Galvanized wire post-treatment tower chemical coating open flame drying system

Abstract

The utility model relates to a galvanizing line post -treatment tower chemical coating open fire drying system, including drying solidification stove, gas mixing chamber, combustion chamber and ignition device, ignition device is located in the combustion chamber, drying solidification stove connects exhaust fan, the ignition device includes main burner and pilot burner, and the pilot burner front end connects ignition transformer, main burner connects gas pipeline and air pipe, and air pipe is equipped with air flow regulating valve, and gas pipeline is sequentially provided with gas solenoid valve and gas flow regulating valve along the air inlet direction, gas solenoid valve is controlled by leak detection controller, and leak detection controller is interactive with combustion safety controller, the combustion chamber still connects ultraviolet flame detector, and the flame detection signal of ultraviolet flame detector is sent to combustion safety controller, the combustion safety controller still controls ignition transformer and exhaust fan work. The utility model has the characteristics of stable ignition, high ignition success rate, and the system whole is more safe and stable.

Description

Technical Field

[0001] This utility model belongs to the field of chemical coating drying technology for post-treatment towers of color coating lines, and specifically relates to an open flame drying system for chemical coatings in post-treatment towers of galvanizing lines. Background Technology

[0002] In the exit area of ​​a continuous hot-dip galvanizing production line, to prevent the qualified strip steel from oxidizing and rusting during subsequent storage and transportation due to contact with air, a chemical post-treatment is required. This involves uniformly coating the upper and lower surfaces of the strip steel with a passivation solution (such as chromium-free passivation solution, chromium-free fingerprint-resistant solution, chromium-free self-lubricating solution, etc.) using a roller coating system. After coating, the strip steel must enter a post-treatment tower, where the coating is cured through a drying and cooling system (the process is as follows). Figure 1 (as shown), thus forming a uniform and dense protective film.

[0003] Currently, the industry commonly uses open-flame direct heating drying systems fueled by natural gas to cure coatings. While this method offers high heating efficiency, existing systems have revealed several key technical flaws in actual operation, severely impacting production safety, stability, and economic efficiency:

[0004] 1. Unstable air-fuel ratio control leads to ignition difficulties and low combustion efficiency: Existing systems typically have a fixed, non-adjustable air outlet for the combustion fan. Its airflow is highly susceptible to changes in the inlet's operating status. When the inlet is blocked, the actual airflow will be lower than the set value, failing to achieve the optimal air-fuel mixture. Furthermore, in the pre-ignition safety procedure, the natural gas pipeline must be purged with nitrogen to prevent deflagration. After purging, a large amount of nitrogen remains in the pipeline, resulting in a severely insufficient initial natural gas concentration, making it difficult to form a combustible mixture and frequently causing ignition failure.

[0005] 2. Inability to adjust exhaust air pressure, disrupting the combustion environment: The system's exhaust fan typically operates at a fixed speed, maintaining a constant exhaust volume. This creates a continuous and significant negative pressure within the ignition pipeline. Under this negative pressure, the introduced natural gas is rapidly drawn away before it can be fully mixed with and ignited, failing to achieve and maintain a suitable air-fuel ratio at the burner head. Even if ignition occurs, the flame will immediately extinguish due to the instantaneous removal of the mixture, and the flame detector will be unable to detect a stable flame signal, leading to an interruption of the ignition process.

[0006] 3. Flame detectors often generate erroneous signals due to environmental factors, such as dirt on the lens preventing proper flame detection. If the ignition controller fails to detect a flame during the ignition phase, it will enter a protection state and cut off the natural gas supply.

[0007] 4. Potential safety and performance risks: Due to the aforementioned issues, the system often requires multiple ignition attempts, resulting in slow heating, disrupting production schedules, and causing significant consumption of natural gas and nitrogen, leading to high energy consumption. More importantly, during repeated ignition, unburned natural gas accumulates in the furnace. Once it reaches its explosive limit and encounters an open flame, it can easily cause a deflagration, posing a significant safety hazard.

[0008] In summary, existing chemical coating open-flame drying systems have significant shortcomings in terms of air-fuel ratio control, exhaust gas pressure matching, ignition success rate, and operational safety. Therefore, there is an urgent need for a novel drying system and method with a reasonable design and precise control to completely solve these problems and achieve safe, stable, and efficient ignition and drying operations. Summary of the Invention

[0009] This utility model provides a chemical coating open flame drying system for a galvanizing line post-treatment tower to solve the technical problems existing in the prior art. It has the characteristics of stable ignition, high ignition success rate, and overall system safety and stability.

