Combustion-supporting air heating process for belt type roasting machine

Abstract

The invention relates to the field of pellet production in the ferrous metallurgical industry, in particular to a belt type roasting machine combustion-supporting air heating process which comprises the steps that S1, power is provided through a belt type roasting machine burner combustion-supporting fan, and normal-temperature combustion-supporting air is conveyed to a cooling outer cavity of a belt type roasting machine; s2, when the normal-temperature combustion-supporting air flows through the cooling outer cavity of the belt type roasting machine, the normal-temperature combustion-supporting air exchanges heat with the inner wall of the cooling outer cavity of the belt type roasting machine, heat dissipated to the cooling outer cavity in the running process of belt type roasting machine equipment is absorbed, and therefore the temperature of the normal-temperature combustion-supporting air is increased, and the normal-temperature combustion-supporting air is converted into high-temperature combustion-supporting air; s3, the high-temperature combustion-supporting air obtained in the step S2 is guided to a burner of a belt type roasting machine; and S4, the high-temperature combustion-supporting air is mixed with fuel in a burner of the belt type roasting machine and participates in a combustion reaction. The heat dissipation energy of the outer surface of the belt type roasting machine is effectively utilized, and meanwhile the effect of reducing the environment temperature in a plant is achieved.

Description

Technical Field

[0001] The present application relates to the field of pellet production in the iron and steel metallurgical industry, and in particular to a belt roaster combustion air heating process. Background Art

[0002] In the modern steel industry, the belt roaster process, the mainstream production technology for iron ore pellets, undertakes the critical task of transforming iron ore concentrate powder into high-quality pellets through drying, preheating, roasting, and cooling. This process requires a temperature gradient within the equipment, ranging from room temperature to approximately 1300°C. To ensure structural stability and minimize heat loss, traditional technologies typically utilize refractory masonry insulation within the belt roaster. However, due to limitations in the material's thermal conductivity and the masonry process, heat spillage from the equipment's exterior remains a significant issue.

[0003] Field measurements show that the average surface temperature of the belt roaster is generally 80-120°C higher than the ambient temperature, causing the surrounding factory temperature to remain at a constant 40-50°C, with local hot spots exceeding 60°C. This high temperature environment not only seriously affects the occupational health and safety of on-site operators, but also accelerates the aging and failure of surrounding electrical equipment and testing instruments, increasing equipment maintenance costs. Furthermore, heat loss from the external surface accounts for 8%-12% of the belt roaster's total energy consumption, resulting in significant energy waste.

[0004] Existing technologies address heat dissipation in industrial kilns and furnaces by optimizing insulation performance or increasing the thickness of insulation layers. However, these approaches present significant limitations for long, mobile equipment like belt roasters. For one thing, excessively thick insulation layers increase the weight of the equipment and occupy limited factory space. Furthermore, the cyclical motion of the roaster trolley can easily crack the insulation structure, exacerbating heat leakage. Actively recycling heat dissipated from external surfaces currently lacks a mature technical solution in the steel industry. Summary of the Invention

[0005] In order to effectively utilize the heat dissipation energy of the outer surface of the belt roaster while reducing the ambient temperature in the factory, the present application provides a belt roaster combustion air heating process.

[0006] The present application provides a belt roaster combustion air heating process, which adopts the following technical solutions:

[0007] A belt roaster combustion air heating process, comprising the following steps:

[0008] S1. Powered by the belt roaster burner combustion fan, the room temperature combustion air is delivered to the belt roaster cooling outer cavity;

[0009] S2. The room temperature combustion air flows through the belt roaster cooling outer cavity, and the inner wall of the belt roaster cooling outer cavity performs heat exchange, absorbing the heat dissipated to the cooling outer cavity during the operation of the belt roaster equipment, thereby increasing the temperature of the room temperature combustion air and converting it into a high temperature combustion air;

[0010] S3. The high-temperature combustion air obtained in step S2 is guided to the belt roaster burner;

[0011] S4. The high-temperature combustion-supporting air is mixed with the fuel in the belt roaster burner and participates in the combustion reaction.

