Title of Invention

"A MULTI-PURPOSE STOVE USEFUL FOR COOKING, BAKING, SPACE HEATING AND DRYING."

Abstract

The present invention relates to a multipurpose stove useful for cooking, baking, space heating and drying The use of the device of the present invention is that this Multipurpose Stove is capable of conducting many heating processes, such as cooking, baking, space heating (room heating) and drying of various materials at a time or separately as per requirement. One of the main uses of this device is pollution free space heating along with cooking with minimal fuel consumption. The said multipurpose stove comprises: a combustion chamber having fitted in lower part of the combustion chamber a corrugated grate with slot opening on top and bottom ridges, a Fuel feed tunnel having a hinged flap being provided in the wall of the chamber above the top of the corrugated grate, a Flue gas duct being provided on the top level of the wall of the chamber, the combustion chamber being provided with an Ash holder plate at its bottom end in such a manner so as to of Combustion create an annular opening between the chamber and outer edge of the Ash holder plate, the chamber being provided with a removable top cover and means for support at the bottom, the exhaust end of said chamber being connected to a chimney through the inlet gas duct at the bottom of a Heat Exchanger comprising a chassis and a heat exchanger box with lid, the said Heat Exchanger box being provided an Outlet. Gas duct at its bottom side wall, top and/or bottom opening with suitable lid and means for support on the ground, the said multipurpose stove characterised in that in combination of combustion chamber, corrugated grate with slot openings, ash holder plate, flue gas duct, inlet and outlet gas duct, heat exchanger box with lid, chassis of heat exchanger and chimney.

