A low-NOx emission aluminum aging furnace

Abstract

This invention discloses a low-NOx emission aluminum aging furnace, comprising an independent combustion chamber and a profile heating chamber. Burners are mounted on the walls of the combustion chamber, and a heat exchanger is arranged in the profile heating chamber. The heat exchanger is connected to the combustion chamber via a hot air duct. An exhaust pipe is installed at the end of the heat exchanger furthest from the hot air duct, and an exhaust fan is installed at the end of the exhaust pipe. This invention innovatively separates the combustion chamber and the profile heating chamber, utilizing a heat exchanger to complete the heat transfer process from the combustion chamber to the profile heating chamber. The air in the profile heating chamber is isolated from the gas in the combustion chamber, preventing the combination of water and oil to form nitrogen oxides. This results in good combustion temperature circulation, a relatively low combustion temperature, and reduced nitrogen oxide production, making it highly promising for application.

Description

Technical Field

[0001] This invention relates to the technical field of aluminum aging heat treatment equipment, and specifically to a low-NOx emission aluminum aging furnace. Background Technology

[0002] An aluminum aging furnace is a specialized equipment for aging heat treatment of aluminum castings after solution treatment. Specifically, it is used to perform aging heat treatment on aluminum castings, aluminum profiles and wires, aluminum plates, aluminum mesh plates, etc., under a stable and uniform high temperature.

[0003] In the aluminum processing process, any material must undergo heating and / or heat treatment once or several times during production. When the combustion temperature of natural gas is higher than 1500℃, it will cause nitrogen and oxygen in the air to combine to form nitrogen oxides. With the continuous advancement of energy conservation and emission reduction, the emission requirements for pollutants such as nitrogen oxides are becoming increasingly stringent. Gas boilers and other equipment that use natural gas for combustion will inevitably produce nitrogen oxides. If the nitrogen oxide concentration is too high, nitrogen oxide adsorption / catalysis devices are needed to reduce the nitrogen oxide content in the exhaust gas. The reasons for the high concentration of nitrogen oxides produced by gas boiler combustion equipment are as follows: (1) When the fuel and air mixture enters the furnace of the gas boiler, the temperature of the mixture rises rapidly due to the convection and radiation heating of the surrounding high-temperature flue gas. When the ignition temperature is reached, the fuel begins to burn, and the temperature rises sharply to near the adiabatic temperature level. Due to the convection and radiation heat exchange between the flue gas and the surrounding medium, the temperature gradually decreases until it is the same as the temperature of the surrounding medium, that is, the flue gas flows through the entire furnace while cooling. The higher the temperature, the more nitrogen oxides are generated. Analysis of the causes of nitrogen oxide generation reveals that, in order to suppress nitrogen oxide generation, in addition to reducing the average temperature inside the furnace, it is also necessary to make the temperature distribution inside the furnace uniform and avoid localized high temperatures.

[0004] For aluminum aging furnaces, the combustion and heating sections are located in the same space. The burners are usually mounted on the furnace wall and directly ignite for heating. This inevitably leads to uneven combustion temperature circulation. Although aging furnaces are often equipped with temperature equalization devices such as circulating fans, they cannot fundamentally solve the problem of uneven combustion temperature circulation. In addition, natural gas, as a fuel, produces water after combustion. This water combines with oil stains left during aluminum processing to generate polluting gases such as nitrogen oxides, which will also deposit and contaminate the surface of the profiles.

[0005] Therefore, developing an aluminum aging furnace that achieves low nitrogen emissions is of great practical significance. Summary of the Invention

[0006] Due to the aforementioned defects in existing technologies, this invention provides an aluminum aging furnace that achieves low nitrogen emissions, overcoming the shortcomings of existing aluminum aging furnaces, such as uneven combustion temperature circulation and excessively high nitrogen oxide concentrations in exhaust gas caused by hot gas (water vapor) directly reacting with oil to generate nitrogen oxides.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A low-NOx emission aluminum aging furnace includes an independent combustion chamber and a profile heating chamber.

[0009] Burners are installed on the walls of the combustion chamber, and a heat exchanger is arranged inside the profile heating chamber. The heat exchanger is connected to the combustion chamber through a hot air pipe. An exhaust pipe is installed at the end of the heat exchanger away from the hot air pipe, and an exhaust fan is installed at the end of the exhaust pipe.

[0010] This invention relates to a low-NOx emission aluminum aging furnace, which innovatively separates the combustion chamber and the profile heating chamber (in existing furnaces, these are interconnected spaces). A heat exchanger is used to transfer heat from the combustion chamber to the profile heating chamber. The air in the profile heating chamber is isolated from the gas in the combustion chamber. During furnace operation, the air in the profile heating chamber does not undergo compositional changes due to reactions in the combustion chamber (such as changes in moisture concentration). This prevents the combination of water and oil to form nitrogen oxides. Furthermore, the separation of the combustion chamber and the profile heating chamber ensures stable reactions within the combustion chamber. Compared to furnaces where the combustion chamber and profile heating chamber are combined, the combustion chamber is a space specifically designed for combustion, resulting in better combustion temperature circulation. The gas in the combustion chamber is discharged immediately after heat exchange via the heat exchanger, minimizing its potential contact with other reactants before discharge. This allows for better control of the combustion temperature and reduces the generation of nitrogen oxides, making it highly promising for future applications.