[0012] By adopting the above technical solution, the efficiency of waste heat utilization is improved by introducing normal temperature combustion air into the cooling outer cavity of the belt roaster, which directly absorbs the high heat emitted during the operation of the equipment, thereby increasing the temperature of the combustion air. Compared with the traditional process in which normal temperature air is directly used as the combustion air, the preheated combustion air can reduce the heating energy consumption during fuel combustion. When the high-temperature combustion air is mixed with the fuel for combustion, the time for the fuel to reach the ignition point can be shortened, the activation of the fuel molecules can be promoted, and the combustion reaction can be more complete. At the same time, the heat dissipated from the cooling outer cavity is optimized by the combustion air, which can reduce the ambient temperature in the surrounding area of ​​the belt roaster, effectively alleviating the high temperature and stuffiness problem in the factory, improving the comfort and work safety of the operators, and at the same time delaying the aging rate of the surrounding electrical equipment and control instruments caused by long-term high temperature, thereby reducing the equipment maintenance cost.

[0013] Preferably, in step S1, the normal temperature combustion-supporting air is directly fed into the inner space of the cooling outer cavity of the belt roaster, or

[0014] The normal temperature combustion-supporting air is fed into a dedicated air duct that is closely adjacent to the inner wall of the cooling outer cavity.

[0015] By adopting the above technical solution, whether direct air supply inside the cooling outer cavity or indirect heat exchange through a dedicated air duct is used, efficient heat exchange is achieved by increasing the contact area between the combustion-supporting air and the outer surface of the equipment. Both air supply methods rely on the existing wind pressure of the burner combustion-supporting fan to drive the airflow. The air supply inside the cooling outer cavity can utilize the original space of the equipment, and the air supply through the dedicated air duct can be adapted to different models of belt roasters through modular design.

[0016] Preferably, in step S2, the heat exchange is to preheat the combustion-supporting air by utilizing the waste heat generated during the operation of the belt roaster equipment and dissipated to the cooling outer cavity.

[0017] By adopting the above technical solution, the ineffective heat dissipated from the outer surface of the equipment is directly captured and converted into effective energy required for preheating the combustion air. The heat exchange process relies entirely on the natural convection / forced convection effect of the equipment's own heat dissipation and the flow of the combustion air, without the need for additional heating devices or drive equipment.

[0018] Preferably, in step S2, the temperature of the high-temperature combustion-supporting air is higher than the temperature of the normal-temperature combustion-supporting air before entering the cooling outer cavity.

[0019] By adopting the above technical solution, the gas temperature is increased by recovering waste heat, thereby optimizing combustion and reducing energy consumption.

[0020] Preferably, in step S3, the high-temperature combustion-supporting air is transported from the output end of the cooling outer cavity of the belt roaster to the combustion-supporting air inlet of the burner of the belt roaster through a dedicated connecting air duct.

[0021] By adopting the above technical solution, the independent flow channel ensures the purity of the combustion air. The dedicated air duct is completely isolated from other gases in the cooling outer cavity, avoiding dust, water vapor and other impurities from mixing into the combustion air and preventing the burner nozzle from being blocked.

[0022] A system for a belt roaster combustion air heating process, comprising:

[0023] The inlet of the belt roaster burner combustion-supporting fan is used to inhale air at normal temperature;

[0024] The belt roaster cooling outer cavity is arranged on the periphery of the belt roaster equipment and has a heat exchange area for accommodating or guiding the heat emitted during the operation of the equipment;

[0025] The belt roaster burner is equipped with combustion air inlet and fuel inlet;

[0026] a first air duct, wherein the inlet end of the first air duct is connected to the air outlet of the burner combustion-supporting air blower of the belt roaster, and the outlet end of the first air duct is connected to the air inlet of the heat exchange area of ​​the cooling outer cavity of the belt roaster, and is used to transport normal temperature combustion-supporting air to the heat exchange area for heating;

[0027] The second air duct, the inlet end of the second air duct is connected to the air outlet of the heat exchange area of ​​the cooling outer cavity of the belt roasting machine, and the outlet end of the second air duct is connected to the combustion air inlet of the burner of the belt roasting machine, for transporting the heated high-temperature combustion air to the burner.

[0028] By adopting the above technical solution, the cooling outer cavity of the belt roaster is used as a natural heat exchange area. Through the closed loop connection of the first air duct (air inlet) and the second air duct (air outlet), the three modules of the combustion-supporting fan, the equipment heat dissipation area, and the belt roaster burner are connected in series. The directional transfer of heat is achieved only through the air duct layout, and extremely simple and efficient energy recovery is achieved from the hardware level.

[0029] Preferably, the first air duct and / or the second air duct is a heat-insulating air duct.

[0030] By adopting the above technical solution and using a thermal insulation design in the first air duct and / or the second air duct, heat loss is minimized and temperature stability is maintained.

