CA3168332A1 - System and method for improving the combustion process of a solid fuel by means of an inert porous medium - Google Patents
System and method for improving the combustion process of a solid fuel by means of an inert porous medium Download PDFInfo
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- CA3168332A1 CA3168332A1 CA3168332A CA3168332A CA3168332A1 CA 3168332 A1 CA3168332 A1 CA 3168332A1 CA 3168332 A CA3168332 A CA 3168332A CA 3168332 A CA3168332 A CA 3168332A CA 3168332 A1 CA3168332 A1 CA 3168332A1
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- combustion
- inert porous
- fireplace
- solid fuel
- porous medium
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23B—METHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
- F23B60/00—Combustion apparatus in which the fuel burns essentially without moving
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23B—METHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
- F23B90/00—Combustion methods not related to a particular type of apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
- F23G7/06—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23M—CASINGS, LININGS, WALLS OR DOORS SPECIALLY ADAPTED FOR COMBUSTION CHAMBERS, e.g. FIREBRIDGES; DEVICES FOR DEFLECTING AIR, FLAMES OR COMBUSTION PRODUCTS IN COMBUSTION CHAMBERS; SAFETY ARRANGEMENTS SPECIALLY ADAPTED FOR COMBUSTION APPARATUS; DETAILS OF COMBUSTION CHAMBERS, NOT OTHERWISE PROVIDED FOR
- F23M20/00—Details of combustion chambers, not otherwise provided for, e.g. means for storing heat from flames
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24B—DOMESTIC STOVES OR RANGES FOR SOLID FUELS; IMPLEMENTS FOR USE IN CONNECTION WITH STOVES OR RANGES
- F24B1/00—Stoves or ranges
- F24B1/18—Stoves with open fires, e.g. fireplaces
- F24B1/191—Component parts; Accessories
- F24B1/197—Hearths
Abstract
The invention relates to a system and a method of combustion of solid fuels using an inert porous medium in the combustion process. The system comprises: a combustion fireplace containing solid fuel inside, the solid fuel is subjected to a combustion process inside the fireplace, which generates combustion gases, an inert porous medium disposed within the combustion fireplace, the inert porous medium is in the proximity of the solid fuel, and flow control means placed in the combustion fireplace. The flow control means are placed to control the operation of: at least one air intake into the combustion fireplace, to inject intake air into the combustion fireplace; and at least one exhaust gas outlet in the combustion fireplace, to release exhaust gases to the outside of the combustion fireplace. The flow control means generate a flow of intake air and combustion gases between the at least one air inlet and the at least one exhaust gas outlet, forming a premix of intake air and combustion gases inside combustion fireplace. The flow control means and the inert porous medium circulate the premix through the inert porous medium, particularly, through the pores of the inert porous medium, causing preheating of the intake air and acceleration of the reaction of the combustion gases inside the pores, combusting the premix inside the pores of the inert porous medium.
Description
I
SYSTEM AND METHOD FOR IMPROVING THE COMBUSTION PROCESS
OF A SOLID FUEL BY MEANS OF AN INERT POROUS MEDIUM
The present invention relates to a system and method comprising the use of an inert porous material disposed in the proximity of a solid fuel, inside a combustion fireplace, to improve the combustion process of said solid fuel.
Background Currently, one of the most widely used fuels in heat generation systems, such as heating stoves or other types of furnaces, are solid fuels, such as biomass, coal, or others.
In general, the wide use of solid fuels as fuel media inside a combustion fireplace is due to the fact that they are usually cheaper than liquid or gaseous fuels.
However, the great disadvantage of solid fuels lies in the low efficiency of the combustion process, which results in a higher emission of polluting exhaust gases and particulate matter compared to the use of liquid or gaseous fuels.
In this context, there is a common need to improve the efficiency of the combustion processes for solid fuels, in order to significantly reduce the emission of pollutants exhaust gases and particulate matter contained in combustion systems that use this type of fuels.
One of the ways to improve the efficiency of the combustion process of a solid fuel is to maximize the delivery and utilization of the calorific value of said solid fuel (e.g., firewood). The common approach to achieve said technical effect is to use specially designed equipment for combustion, operated according to methods appropriate to the type of fuel. For example, in combustion fireplaces it is common to use heat-resistant materials and to implement appropriate fireplace designs to reduce losses to the outside, while maintaining a high and constant temperature inside the fireplace.
Among the most commonly used fireplace designs are the implementation of appropriate air intake controls, which often increase the efficiency of the combustion
SYSTEM AND METHOD FOR IMPROVING THE COMBUSTION PROCESS
OF A SOLID FUEL BY MEANS OF AN INERT POROUS MEDIUM
The present invention relates to a system and method comprising the use of an inert porous material disposed in the proximity of a solid fuel, inside a combustion fireplace, to improve the combustion process of said solid fuel.
Background Currently, one of the most widely used fuels in heat generation systems, such as heating stoves or other types of furnaces, are solid fuels, such as biomass, coal, or others.
In general, the wide use of solid fuels as fuel media inside a combustion fireplace is due to the fact that they are usually cheaper than liquid or gaseous fuels.
However, the great disadvantage of solid fuels lies in the low efficiency of the combustion process, which results in a higher emission of polluting exhaust gases and particulate matter compared to the use of liquid or gaseous fuels.
In this context, there is a common need to improve the efficiency of the combustion processes for solid fuels, in order to significantly reduce the emission of pollutants exhaust gases and particulate matter contained in combustion systems that use this type of fuels.
One of the ways to improve the efficiency of the combustion process of a solid fuel is to maximize the delivery and utilization of the calorific value of said solid fuel (e.g., firewood). The common approach to achieve said technical effect is to use specially designed equipment for combustion, operated according to methods appropriate to the type of fuel. For example, in combustion fireplaces it is common to use heat-resistant materials and to implement appropriate fireplace designs to reduce losses to the outside, while maintaining a high and constant temperature inside the fireplace.
Among the most commonly used fireplace designs are the implementation of appropriate air intake controls, which often increase the efficiency of the combustion
2 process. In addition, modern fireplaces incorporate metal walls on their side faces and have a space between the fireplace casing and the adjoining walls where the fireplace is located, for example, the rear of a wood burning stove, which allows free air circulation between the stove and the adjoining walls.
In the context of residential wood burning stoves, there are different types of stoves that use firewood as fuel on the market, among which are: fireplaces, salamanders, slow combustion stoves and double chamber slow combustion stoves. The most commonly used designs comprise an air inlet near the floor of the building, and an air outlet near the stove shelf (located at the top of the fireplace door). This design results in a convective circulation of hot air, in addition to the radiant heat from the fireplace itself. However, the technique of admitting air through the bottom of the fireplace, which allows hot air to rise through the fireplace bed and then escape through the stove outlet ducts, proves to be inefficient. Indeed, it has been found that to heat efficiently, the combustible gases released during the wood combustion process, or combustion gases, must be mixed with a large amount of oxygen at a minimum temperature of 1,100 C. In addition, for complete combustion of the combustible gases released by the wood, about 80% more than the amount of air needed for the fuel must be supplied.