[0010] This utility model includes the following technical solution: a chemical coating open flame drying system for a galvanizing line post-treatment tower, comprising a drying and curing oven, a mixing chamber, a combustion chamber, and an ignition device. The ignition device is located in the combustion chamber, and the drying and curing oven is connected to an exhaust fan. The ignition device includes a main burner and an ignition burner, with the ignition burner connected to an ignition transformer at its front end. The main burner is connected to a gas pipeline and an air pipeline. An air flow regulating valve is installed on the air pipeline, and a gas solenoid valve and a gas flow regulating valve are sequentially installed on the gas pipeline along the air intake direction. The gas solenoid valve is controlled by a leak detection controller, which interacts with a combustion safety controller. The combustion chamber is also connected to an ultraviolet flame detector, and the flame detection signal from the ultraviolet flame detector is sent to the combustion safety controller. The combustion safety controller also controls the operation of the ignition transformer and the exhaust fan.

[0011] Furthermore, the leak detection controller is connected to a leak detection pressure switch, which is installed near the gas pipeline behind the main burner. Its function is to detect whether there is combustible gas flowing out when the gas solenoid valve is closed, so as to ensure the amount of combustible gas in the furnace and prevent the occurrence of excessive gas ignition and flashover caused by abnormal gas leakage from the gas solenoid valve.

[0012] Furthermore, the combustion safety controller monitors the pressure status of the gas pipeline, air pipeline, and exhaust gas pipeline through a gas pipeline pressure detector, an air pipeline pressure detector, and an exhaust gas pipeline pressure detector, respectively.

[0013] Furthermore, the combustion safety controller is signal-connected to the gas flow regulating valve and the air flow regulating valve, and the data from the air flow regulating valve is sent to the gas flow regulating valve to regulate the gas flow.

[0014] Furthermore, the air inlet of the mixing chamber is connected to the combustion chamber, and the two sides of the combustion chamber are connected to the drying and curing oven via air outlet ducts and return air ducts, respectively. A circulating fan is installed on the return air duct; the exhaust duct of the drying and curing oven is connected to a waste exhaust fan. By setting up a circulating fan to accelerate the circulation of hot air, thermal energy can be fully utilized, and the waste exhaust fan ensures that the air pressure remains stable within the safe operating range.

[0015] Furthermore, the detection point of the ultraviolet flame detector is set near the ignition burner, and the ultraviolet flame detector is connected to the flame signal amplifier to improve the accuracy of flame detection.

[0016] Furthermore, the ignition transformer sends high voltage to the spark plug, which generates a spark to ignite the ignition burner, producing an open flame that then ignites the main burner.

[0017] Furthermore, a combustion-supporting fan is installed on the air duct to increase the air flow rate, and the combustion-supporting fan is located downstream of the air flow regulating valve.

[0018] Furthermore, the combustion chamber is connected to the drying and curing oven via a mixing chamber.

[0019] Furthermore, the combustion safety controller is equipped with an information display panel that can record the combustion process, display status and alarm information, and provide alarm handling prompts.

[0020] The advantages and positive effects of this utility model are as follows:

[0021] 1. This utility model improves the safety, stability and convenience of ignition operation by setting an ignition burner and an ignition transformer for the main burner ignition operation, thereby achieving the goals of energy saving, consumption reduction and safe production, ensuring the stable operation of the production line, and improving product yield and quality.

[0022] 2. This utility model uses a combustion safety controller to connect a gas pipeline pressure detector, an air pipeline pressure detector, and an exhaust gas pipeline pressure detector to monitor the pressure status of the gas pipeline, air pipeline, and exhaust gas pipeline respectively, ensuring that the internal pressure of the pipeline is within a safe value, increasing early warning, and avoiding the existence of dangerous factors such as overpressure explosion without being aware of them.