[0031] Preferably, the heat exchange area of ​​the cooling outer cavity of the belt roaster includes its internal space, and the outlet end of the first air duct leads into the internal space.

[0032] By adopting the above technical solution, the outlet end of the first air duct directly delivers normal temperature combustion-supporting air into the internal space of the cooling outer cavity, so that the combustion-supporting air forms a 360° surround contact with the outer wall of the equipment, the heat exchange area is increased, and the gap between the cooling outer cavity and the equipment body is used as a heat exchange place. There is no need to add an independent air duct on the periphery of the equipment, saving factory space.

[0033] Preferably, the heat exchange area of ​​the cooling outer cavity of the belt roaster includes a dedicated air duct arranged on its inner wall, and the outlet end of the first air duct is connected to the inlet of the dedicated air duct.

[0034] By adopting the above technical solution, the dedicated air duct is close to the inner wall of the cooling outer cavity, forming an independent heat exchange space, which is completely isolated from the process gas inside the cooling outer cavity, avoiding the mixing of combustion-supporting air and the original cooling medium.

[0035] Preferably, when the system is in operation, the temperature of the high-temperature combustion-supporting air flowing through the second air duct is higher than the temperature of the normal-temperature combustion-supporting air flowing through the first air duct.

[0036] In summary, this application includes at least one of the following beneficial technical effects:

[0037] The efficiency of waste heat utilization is improved by introducing normal temperature combustion-supporting air into the cooling outer cavity of the belt roaster, which directly absorbs the high heat emitted during the operation of the equipment, thereby increasing the temperature of the combustion-supporting air. Compared with the traditional process in which normal temperature air is directly used as the combustion-supporting air, the preheated combustion-supporting air can reduce the heating energy consumption during fuel combustion. When the high-temperature combustion-supporting air is mixed with the fuel for combustion, the time for the fuel to reach the ignition point can be shortened, the activation of the fuel molecules can be promoted, and the combustion reaction can be more complete. At the same time, the heat dissipated from the cooling outer cavity is optimized by the combustion-supporting air, which can reduce the ambient temperature in the surrounding area of ​​the belt roaster, effectively alleviating the high temperature and stuffiness problem in the factory, improving the comfort and work safety of the operators, and at the same time delaying the aging rate of the surrounding electrical equipment and control instruments due to long-term high temperature, thereby reducing the equipment maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a process flow chart of the combustion air heating process of the belt roaster in the embodiment of the present application.

[0039] Explanation of the accompanying symbols: 1. Belt roasting machine burner combustion-supporting fan; 2. Belt roasting machine cooling outer cavity; 3. Belt roasting machine burner. DETAILED DESCRIPTION

[0040] The following is combined with Figure 1 This application is described in further detail.

[0041] The embodiment of the present application discloses a belt roasting machine combustion air heating process. Figure 1 The belt roaster combustion air heating process includes the following steps:

[0042] S1. The belt roaster burner combustion-supporting fan 1 provides power to deliver the normal temperature combustion-supporting air to the belt roaster cooling outer cavity 2.

[0043] Among them, room-temperature combustion-supporting air is directly fed into the interior space of the belt roaster's cooling outer cavity 2, or into a dedicated air duct located closely adjacent to the inner wall of the belt roaster's cooling outer cavity 2. Whether using direct air supply inside the belt roaster's cooling outer cavity 2 or indirect heat exchange through a dedicated air duct, efficient heat exchange is achieved by increasing the contact area between the combustion-supporting air and the equipment's outer surface. Both air supply methods rely on the existing wind pressure of the belt roaster's burner 3 combustion-supporting air fan to drive the airflow. Air supply inside the belt roaster's cooling outer cavity 2 can utilize the equipment's native space, while air supply through the dedicated air duct can be adapted to different models of belt roasters through a modular design.

[0044] S2. When the normal-temperature combustion-supporting air flows through the belt roaster's cooling outer chamber 2, it exchanges heat with the inner wall of the belt roaster's cooling outer chamber 2, absorbing the heat dissipated to the belt roaster's cooling outer chamber 2 during the operation of the belt roaster equipment, thereby increasing the temperature of the normal-temperature combustion-supporting air and converting it into high-temperature combustion-supporting air.

[0045] Heat exchange utilizes the waste heat generated by the belt roaster during operation and dissipated into the cooling chamber to preheat the combustion air. This process directly captures the ineffective heat dissipated from the equipment's outer surface and converts it into the effective energy required to preheat the combustion air. The heat exchange process relies entirely on the equipment's own heat dissipation and the natural / forced convection of the combustion air flow, eliminating the need for additional heating devices or drive equipment. The high-temperature combustion air is higher than the ambient temperature before entering the cooling chamber. By recovering waste heat to increase gas temperature, combustion is optimized, reducing energy consumption.

