Title of Invention

HIGH EFFICIENCY DOMESTIC OIL PRESSURE STOVE

Abstract

High efficiency domestic oil pressure stove The present invention relates to high efficiency domestic oil pressure stove. The optimized angle of flame spreader of the invented stove directs the flame towards the centre of the bottom of the pan being heated and thereby more and rapid heat transfer to the pan and material in pan being heated [reference may be made to figure 4a and 4b]. The invented oil stove is fuel efficient. It produces smoke free intensive hot and blue flames as compared to the conventional stoves. The device of the present invention gives more than 65% thermal efficiency as compared to less than 53% in the existing stoves.

Full Text

The present invention relates to a high efficiency domestic oil pressure stove. The present stove may be used in house-holds, restaurants, road side tea shops and hospitals using kerosene as fuel. These stoves are either used regularly in village houses or kept as stand by arrangement. They are popular in rural masses and are also used in urban and semi-urban areas. In the offset burner type pressure stove, fuel tank is separated from the burner. The burners fitted in these stoves are of two types: Roarer type with 55% thermal efficiency, and Silencer type with 58% thermal efficiency. Stoves fitted with roarer type burner are more popular, and should have 55% thermal efficiency as per following ISI standards:- IS : 1342 - "Specification for oil pressure stoves" IS : 10109 - "Specification for oil pressure stoves offset burner type" and IS : 8808 - "Specification for burners for oil pressure stoves and oil pressure burners". These stoves are operated at 1.4 kgf/cm2 air pressure comprising of burner, nozzle, spirit cup, flame spreader, oil feed pipe, oil container, oil filling cap, pressure release screw and air pump. These components are common to both conventional [existing] and invented stoves. In most of the existing oil pressure stoves, achievable thermal efficiency is much below this figure for all pressure stoves, and hence there is a large scope of improvement of these stove burners, which leads to substantial fuel saving. The main object of the present invention is to provide a high efficiency domestic oil pressure stove [offset burner type]. Another objective of the present invention is to extract maximum useful heat output and to achieve maximum thermal efficiency to make it fuel efficient. features of the improved oil pressure stove are angle of the flame spreader, to provide optimum distance between bottom of the pan to top of the burner, provision of spill tray and to provide optimum distance between top of nozzle to bottom of the burner top. In the drawings accompanying this specification i) Fig. 1 (a) represents sectional elevation of the conventional (existing) oil pressure stove offset burner type. ii) Fig. 1 (b) represents plan view of the conventional (existing) oil pressure stove offset burner type. iii) Fig. 2 represents flame spreader of the conventional oil pressure stove offset burner type. iv) Fig. 3 represents burner and nozzle of the conventional oil pressure stove offset burner type. v) Fig. 4 (a) represents sectional elevation of the improved oil pressure stove offset burner type. vi) Fig. 4 (b) represents plan view of the improved oil pressure stove offset burner type. vii) Fig. 5 represents flame spreader of the improved oil pressure stove offset burner type. \ viii) Fig. 6 represents burner, nozzle, adopter of the improved oil pressure stove offset burner type. ix) Fig. 7 (a) represents sectional elevation of the spill tray of the improved oil pressure stove offset burner type. x) Fig. 7 (b) represents plan view of the spill tray of the improved oil pressure stove offset burner type. Figure 1 (a&b) represents the existing oil pressure stove offset burner type in which burner (1) is fitted into burner socket (2) which is welded to fuel feed pipe (3) closed at one end and other end is welded to bottom side of the cylindrical oil container (4). A spirit cup (5) is also provided at the bottom of the burner (1). An air pump (6) is welded on the front flat face of the cylindrical oil container (4) and one oil filler (7) with a pressure release screw (8) and oil filler cap (9) is also welded on the top of oil container (4). A nozzle (10) is fitted to the burner and one flame spreader (11) is also provided to the burner (1). The assembly is mounted on a frame (12) which also serves the purpose of pan supports (18) over which the pan to be heated is being kept. Kerosene is filled