[Stoves] Lots of primary air

[Crispin Pemberton-Pigott]

Dear Marc

You have a lot of secondary air ‎entering the upper fire with the primary air. This is typical for that layout.

Being invisible does not mean there is no smoke. It just might be diluted by excess air.

A crossdraft stove might have a quarter of the secondary air you do. ‎It depends on a lot of things. If you want to progress further you need a combustion analyser. You want to have an oxygen level in the exhaust (right at the edge or under the edge) of the pot of under 10.5%.

There are still a couple of things you can try. Put a grate above the primary air to catch the charcoal and burn it. It will save fuel. Then, make an opening at the back of the stove to admit the air.

Regards
Crispin

BBM 'Crispin'
From: Marquitusus
Sent: Friday, June 5, 2015 19:14
To: stoves at lists.bioenergylists.org
Reply To: Discussion of biomass cooking stoves
Subject: [Stoves] Lots of primary air


Hi to all,
Running my rocket stove, which is under a low-mass mud oven (which allows to clearly see if I the stove produces smoke or not) I have always observed that the cleanest burning happens when the primary air is not obstructed by ashes or coals. Also in all the rocket stoves I have seen, it is mantain the air entrance free from obstacles for them to burn clean. The more primary air, the less smoke.
So I build a combustion chamber with a lot of space below the burning sticks, so it can have a lot of primary air, never obstructed by ashes or burning coals. I also put a longer combustion tube, about 50cm long, to give the gases enough space and time to completely burn. I also put some secondary air holes about 10cm above the burning sticks: 16 holes about 1cm diameter each.
The result is quite satisfactory: most of the time I have no smoke, and only in the begining and when I put too much fuel I have smoke until the tips are well ignited. With this cleaningness of combustion, I'm using it again to power my oven without the fear of getting the food "blackened" due to smoke.
I know this experience does not agree with the clean combustion "laws" about primary/secondary air ratios of 1/4 or less, but this has really worked for me. I've tried this configuration a lot of times in the lasts months, and I've always found that more primary air, gives less smoke.
What do you think about it?
Regards,Marc


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20150605/c9d64155/attachment.html>
-------------- next part --------------
_______________________________________________
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://stoves.bioenergylists.org/