,
> Ronald von Vermindertenerkältungssymptome    :D
>
>
> On 25.01.2013 08:20, Bjarne Laustsen wrote:
>> Dear Crispin
>>
>> The secondary air enter into the combustion through 3 rows of holes 
>> in the bottom part of the internal chimney in the top part of the 
>> stove. We have designed this internal chimney to have a height 
>> allowing the gasses to burn without going over the top of the stove. 
>> So the flame will not reach the pot if the stove is operated in the 
>> right way.
>>
>> We have earlier tried to bring in the secondary air closer to the 
>> fuel bed, however it was not very successful. For me to see it is 
>> necessary to have a separation of of the fuel bed and the burning of 
>> the volume where the gasses are burnt if you operate gasification 
>> stove, else it does not work satisfactory.
>>
>> The burning of the gases in the internal chimney gives heat enough to 
>> keep the pellets hot enough to release the gasses so that is not a 
>> problem.
>>
>> A problem with this separation of the two is that in strong winds the 
>> flames can be blown out, if this happens the stove stops operating 
>> and a lot of smoke will develop. This is not a big problem here as 
>> most households cook in sheltered places, so we have not got 
>> complains on that. The stove can also get started again if a light 
>> match are dropped down into the internal chimney, this will get the 
>> gases to burn again.
>>
>> Yours
>> Bjarne Laustsen
>>
>>
>>
>> On 1/24/2013 5:04 PM, Crispin Pemberton-Pigott wrote:
>>> Dear Bjarne
>>>
>>> It is now clear - there are two sections of the stove - a gas making 
>>> unit
>>> and a mixing/burning unit.
>>>
>>> I am still missing one critical piece of information: where does the
>>> secondary air enter the upper unit? It seems to have all the basic 
>>> parts in
>>> place.
>>>
>>> There is a feature, not in the positive sense, that man gasifiers 
>>> have which
>>> is to separate the gas burning from the fuel bed. There is no essential
>>> reason for doing this. It actually introduces two new problems that 
>>> should
>>> not be there which are: separating the radiated heat from the 
>>> underside of
>>> the flame from fuel bed and the addition of the problems related to the
>>> flame going out and not re-lighting.
>>>
>>> Thus, where you add the secondary air is critical. It can prevent both
>>> problems. It would be unfortunate if you were spending money and 
>>> effort to
>>> create a problem that should not be there.
>>>
>>> I did not realise without the photos that you had a removable upper 
>>> section.
>>> The photos helped a lot in clearing that up. If the secondary air were
>>> pushed into the gas at the top of the fuel containing section and 
>>> the plate
>>> with the triangular holes were not present, what happens? If there 
>>> was the
>>> same top round disk placed at the top if the fuel container - or 
>>> better, at
>>> the bottom of the upper unit so it is removable - it would push the
>>> secondary air into the gas near enough to the fuel to help keep it 
>>> hot. The
>>> 'disk' could have any of a number of complex shapes to promote 
>>> mixing, but
>>> the point is that the secondary air should not be added near the top 
>>> because
>>> it means the flames will be running against the pot spoiling the CO 
>>> and PM
>>> burn. That is why I am asking about where (am perhaps how) the 
>>> secondary air
>>> is introduced.
>>>
>>> The stove looks quite strong.
>>>
>>> Regards
>>> Crispin
>>>
>>>
>>> Dear Crispin
>>> 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.
>>>
>>> Yours
>>> Bjarne Laustsen
>>>
>>>
>>> _______________________________________________
>>> Stoves mailing list
>>>
>>> to Send a Message to the list, use the email address
>>> stoves at lists.bioenergylists.org
>>>
>>> to UNSUBSCRIBE or Change your List Settings use the web page
>>> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org 
>>>
>>>
>>> for more Biomass Cooking Stoves,  News and Information see our web 
>>> site:
>>> http://www.bioenergylists.org/
>>>
>>
>>
>> _______________________________________________
>> Stoves mailing list
>>
>> to Send a Message to the list, use the email address
>> stoves at lists.bioenergylists.org
>>
>> to UNSUBSCRIBE or Change your List Settings use the web page
>> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org 
>>
>>
>> for more Biomass Cooking Stoves,  News and Information see our web site:
>> http://www.bioenergylists.org/
>>
>>
>>
>> -----
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 10.0.1430 / Virus Database: 2639/5553 - Release Date: 01/23/13
>>
>>
>
>
> _______________________________________________
> Stoves mailing list
>
> to Send a Message to the list, use the email address
> stoves at lists.bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org 
>
>
> for more Biomass Cooking Stoves,  News and Information see our web site:
> http://www.bioenergylists.org/
>