Full Text

The present invention relates to a multipurpose stove useful for cooking, baking, space heating and drying The use of the device of the present, invention is that; this Multipurpose Stove in capable of conducting many heating processes, such its cooking, bak ing , space heating (room heat i ng ) and drying This device is suit.able for domestic as well as for small enterprises, tiny and cottage industries. This can also be utilised for industrial processes for clean drying or hot air supp.1 y . There is no such Multipurpose stove available inside or outside India, which does cooking, baking, apace heating and drying at a time or separately by burning solid fuels efficiently without using any additional fixture. The main object of the present invention is to provide a multipurpose st.ove useful for cooking, baking, space heating and drying. Another object of the present invention is to provide complete combustion of different solid fuelsK and maximum ut i 1 i sati on of heat, energy of the fuel for different heating Still another object of the invention is to provide heating processes in smoke/pollution free atmosphere for domestic or industrial applications. Yet another object of the present invention is to provide cooking, space heating, baking and drying processes together or separately as per requirement. Accordingly the present invention provides a multipurpose stove useful for cooking, baking, space heating and drying which comprises: a combustion chamber having fitted in lower part of the combustion chamber a corrugated grate with slot opening on top and bottom ridges, a Fuel feed tunnel having a hinged flap being provided in the wall of the chamber above the top of the corrugated grate, a flue gas duct being provided on the top level of the wall of the chamber, the combustion chamber being provided with an ash holder plate at its bottom end in such a manner so as to of combustion create an annular opening between the chamber and outer edge of the ash holder plate, the chamber being provided with a removable top cover and means for support at the bottom, the exhaust end of said chamber being connected to a chimney through the inlet gas duct at the bottom of a heat exchanger comprising a chassis and a heat exchanger box with lid, the said heat exchanger box being provided an outlet, gas duct at its bottom side wall, top and/or bottom opening with suitable lid and means for support on the ground, the said multipurpose stove characterised in that in combination of combustion chamber, corrugated grate with slot openings, ash holder plate, flue gas duct, inlet and outlet gas duct, heat exchanger box with lid, chassis of heat exchanger and chimney. In an embodiment of the present invention the corrugating of the grate with slot openings at its top and bottom ridges are so dimensioned that it provides space for continuous and in depending burning of the residual ember (fixed carbon) of the fuel in a controlled manner to achieve highest temperature and to preheat the primary air bellow the grate at a highest order, resulting faster and continuous devolatilation & ignition of the fresh or unburnt fuel over the grate for continuous burning of the fuel in the combustion chamber. In another embodiment of the present invention the annular opening around ash holder plate at bottom of the combustion chamber is so dimensioned that required volume of primary air flows through it to the corrugated grate at a proper ratio with the volume of the secondary air which flows to the combustion chamber through the fuel feed tunnel. Both streams of air flow to the combustor by effect of the draught of the chimney for sincronized burning of volatiles with fixed carbon to achieve continuous and complet combustion of the fuel without help of air blowing. In yet another embodiment of the present invention the combination of size of the openings of the flue gas duct and Inlet & Outlet gas duct with size of the chimney provide for required amount of air flow in to the combustor for complet combustion of fuels as well as smooth flow of hot exhaust gases from the combustor to the chimney through the heat exchanger at a controlled speed without leakage of smoke or hot gas in to the workplace from the device. The shape and size of the combustor and rectangular shaped vertical heat exchanger box provide to achieve maximum heat transfer to the cook pot and or to the space arround the device from the flume and hot gases during cooking, baking, space heating and drying. In the drawing accompanying this specification, Fig - 1 shows the sectional view of an embodiment of the multipurpose stove of the present invention. The combustion chamber (1) is made of mild steel sheet rolled to a cylinderical shape. The top edge of the cylinder is inverted to hold the cook pot and bottom end is open. The joint of the cylinder is welded. A rectangular opening is made on middle of the vertical wall of the cylinder to connect the Fuel feed tunnel (4). Another rectangular opening is made on the upper level of the vertical wall of the cylinder, in opposite direction of the Fuel