In this context, the desirability of having an air supply above the fireplace bed to heat the combustible gases released during the combustion process has led to the design of "downdraft" heating equipment. Such equipment forces the circulation of combustible gases through internal structures arranged as "labyrinths", where they are mixed with a stream of hot air, achieving a virtually complete combustion, reducing pollutants in the exhaust gases. In less efficient equipment, these combustible gases escape through the chimney in the form of exhaust gases, or are deposited in the duct in the form of soot and/or creosote.
In recent years, the development of new technologies to improve combustion efficiency has made great advances, as in the case of the application of inert porous media. For example, patent document CL 2014-01778 uses a mixture of inert porous media (alumina spheres) with a solid fuel (biomass, coal or other) for synthesis gas generation. However, said document does not focus on improving the
In the context of residential wood burning stoves, there are different types of stoves that use firewood as fuel on the market, among which are: fireplaces, salamanders, slow combustion stoves and double chamber slow combustion stoves. The most commonly used designs comprise an air inlet near the floor of the building, and an air outlet near the stove shelf (located at the top of the fireplace door). This design results in a convective circulation of hot air, in addition to the radiant heat from the fireplace itself. However, the technique of admitting air through the bottom of the fireplace, which allows hot air to rise through the fireplace bed and then escape through the stove outlet ducts, proves to be inefficient. Indeed, it has been found that to heat efficiently, the combustible gases released during the wood combustion process, or combustion gases, must be mixed with a large amount of oxygen at a minimum temperature of 1,100 C. In addition, for complete combustion of the combustible gases released by the wood, about 80% more than the amount of air needed for the fuel must be supplied.
In this context, the desirability of having an air supply above the fireplace bed to heat the combustible gases released during the combustion process has led to the design of "downdraft" heating equipment. Such equipment forces the circulation of combustible gases through internal structures arranged as "labyrinths", where they are mixed with a stream of hot air, achieving a virtually complete combustion, reducing pollutants in the exhaust gases. In less efficient equipment, these combustible gases escape through the chimney in the form of exhaust gases, or are deposited in the duct in the form of soot and/or creosote.
In recent years, the development of new technologies to improve combustion efficiency has made great advances, as in the case of the application of inert porous media. For example, patent document CL 2014-01778 uses a mixture of inert porous media (alumina spheres) with a solid fuel (biomass, coal or other) for synthesis gas generation. However, said document does not focus on improving the
3 efficiency of the combustion process or heat production, but only seeks to generate synthesis gas from the gasification of the solid fuel itself.
Another combustion solution using inert materials is described in patent document US 10401023 B2. Said document refers to a burner comprising a combustion chamber with a porous material enhanced with a perovskite catalyst composition that coats the pores of the porous material, producing a stable combustion of a mixture of natural gas and air. Although this document refers to the use of porous materials to stabilize combustion, it does not refer to heat production, but only seeks to increase the contact surface between the catalyst composition and the mixture of natural gas and air, using for this purpose the pores of the inert material.
Therefore, it is necessary to have a combustion system and method to improve the efficiency of the combustion process of solid fuels, decreasing the polluting emissions of said type of solid fuels.
Description of the invention The invention relates to a combustion system and method for improving the efficiency of the combustion process of solid fuels.
In particular, the solid fuel combustion system of the present invention comprises:
- a combustion fireplace containing solid fuel inside, wherein said solid fuel is subjected to a combustion process inside the combustion fireplace;
- an inert porous medium placed inside said combustion fireplace, wherein said inert porous medium is in the proximity of the solid fuel; and - flow control means placed in the combustion fireplace.
The flow control means are placed to control the operation of at least one air inlet and at least one exhaust gas outlet placed in the fireplace. The air inlet is designed or configured to inject intake air into the fireplace. The gas outlet is designed or configured to release unreacted combustion gases to the outside of the
Another combustion solution using inert materials is described in patent document US 10401023 B2. Said document refers to a burner comprising a combustion chamber with a porous material enhanced with a perovskite catalyst composition that coats the pores of the porous material, producing a stable combustion of a mixture of natural gas and air. Although this document refers to the use of porous materials to stabilize combustion, it does not refer to heat production, but only seeks to increase the contact surface between the catalyst composition and the mixture of natural gas and air, using for this purpose the pores of the inert material.
Therefore, it is necessary to have a combustion system and method to improve the efficiency of the combustion process of solid fuels, decreasing the polluting emissions of said type of solid fuels.
Description of the invention The invention relates to a combustion system and method for improving the efficiency of the combustion process of solid fuels.
In particular, the solid fuel combustion system of the present invention comprises:
- a combustion fireplace containing solid fuel inside, wherein said solid fuel is subjected to a combustion process inside the combustion fireplace;
- an inert porous medium placed inside said combustion fireplace, wherein said inert porous medium is in the proximity of the solid fuel; and - flow control means placed in the combustion fireplace.
The flow control means are placed to control the operation of at least one air inlet and at least one exhaust gas outlet placed in the fireplace. The air inlet is designed or configured to inject intake air into the fireplace. The gas outlet is designed or configured to release unreacted combustion gases to the outside of the
4 fireplace, in the form of exhaust gases, wherein said combustion gases are generated by the combustion process occurring inside the fireplace.
The flow control means are designed or configured to generate a flow of intake air and combustion gases into the combustion fireplace, between the at least one air inlet and the at least one exhaust gas outlet. The flow of intake air and combustion gases forms a premix of intake air and combustion gases inside the fireplace. Additionally, the flow control means and the inert porous medium are configured to circulate said premix through the inert porous medium. In particular, the premix is circulated through the pores of the inert porous medium, which causes preheating of the intake air and acceleration of the combustion gas reaction within said pores. Thereby, the circulating premix is combusted inside the pores of the inert porous medium.
At this point it is important to emphasize that the present invention does not intend to describe with the usual components of solid fuel combustion systems, such as the means for controlling the flow of intake air and combustion gases, or the use of double chambers and other mechanisms currently implemented in different systems, such as the existing wood stoves. Indeed, the elements described are those which have a direct participation in obtaining the advantages proposed by the invention, associated with the use of inert porous media in the combustion process.