through oil filler (7) in the cylindrical oil container (4) to 3/4 of its capacity. The oil filler cap (9) and pressure release screw (8) are closed. The spirit is filled in the spirit cup (5) and lighted with a matchstick. When the burner is heated sufficiently the air is pumped by air pump (6). The kerosene getting vaporised in the burner tubes (13) comes out as a premixed fuel / air mixture from the nozzle (10) mixed with atmospheric secondary air (14) burns forming full flaged flame (15) in the annular space (16) between burner top and flame spreader (11). The flame of the spirit cup (5) extinguish after sometime when spirit is burnt completely. New Principle under lying the invention are : Optimized angle of flame spreader of the invented stove directs the flame towards the centre of the bottom of the pan being heated and thereby more and rapid heat transfer to the pan and material in pan being heated. In the conventional oil pressure stove offset burner type the angle of the flame spreader is more and flame is not directed towards the centre of the bottom of the pan, thereby more heat losses as it escapes out in the atmosphere from the ends of the bottom of pan. More distance between top of the burner and bottom of the pan causes heat losses from flame to atmosphere and if this distance is less beyond optimum value combustion process and heat transfer from flame to pan gets effected adversely due to chilling of the flame. Hence only at the optimum distance between burner top and bottom of the pan, thermal efficiency is found to be maximum. Spill tray, which is not present in the conventional oil pressure stove offset burner type, but provided in the improved stove, directs the air currents to produce hot and blue flame. The correct and optimized distance between burner nozzle top to bottom plate of burner top, provide desired amount of fuel / air mixture required for completing the combustion. Accordingly the present invention provides an improved high efficiency domestic oil pressure stove (offset burner type) characterised in having optimum angle of the flame spreader to provide optimum distance between bottom of the pan to top of the burner with provision of spill tray and to provide optimum distance between top of nozzle to bottom of the burner top wherein the said burner comprising a nozzle (10) fitted to a brass adopter (17) wherein said adaptor being fitted to a burner (1) and the said burner being fitted into the burner socket (2) welded to a fuel feed pipe (3) closed at one end and with other end being welded to the bottom side of the cylindrical oil container (4) and a sprit cup (5) being provided at the bottom of the burner (1), an air pump (6) being welded on the front flat face of the cylindrical oil container (4) and one oil filler (7) with a pressure release screw (8) and oil filler cap (9) being welded on the top of the said cylindrical oil container (4) with a flame spreader (11) being also provided to the said burner (1) and the whole assembly being mounted on a frame (12) with pan supports (18) welded on the frame (12) and spill tray (19) with concentric hole (20) to the burner (1) being also provided. In an embodiment of the present invention the angle of the flame spreader ranges between 30° to 35°C. the vertical is provided separately or an integral part of the burner. In another embodiment of the present invention a spill tray is provided separately or an integral part of the same with pan supports with concentric hole of dia 104 + 2 mm with 5 mm collar downwards. In yet another embodiment of the present invention the distance between top of nozzle to bottom plate of the burner is reduced either by providing adopter or by reducing the length of burner tube in which nozzle is fitted. In still another embodiment of the present invention the burner provides thermal efficiency more than 65%. In still another embodiment of the present invention spill tray directs the air current to produce hot and blue flame. In still another embodiment of the present invention optimized distance between burner nozzle tip to bottom plate of burner tip provides optimum amount of fuel and mixture required for combustion. Detailed technical description of the invented oil pressure stove offset burner type Present invented oil pressure stove offset burner type, designed and developed at Indian Institute of Petroleum operates on kerosene and is fuel efficient. It produces smoke - free intensive hot and blue flames as compared to the conventional (existing) marketed stoves. The improved stove gives 65% plus thermal efficiency