feed tunnel (4), where the flue gas duct (6) is connected. The Flue gas duct (6), made out of mild steel sheet, is a rectangular tube. Both the fuel feed tunnel (4) and Flue gas duct (6) are welded with the Cylinder (1) in the respective places. The Fuel feed tunnel (4) is a rectangular duct made of mild steel sheet. The length of its bottom plate (4a) is larger than its other walls. A mild steel damper plate (5) is hinged and welded with fuel feed tunnel (4) which rotate arround the hinge as shown in the figure. Ash holder plate (2), a circular mild steel plate whose diameter is less than the diameter of the combustion chamber (1), is fitted at the bottom of the combustion chamber by few spacers made-up mild steel strips. The spacers are welded with wall of combustion chamber (1) as well as with Ash holder plate (2)by which annular opening of uniform width between the outer edge of the ash holder plate (4) and wall of the combustion chamber is created. The corrugated grate (3), is made out of mild steel flat strips having equal width but of different lengths. The strips are welded on inside surface of the wall of the combustion chamber in opposite inclined direction, as shown in the figure, to obtain optimum corrugation of the grate and slot openings at top and bottom ridges of the corrugation. The top surface of the corrugated grate (3) remains in the plane of bottom plate (4a) of the Fuel feed tunnel (4), where as a vertical gap of optimum height is always maintained between ash holder plate (2) and bottom surface of the grate (3) . Three legs, made of mild steel rod having equal length, are welded with outer surface of the combustion chamber at its bottom to support the combustor on the ground. The Combustor lid (8) is made out of a circular mild steel o sheet. The circular edge of the lid is folded to 90 around its perifery. A handle made of mild steel rod is also welded on top of the lid (8) . The Heat exchanger comprises of a chassis and a Heat exchanger box with lid. The Chassis (9) is a rectangular frame connected with four legs (14) to support over the ground. The frame and legs are made out of mild steel angle. There are two vertical mild steel plates (10 & lOa) are welded over the top surface of the chassis in lateral direction, which are facing to each other. The upper edge of the vertical plates (10 & lOa) are connected with each other by Mild Steel strips (13) to form a rigid structure with the chassis. Both vertical plates (10 & lOa) have rectangular openings at its bottom level. The Inlet gas Duct (11) is a horizontal tube of rectangular cross section and made of mild steel sheet. One end of the duct is welded on the opening of the vertical plate . The cross section of the inlet gas duct (11) is always more than Flue gas duct (6) for easy assembly. Similarly one end of the outlet gas duct (12), which is a horizontal tube of rectangular cross section and made of mild steel sheet, welded on the rectangular opening of the vertical plate (lOa). The other end of the outlet gas duct (12) is connected with the bottom opening of the chimney (18). The Heat Exchanger Box (15), made out of Galvanised Iron Sheet, is fitted inside the Chessis (9). The Box (15) has either top or bottom opening as per the requirement.' It is preferable to have top opening when the device is used for drying, space heating, baking and cooking, otherwise the box should have bottom opening when baking is not required. The side vertical walls of the Heat exchanger Box (15) have rectangular openings at its bottom, whose sizes are equal to the openings of inlet gas duct (11) and outlet gas duct (12) respectively. The said vertical walls of the Heat Exchanger box (15) are rigidly connected with the vertical plates (10 & lOa) respectively by rivets, so that its openings are matched with the openings of the Inlet and Outlet gas ducts, (11 & 12). There are two detachable racks (16 & 17) made with wiremesh are placed inside Heat exchanger box (15) at different depths. The Heat Exchanger Lid (16), made of G.I. Sheet, is a rectangular in shape. It has vertical walls of optimum height around all sides. The Lid (16) is press fitted around the top opening of the heat exchanger Box (15). Two handles are also connected on the external surface of the Lid (16) for handling. The Heat Exchanger Box (15) and Lid (16) are fabricated out of G.I. Sheet. The horizontal and vertical walls of these two parts are joined by folding. A Chimney (18), made out of Mild steel sheet and G.I. sheet, is a vertical duct of optimum height and square cross section. The top end of the chimney remains open for exit of gas and its bottom is closed. The chimney has a rectangular opening on its side vertical wall at bottom level where other end of the outlet gas duct (12) is connected. The Combustor, comprising parts like combustion Chamber (1), Ash holder Plate (2), Corrugated Grate (3), Fuel Feed Tunnel (4), Hinged Damper (5), Flue Gas Duct (6) and Legs (7) are welded together to form a rigid body, where as combustor Lid (8) remain as a axullary part. Similarly the Heat Exchanger, comprising parts