Hi CVKrishna, Here are the details about the Rajendra Prasad Stove (Varun Stove)
Description This is a metal stove, easily transportable, strong and sturdy, easy to handle, safe to operate, much less smoky, fast and efficient burning, not too costly (about 200 Indian rupees (USA) for the large size and about 15() Indian rupees (US$6) for the medium one). This is in a way a double walled cylindrical stove, the outer wall is a thin plain sheet metal one while the inner one carries several rows of small (a few mm dia) holes. The 2mm gap between the walls is open towards the bottom of the stove while the top is sealed. The grate is made of 0.5 cm thick iron rods, at 0.5 cm spacing having about the same amount of spacing between them. The stove is provided with legs, handles and pot supports. It is simple to manufacture in any village sheet metal workshop. All the materials of construction are available in the market without difficulty. No special skill is required to manufacture or to use it. Technical Design The gap between the two walls has a double function. One, is to act as an insulator reducing the heat losses to the atmosphere. This results in higher temperatures inside the firebox, easy ignition and more complete fuel combustion. Second, the hot air in the gap is drawn through three rows of small holes in the firebox wall to supply hot secondary air which is extremely useful for the efficient combustion of the fuel and the volatile generated. Clear blue flames appear at those holes where the hot air meets the volatile gases. The grate supplies the required primary air for the combustion of the fuel and allows the ash to fall down without choking the air flow. This type of grate is not needed for wood fuel as the ash content is much lower and such large spacings create too much free space causing heat losses, cooling off the fuel and reducing temperatures inside the fuel thus causing difficulties in the ignition of the fuel. Performance The performance of the stove is very good. It reduces the smoke output, which is normally bad with cowdung fuel, makes lighting up easier, needs less attention and reduces the risk of the fire going out when re-fueling. Over feeding or under feeding or delays in feeding do not cause the fire to go out immediately. The control and range of operation of the stove at low power outputs and high power outputs is improved. The long steady flames generally visible with wood combustion are a rare sight with cowdung cakes. In this stove, cowdung cakes almost compete with the wood in this regard. The high volatile content generally found a nuisance during combustion by causing intense smoke has been converted to an advantage by burning after mixing with preheated secondary air. Results There is a gain both in terms of better combustion efficiency of the fuel and better heat transfer to the vessel. Assuming a net calorific value of 2500 kcal/kg for the cowdung cakes, efficiency over 30% has been achieved for the large sized stove (suitable for cooking around 10 kg of material at a time) and over 20% for the medium sized stove of about half that capacity. Cooking is quicker and pans are cleaner. He calls the stove "Varun Chulha Dung Stove" Best Regards, Sarbagya Tuladhar On 9/25/10, Choppalli Venkata Krishna <[email protected]> wrote: > Dear Sarbagya > > Please provide the details about Rajendra Prasad Stove using Dung as fuel. > > regards > > CVKrishna > > > > On Fri, 24 Sep 2010 10:58:38 +0530 wrote > >>Hi Stovers, > > > > > > > > Has anyone gone through the Rajendra Prasad design of a cookstove for > > > > the clean burning of dung..he actually claims that secondary > > > > combustion is possible in such a small stove and in the primary > > > > combustion chamber (if I understood that right)...Need help on this > > > > ??? > > > > > > > > Cheers > > > > > > > > Sarbagya > > > > > > > > On Thu, Sep 16, 2010 at 1:46 PM, rozis jean-francois > > > > wrote: > > > >> Dear Crispin, > > > >> > > > >> I think it can be useful for stovers who want to equip some field lab with > > > >> combustion and particles analysers to understand better the method you > > > >> develop with a dusttrak DRX adapted usually for ambient air. Combustion > > > >> analyser is easy to operate, and after reading your comments on your > > > >> Dustrakk DRX it seems same easiness to characterize particles. > > > >> Your method based with a previous dilution (lower temperature, lower > > > >> concentration to avoid laser saturation) can be fruitful for everyone who > > > >> want to improve/understand their biomass equipment in front of emitted > > > >> particles. > > > >> > > > >> So, my question is, could you produce a small paper to explain your > > > >> installation, roughly the procedure and interest/accuracy/difficulty to > > > >> reproduce it. > > > >> > > > >> Thanks by advance for your contribution... > > > >> > > > >> -- > > > >> J-F Rozis > > > >> Tél :0467643816 > > > >> > > > >> > > > >> > > > >> > > > >> _______________________________________________ > > > >> Stoves mailing list > > > >> [email protected] > > > >> http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org > > > >> http://stoves.bioenergylists.org > > > >> http://info.bioenergylists.org > > > >> > > > >> UNSUBSCRIBE HERE; > > > >> http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org > > > >> > > > > > > > > _______________________________________________ > > > > Stoves mailing list > > > > [email protected] > > > > http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org > > > > http://stoves.bioenergylists.org > > > > http://info.bioenergylists.org > > > > > > > > UNSUBSCRIBE HERE; > > > > http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org > > > > _______________________________________________ Stoves mailing list [email protected] http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org http://stoves.bioenergylists.org http://info.bioenergylists.org UNSUBSCRIBE HERE; http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