[0046] S3. The high-temperature combustion-supporting air obtained in step S2 is guided to the burner 3 of the belt roaster.

[0047] High-temperature combustion air is delivered from the output of the belt roaster's cooling chamber 2 to the combustion air inlet of the belt roaster's burner 3 via a dedicated connecting air duct. This independent flow channel ensures the purity of the combustion air. The dedicated air duct is completely isolated from other gases in the belt roaster's cooling chamber 2, preventing impurities such as dust and moisture from entering the combustion air and preventing burner nozzle clogging.

[0048] S4. The high-temperature combustion-supporting air mixes with the fuel in the belt roaster burner 3 and participates in the combustion reaction.

[0049] Also disclosed is a system utilizing a belt roaster combustion-supporting air heating process, comprising a belt roaster burner combustion-supporting air blower 1, a belt roaster cooling outer chamber 2, a belt roaster burner 3, a first air duct, and a second air duct. The inlet of the belt roaster burner combustion-supporting air blower 1 is used to draw in ambient temperature air; the belt roaster cooling outer chamber 2 is disposed outside the belt roaster equipment and has a heat exchange area for accommodating or directing heat generated during equipment operation; and the belt roaster burner 3 is provided with a combustion-supporting air inlet and a fuel inlet.

[0050] The inlet end of the first air duct is connected to the air outlet of the belt roaster burner combustion-supporting air blower 1, and the outlet end of the first air duct is connected to the air inlet of the heat exchange area of ​​the belt roaster cooling outer cavity 2, so as to transport the normal temperature combustion-supporting air to the heat exchange area for heating; the inlet end of the second air duct is connected to the air outlet of the heat exchange area of ​​the belt roaster cooling outer cavity 2, and the outlet end of the second air duct is connected to the combustion-supporting air inlet of the belt roaster burner 3, so as to transport the heated high-temperature combustion-supporting air to the burner. In an optional embodiment, the belt roaster cooling outer cavity 2 is used as a natural heat exchange area, and the three modules of the belt roaster burner combustion-supporting air blower 1, the equipment heat dissipation area, and the belt roaster burner 3 are connected in series through the closed-loop connection of the first air duct (air inlet) and the second air duct (air outlet). The directional transfer of heat is achieved only through the air duct layout, and extremely simple and efficient energy recovery is achieved from the hardware level.

[0051] The first air duct and / or the second air duct are heat-insulating air ducts. By adopting a heat-insulating design in the first air duct and / or the second air duct, heat loss is minimized and temperature stability is maintained. When the system is in operation, the temperature of the high-temperature combustion-supporting air flowing through the second air duct is higher than the temperature of the normal-temperature combustion-supporting air flowing through the first air duct. The heat exchange area of ​​the cooling outer cavity 2 of the belt roaster includes its internal space, and the outlet end of the first air duct leads to the internal space. In an optional embodiment, the outlet end of the first air duct directly sends the normal-temperature combustion-supporting air into the internal space of the cooling outer cavity, so that the combustion-supporting air forms a 360-degree surrounding contact with the inner wall of the equipment, the heat exchange area is increased, and the gap between the cooling outer cavity and the equipment body is used as a heat exchange place. There is no need to add independent air ducts on the periphery of the equipment, saving factory space. In an optional embodiment, the heat exchange area of ​​the cooling outer cavity 2 of the belt roaster includes a dedicated air duct arranged on its inner wall, and the outlet end of the first air duct is connected to the inlet of the dedicated air duct. The dedicated air duct is close to the inner wall of the cooling outer cavity to form an independent heat exchange space, which is completely isolated from the process gas inside the cooling outer cavity to avoid mixing of the combustion-supporting air with the original cooling medium.

[0052] The implementation principle of the embodiment of the present application is: the efficiency of waste heat utilization is improved by introducing normal temperature combustion-supporting air into the cooling outer cavity 2 of the belt roasting machine, directly absorbing the high heat emitted during the operation of the equipment, so that the temperature of the combustion-supporting air is increased. Compared with the traditional process in which the combustion-supporting air is directly adopted as normal temperature air, the preheated combustion-supporting air can reduce the heating energy consumption during fuel combustion. When the high-temperature combustion-supporting air is mixed with the fuel for combustion, the time for the fuel to reach the ignition point can be shortened, the activation of the fuel molecules can be promoted, and the combustion reaction can be more complete. At the same time, the heat dissipation of the cooling outer cavity is optimized by the combustion-supporting air, which can reduce the ambient temperature of the surrounding area of ​​the belt roasting machine, effectively alleviate the high temperature and stuffiness problem in the factory, improve the comfort and work safety of the operators, and at the same time delay the aging speed of the surrounding electrical equipment and control instruments caused by long-term high temperature, thereby reducing the equipment maintenance cost.