like Chassis (9), Vertical Plates (10 & lOa), Inlet Gas Duct (11), Outlet Gas Duct (12), Bracing Strips (13), legs (14) and the Chimney (18) are welded together to form a rigid body. The Heat Exchanger Box (15) is fitted rigidly with the chassis by rivets, where as the Heat Exchanger Lid (16) is a detachable part. All above parts form Heat Exchanger and Chimney. The combustor is Assembled with the Heat Exchanger & chimney by push fitting the Duct (6) into the duct (11) to. form a complet device. Now Multipurpose stove is ready for operation. Main principle underlying in this invention is smoke free complete combustion of solid fuels with minimum excess air for high temperature of the flame which is achieved by burning volatile matters of fuels in the combustion chamber and residual fixed carbon (ember) of the fuels in the troughs of the corrugated grate of the combustor, when air is sucked into the combustor in controlled manner through fuel feeding door and slot openings of corrugated grate at lower part of the combustor; and a part of heat from the high temperature flame transfers to the cook pot on the combustor for cooking, if any, otherwise the hot flue gas flows from the combustor to the chimney through the down draft heat exchanger by the effect of natural draught of the chimney, resulting a major part of heat carried in the flue gas transfers to the space around the device through walls of the heat exchanger by combined radiation and natural convection, which causes maximum utilisation of heat energy of the fuels for heating and drying processes, in addition to maintaining uniform temperature inside the heat exchanger due to downdraft principle which helps to obtain high quality baking of confectionaries inside the heat exchanger (oven) and efficient space heating and drying at outside of heat exchanger. The combination of Combustion Chamber, Corrugated Grate with slot openings, Ash holder Plate, Flue gas duct, Inlet & Outlet gas duct, Heat Exchanger Box with Lid, Chessis of Heat Exchanger and Chimney imparts the characteristic novelty of the Multipurpose stove. The characteristic of the multipurpose stove of the present invention are : i) Two stage combustion is effected as the emitted volatiles of the fuel burns in the combustion chamber and residue charcoal or fixed carbon of the fuel burns in the troughs' of the corrugated grate. , ii)'Smoke free burning of fuels with high temperature flame and self ignition of subsiquent fresh fuels without aid of air blowing are achieved due to controlled flow of Primary and Secondary air by the combination of combustion chamber, Ash holder plate, Corrugated grate, Fuel feed tunnel, Flue gas duct and Chimney. iii) Syncronized burning of residue charcoal or fixed carbon with emmitted volatiles of fuel achieving complete combustion due to combination of draught of chimney, Fuel feed tunnel opening and annular opening around Ash holder plate. iv) The vertical walls of Heat Exchanger, which comprises major surface area of the Heat Exchanger Box, facilitate for rapid heat transfer from the hot gas to the space around it, inturn faster cooling of gas along the vertical walls, thereby up and down movements of the gas in the box due to progressive cooling and flow of hot has into the box resulting uniform temperature in the Heat Exchanger. v) Placement of Inlet and Outlet gas ducts in opposite direction at bottom of the side walls of rectangular shape vertical Heat Exchanger box creates down draft movement of hot gas in the Heat Exchanger to achieve uniform gas temperature inside the Heat Exchanger. vi) The Heat Exchanger of the Multipurpose Stove functions like a heat sink due to down draft gas movement in the rectangular shape vertical heat exchanger box. vii) The combination of openings of Inlet & Outlet gas ducts of the Heat Exchanger and size of the chimney increases the residence time of the hot gas in the Heat Exchanger box which helps to achieve maximum heat recovery from the hot exhaust gas. viii) Thermal efficiency in highest order is achieved due to _> complet combustion of fuel and high rate of heat transfer from the flame & gas to the cook pot & space. High rate of heat transfer to the space for efficient room heating as well as drying of various materials, efficient baking and cooking in a smoke & shoot free environment are obtained by burning significantly less quantity of different solid fuels in the device. The Multipurpose stove operates similar to any stove or oven. The exit end of the chimney remains always at outside of the work place to avoid contamination of smoke/hot gases in to the work place. The damper (5) always remains open during burning of the fuels, otherwise it is in closed position after completion of burning. Similarly Heat Exchanger Lid (16) is always fitted on top of the Heat Exchanger Box (15), except during loading and unloading of materials from the box (15) for baking or similar activities. The combustor (1) top opening is always closed by a cook pot during working, otherwise it is closed by the Lid (8) during othere heating operations. The ignition of