Smokeless Stove - Essay Example

Smokeless stove This paper is an evaluation of a smokeless stove which was designed to provide the people of Tamil Nadu with clean energy. In order to come up with the best design three smokeless stoves were already in use in the area were looked at, namely Philips Chulha; Prakti Stove and ONIL Stove. The Chulha stove was found to put the exposure to smoke to minimal by virtue of it having a chamber that channels the smoke out through a chimney. The designs plans are available for free for modification as the design is an open source. The material for use in the construction of this stove is readily available locally although he cost of producing the stove was found to be quite high. The other weakness that was found in the stove was lack of heat containment in the stove as the walls of the stove was strictly relied upon to serve this purpose. This stove does not require any form of prior experience for one to be able to use it with its operation being found to be undemanding for adults. (Anderson 2010). One of the outstanding features of the ONIL stove was found be that it had a large combustion chamber and there is incorporation of insulating materials thus enabling efficient cooking of food. The stove was recognized as having is high versatility where two pots can be cooked simultaneously. The main body of the ONIL stove is constructed from the cast concrete so as to ensure high strength and durability. The stove shows further versatility by coming with a number of steel plates of varying sizes thus enabling cooking of food to be done in various pots sizes. The ONIL stove use results was also noted for the reduction in wood consumption of up to 70% when there is a comparison with open fire cooking. The fact that the stove did not allow cooking while seating was considered a short coming because the rural people would prefer undertaking cooking when seating. The ONIL stove is costed at $87USD and this is considered to be beyond the reach of the intended beneficiaries (Global Living 2006). Figure 1:Chulha stove Final Concept Selection When EWB challenge group were coming up with a final concept it was noted that the Chulha stove displayed high versatility and was in conformation with the cooking preferences of the people who were being targeted while ONIL displayed high level of efficiency, has high functionality as well as having high level of safety. The final concept was thus to use elements from the two stoves integrating them into a single design to come up with a stove with high simplicity aimed at fulfilling the specific needs of the Tamil Nadu people. Design details Design Summary The stove design was to be simple, easy o assemble and its manufacturing cost being low. The stove is made of clay slabs that are assembled in a box like shape that is similar to both the Chulha and ONIL stoves. There are five important elements of the stove: fuel input door, combustion chamber, the insulation chamber and the stove top. Fuel input door This is the area that is used for putting fuel that includes wood and agricultural waste into the combustion chamber. The door is 140mm by 140mm in size which is slightly larger than the size of the existing designs as there had been complaints that smaller size resulted into reduced cooking peed. This door size that was settled for was neither too large and thus it served to ensure that there was reduction in fuel usage and thus ensuring sustainability. Figure 2 : Fuel input door Source: Antioch T. et al. (2011). Combustion Chamber The combustion chamber is where there is ignition of fuels. The fuels is laid on a grate where there if consistent supply of airflow from underneath the fire with there being a direct path of flow through the stove. This arrangement ensures that there is no re-circulation of smoky air, thus ensuring that there is efficient flame and thus ensuring reduced chance of oxygen deprivation Stovetop The stovetop design was such that it could accommodate two pots each at one of the two openings as illustrated in figure. The fist pot is directly above the flame while the second pot derives heat from the smoke that is passing under it. This is found to be very appropriate to the Tamil Nadu people as it allows boiling and frying to be undertaken simultaneously and thus the traditional cooking method where rise is boiled and vegetables fried is addressed. The third opening in the stove is to accommodate the chimney which is used in expulsion of smoke. Figure 3: Stovetop Source: Antioch T. et al. (2011). Insulation Chamber Unlike the other designs that were used in coming up with this stove, the new smokeless stove has insulation chamber is such that there is reduced thermal conduction from the heavier materials used in the smokeless stove. Materials of high density which inch include the ground on which the stove is laid has tendency to absorb large quantities of heat as a result the heat transferred to the pots is reduced considerably. This issue is addressed by reuse of ash and charcoal which are waste generated from the stove, to serve as the insulating materials by this materials being deposited in the insulating chamber. The insulation