On the other hand, the method of solid fuel combustion of the present invention comprises the following steps:
a) placing solid fuel and placing an inert porous medium inside a combustion fireplace of a solid fuel combustion system, wherein the inert porous medium is placed in the proximity of the solid fuel;
b) injecting intake air into the combustion fireplace through at least one air inlet placed in the combustion fireplace, wherein the injection of said intake air is controlled by flow control means placed in the combustion fireplace;
c) igniting the solid fuel, subjecting said solid fuel to a combustion process inside the combustion fireplace;
d) generating a flow of intake air and combustion gases between the at least one air inlet and at least one exhaust gas outlet also placed in the combustion
The flow control means are designed or configured to generate a flow of intake air and combustion gases into the combustion fireplace, between the at least one air inlet and the at least one exhaust gas outlet. The flow of intake air and combustion gases forms a premix of intake air and combustion gases inside the fireplace. Additionally, the flow control means and the inert porous medium are configured to circulate said premix through the inert porous medium. In particular, the premix is circulated through the pores of the inert porous medium, which causes preheating of the intake air and acceleration of the combustion gas reaction within said pores. Thereby, the circulating premix is combusted inside the pores of the inert porous medium.
At this point it is important to emphasize that the present invention does not intend to describe with the usual components of solid fuel combustion systems, such as the means for controlling the flow of intake air and combustion gases, or the use of double chambers and other mechanisms currently implemented in different systems, such as the existing wood stoves. Indeed, the elements described are those which have a direct participation in obtaining the advantages proposed by the invention, associated with the use of inert porous media in the combustion process.
On the other hand, the method of solid fuel combustion of the present invention comprises the following steps:
a) placing solid fuel and placing an inert porous medium inside a combustion fireplace of a solid fuel combustion system, wherein the inert porous medium is placed in the proximity of the solid fuel;
b) injecting intake air into the combustion fireplace through at least one air inlet placed in the combustion fireplace, wherein the injection of said intake air is controlled by flow control means placed in the combustion fireplace;
c) igniting the solid fuel, subjecting said solid fuel to a combustion process inside the combustion fireplace;
d) generating a flow of intake air and combustion gases between the at least one air inlet and at least one exhaust gas outlet also placed in the combustion
5 fireplace, wherein said flow of intake air and combustion gases is controlled by said flow control means, forming a premix of intake air and combustion gases inside the combustion fireplace;
e) circulating the premix through the inert porous medium, in particular, through the pores of said inert porous medium, to preheat the intake air and accelerate the reaction of the combustion gases within said pores, wherein the circulation of the premix is controlled by said flow control means and said inert porous medium, and wherein said premix is combusted inside the pores of the inert porous medium; and f) releasing unreacted combustion gases to the outside of the combustion fireplace, in the form of exhaust gases, wherein the release of said exhaust gases is controlled by said flow control means.
The arrangement of the inert porous medium in the proximity of the solid fuel allows establishing a thermal contact between said inert porous medium and said solid fuel, wherein thermal contact is to be understood the occurrence of heat transfer mechanisms between the inert porous medium and the solid fuel.
According to an embodiment of the invention, the step of injecting intake air is controlled according to the desired amount of air for the combustion process, by means of the control of the at least one air inlet. The desired amount of air for the combustion process can be selected according to the state of the combustion process inside the fireplace, either by means of temperature measurements inside the fireplace and/or combustion gases towards the at least one outlet.
Preferably, the amount of air injected into the fireplace depends on the oxygen required for the chemical reactions involved in the combustion process, seeking to avoid imperfect combustion of the solid fuel.
Notwithstanding the foregoing, and in the understanding that the combustion process usually involves imperfect combustion, avoiding excess air that generates heat losses, the step of injecting intake air and/or the step of releasing exhaust gases are controlled according to the desired premix circulation through the inert porous medium, by controlling the at least one air inlet and the at least one exhaust gas outlet. In this sense, the circulation of the premix through the pores of the inert porous medium allows the combustion gases, generated as gases from the
e) circulating the premix through the inert porous medium, in particular, through the pores of said inert porous medium, to preheat the intake air and accelerate the reaction of the combustion gases within said pores, wherein the circulation of the premix is controlled by said flow control means and said inert porous medium, and wherein said premix is combusted inside the pores of the inert porous medium; and f) releasing unreacted combustion gases to the outside of the combustion fireplace, in the form of exhaust gases, wherein the release of said exhaust gases is controlled by said flow control means.
The arrangement of the inert porous medium in the proximity of the solid fuel allows establishing a thermal contact between said inert porous medium and said solid fuel, wherein thermal contact is to be understood the occurrence of heat transfer mechanisms between the inert porous medium and the solid fuel.
According to an embodiment of the invention, the step of injecting intake air is controlled according to the desired amount of air for the combustion process, by means of the control of the at least one air inlet. The desired amount of air for the combustion process can be selected according to the state of the combustion process inside the fireplace, either by means of temperature measurements inside the fireplace and/or combustion gases towards the at least one outlet.
Preferably, the amount of air injected into the fireplace depends on the oxygen required for the chemical reactions involved in the combustion process, seeking to avoid imperfect combustion of the solid fuel.
Notwithstanding the foregoing, and in the understanding that the combustion process usually involves imperfect combustion, avoiding excess air that generates heat losses, the step of injecting intake air and/or the step of releasing exhaust gases are controlled according to the desired premix circulation through the inert porous medium, by controlling the at least one air inlet and the at least one exhaust gas outlet. In this sense, the circulation of the premix through the pores of the inert porous medium allows the combustion gases, generated as gases from the
6 devolatilization of the solid fuel, to mix with the intake air, favoring the formation of the premix and its combustion inside the pores.
According to an embodiment of the invention, the step of placing the solid fuel comprises placing two or more solid units forming said solid fuel. The solid units may or may not be of different dimensions and may or may not be randomly positioned inside the fireplace. According to the various embodiments of the invention, the solid fuel, and the solid units forming said solid fuel, are selected from biomass, coal, or a combination of both. By way of example, biomass should be understood as:
- wood, in any of its forms, e.g., logs, pellets, sawdust, etc.;
- wheat residues, straw, nut shells, or other natural fibrous materials;
In addition, the present invention also considers as solid fuel different types of coal, independent of its moisture, amount of ash, and/or calorific value.
Some types of coal are lignite, sub-bituminous coal, coal (fat, semi-fat and/or dry), bituminous coal, anthracite, and coking coal, among others.
Other solid fuels that can also be used by means of the present invention, in addition to biomass and coal, can be peat, combustible wastes, or other natural or artificial solid fuels.
According to one embodiment of the invention, the step of placing the inert porous medium inside the combustion fireplace comprises placing at least one inert porous unit inside the combustion fireplace. Said at least one inert porous unit forming the inert porous medium. Alternatively, the inert porous medium inside the combustion fireplace comprises two or more inert porous units, said two or more inert porous units placed inside the combustion fireplace in different positions.
Preferred embodiments of the invention comprise placing the one or more porous inert units in physical contact with the solid fuel, in positions which maximize and ensure said physical contact with the solid fuel. The physical contact between the solid fuel and the inert porous medium, which generates a thermo-physical contact, intensifies heat transfer, mainly by conduction, convection, and radiation, and thus the solid fuel is able to combust at a higher temperature and more efficiently.