[0023] 3. This utility model uses an ultraviolet flame detector to generate an electrical signal by sensing ultraviolet radiation of a specific wavelength in the flame. It is less affected by the working environment and has a high accuracy rate. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall process flow of the post-processing tower;

[0025] Figure 2 This is a schematic diagram of the overall structure of this utility model;

[0026] In the diagram, 1-Roller coater; 2-Drying and curing oven; 3-Upward cooling air box; 4-Downward cooling air box; 5-Ignition device; 6-Combustion chamber; 7-Main burner; 8-Ignition burner; 9-Gas flow regulating valve; 10-Air flow regulating valve; 11-Gas solenoid valve; 12-Leak detection controller; 13-Leak detection pressure switch; 14-Combustion safety controller; 15-Ultraviolet flame detector; 16-Gas pipeline pressure detector; 17-Air pipeline pressure detector; 18-Ignition transformer; 19-Mixing chamber; 20-Exhaust gas pipeline pressure detector; 21-Exhaust fan; 22-Circulating fan; 23-Combustion fan. Detailed Implementation

[0027] To further disclose the invention content, features, and effects of this utility model, the following examples are provided in conjunction with the accompanying drawings for detailed description. In the following description of the embodiments, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this patent and simplifying the description. They do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this patent.

[0028] In the following description of the embodiments, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0029] Example: See Appendix Figure 2A chemical coating open-flame drying system for a galvanizing line post-processing tower includes a drying and curing oven 2, a mixing chamber 19, a combustion chamber 6, and an ignition device 5. The ignition device 5 is located inside the combustion chamber 6. The drying and curing oven 2 is connected to an exhaust fan 21. The combustion chamber 6 is connected to the drying and curing oven 2 via the mixing chamber 19. The air inlet of the mixing chamber 19 is connected to the combustion chamber 6. The combustion chamber 6 is connected to the drying and curing oven 2 via an outlet air pipe and a return air pipe on both sides. A circulating fan 22 is installed on the return air pipe. The exhaust pipe of the drying and curing oven 2 is connected to the exhaust fan 21. The circulating fan 22 accelerates the hot air circulation to fully utilize thermal energy, and the exhaust fan 21 ensures that the air pressure remains stable within a safe operating range. The ignition device 5 includes a main burner 7 and an ignition burner 8. The front end of the ignition burner 8 is connected to an ignition transformer 18. The ignition transformer 18 sends high voltage to the spark plug, generating a spark that ignites the ignition burner 8, which then produces an open flame that ignites the main burner 7.

[0030] The main burner 7 is connected to a gas pipeline and an air pipeline. An air flow regulating valve 10 is installed on the air pipeline, and a combustion-supporting fan 23 is installed on the air pipeline to increase air flow. The combustion-supporting fan 23 is located downstream of the air flow regulating valve 10. A gas solenoid valve 11 and a gas flow regulating valve 9 are sequentially installed along the gas inlet direction on the gas pipeline. The gas solenoid valve 11 is controlled by a leak detection controller 12, which interacts with a combustion safety controller 14. The leak detection controller 12 is connected to a leak detection pressure switch 13. The leak detection pressure switch 13 is installed near the gas pipeline downstream of the main burner 7. Its function is to detect whether combustible gas flows out when the gas solenoid valve 11 is closed, to ensure the amount of combustible gas in the furnace and prevent excessive ignition and flashover caused by abnormal gas leakage from the gas solenoid valve 11. The combustion chamber 6 is also connected to an ultraviolet flame detector 15, whose flame detection signal is sent to the combustion safety controller 14. The detection point of the ultraviolet flame detector 15 is located near the ignition burner 8. The ultraviolet flame detector 15 is connected to a flame signal amplifier to improve the accuracy of flame detection. The combustion safety controller 14 also controls the operation of the ignition transformer 18, the circulating fan 22, the combustion-supporting fan 23, and the exhaust fan 21.

[0031] The combustion safety controller 14 monitors the pressure status of the gas pipeline, air pipeline, and exhaust gas pipeline through a gas pipeline pressure detector 16, an air pipeline pressure detector 17, and an exhaust gas pipeline pressure detector 20, respectively. The combustion safety controller 14 is signal-connected to the gas flow regulating valve 9 and the air flow regulating valve 10, with data from the air flow regulating valve 10 being sent to the gas flow regulating valve 9. The combustion safety controller 14 has an information display panel that can record the combustion process, display status and alarm information, and provide alarm handling prompts.

[0032] Working Principle: The post-treatment tower process of the continuous hot-dip galvanizing unit specifically uses open-flame burners to heat the temperature of the circulating gas inside the furnace. After the strip steel is evenly coated with passivation liquid by the roller coater, the high-temperature gas heats the surface of the strip steel to the set temperature. Subsequently, the strip steel passes through one upward cooling air box 3 and two downward cooling air boxes 4, and the temperature of the strip steel drops to room temperature. The purpose of this process is to first raise the temperature to allow the passivation liquid to fully react with the surface of the strip steel to form a thin film, and then dry it before cooling it to room temperature to solidify the passivation liquid into a passivation film.