the combustor take place by lighting small pieces of firewood over the corrugated grate (3). As it burns thoroughly, fuel is fed in to the combustor through the fuel feed Tunnel (4) which start burning quickly without emmiting smoke. When the device operates without cooking, the top opening of the combustion chamber (1) is always closed by the lid (8). Then fresh fuel is fed intermittently like conventional cook stove. The burning of fuel stabilised within 5 minutes. During burning of fuel, the volatile matters of the fuel burns in luminous flame in the combustion chamber, where as the residue charcoal (fixed carbon) burns in the troughs of the corrugated grate (3). The burning of volatiles complet inside the combustion chamber and the flame propagates from the combustion chamber to end of the flue gas duct (6) below the cook pot during cooking, otherwise at bottom of the lid (8) during other heating operations. There after the hot flue gas flows from the combustor to the heat exchanger box (15) through its Inlet gas duct (11). As all sides of the heat exchanger box (15) are closed, except the Inlet & Outlet gas duct openings (11, 12), the hot flue gas finds a exit into the chimney through the outlet gas duct (12). The hot gas enters in to the chimney (18) at its bottom and then discharges outside through the exit of the chimney. Draught or suction is created inside the chimney during flow of hot gases. As the Chimney, Heat exchanger and combustor are assembled together, the suction of the chimney extends up to the Heat Excha.nger and the combustor, resulting continuous flow of air into the combustor through the Fuel Feed Tunnel (4) and annular opening around the Ash holder Plate (2) during burning of fuel. The air stream flows to the combustion chamber through the Fuel feed Tunnel (4) is called secondary air, which burn the volatiles completely in the combustion chamber, where as other stream of air enters into the grate through annular openings of Ash holder plate, called Primary air, burn the residue charcoal (fixed carbon) of the fuel in the troughs of the corrugated grate as well as ignite the volatiles of the fuel. When fuels like wood, twig, agricultural wastes are fed in to the combustion chamber (1), all of them receive the required heat from the hot ember or fixed carbon, which are burning in the grate (3), and also from adjacent burning fuel pieces to devolatise the fuels. Then emmitted volatile matters mixes with the secondary air in the combustion chamber, and most of volatiles burns here. The rest of volatiles mixes with air in the flue gas duct (6) in a torbulant manner which burn completely before entering in to Heat Exchanger. So almost all volatile matters burn inside the combustion chamber with low excess air which helps to obtain a high temperature short flame in the combustor. After devolatisation of the fuel, the left over fixed carbon or charcoal falls into the troughs of the corrugated grate. The charcoal burns continuously in the troughs of the gratee as air gets sucked in to the grate continuously through bottom slot openings of the grate by the effect of suction created by the chimney in the device. Similarly a part of air also blows in to the combustion chamber through top slot openings at the grate, by the effect of suction, which helps to achieve complet burning of charcoal as well as to ignite the volatile matters emmitted from the unburnt fuels. The air which flows to the combustion chamber through the top slot openings of the grate receive heat from the hot surfaces of the grate plate and air gets preheated to achieve a high temperature in the combustor. Like this two stage combustion of fuel takes place inside the combustor by use of primary and secondary air, as a result high temperature, smoke free and less shoot, short flame and clean flue gas are obtained. When the multipurpose stove is used for heating processes along with cooking, a part of heat from the flame and hot gas is utilised for cooking on top of the combustion chamber, otherwise most of its heat energy is utilesed for heating processes through the heat exchanger. During burning of fuel, additional air blowing as well as pocking of fuel is also not required in case of burning of firewood or similar biomass fuels. Slow and first heating are also possible by increasing or decreasing the rate of fuel feeding. After burning of fuel in the combustor, the hot flue gas flows into the heat exchanger by suction effect of the chimney. As the heat Exchanger is a rectangular shaped vertical box having narrow width side walls and its Inlet &. Outlet openings are placed at bottom level of the narrow width vertical walls in opposite direction, the hot gas always moves upwards after entering in to the Heat Exchanger box. The metallic body of the heat exchanger gets heated ;r rapidly and heat is transfered from walls of the box to the space around the device by radiation and convection. The typical geometry of the Heat exchanger box provides more vertical surface area than horizontal walls which helps for rapid and efficient heat transfer from hot gas to