<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal>Dear Stoves experts I am looking for some advice and help from experts in the field on a specific project.<o:p></o:p></p><p class=MsoNormal>Cooking Stoves for a School<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Currently this international school in Indonesia is using Rocket style cookstoves with sawdust as fuel source. (and some used timber/bamboo)<o:p></o:p></p><p class=MsoNormal>Typical daily activity is to prepare food for up to 600 people, smaller breakfast, full on lunch.<o:p></o:p></p><p class=MsoNormal>The stoves are used for all types of cooking, typically in large pots 20-40lt. There are up to 10 stoves running at any one time in a covered but not indoor area.<o:p></o:p></p><p class=MsoNormal>Most of the stoves are constructed from bricks with some metal gratings<o:p></o:p></p><p class=MsoNormal>The current cookstoves were a part of a previous environmentally focused student lead project.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The key issues are: <o:p></o:p></p><p class=MsoNormal>The rocket stoves though not very labor intensive are normally not functioning even close to original designs in practice with variable output and quite often loss of the “rocket” during burn.<o:p></o:p></p><p class=MsoNormal>The kitchen staff do not have a lot of time to devote to maintenance and operation, they need a stable and repeatable solution.<o:p></o:p></p><p class=MsoNormal>The current stoves are not very efficient creating considerable smoke, attempts to add some forced air as both primary and secondary air have been largely unsuccessful (too complicated to control)<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>This link shows some pictures of current setup:<o:p></o:p></p><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Helvetica",sans-serif;color:#212121;background:white'><a href="https://goo.gl/photos/6PfARtHjAYwB66oo8">https://goo.gl/photos/6PfARtHjAYwB66oo8</a><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have been following this list now for last 6 months or so and reviewing with interest many of the projects in particular the TLUD concepts and some of the innovative use of venturi from both air and water(steam) and am looking for some advice/ideas to move ahead with a better concept and direction for both the stoves and maybe the fuel in this application.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Key design points for up to 10 stoves:<o:p></o:p></p><p class=MsoNormal>Sawdust as fuel source<o:p></o:p></p><p class=MsoNormal>Fast load and start<o:p></o:p></p><p class=MsoNormal>2-4 hours of efficient burn time (prefer continuous feed if practical for some units)<o:p></o:p></p><p class=MsoNormal>20-40Liter Cook Pots or Wok of similar size.<o:p></o:p></p><p class=MsoNormal>Ability to adjust or divert heat as temperature control<o:p></o:p></p><p class=MsoNormal>Simple maintenance and control, long stove life<o:p></o:p></p><p class=MsoNormal>Control of effluent / exhaust in the work area – we are thinking in terms of chimneys or ducting. <o:p></o:p></p><p class=MsoNormal style='text-indent:.5in'>Current stoves vent around the pot.<o:p></o:p></p><p class=MsoNormal>Fuel – is it worth to add steps (pelletizing?) to the fuel preparation<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Soft features:<o:p></o:p></p><p class=MsoNormal>Ability to use instrumentation and control for development of project and student training on the use of advanced cook stoves, on use of BioFuels for cooking and Biochar creation and to develop the best in class design for this kitchen.<o:p></o:p></p><p class=MsoNormal>Primary& Secondary air measurement and control<o:p></o:p></p><p class=MsoNormal>Monitoring/Observing the burn real time (hard to see under the pot<span style='font-family:Wingdings'>J</span>)<o:p></o:p></p><p class=MsoNormal>Burn efficiency (thermal and chemical) monitoring/measurement and effluent testing, both gases and solid waste<o:p></o:p></p><p class=MsoNormal>Overall energy efficiency – low / no use of external power (electricity) preferred but not a showstopper<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Longer term if project is successful simpler designs would be rolled out to neighboring school and community facilities as currently the sawdust is available as a local “waste” product. It is very likely that existing TLUD designs can fit the community needs but some convincing is needed for the local community.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I understand that this is a little away from the typical focus of this group but there is no doubt that at the moment Indonesia has a massive “burning” problem affecting health and well being of people and animals. We want to increase students knowledge and interest in the real opportunities that managed burning and Biochar creation could have over the current practices of open fires for both cooking and disposal of organic waste. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>For sure whatever we end up doing will be shared with this (stoves) community.<o:p></o:p></p><p class=MsoNormal>We expect some or all of this project to be student lead or student involved.<o:p></o:p></p><p class=MsoNormal>Some key questions:<o:p></o:p></p><p class=MsoNormal>Is TLUD the recommended solution type for this application or is some other approach more suitable?<o:p></o:p></p><p class=MsoNormal>How to maintain cooking efficiency but include exhaust duct/chimney in the design? <o:p></o:p></p><p class=MsoNormal>If continuous feed or in-situ reloading is not feasible is there some kind of quick change design that would allow cooking to resume with minimal downtime between burns?<o:p></o:p></p><p class=MsoNormal>Is there something that could be done with multiple stoves to simplify design (ducting?)<o:p></o:p></p><p class=MsoNormal>Are bricks and mortar a suitable building material or should the focus move to steel?<o:p></o:p></p><p class=MsoNormal>How to efficiently “tune” a stove for efficiency – correct amounts of primary, secondary air. Previous local experiments are inconclusive as there have been far too many variables.<o:p></o:p></p><p class=MsoNormal>Is sawdust a suitable fuel?? or should it be compressed/pelletized for use??<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman",serif'>Tony Vovers <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman",serif'>+62 (813) 3888 9062</span><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>