[0033] Before operation, the system is purged with nitrogen to confirm that there are no abnormalities in pressure and leak detection. Ignition then begins, with high voltage from the ignition transformer 18 sent to the spark plug and spark igniter, producing an open flame in the ignition burner 8. If no open flame is produced and the ultraviolet flame detector 15 does not detect a flame, the gas solenoid valve 11 closes to prevent natural gas leakage. When the ultraviolet flame detector 15 detects a flame signal, it ignites the main burner 7. The opening of the gas solenoid valve 11 for the main burner 7 can be adjusted according to the difference between the set temperature and the actual temperature. A larger opening results in a larger flame and higher temperature, while a smaller opening results in a smaller flame and lower temperature. The heat generated by combustion is mixed in the mixing chamber 19, and the hot air is continuously heated to 50℃-90℃ by the circulating fan 22. At regular intervals, the exhaust gas is discharged through the exhaust pipe and the smoke exhaust fan 21 to ensure that the gas pressure remains stable within a safe range. This system has been verified through actual operation, and all functions operate well.

[0034] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other modifications under the guidance of the present invention without departing from the spirit and scope of the claims. These modifications all fall within the protection scope of the present invention.

Claims

1. A chemical coating open-flame drying system for a galvanizing line post-treatment tower, comprising a drying and curing oven, a mixing chamber, a combustion chamber, and an ignition device, wherein the ignition device is located in the combustion chamber, and the drying and curing oven is connected to an exhaust fan, characterized in that: The ignition device includes a main burner and an ignition burner, with the ignition burner connected to an ignition transformer at its front end. The main burner is connected to a gas pipeline and an air pipeline. An air flow regulating valve is installed on the air pipeline, and a gas solenoid valve and a gas flow regulating valve are sequentially installed on the gas pipeline along the air intake direction. The gas solenoid valve is controlled by a leak detection controller, which interacts with a combustion safety controller. The combustion chamber is also connected to an ultraviolet flame detector, and the flame detection signal from the ultraviolet flame detector is sent to the combustion safety controller. The combustion safety controller controls the operation of the ignition transformer and the exhaust fan.

2. The chemical coating open flame drying system for the galvanizing line post-treatment tower according to claim 1, characterized in that: The leak detection controller is connected to a leak detection pressure switch.

3. The chemical coating open flame drying system for the galvanizing line post-treatment tower according to claim 1, characterized in that: The combustion safety controller monitors the pressure status of the gas pipeline, air pipeline, and exhaust gas pipeline through a gas pipeline pressure detector, an air pipeline pressure detector, and an exhaust gas pipeline pressure detector, respectively.

4. The chemical coating open flame drying system for the galvanizing line post-treatment tower according to claim 1, characterized in that: The combustion safety controller is connected to the gas flow regulating valve and the air flow regulating valve via signal connection, and the data from the air flow regulating valve is sent to the gas flow regulating valve.

5. The chemical coating open flame drying system for the galvanizing line post-treatment tower according to claim 1, characterized in that: The air inlet of the mixing chamber is connected to the combustion chamber, and the two sides of the combustion chamber are connected to the drying and curing oven through the air outlet pipe and the air return pipe, respectively. A circulating fan is installed on the air return pipe; the exhaust pipe of the drying and curing oven is connected to the exhaust fan.

6. The chemical coating open flame drying system for the galvanizing line post-treatment tower according to claim 1, characterized in that: The detection point of the ultraviolet flame detector is set near the ignition burner, and the ultraviolet flame detector is connected to the flame signal amplifier.

7. The chemical coating open flame drying system for the galvanizing line post-treatment tower according to claim 1, characterized in that: The ignition transformer sends high voltage to the spark plug, which generates a spark to ignite the ignition burner, producing an open flame that then ignites the main burner.

8. The chemical coating open flame drying system for the galvanizing line post-treatment tower according to claim 1, characterized in that: A combustion-supporting fan is installed on the air duct, and the combustion-supporting fan is located downstream of the air flow regulating valve.

9. The chemical coating open flame drying system for the galvanizing line post-treatment tower according to claim 1, characterized in that: The combustion chamber is connected to the drying and curing oven via a mixing chamber.

10. The chemical coating open flame drying system for the galvanizing line post-treatment tower according to any one of claims 1-9, characterized in that: The combustion safety controller has an information display panel.

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