According to an embodiment of the invention, the step of placing the solid fuel comprises placing two or more solid units forming said solid fuel. The solid units may or may not be of different dimensions and may or may not be randomly positioned inside the fireplace. According to the various embodiments of the invention, the solid fuel, and the solid units forming said solid fuel, are selected from biomass, coal, or a combination of both. By way of example, biomass should be understood as:
- wood, in any of its forms, e.g., logs, pellets, sawdust, etc.;
- wheat residues, straw, nut shells, or other natural fibrous materials;
In addition, the present invention also considers as solid fuel different types of coal, independent of its moisture, amount of ash, and/or calorific value.
Some types of coal are lignite, sub-bituminous coal, coal (fat, semi-fat and/or dry), bituminous coal, anthracite, and coking coal, among others.
Other solid fuels that can also be used by means of the present invention, in addition to biomass and coal, can be peat, combustible wastes, or other natural or artificial solid fuels.
According to one embodiment of the invention, the step of placing the inert porous medium inside the combustion fireplace comprises placing at least one inert porous unit inside the combustion fireplace. Said at least one inert porous unit forming the inert porous medium. Alternatively, the inert porous medium inside the combustion fireplace comprises two or more inert porous units, said two or more inert porous units placed inside the combustion fireplace in different positions.
Preferred embodiments of the invention comprise placing the one or more porous inert units in physical contact with the solid fuel, in positions which maximize and ensure said physical contact with the solid fuel. The physical contact between the solid fuel and the inert porous medium, which generates a thermo-physical contact, intensifies heat transfer, mainly by conduction, convection, and radiation, and thus the solid fuel is able to combust at a higher temperature and more efficiently.
7 As an example, a first inert porous unit is positioned between the solid fuel and a side wall of the combustion fireplace, and a second inert porous unit is positioned between the solid fuel and another side wall of the combustion fireplace.
Thus, a combustion fireplace having at least four walls, two side walls, a rear wall, and a front wall, comprises inert porous units disposed at least between the solid fuel and the side walls of the fireplace. Alternatively, a third inert porous unit is positioned between the solid fuel and a rear wall of the combustion fireplace.
This lateral and rear location of the inert porous units allows the emission of particulate matter to be reduced by 50%, considering the stove without inert porous media as a point of comparison.
Although it is possible to add a fourth inert porous unit between the solid fuel and the front wall of the fireplace, in conventional combustion systems the front wall is also the access door to the interior of the fireplace, usually comprising a glass pane. Then, the operation of the fourth inert porous unit placed towards said front wall will be affected by the opening/closing operations of the fireplace access door and/or by the increased heat transfer occurring from said front wall to the outside of the fireplace.
In this context, the position where the inert porous medium is placed in contact with the solid fuel must not only favor the generation of the premix and the combustion of the same, as is achieved with the lateral and rear positions indicated above, but must also favor an optimal cleaning of the ashes generated after the combustion process. In this regard, while it is also possible to place porous inert units towards the top wall of the fireplace, this has been shown to be not as effective and functional compared to dissipations towards the side and rear walls. On the other hand, with respect to the bottom wall of the fireplace, although it is possible to improve the combustion process by using this location for porous inert units, placing one or more porous inert units under the solid fuel prevents optimal ash cleaning, saturating the pores of the porous inert medium with said ash and rapidly losing the advantages of using the porous inert medium inside the fireplace.
At this point it is relevant to point out that each inert porous unit can be formed by one or more inert porous elements, said elements usually presented in the form of discs with the appearance of porous sponges. In this regard, the inert porous
Thus, a combustion fireplace having at least four walls, two side walls, a rear wall, and a front wall, comprises inert porous units disposed at least between the solid fuel and the side walls of the fireplace. Alternatively, a third inert porous unit is positioned between the solid fuel and a rear wall of the combustion fireplace.
This lateral and rear location of the inert porous units allows the emission of particulate matter to be reduced by 50%, considering the stove without inert porous media as a point of comparison.
Although it is possible to add a fourth inert porous unit between the solid fuel and the front wall of the fireplace, in conventional combustion systems the front wall is also the access door to the interior of the fireplace, usually comprising a glass pane. Then, the operation of the fourth inert porous unit placed towards said front wall will be affected by the opening/closing operations of the fireplace access door and/or by the increased heat transfer occurring from said front wall to the outside of the fireplace.
In this context, the position where the inert porous medium is placed in contact with the solid fuel must not only favor the generation of the premix and the combustion of the same, as is achieved with the lateral and rear positions indicated above, but must also favor an optimal cleaning of the ashes generated after the combustion process. In this regard, while it is also possible to place porous inert units towards the top wall of the fireplace, this has been shown to be not as effective and functional compared to dissipations towards the side and rear walls. On the other hand, with respect to the bottom wall of the fireplace, although it is possible to improve the combustion process by using this location for porous inert units, placing one or more porous inert units under the solid fuel prevents optimal ash cleaning, saturating the pores of the porous inert medium with said ash and rapidly losing the advantages of using the porous inert medium inside the fireplace.
At this point it is relevant to point out that each inert porous unit can be formed by one or more inert porous elements, said elements usually presented in the form of discs with the appearance of porous sponges. In this regard, the inert porous
8 medium may be of a ceramic material, and may have a porosity of at least 50%
and a pore density of at least 20 ppi.
According to an embodiment of the invention, a data acquisition unit is provided, for executing a step of acquiring operation data of the combustion system.
In this context, the present invention makes it possible to generate a combustion process with the active participation of the inert porous medium, which intensifies the heat transfer mechanisms (conduction, convection, and radiation). In addition, the active participation of the inert porous medium allows the air required for the combustion process to be preheated and the volatile combustion gases, product of the devolatilization of the solid fuel, to mix with the air and react rapidly inside the pores.
Brief description of the figures As part of the present invention, the following representative figures of the same are presented, which show preferred configurations of the invention and, therefore, are not to be considered as limiting to the definition of the claimed subject matter.
FIG. 1 a, 1 b, and 1 c show right lateral, front, and left lateral views of a schematic representing the interior of the combustion fireplace, according to one embodiment of the invention.
FIG. 2 is a schematic of the wood combustion process.
Detailed description of the figures FIGs. 1 a, 1 b, and 1 c show views of a representative schematic of the combustion fireplace (10) according to one embodiment of the invention. FIGs.
1 a and 1 c, showing right and left side views, respectively, show a schematic arrangement of the solid fuel (11) with respect to the inert porous medium (12) inside the combustion fireplace (10). In addition, said figures schematically show the circulation of intake air and combustion gases (13), including the formation of the
and a pore density of at least 20 ppi.
According to an embodiment of the invention, a data acquisition unit is provided, for executing a step of acquiring operation data of the combustion system.