[0011] As a preferred technical solution:

[0012] As described above, in a low-NOx emission aluminum aging furnace, one end of the hot air pipe is connected to a hot air outlet on the wall of the combustion chamber, and the other end is connected to the heat source inlet of the heat exchanger.

[0013] In the low-NOx emission aluminum aging furnace described above, the hot air outlet is located on the wall of the combustion chamber away from the burner. The hot air here is hot gas that has been fully circulated in the combustion chamber, which can avoid affecting the combustion at the burner.

[0014] In the low-NOx emission aluminum aging furnace described above, the opening direction of the hot air outlet is perpendicular to the arrangement direction of the burners.

[0015] As described above, in a low-NOx emission aluminum aging furnace, the combustion chamber is located above the profile heating chamber, with the combustion chamber positioned in the middle of the profile heating chamber and symmetrical to it. This structural design is reasonable, facilitating the arrangement of heat exchangers, exhaust pipes, and hot air pipes. It not only ensures the uniformity of temperature within the profile heating chamber but also reduces the length of exhaust pipes and hot air pipes, thereby lowering costs.

[0016] As described above, in a low-NOx emission aluminum aging furnace, there are two sets of heat exchangers, and the two sets of heat exchangers are symmetrically arranged on both sides of the profile heating chamber relative to the combustion chamber.

[0017] As described above, in a low-NOx emission aluminum aging furnace, the exhaust pipes of all heat exchangers are connected into a single exhaust manifold, and an exhaust fan is installed at the connection point between the exhaust manifold and the outside. By controlling the airflow using the exhaust fan, the temperature of the profile heating chamber can be controlled, and the hot air in the combustion chamber can be discharged, ensuring uniform combustion temperature circulation in the combustion chamber.

[0018] In the low-NOx emission aluminum aging furnace described above, all heat exchangers are arranged on the same side of the profile heating chamber.

[0019] As described above, in a low-NOx emission aluminum aging furnace, one or more profile conveying devices are installed in the profile heating chamber, and the profile conveying devices are arranged on the side of the profile heating chamber where no heat exchanger is arranged.

[0020] The above technical solution is only one feasible technical solution of the present invention. The scope of protection of the present invention is not limited thereto. Those skilled in the art can reasonably adjust the specific design according to actual needs.

[0021] The above invention has the following advantages or beneficial effects:

[0022] (1) The low-NOx emission aluminum aging furnace of the present invention is the first in the field of aluminum aging furnaces to separate the combustion chamber and the profile heating chamber (the combustion chamber and the profile heating chamber in the present invention are connected spaces). The heat exchanger is used to complete the heat transfer process from the combustion chamber to the profile heating chamber. The air in the profile heating chamber is isolated from the gas in the combustion chamber. During the operation of the aging furnace, the air in the profile heating chamber will not change its composition due to the reaction in the combustion chamber (such as the change of moisture concentration in the air). This can avoid the combination of water and oil stains to generate nitrogen oxides, and also avoid the contamination of the profile by impurities from combustion.

[0023] (2) The low-NOx emission aluminum aging furnace of the present invention has a separate combustion chamber and a profile heating chamber. The reaction in the combustion chamber is stable. Compared with the combustion chamber and profile heating chamber being together, the combustion chamber is a space specifically designed for combustion. Its combustion temperature circulation is good. The gas in the combustion chamber is discharged after heat exchange by the heat exchanger. That is, before it is discharged, the possibility of it coming into contact with other reactants is minimized, which can better control the combustion temperature and reduce the generation of nitrogen oxides.

[0024] (3) The low-NOx emission aluminum aging furnace of the present invention has a low concentration of nitrogen oxides in the exhaust gas (<30mg / m³). 3 The flue gas temperature is stable, making it a promising technology for application. Attached Figure Description

[0025] The invention, its features, shape, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Like reference numerals denote like parts throughout the drawings. The drawings are not drawn to scale; the emphasis is on illustrating the main points of the invention.

[0026] Figure 1 and 2 These are, respectively, the front view and the top view of the low-NOx emission aluminum aging furnace of the present invention;

[0027] Figure 3 and 4 They are respectively Figure 1 Cross-sectional view of positions AA and BB;

[0028] Among them, 1-combustion chamber, 2-hot air duct, 3-heat exchanger, 4-profile heating chamber, 5-burner, 6-exhaust pipe, 7-exhaust fan. Detailed Implementation

[0029] The structure of the present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0030] Example 1

[0031] A low-NOx emission aluminum aging furnace, such as Figures 1-4 As shown, it includes an independent combustion chamber 1 and a profile heating chamber 4. The combustion chamber 1 is located above the profile heating chamber 4, and the combustion chamber 1 is arranged in the middle of the profile heating chamber 4, with the profile heating chamber 4 being symmetrical to the combustion chamber 1.