as compared to less than 53% in existing stoves. Construction The improved oil pressure stove offset burner type consists of burner, nozzle with adopter, spirit cup, flame spreader, oil feed pipe, oil container, oil filling cap, pressure release screw, air pump and spill tray. The assembly is mounted on the frame over which pan supports are welded. The burner is made of copper, the nozzle and adopter are made of brass and rest parts are made of mild steel. Operation Kerosene is filled in the oil container of 3/4 of its capacity through oil filler and oil filler cap and pressure release screw are closed. Spirit is filled in the spirit cup and then ignited with a match stick. After sometime when burner is heated sufficiently, the air pumped gently with the air pump. The kerosene vaporizes in the hot burner tube comes out as a premixed vaporized fuel / air mixture through the nozzle, due to pressure. The velocity of the premixed vapour air stream creates a partial vacuum and atmospheric air is then entrained. These vapours mix thoroughly with this entrained air and surrounding atmospheric secondary air burns forming full fledged blue flame in the annular space between burner top and flame spreader. The flame of spirit cup extinguishes after sometime when the spirit is burnt completely. By designing the constructional features like optimized angle of flame spreader, optimized distance between bottom of pan to top of the burner, provision of spill tray and optimized distance between burner nozzle top to bottom plate of burner, an oil pressure stove offset burner type has been developed which gives thermal efficiency of the order of 54 percent plus. During the course of research, it has been found by the invention that: By increasing the centralized heat transfer area of the pan kept on the burner of the oil pressure stove offset burner type, thermal efficiency increases. By striking the flame closer to the centre of the pan, effective heat transfer area of the pan increases. By increasing the effective heat transfer area, amount of heat entering the pan increases. By increasing the heat entering in the pan, thermal efficiency increases. By increasing the thermal efficiency of the burner, quantity of the kerosene is reduced for doing the same work. By reducing the quantity of kerosene, which is wasted during heat losses, there is saving of kerosene. In Fig. 4 (a&b) of the improved oil pressure stove offset burner type, nozzle (10) is fitted to a brass adopter (17) which is fitted to the burner (1). The burner (1) is fitted into burner socked (2) which is welded to fuel feed pipe (3) closed at one end and other end is welded to the bottom side of the cylindrical oil container (4). A spirit cup (5) is also provided at the bottom of the burner (1). An air pump (6) is welded on the front flat face of the cylindrical oil container (4). One oil filler (7) with a pressure release screw (8) and oil filler cap (9) is also welded on the top of the cylindrical oil assembly is mounted on a frame (12). Pan supports (18) are also welded on the frame (12). Spill tray (19) with concentric hole (20) to the burner (1) is also provided. Kerosene is filled through oil filler (7) in the cylindrical oil container (4) to 3/4 of its capacity. The oil filler cap (9) and pressure release screw (8) are closed. The spirit is filled in the spirit cup (5) and lighted with a match stick. When the burner is heated sufficiently the air is pumped gently by air pump (6). The kerosene vaporises in the heated burner tubes (13), premixes with air comes out as a premixed fuel / air mixture from the nozzle (10) fixed in the brass adopter (17) fitted to the burner (1), under pressure. Due to velocity, it entrains the air from the surrounding atmosphere through openings of the burner and through openings (2) of spill tray (19) as secondary air (14) burns forming full fledged blue flame (15) in the annular space (16) between burner top and flame spreader (11). The flame of the spirit cup (5) extinguishes after sometime when the spirit is burnt completely. In Fig. 2, the flame spreader (11) of the burner (1) of conventional oil pressure stove offset burner type is shown. The shape is divergent type and flame spreader on the outer side of the pan being heated, thereby heat losses. In Fig. 5, the angle of the flame spreader (11) of the burner (1) of the improved oil pressure stove offset burner type is optimized so that the flame spread is closer to the centre of the pan being heated and heat losses are reduced, thereby increase in thermal efficiency. In Fig. 3, the burner (1) with nozzle (10) of the conventional oil pressure stove offset burner type is shown. In this burner (1) the distance between top of the nozzle (10) to the bottom of the burner top is fixed. The fuel / air mixture coming out of the jet under pressure entrain excess air thereby heat losses and hence less thermal efficiency. In Fig. 6, a brass socket (17) of optimum length is provided below the nozzle (10) of the burner (1) in case of improved oil pressure stove offset burner type. The distance between top of the nozzle (10) to the bottom of the burner top is optimized. Hence the fuel / air mixture coming out of the jet under pressure entrains proper quantity of the air thereby better combustion and hence, there is increase in thermal efficiency. The premixed fuel / air mixture under process passes through the adopter fitted to the burner and then through nozzle comes out as a spray, mixed properly with surrounding entrained, secondary air due to jet effect. This mixture catches fire due to the flame of spirit cup and burns forming a full fledged blue flame. A very intense blue flame is produced when compared with the flame of conventional oil pressure stove offset burner The main advantages of the invention are Reduction of heat losses by providing, optimized angle of flame spreader, thus increasing the thermal efficiency of the burner. There is a gain of 5-6 percent in thermal efficiency by this parameter. Reduction of heat losses by providing optimum distance between bottom of pan to the top of the burner, thus increasing the thermal efficiency of the burner. There is a gain of 6-7 percent in thermal efficiency by this parameter. By providing spill-tray on the burner top, the thermal efficiency has increased by 2 to 2.5 percent by reducing the atmospheric air currents. By optimization of the distance between top of nozzle to bottom of burner top, there is a gain of about 2 percent in thermal efficiency. Thus there is an increase of 12-14 percent thermal efficiency by incorporating the above optimized and designed parameters. We claim: 1. High efficiency domestic oil pressure stove characterized in that it is having optimum angle of the flame spreader to provide optimum distance between bottom of the pan to top of the burner with provision of spill tray and to provide optimum distance between top of nozzle to bottom of the burner top, wherein the said burner comprising a nozzle [10] fitted to a brass adaptor [17] fitted to a burner [1] and the said burner being fitted into the burner socket [2] welded to a fuel pipe [3] closed at one end and with other end being welded to the bottom side of the cylindrical oil container [4] and a spirit cup [5] being provided at the bottom of the burner [1], an air pump [6] being welded on the front flat face of the cylindrical oil container [4] and one oil filler [7] with a pressure release screw [8] and oil filler cap [9] being welded on the top of the said cylindrical oil container [4] with a flame spreader [11] being also provided to the said burner [1] and the whole assembly being mounted on a frame [12] with pan supports [18] welded on the frame [12] and spill tray [19] with concentric hole [20] to the burner [1] also being provided. 2. A stove as claimed in claim 1, wherein the angle of flame spreader ranges between 30 to 35 degree C. 3. A stove as claimed in claim 1, wherein the spill tray [19] is provided separately or as an integral part of the claimed stove with concentric holes of diameter 104 ± 2 mm with 5mm collar downwards. 4. A stove as claimed in claim 1, wherein the distance between the top of nozzle to bottom plate of the burner is reduced either by providing adaptor or by reducing the length of burner tube in which the nozzle is fitted.

Documents:

396-DEL-2002-Abstract-(02-01-2009).pdf

396-DEL-2002-Abstract-(12-01-2009).pdf

396-del-2002-abstract.pdf

396-DEL-2002-Claims-(02-01-2009).pdf

396-DEL-2002-Claims-(12-01-2009).pdf

396-del-2002-claims.pdf

396-DEL-2002-Correspondence-Others-(02-01-2009).pdf

396-DEL-2002-Correspondence-Others-(12-01-2009).pdf

396-del-2002-correspondence-others.pdf

396-del-2002-correspondence-po.pdf

396-DEL-2002-Description (Complete)-(12-01-2009).pdf

396-del-2002-description (complete).pdf

396-del-2002-drawings.pdf

396-DEL-2002-Form-1-(02-01-2009).pdf

396-DEL-2002-Form-1-(12-01-2009).pdf

396-del-2002-form-1.pdf

396-DEL-2002-Form-18-(12-01-2009).pdf

396-del-2002-form-18.pdf

396-DEL-2002-Form-2-(02-01-2009).pdf

396-DEL-2002-Form-2-(12-01-2009).pdf

396-del-2002-form-2.pdf

396-DEL-2002-Form-3-(02-01-2009).pdf

396-del-2002-form-3.pdf