In this context, the present invention makes it possible to generate a combustion process with the active participation of the inert porous medium, which intensifies the heat transfer mechanisms (conduction, convection, and radiation). In addition, the active participation of the inert porous medium allows the air required for the combustion process to be preheated and the volatile combustion gases, product of the devolatilization of the solid fuel, to mix with the air and react rapidly inside the pores.
Brief description of the figures As part of the present invention, the following representative figures of the same are presented, which show preferred configurations of the invention and, therefore, are not to be considered as limiting to the definition of the claimed subject matter.
FIG. 1 a, 1 b, and 1 c show right lateral, front, and left lateral views of a schematic representing the interior of the combustion fireplace, according to one embodiment of the invention.
FIG. 2 is a schematic of the wood combustion process.
Detailed description of the figures FIGs. 1 a, 1 b, and 1 c show views of a representative schematic of the combustion fireplace (10) according to one embodiment of the invention. FIGs.
1 a and 1 c, showing right and left side views, respectively, show a schematic arrangement of the solid fuel (11) with respect to the inert porous medium (12) inside the combustion fireplace (10). In addition, said figures schematically show the circulation of intake air and combustion gases (13), including the formation of the
9 premix (14) that circulates through the inert porous medium (12), for combustion within the pores of said inert porous medium (12).
On the other hand, FIGs. 1 a and 1 c also show an inner plate (15) as a flow control means, in this case represented as a double chamber, which allows directing the circulation of the flow of intake air and combustion gases towards an outlet (16), for the release of unreacted combustion gases, or exhaust gases (17).
On the other hand, FIG. 1 b, which shows the front view of the combustion fireplace (10) scheme, allows to identify how the solid fuel (12) is surrounded by the inert porous medium (12), represented by first and second lateral porous units (12', 12") and by a third rear inert porous unit (12'").
It should be understood that the above figures are representative diagrams of the combustion fireplace, which aim to facilitate the visualization of the components of the combustion system claimed, and not to show a preferred mode of the arrangement or design of said components.
Examples of application By way of example, the present invention is implemented in a combustion system using firewood as a solid fuel. Firewood is not a homogeneous fuel, such as oil or natural gas. Compared to liquid and gaseous fuels, several reaction phases are identified in the wood combustion process:
- Drying of wood:
Initially, the outer surface of the wood receives heat by radiation from the flames, heating the water contained in the wood above its evaporation point.
At this point the drying process begins, releasing the moisture in the form of water vapor.
This drying process consumes an important fraction of the energy released in the combustion process. The higher the initial water content of the firewood, the more energy will be consumed in this drying process and the slower the first step of heating the firewood becomes;
- Gasification and oxidation of the volatile material:
On the other hand, FIGs. 1 a and 1 c also show an inner plate (15) as a flow control means, in this case represented as a double chamber, which allows directing the circulation of the flow of intake air and combustion gases towards an outlet (16), for the release of unreacted combustion gases, or exhaust gases (17).
On the other hand, FIG. 1 b, which shows the front view of the combustion fireplace (10) scheme, allows to identify how the solid fuel (12) is surrounded by the inert porous medium (12), represented by first and second lateral porous units (12', 12") and by a third rear inert porous unit (12'").
It should be understood that the above figures are representative diagrams of the combustion fireplace, which aim to facilitate the visualization of the components of the combustion system claimed, and not to show a preferred mode of the arrangement or design of said components.
Examples of application By way of example, the present invention is implemented in a combustion system using firewood as a solid fuel. Firewood is not a homogeneous fuel, such as oil or natural gas. Compared to liquid and gaseous fuels, several reaction phases are identified in the wood combustion process:
- Drying of wood:
Initially, the outer surface of the wood receives heat by radiation from the flames, heating the water contained in the wood above its evaporation point.
At this point the drying process begins, releasing the moisture in the form of water vapor.
This drying process consumes an important fraction of the energy released in the combustion process. The higher the initial water content of the firewood, the more energy will be consumed in this drying process and the slower the first step of heating the firewood becomes;
- Gasification and oxidation of the volatile material:
10 As the dry wood is heated above the boiling point of water, the second pyrolysis phase begins with the release of volatile matter or devolatilization.
At this step, the firewood begins to smoke. The smoke is the visible result of the thermal decomposition of the firewood and consists mainly of a cloud of combustible droplets of gases and hydrocarbons (tar). These only oxidize under high temperatures and if sufficient oxygen is present. This combustion process with heat release produces long, bright flames, which are characteristic of the combustion of dry firewood.
If the volatile matter is not completely burned inside the stove, unburned gases or exhaust gases will be emitted, which will condense on the cold walls of the exhaust ducts, forming creosote deposits. These unburned compounds will also be emitted later as visible colored smoke with a strong atmospheric pollution in the area. The smoke also represents a loss of efficiency, because it contains a large part of the energy present in the wood.
- Burning of residual charcoal:
When the volatile matter is completely released from the wood, solid coal together with non-combustible ash remains as a residual product. This solid compound is equivalent to wood charcoal and is characterized by its surface combustion with a red glow and very small flame that generates a high temperature between 600 and 1,000 [ C]. Charcoal is a clean fuel that burns easily in the presence of sufficient oxygen without generating smoke, but nevertheless generates carbon monoxide (CO).
In practice, the three above-mentioned phases of wood combustion occur simultaneously. This means that the gases from the volatile matter may be burning with long flames while on the surface of the fuel the charcoal burns with the characteristic red glow and the water in the center of the firewood slowly evaporates.
FIG. 2 shows a schematic of the three phases of wood combustion occurring simultaneously.
To achieve complete combustion of the thermal decomposition products of wood, the following conditions are required, which are summarized in the "3T's" rule known in the technical field of combustion.
At this step, the firewood begins to smoke. The smoke is the visible result of the thermal decomposition of the firewood and consists mainly of a cloud of combustible droplets of gases and hydrocarbons (tar). These only oxidize under high temperatures and if sufficient oxygen is present. This combustion process with heat release produces long, bright flames, which are characteristic of the combustion of dry firewood.
If the volatile matter is not completely burned inside the stove, unburned gases or exhaust gases will be emitted, which will condense on the cold walls of the exhaust ducts, forming creosote deposits. These unburned compounds will also be emitted later as visible colored smoke with a strong atmospheric pollution in the area. The smoke also represents a loss of efficiency, because it contains a large part of the energy present in the wood.
- Burning of residual charcoal:
When the volatile matter is completely released from the wood, solid coal together with non-combustible ash remains as a residual product. This solid compound is equivalent to wood charcoal and is characterized by its surface combustion with a red glow and very small flame that generates a high temperature between 600 and 1,000 [ C]. Charcoal is a clean fuel that burns easily in the presence of sufficient oxygen without generating smoke, but nevertheless generates carbon monoxide (CO).
