Improved Biomass Cooking Stoves

I've attached a diagram of how I'm now planning to build the grate and throat area. (I took the liberty of modifying the GIZ diagram Crispin kindly sent to explain an appropriate layout)

As I'm only going to be burning wood and in my experience of wood stoves all the wood burns to a light ash which would easily fall through the grate I am planning to have a stationary grate. Am I making the wrong decision here?

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Getting close to completing this stove now.

Some photos are attached.

I've also attached a drawing of how things stand now (not to scale)

The door and hatch are made and have fire rope seals. These will be fitted once everything else is together.

I've used a cast iron grate from an old coal stove that was the perfect size.

A couple of things I'm wondering

*At the moment all the secondary air is going in through some square section pipe with an internal diameter of 20x20mm that enters at the rear of the combustion chamber above the ceramic blocks. (shown as blue square in stove2-7.jpg). Is this going to supply enough air or should I put a similar sized secondary air inlet on the front of the stove also?

*Crispins GIZ design has an area where the combustion chamber tapers wider (an expansion chamber?). I've drawn this in green in stove2-7.jpg . How important is this? I could make these sloping walls from sheet steel or I guess buy some refractory material sheets (my x partner who is making this with me had some jewellers heat mats that would appear suitable although she appeared reluctant to give them up) Is this a crucial detail? What effect does it have on combustion? what would happen if I leave them out?

Thanks in advance for any pointers. Hopefully I should finish and test fire it in the coming week.

Dear Friends

Further to Darren’s efforts, a reminder that the original drawings for the combustor and one of the stoves that incorporates it is in the Library at New Dawn Engineering at the very much enlarged (this week) website. That is not to say there is so much there, just that we can now make very large files such as high-res video originals available. As time passes more will be available.

The Low Smoke Chulha has been enabled by Philips Design in close co-operation with NGOs, self-help groups, local entrepreneurs and potential users. Low Smoke Chulha provides a safer home environment for families, reduces the risk of respiratory illness, and supports indigenous ways of cooking. The Low Smoke Chulha is not only smokeless but also helps every household save 10 kilos of firewood each house each day which is 4 tones of firewood a year!

See our page: http://www.lowsmokechulha.com/

The TChar(tm) stove is a TLUD stove that lifts off at the end of the gasification stage to drop the charcoal into a T-base(tm): a charcoal stove to continue cooking with the charcoal created or a quench base to save the charcoal for biochar or other use.
Download Part A of TChar Technology for Cookstoves at:
http://drtlud.com/『アディダス』に分類された記事一覧

I was finally able to complete my tractor jack briquette press on a recent trip to Haiti. I started it in the spring, but had to load it into a shipping container in May before I could complete and test it. It uses a 3 1/2 ton (3.2 tonne) 48" (122cm) tractor jack. About 30" (76cm) pressing cylinder, 3" (76mm) diameter PVC . Two 3/4" (19mm) threaded rods for tensile members. 4' x 6" (10cm x 15cm) rectangular steel tubing base. Shouldered hole in bottom to hold cylinder base while allowing briquette ejection. 4" x 4" (10cm x 10cm) square steel tubing top. Wood frame. Removable steel plate covers ejection hole for pressing. The machine tips to horizontal for briquette ejection.
The long stroke allows for production of multiple briquettes at once with plastic disc spacers.
The current design produces pucks. Holey briquettes are possible with some modifications. We hand tore the paper and only soaked it briefly. The briquettes were quite dense and held together well.Nike Air Max 200