[0032] A burner 5 is installed on the wall of the combustion chamber 1. A hot air outlet is opened on the wall of the combustion chamber 1 away from the burner 5, and the opening direction of the hot air outlet is perpendicular to the arrangement direction of the burner 5. A hot air pipe is installed at the hot air outlet.

[0033] Two sets of heat exchangers 3 are arranged in the profile heating chamber 4 (the two sets of heat exchangers 3 are symmetrically arranged on both sides of the profile heating chamber 4 relative to the combustion chamber 1, and all heat exchangers 3 are arranged on the same side of the profile heating chamber 4. There is also one or more profile conveying devices installed in the profile heating chamber 4, and the profile conveying devices are arranged on the side of the profile heating chamber 4 where the heat exchangers 3 are not arranged). The heat source inlet of the heat exchanger 3 is connected to the hot air outlet of the combustion chamber 1 through the hot air pipe 2. The end of the heat exchanger 3 away from the hot air pipe 2 is equipped with a smoke exhaust pipe 6. All the smoke exhaust pipes 6 of the heat exchangers 3 are connected to form a smoke exhaust main pipe, and a smoke exhaust fan 7 is installed at the connection point between the smoke exhaust main pipe and the outside.

[0034] In actual operation, the low-NOx emission aluminum aging furnace of this invention monitors the flue gas discharged from the end of the exhaust manifold in real time, and the concentration of nitrogen oxides in the flue gas is maintained at 30 mg / m³. 3 The flue gas temperature was maintained at 280±5℃. The stability of the flue gas exhaust temperature reflects the stability of the combustion reaction in the combustion chamber. The above tests show that the aluminum aging furnace can achieve low nitrogen emissions and separate the profile from the combustion medium (without contaminating the profile).

[0035] Verification has shown that the low-NOx emission aluminum aging furnace of this invention is the first in the field of aluminum aging furnaces to separate the combustion chamber and the profile heating chamber (in existing furnaces, the combustion chamber and profile heating chamber are interconnected spaces). A heat exchanger is used to complete the heat transfer process from the combustion chamber to the profile heating chamber. The air in the profile heating chamber is isolated from the gas in the combustion chamber. During furnace operation, the air in the profile heating chamber will not undergo compositional changes due to reactions in the combustion chamber (such as changes in air moisture concentration), thus preventing the combination of water and oil to form nitrogen oxides and avoiding contamination of the profile by impurities from combustion. The separation of the combustion chamber and the profile heating chamber ensures stable reactions within the combustion chamber. Compared to furnaces where the combustion chamber and profile heating chamber are combined, the combustion chamber is a space specifically designed for combustion, resulting in better combustion temperature circulation. The gas in the combustion chamber is discharged immediately after heat exchange via the heat exchanger, minimizing its contact with other reactants before discharge, thus better controlling the combustion temperature and reducing nitrogen oxide production. The nitrogen oxide concentration in the exhaust gas is low (<30 mg / m³). 3 The flue gas temperature is stable, making it a promising technology for application.

[0036] Those skilled in the art should understand that variations can be implemented by combining existing technology with the above embodiments, which will not be elaborated here. Such variations do not affect the essence of the present invention, and will not be elaborated here either.

[0037] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a conventional manner in the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention's technical solutions still fall within the protection scope of the present invention.

Claims

1. A low-NOx emission aluminum aging furnace, characterized in that: This includes independent combustion chambers and profile heating chambers; Burners are installed on the walls of the combustion chamber, and a heat exchanger is arranged inside the profile heating chamber. The heat exchanger is connected to the combustion chamber through a hot air pipe. An exhaust pipe is installed at the end of the heat exchanger away from the hot air pipe, and an exhaust fan is installed at the end of the exhaust pipe. The combustion chamber is located above the profile heating chamber, and the combustion chamber is arranged in the middle of the profile heating chamber and is symmetrical to the combustion chamber. One end of the hot air duct is connected to a hot air outlet on the wall of the combustion chamber, and the other end is connected to the heat source inlet of the heat exchanger. The hot air outlet is located on the wall of the combustion chamber away from the burner; The opening direction of the hot air outlet is perpendicular to the arrangement direction of the burner; There are two sets of heat exchangers, and the two sets of heat exchangers are symmetrically arranged on both sides of the profile heating chamber relative to the combustion chamber.

2. The low-NOx emission aluminum aging furnace according to claim 1, characterized in that, All the exhaust pipes of the heat exchangers are connected into a single exhaust manifold, and an exhaust fan is installed at the connection point between the exhaust manifold and the outside.

3. The low-NOx emission aluminum aging furnace according to claim 2, characterized in that, The profile heating chamber is also equipped with one or more profile conveying devices, and the profile conveying devices are arranged on the side of the profile heating chamber where no heat exchanger is arranged.

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