In practice, the three above-mentioned phases of wood combustion occur simultaneously. This means that the gases from the volatile matter may be burning with long flames while on the surface of the fuel the charcoal burns with the characteristic red glow and the water in the center of the firewood slowly evaporates.
FIG. 2 shows a schematic of the three phases of wood combustion occurring simultaneously.
To achieve complete combustion of the thermal decomposition products of wood, the following conditions are required, which are summarized in the "3T's" rule known in the technical field of combustion.
11 - Temperature: The minimum temperature required to be maintained inside a fireplace to ensure complete combustion of the gaseous products should be as high as possible. Literature indicates average values in the combustion zone from minimum 800 C to maximum 1,000 C.
- Time: To achieve complete combustion, a minimum residence time of the combustion gases inside the fireplace must be guaranteed. For example, if temperatures above 900 C are present, the minimum residence time must exceed 0.5 seconds.
- Turbulence: The last condition necessary to ensure optimum combustion is related to intense turbulence required to mix oxygen with the volatile matter in combustion. To intensify this mixing process, it is customary to inject preheated secondary air directly into the combustion zone above the fuel bed.
Only by complying with these three basic rules of minimum temperature, minimum residence time, and high turbulence can the conditions for optimum combustion of fire fuel with minimum emission of pollutants be created. The challenge of an optimal design of a fireplace or a stove is to combine these three basic conditions allowing to always guarantee a complete combustion, minimizing the emission of pollutants. In particular, the characteristics of humidity, density, size, and species of wood must be considered in order to correctly dimension the volume and shape of the combustion chamber. This is the only way to achieve high efficiencies and clean exhaust gases without the presence of visible smoke.
Then, with the application of the inert porous medium inside the stove, the temperature of the combustion fireplace is increased, which produces an improvement in the combustion of wood.
Based on the above, and having as a base test the process of firewood combustion without inert porous media, two tests of inert porous media configurations inside the same combustion fireplace are conducted.
Test 1 In this context, in the present test, a residential heater equivalent to that of the base test was used, and the solid fuel to be placed inside the combustion
- Time: To achieve complete combustion, a minimum residence time of the combustion gases inside the fireplace must be guaranteed. For example, if temperatures above 900 C are present, the minimum residence time must exceed 0.5 seconds.
- Turbulence: The last condition necessary to ensure optimum combustion is related to intense turbulence required to mix oxygen with the volatile matter in combustion. To intensify this mixing process, it is customary to inject preheated secondary air directly into the combustion zone above the fuel bed.
Only by complying with these three basic rules of minimum temperature, minimum residence time, and high turbulence can the conditions for optimum combustion of fire fuel with minimum emission of pollutants be created. The challenge of an optimal design of a fireplace or a stove is to combine these three basic conditions allowing to always guarantee a complete combustion, minimizing the emission of pollutants. In particular, the characteristics of humidity, density, size, and species of wood must be considered in order to correctly dimension the volume and shape of the combustion chamber. This is the only way to achieve high efficiencies and clean exhaust gases without the presence of visible smoke.
Then, with the application of the inert porous medium inside the stove, the temperature of the combustion fireplace is increased, which produces an improvement in the combustion of wood.
Based on the above, and having as a base test the process of firewood combustion without inert porous media, two tests of inert porous media configurations inside the same combustion fireplace are conducted.
Test 1 In this context, in the present test, a residential heater equivalent to that of the base test was used, and the solid fuel to be placed inside the combustion
12 chamber of said heater was prepared in a manner equivalent to that of the base test. Since the useful volume of the fireplace or combustion chamber of the tested heater does not exceed 0.02 m3, three pieces of eucalyptus wood of 0.25 m length were dimensioned, with variable width to achieve the mass required for the test, according to the useful volume of the combustion chamber, based on a volumetric load density of 112 11.2 kg/m3.
In contrast to the base test, an inert porous medium of Silicon Carbide (SiC) material was incorporated in the form of a 200 mm diameter, 30 mm thick, 82.5%
porosity disc. For this example, the SiC disc was placed horizontally on the bottom wall of the fireplace, with the firewood load on top of the disc. Using this configuration, it is expected that the disc will generate a preheating of the primary air that rises through the heater and passes through the fuel, to improve the oxidation of the wood, decrease the evaporation time of the moisture present in the wood, and decrease the cooling in the combustion chamber caused by the entry of cold air, in addition to delivering heat by conduction and radiation to the fuel.
Test 2 In this test, unlike test 1, two half-discs were used, prepared from a disc of the same dimensions as in example 1, which were positioned between the logs of the test load inside the combustion chamber. Using this configuration, it is expected that the half-discs, by means of conduction and radiation, deliver heat to the fuel, preheating the air-fuel mixture, in addition to providing heat to the combustion gases that rise between the spaces between one log and the other.
Conclusions The heat delivered by the combustion of firewood to the environment through the walls of the heater was significantly higher when using the inert porous medium, reaching a maximum of approximately 1,000 W, compared to the maximum of 500 W of the heater without inert porous medium, using maximum air intake. This is due to the increase in the average temperature of the combustion chamber when using inert porous media, which causes a higher heat flow by radiation and convection to the environment. The increase in the heater wall temperature is due to the heat
In contrast to the base test, an inert porous medium of Silicon Carbide (SiC) material was incorporated in the form of a 200 mm diameter, 30 mm thick, 82.5%
porosity disc. For this example, the SiC disc was placed horizontally on the bottom wall of the fireplace, with the firewood load on top of the disc. Using this configuration, it is expected that the disc will generate a preheating of the primary air that rises through the heater and passes through the fuel, to improve the oxidation of the wood, decrease the evaporation time of the moisture present in the wood, and decrease the cooling in the combustion chamber caused by the entry of cold air, in addition to delivering heat by conduction and radiation to the fuel.
Test 2 In this test, unlike test 1, two half-discs were used, prepared from a disc of the same dimensions as in example 1, which were positioned between the logs of the test load inside the combustion chamber. Using this configuration, it is expected that the half-discs, by means of conduction and radiation, deliver heat to the fuel, preheating the air-fuel mixture, in addition to providing heat to the combustion gases that rise between the spaces between one log and the other.
Conclusions The heat delivered by the combustion of firewood to the environment through the walls of the heater was significantly higher when using the inert porous medium, reaching a maximum of approximately 1,000 W, compared to the maximum of 500 W of the heater without inert porous medium, using maximum air intake. This is due to the increase in the average temperature of the combustion chamber when using inert porous media, which causes a higher heat flow by radiation and convection to the environment. The increase in the heater wall temperature is due to the heat
13 transfer phenomenon present between the air-fuel premix reaction and the inert porous medium, which generates an increase in the temperature of the inert porous medium due to the heat transferred from the air-fuel premix reaction, resulting in an increase in the combustion fireplace temperature.