the sorrounding space, resulting faster cooling of hot gas along the vertical walls. As the temperature of the gas in the heat exchanger box drops, the gas moves downward and its space is filled-up by incoming fresh hot gases. By this process the hot flue gas moves up and down in the heat exchanger before exiting to the chimney resulting uniform temperature maintained in the heat exchanger box. So high quality baking is achieved inside the heat exchanger box. After loosing maximum heat energy of the gas in the heat exchanger box, the flue gas flows further to the chimney through the outlet gas duct at bottom level, in a direction opposite to the Inlet gas duct. So the heat exchanger always functions like a heat sink. In this process the hot gas flows continuously from the combustor to the chimney through the Heat Exchanger during burning of fuel, resulting continuous heat transfer to the space around the device, without leakage of smoke in the work place. Therefore rapid and uniform space heating is achieved. Drying of various materials, grains etc. and baking of paints are achieved when the device operates in a confined space. As the exit of the chimney is always at outside the work place, drying and space heating without contamination of smoke or hot gas are carried out at a very high thermal efficiency. The rate of drying, space heating and baking depends upon fuel feeding rate in the combustor. The following examples are given by way of illustration of the present invention and should not be construed to limit the scope of the present invention. All, parts of the device are very much interlinked to achieve high thermal efficiency and best performance of the Multipurpose Stove. The device will work with reduced efficiency by changing the dimensions of its parts. Four models have been designed progressively to achieve best performance. The models are named as A, B, C, D and the experiment data of the models are analysed and the device is modified progressively for better result. Finally model 'D' has been designed for the best performance. (Table Removed) All design variables of this Multipurpose Stove are combustion chamber, Fuel feed tunnel, Corrugated grate, Ash holder Annular opening, Flue gas duct, Inlet & Outlet gas duct, Heat exchanger box and Chimney. The height and diameter of the combustion chamber influence the heat transfer from flame and hot gas to the cook pot, and burning capacity of the fuel. The opening of fuel feed tunnel and annular opening around Ash holder plate control the flow of air in to the combustor for burning of fuel, which influence the combustion efficiency. The openings of the Flue gas duct, Inlet & Outlet gas ducts have direct influence over the residence time as well as speed of flame and hot gas in the combustor & Heat Exchanger respectively, inturn rate of heat recovery from the flame & hot gas during heating processes. The depth of troughs and width of slot openings of the corrugated grate control the rate of burning of the fixed carbon of fuel as well as keep a balance of burning of ember with volatiles of the fuels. These dimensions determine the temperature in the grate. The size and material of Heat Exchanger box and placement of Inlet & Outlet gas duct have direct influence over the rate of heat recovery from the hot gases for baking, space heating and drying processes. The efficiency of the heating processes absolutely depends upon above said variables of the heat exchanger box. The height and size of the chimney in coordination with openings of fuel feed tunnel, annular opening of Ash holder plate, Flue gas duct, Inlet & Outlet gas duct are designed on basis of residence time, speed of the flame & hot gas and the total draught, so that clean flame without smoke and less shoot with less excess air can be obtained and maximum possible heat transfer from the hot gas to the space through heat exchanger is achieved. The chimney has direct influence over the overall performance of the device. The new results achieved as follows :- i) Multiple heating processes, such as cooking, space heating, baking and drying are carried out efficiently at a time or separately by a single portable device for the uso of domestic as well as cottage industry sector. ii) The heating processes are carried out by complete combustion of different solid fuels without blowing of air and liberation of smoke with negligible shoot. iii) The combination of troughs and slot openings of the corrugated grate provides space for independent and continuous burning of the fixed carbon (ember) of the fuel resulting high temperature in the grate. The high temperature helps to crack the unburnt or fresh fuel for continuous liberation of volatiles. The volatiles gets ignited easily by the preheated Primary air which flows through the slot openings. iv) The complete burning of volatiles take place inside the combustion chamber due to high residence time of the flame and continuous flow of secondary air through the fuel feed tunnel by the effect of natural draught of the chimney, resulting in drastic reduction of shoot and smokeless