[0053] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A belt roaster combustion air heating process, characterized in that: Including steps: S1. Powered by a belt roaster burner combustion fan (1), the combustion air at room temperature is delivered to the belt roaster cooling outer cavity (2); S2. When the normal temperature combustion-supporting air flows through the cooling outer cavity (2) of the belt roaster, it exchanges heat with the inner wall of the cooling outer cavity (2) of the belt roaster, absorbing the heat emitted to the cooling outer cavity (2) during the operation of the belt roaster equipment, thereby increasing the temperature of the normal temperature combustion-supporting air and converting it into high temperature combustion-supporting air; S3. The high-temperature combustion air obtained in step S2 is directed to the belt roaster burner (3); S4. The high-temperature combustion-supporting air is mixed with the fuel in the belt roaster burner (3) and participates in the combustion reaction.

2. The belt roaster combustion air heating process according to claim 1, characterized in that: In step S1, the normal temperature combustion air is directly fed into the inner space of the cooling outer cavity (2) of the belt roaster, or The normal temperature combustion-supporting air is fed into a dedicated air duct arranged closely adjacent to the inner wall of the cooling outer cavity (2).

3. The belt roaster combustion air heating process according to claim 1, characterized in that: In step S2, the heat exchange is to preheat the combustion-supporting air by utilizing the waste heat generated when the belt roasting machine equipment is in operation and dissipated to the cooling outer cavity (2).

4. The belt roaster combustion air heating process according to claim 3, characterized in that: In step S2, the temperature of the high-temperature combustion-supporting air is higher than the temperature of the normal-temperature combustion-supporting air before entering the cooling outer cavity (2).

5. The belt roaster combustion air heating process according to claim 1, characterized in that: In step S3, the high-temperature combustion-supporting air is transported from the output end of the belt roaster cooling outer cavity (2) to the combustion-supporting air inlet of the belt roaster burner (3) through a dedicated connecting air duct.

6. A system for implementing the belt roaster combustion air heating process according to any one of claims 1 to 5, characterized in that: include: A belt roaster burner combustion-supporting fan (1), the inlet of which is used to draw in air at normal temperature; The belt roaster cooling outer cavity (2) is arranged on the periphery of the belt roaster equipment and has a heat exchange area for accommodating or guiding the heat emitted during the operation of the equipment; The belt roaster burner (3) is provided with a combustion air inlet and a fuel inlet; A first air duct, wherein the inlet end of the first air duct is connected to the air outlet of the burner combustion-supporting air blower (1) of the belt roaster, and the outlet end of the first air duct is connected to the air inlet of the heat exchange area of ​​the cooling outer cavity (2) of the belt roaster, and is used to transport normal temperature combustion-supporting air to the heat exchange area for heating; A second air duct, wherein the inlet end of the second air duct is connected to the air outlet of the heat exchange area of ​​the cooling outer cavity (2) of the belt roaster, and the outlet end of the second air duct is connected to the combustion air inlet of the burner (3) of the belt roaster, and is used to transport the heated high-temperature combustion air to the burner (3).

7. The belt roaster combustion air heating process according to claim 6, characterized in that: The first air duct and / or the second air duct are heat-insulating air ducts.

8. A system for implementing the belt roaster combustion air heating process according to any one of claim 6, characterized in that: The heat exchange area of ​​the cooling outer cavity (2) of the belt roaster includes its inner space, and the outlet end of the first air duct leads into the inner space.

9. The belt roaster combustion air heating process according to claim 6, characterized in that: The heat exchange area of ​​the cooling outer cavity (2) of the belt roaster comprises a dedicated air duct arranged on its inner wall, and the outlet end of the first air duct is connected to the inlet of the dedicated air duct.

10. The belt roaster combustion air heating process according to claim 6, characterized in that: When the system is in operation, the temperature of the high-temperature combustion-supporting air flowing through the second air duct is higher than the temperature of the normal-temperature combustion-supporting air flowing through the first air duct.

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