In this context, the configuration of test 2 has a better performance with respect to CO emission compared to the configuration of test 1. This difference is due to the configuration of the inert porous media in each test, inside the combustion chamber, since in test 2 said inert porous media covers a greater height of the fireplace, also causing a heat transfer by convection from the reaction of the air-fuel premix to the porous media, so that the combustion gases when ascending and coming into contact with the ceramic half-discs increase their temperature and burn again lowering the CO concentration. In addition, the configuration of test 1, with the inert porous medium under the solid fuel, causes the pores to become saturated when ash is produced during the combustion process, hindering the circulation of the air-fuel premix through said inert porous medium.
In this context, the base test, which does not use inert porous medium, shows a thermal efficiency of 68.91 %, while test 1 shows an efficiency of 81.41 %
and test 2 shows an efficiency of 91.04 %. Then, it is demonstrated that the use of inert porous media considerably improves the thermal efficiency of the tested wood-fired heater, as well as it is demonstrated that positioning the inert porous media towards the side walls of the heater, between the solid fuel and said walls, is advantageous over positioning the inert porous media under the solid fuel.
In this context, the configuration of test 2 has a better performance with respect to CO emission compared to the configuration of test 1. This difference is due to the configuration of the inert porous media in each test, inside the combustion chamber, since in test 2 said inert porous media covers a greater height of the fireplace, also causing a heat transfer by convection from the reaction of the air-fuel premix to the porous media, so that the combustion gases when ascending and coming into contact with the ceramic half-discs increase their temperature and burn again lowering the CO concentration. In addition, the configuration of test 1, with the inert porous medium under the solid fuel, causes the pores to become saturated when ash is produced during the combustion process, hindering the circulation of the air-fuel premix through said inert porous medium.
In this context, the base test, which does not use inert porous medium, shows a thermal efficiency of 68.91 %, while test 1 shows an efficiency of 81.41 %
and test 2 shows an efficiency of 91.04 %. Then, it is demonstrated that the use of inert porous media considerably improves the thermal efficiency of the tested wood-fired heater, as well as it is demonstrated that positioning the inert porous media towards the side walls of the heater, between the solid fuel and said walls, is advantageous over positioning the inert porous media under the solid fuel.
Claims (22)
1. A solid fuel combustion system, CHARACTERIZED in that it comprises:
- a combustion fireplace containing solid fuel in its interior, wherein said solid fuel is subjected to a combustion process inside the combustion fireplace, generating combustion gases;
- an inert porous medium placed inside the combustion fireplace, wherein said inert porous medium is in the proximity of the solid fuel; and - flow control means placed in the combustion fireplace, wherein said flow control means are placed to control the operation of:
o at least one air inlet placed in the combustion fireplace, configured to inject intake air into the combustion fireplace; and o at least one gas outlet placed in the combustion fireplace, configured to release unreacted combustion gases to the outside of the combustion fireplace, in the form of exhaust gases;
wherein said flow control means are configured to generate a flow of intake air and combustion gases between the at least one air inlet and the at least one exhaust gas outlet, forming a premix of intake air and combustion gases inside the combustion fireplace; and wherein said flow control means and said inert porous medium are configured to circulate said premix through the inert porous medium, in particular through the pores of said inert porous medium, causing preheating of the intake air and acceleration of the reaction of the combustion gases inside said pores, combusting the premix inside the pores of the inert porous medium.
- a combustion fireplace containing solid fuel in its interior, wherein said solid fuel is subjected to a combustion process inside the combustion fireplace, generating combustion gases;
- an inert porous medium placed inside the combustion fireplace, wherein said inert porous medium is in the proximity of the solid fuel; and - flow control means placed in the combustion fireplace, wherein said flow control means are placed to control the operation of:
o at least one air inlet placed in the combustion fireplace, configured to inject intake air into the combustion fireplace; and o at least one gas outlet placed in the combustion fireplace, configured to release unreacted combustion gases to the outside of the combustion fireplace, in the form of exhaust gases;
wherein said flow control means are configured to generate a flow of intake air and combustion gases between the at least one air inlet and the at least one exhaust gas outlet, forming a premix of intake air and combustion gases inside the combustion fireplace; and wherein said flow control means and said inert porous medium are configured to circulate said premix through the inert porous medium, in particular through the pores of said inert porous medium, causing preheating of the intake air and acceleration of the reaction of the combustion gases inside said pores, combusting the premix inside the pores of the inert porous medium.
2. The system according to claim 1, CHARACTERIZED in that the operation of the at least one air intake is controlled according to the desired amount of air for the combustion process.
3. The system according to any one of claims 1-2, CHARACTERIZED in that the operation of the at least one air inlet and/or the at least one exhaust gas outlet are controlled according to the desired premix circulation through the inert porous medium.
4. The system according to any one of claims 1-3, CHARACTERIZED in that the solid fuel comprises two or more solid units having different dimensions, randomly positioned inside the combustion fireplace.
5. The system according to any one of claims 1-4, CHARACTERIZED in that the inert porous medium comprises at least one inert porous unit placed in physical contact with the solid fuel.
6. The system according to claim 5, CHARACTERIZED in that the inert porous medium comprises two or more inert porous units, said two or more inert porous units placed inside the combustion fireplace in different positions, which ensure physical contact with the solid fuel.
7. The system according to claim 6, CHARACTERIZED in that a first inert porous unit is positioned between the solid fuel and a side wall of the combustion fireplace, and in that a second inert porous unit is positioned between the solid fuel and another side wall of the combustion fireplace.
8. The system according to claim 7, CHARACTERIZED in that a third inert porous unit is positioned between the solid fuel and a rear wall of the combustion fireplace.
9. The system according to any one of claims 1-8, CHARACTERIZED in that the solid fuel is selected from biomass, coal, or a combination thereof.
10. The system according to any one of claims 1-9, CHARACTERIZED in that the inert porous medium is made of a ceramic material, having a porosity of at least 50% and a pore density of at least 20 ppi.
11. The system according to any one of claims 1-10, CHARACTERIZED in that it further comprises a data acquisition unit, for acquiring combustion system operation data.