operation. v) The placement of inlet and outlet gas ducts on opposite side vertical walls of the heat exchanger at its bottom level allows the heat exchanger to store hot gases and acts like a heat sink. This provides to increase the temperature of the bare metallic walls of the heat exchanger for continuous heat transfer from hot gases to the surrounding space by combined radiation and convection. vi) The Heat exchanger comprises of a narrow width rectangular shape vertical G.I. Box which provides maximum vertical and minimum horizontal surfaces to facilitate high rate of heat transfer from hot gas to the space through the metallic walls by combined radiation and convection principles. vii) The down draught flow of hot gases inside the heat exchanger and narrow width of the rectangular shape vertical box of the heat exchanger helps to maintain a uniform temperature in the box. viii) During burning of fuels, the flame travel below the bottom surface of the cook pot as the exhaust port (flue gas duct) of the combustor is placed at its top level, which helps; to achieve high rate of heat transfer from the flame to the cook pot during cooking. ix) The device achieves very high thermal efficiency due to high rate of heat recovery from the flame by the cook pot in the combustor and from the hot exhaust gases by the heat exchanger for space heating, drying and baking. The main advantages of the present invention are- a) Various heating processes can be carried out at different temperatures by this Multipurpose Stove. b) Cooking, space heating (room heating), baking of bread, cake etc. and drying of various materials for domestic as well as cottage industries and baking of enamel paints can be carried out at a time or separately by this stove. c) A wide variety of solid fuels can burn in this stove. d) This device operates at very high thermal efficiency during heating processes. e) Complet combustion of fuels and high heat release is possible in this device. f) It operates in a smoke free environment with little shoot formation in the device. g) Maximum utilisation of heat energy of the fuels in the heating processes is possible. h) Fuel consumption in the heating processes is drastically low. i) Pollution free space heating, drying, cooking and baking are achieved. j ) Better quality confectionaries due to uniform temperature in the heat exchanger is achieved. k) Higher rate of heat transfer from the surfaces of the device to the surrounding space is achieved. 1) Faster space heating and drying of various food and industrial material are made. m) The device is portable in use. n) No casting is involved. o) The device is quite easy to fabricate. p) The device is quite low cost. We Claim: 1. A multipurpose stove useful for cooking, baking, space heating and drying which comprises: a combustion chamber having fitted in lower part of the combustion chamber a corrugated grate with slot opening on top and bottom ridges, a Fuel feed tunnel having a hinged flap being provided in the wall of the chamber above the top of the corrugated grate, a flue gas duct being provided on the top level of the wall of the chamber, the combustion chamber being provided with an ash holder plate at its bottom end in such a manner so as to of combustion create an annular opening between the chamber and outer edge of the ash holder plate, the chamber being provided with a removable top cover and means for support at the bottom, the exhaust end of said chamber being connected to a chimney through the inlet gas duct at the bottom of a heat exchanger comprising a chassis and a heat exchanger box with lid, the said heat exchanger box being provided an outlet, gas duct at its bottom side wall, top and/or bottom opening with suitable lid and means for support on the ground, the said multipurpose stove characterised in that in combination of combustion chamber, corrugated grate with slot openings, ash holder plate, flue gas duct, inlet and outlet gas duct, heat exchanger box with lid, chassis of heat exchanger and chimney. 2. A multipurpose stove as claimed in claim 1 wherein wire mesh shelves are provided in the Heat Exchanger box. 3. A multipurpose stove as claimed in claim 1 wherein the Inlet and outlet gas openings are provided at bottom of opposite vertical side walls of the Heat Exchanger box respectively. 4. A multipurpose stove as claimed in claim 1 wherein the corrugated grate is placed at lower level in the combustion chamber, above the ash holder plate. 5. A multipurpose stove as claimed in claim 1 wherein the flue gas duct is placed at upper level of the combustion chamber. 6. A multipurpose stove useful for cooking, baking, space heating and drying substantially as herein described with reference to the examples and drawing accompanying this specification.

Documents:

1114-del-1998-abstract.pdf

1114-del-1998-claims.pdf

1114-del-1998-correspondence-others.pdf

1114-del-1998-correspondence-po.pdf

1114-del-1998-description (complete).pdf

1114-del-1998-drawings.pdf

1114-del-1998-form-1.pdf

1114-del-1998-form-19.pdf

1114-del-1998-form-2.pdf

1114-del-1998-form-3.pdf