ensures that there is increased level of heat transfer from the smoke that is transferred to the cooking pot and thus resulting to an increase in the stove efficiency. In figure the insulation material is displayed in orange. Figure 4 : Insulation chamber Source: Antioch T. et al. (2011). Running & Maintenance Using the stove The design of the smokeless stove was such that most of the aspects of stove there use can be learned by intuition though some outstanding differences from traditional ways of cooking need some emphasis. Wood that is to be used in this stove is supposed to be split into small pieces so as to ensure that they can easily fit into the combustion chamber. Smaller pieces have higher surface area to volume ration and thus there is more surface exposed to oxygen and high temperature and this brings about increased efficiency and low level of smoke generation. The wood supply should be in accordance to the needs of the house hold and after the cooking for the day is over the wood to be used for the next day can be placed on top of the stove so as to dry it off. In order to maintain high temperatures and high level of efficiency it is recommended fire is to be tended more closely in comparison to traditional stoves. In the fuel chamber there should be uneven stacking of wood to facilitate flow of air through the wood from below. A pot which is not in use at a particular time is to be cover so as to prevent heat loss. A block of wood or clay may act as a damper when placed in front of the air intake controlling the amount of air flowing through the stove and regulating the cooking temperature. Cleaning In order to ensure there is no blockages of air flow there is need for the combustion chamber to be cleaned on a daily basis. This exercise is recommendation to be undertaken in the morning before any cooking is done as this is the time when the ash can be removed easily as it is cook. Lids are to be placed on the pot holes for prevention of the disturbed ash being dispersed in the air and the ash is then to be scraped out. Ash being a biodegradable material it breaks down naturally when placed outside. The ash should be spread on a wide area to eliminate chances of having high concentration at any particular point and this will eliminate any chances of any local environmental impact. The chimney needs to be cleaned at least once in every six months so as to prevent occurrence of blockages and chimney fires (Wood Conserving Cook Stoves, 1980). The best way of cleaning the chimney is by first placing lids on pot holes, removing the cap from the chimney and the scrap the inside surface by use of a bamboo or any piece of wood of appropriate size. Estimated Component Lifetime Each component of the stove can last up to 3 years putting into consideration the durability of similar clay stoves (Khennas 1990). However incase of any accidental breakages the components replacement should be effected immediately to ensure that the stove functions as expected. The individual parts will be readily available in case the need for replacement arises and thus there will be no need for replacing the entire stove when a single piece fails. This type of arrangement will result to the life of the stove being extended indefinitely. The top piece is most vulnerable to breakage owing to its exposure to high temperatures and impacts from pots and pans. This is also the largest piece making it to have the highest level of thermal expansion and contraction. Addition of sand in the clay used in making this component will reduce its thermal expansion and contraction even though this will lower its strength. Fuel Required The smokeless stove has been found to serve well in addressing the need of having a variation of the temperature according to the type of food that is to be cooked, where more wood can be placed in the combustion chamber for high temperature achievement.. More wo0d into the combustion chamber would result into increased heat generation (Improved Biomass Cooking Stoves 2006). The amount of wood to be used will be dependent on the user and no limit is put on the amount of fuel required as Tamil Nadu residents indicated supply of wood was abundant (Engineers without Borders 2010). References Anderson, P.( 2010) Chulha. [Online] Available from: http://www.designtoimprovelife.dk/index.php?option=com_content&view=article&id=112:chulha&catid=10:finalists-2009&Itemid=20. [Accessed: 11th October 2014] Antioch T. et al. (2011) EWB - Smokeless Stove [Online] Available from: https://www.google.com/?gws_rd=ssl#q=smokeless+stove+(Philip+Chulha+and+ONIL+stoves > [Accessed: 11th October 2014] Engineers without Borders.( 2010) Innovations Report: Chapter 3 . [Online] Available from: http://www.engineersaustralia.org.au/shadomx/apps/fms/fmsdownload.cfm?file_uuid=F0647595-C7FE-7720-EA17-70AC27062E0B&siteName=ieaust. [Accessed: 11th October 2014] Global Living.( 2006) The ONIL Stove[Online] Available from: .[Accessed: 11th October 2014] Improved Biomass Cooking Stoves 2006, Design Principles for Wood Burning Cook Stoves, Khennas, S. 1990, Energy Case Study, Wood Conserving Cook Stoves 1980, Volunteers in Technical Assistance, Maryland USA. Read More