12. A method of combustion of solid fuels, CHARACTERIZED in that it comprises the following steps:
a) placing solid fuel and an inert porous medium inside a combustion fireplace of a solid fuel combustion system, wherein the inert porous medium is placed in the proximity of the solid fuel;
b) injecting intake air into the combustion fireplace through at least one air inlet placed in the combustion fireplace, wherein the injection of said intake air is controlled by flow control means placed in the combustion fireplace;
c) igniting the solid fuel, subjecting said solid fuel to a combustion process inside the combustion fireplace;
d) generating a flow of intake air and combustion gases between the at least one air inlet and at least one exhaust gas outlet also placed in the combustion fireplace, wherein said flow of intake air and combustion gases is controlled by said flow control means, forming a premix of intake air and combustion gases inside the combustion fireplace;
e) circulating the premix through the inert porous medium, in particular, through the pores of said inert porous medium, to preheat the intake air and accelerate the reaction of the combustion gases within said pores, wherein the circulation of the premix is controlled by said flow control means and said inert porous medium, and wherein said premix is combusted inside the pores of the inert porous medium; and f) releasing unreacted combustion gases to the outside of the combustion fireplace, in the form of exhaust gases, wherein the release of said exhaust gases is controlled by said flow control means.
a) placing solid fuel and an inert porous medium inside a combustion fireplace of a solid fuel combustion system, wherein the inert porous medium is placed in the proximity of the solid fuel;
b) injecting intake air into the combustion fireplace through at least one air inlet placed in the combustion fireplace, wherein the injection of said intake air is controlled by flow control means placed in the combustion fireplace;
c) igniting the solid fuel, subjecting said solid fuel to a combustion process inside the combustion fireplace;
d) generating a flow of intake air and combustion gases between the at least one air inlet and at least one exhaust gas outlet also placed in the combustion fireplace, wherein said flow of intake air and combustion gases is controlled by said flow control means, forming a premix of intake air and combustion gases inside the combustion fireplace;
e) circulating the premix through the inert porous medium, in particular, through the pores of said inert porous medium, to preheat the intake air and accelerate the reaction of the combustion gases within said pores, wherein the circulation of the premix is controlled by said flow control means and said inert porous medium, and wherein said premix is combusted inside the pores of the inert porous medium; and f) releasing unreacted combustion gases to the outside of the combustion fireplace, in the form of exhaust gases, wherein the release of said exhaust gases is controlled by said flow control means.
13. The method according to claim 12, CHARACTERIZED in that the step of injecting intake air is controlled according to the amount of air desired for the combustion process.
14. The method according to any one of claims 12-13, CHARACTERIZED in that the step of injecting intake air and/or the step of releasing exhaust gases are controlled according to the desired premix circulation through the inert porous medium.
15. The method according to any one of claims 12-14, CHARACTERIZED in that the step of placing the solid fuel comprises placing two or more solid units forming said solid fuel, wherein said solid units have different dimensions and are randomly positioned inside the combustion fireplace.
16. The method according to any one of claims 12-15, CHARACTERIZED in that the step of placing the inert porous medium inside the combustion fireplace comprises placing at least one inert porous unit inside the combustion fireplace in physical contact with the solid fuel.
17. The method according to claim 16, CHARACTERIZED in that the step of placing the inert porous medium inside the combustion fireplace comprises placing two or more inert porous units inside the combustion fireplace, said two or more inert porous units placed inside the combustion fireplace in different positions, which ensure physical contact with the solid fuel.
18. The method according to claim 17, CHARACTERIZED in that a first inert porous unit is positioned between the solid fuel and a side wall of the combustion fireplace, and in that a second inert porous unit is positioned between the solid fuel and another side wall of the combustion fireplace.
19. The method according to claim 18, CHARACTERIZED in that a third inert porous unit is positioned between the solid fuel and a rear wall of the combustion fireplace.
20. The method according to any one of claims 12-19, CHARACTERIZED in that the solid fuel is selected from biomass, coal, or a combination thereof.
21. The method according to any one of claims 12-20, CHARACTERIZED in that the inert porous medium is made of a ceramic material, having a porosity of at least 50% and a pore density of at least 20 ppi.
22.
The method according to any one of claims 12-21, CHARACTERIZED in that it further comprises the step of acquiring combustion system operation data, by means of a data acquisition unit.
The method according to any one of claims 12-21, CHARACTERIZED in that it further comprises the step of acquiring combustion system operation data, by means of a data acquisition unit.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CL3683-2019 | 2019-12-16 | ||
| CL2019003683A CL2019003683A1 (en) | 2019-12-16 | 2019-12-16 | System and method to improve the combustion process of a solid fuel using an inert porous medium. |
| PCT/CL2020/050179 WO2021119871A1 (en) | 2019-12-16 | 2020-12-15 | System and method for improving the combustion process of a solid fuel by means of an inert porous medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA3168332A1 true CA3168332A1 (en) | 2021-06-24 |
Family
ID=70457335
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA3168332A Pending CA3168332A1 (en) | 2019-12-16 | 2020-12-15 | System and method for improving the combustion process of a solid fuel by means of an inert porous medium |
Country Status (4)
| Country | Link |
|---|---|
| CA (1) | CA3168332A1 (en) |
| CL (1) | CL2019003683A1 (en) |
| PE (1) | PE20221616A1 (en) |
| WO (1) | WO2021119871A1 (en) |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4574774A (en) * | 1984-10-09 | 1986-03-11 | Wells Harold D | Fireplace accessory |
| US6237587B1 (en) * | 1999-08-05 | 2001-05-29 | Temeku Technologies Inc. | Woodburning fireplace exhaust catalytic cleaner |
| US8622054B1 (en) * | 2007-03-13 | 2014-01-07 | Clear Skies Unlimited, Inc. | Methods and systems for reducing combustion emissions |
| DE202007006055U1 (en) * | 2007-04-25 | 2007-12-27 | Hark Gmbh & Co. Kg Kamin- Und Kachelofenbau | Fireplace hearth |
| NL2001058C2 (en) * | 2007-12-05 | 2009-06-08 | D & J Holding B V | Fireplace and method for cleaning combustion gases from a fire. |
| CN102213447A (en) * | 2011-05-25 | 2011-10-12 | 浙江工业大学 | Solid fuel energy-saving and environment-friendly fireplace |
| CL2012003372A1 (en) * | 2012-11-30 | 2013-08-09 | Univ Santiago Chile | Post combustor to increase thermal efficiency and reduce the emission of pollutants from wood heating equipment that have a combustion chamber, has a plurality of layers of solid particles that generate a porous medium and are contained in an inner container that has at least one lower opening for the inlet gases, and at least one upper opening for the outlet gases; and associated method. |
| CA2941234A1 (en) * | 2014-03-05 | 2015-09-11 | Lance Carl Grace | Emission reduction device for a wood heater |
| KR20160141097A (en) * | 2015-05-28 | 2016-12-08 | 여은석 | The stove of high efficiency |
| JP2018021738A (en) * | 2016-08-05 | 2018-02-08 | 登美夫 望月 | Heater |
-
2019
- 2019-12-16 CL CL2019003683A patent/CL2019003683A1/en unknown
-
2020
- 2020-12-15 PE PE2022001112A patent/PE20221616A1/en unknown
- 2020-12-15 CA CA3168332A patent/CA3168332A1/en active Pending
- 2020-12-15 WO PCT/CL2020/050179 patent/WO2021119871A1/en active Application Filing
Also Published As
| Publication number | Publication date |
|---|---|
| PE20221616A1 (en) | 2022-10-12 |
| CL2019003683A1 (en) | 2020-04-17 |
| WO2021119871A1 (en) | 2021-06-24 |
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