Automatic ignition method and system applied to hot-metal ladle scrap steel baking device

Abstract

The invention discloses an automatic ignition method and system applied to a hot-metal ladle scrap steel baking device, and belongs to the technical field of steel smelting, and the automatic ignition method comprises the steps that a power source of the hot-metal ladle scrap steel baking device is started; power is supplied based on a power source of the hot-metal ladle scrap steel baking device, and a low-pressure baking-hot rod arranged in the hot-metal ladle scrap steel baking device is preheated by igniting a high-temperature-resistant cable; when preheating of the low-pressure baking-hot rod is completed and a preset ignition condition is met, a fuel gas supply mechanism and a compressed air mechanism of the hot-metal ladle scrap steel baking device are triggered to convey fuel gas and compressed air to an ignition area correspondingly, and combustible mixed gas is formed; and high-pressure sparks generated by the ignition burner act on the surface of the low-pressure searing rod to ignite the combustible mixed gas, so that automatic ignition of the hot-metal ladle scrap steel baking device is realized. Rapid and uniform heating is achieved, energy consumption caused by long open fire is reduced, the baking efficiency is improved, field manual operation is reduced, the operation risk is reduced, and the safety of overall operation is improved.

Description

Technical Field

[0001] This invention belongs to the field of iron and steel smelting technology, and particularly relates to an automatic ignition method and system for a scrap steel baking device for molten iron ladles, and especially to an efficient, energy-saving, and safe automatic ignition solution based on dual-mode ignition, intelligent control and dynamic parameter optimization. Background Technology

[0002] In the steelmaking process, scrap steel added to the molten iron ladle needs to be preheated to increase its temperature, improve the iron-to-steel ratio, and reduce the amount of molten iron added, thereby significantly reducing smelting costs. Traditional scrap steel preheating methods mostly rely on manual ignition. By introducing a fire source and using an ignition rod to light a persistent open flame, gas can be introduced for heating. This method is not only inefficient but also poses safety hazards in the surrounding gas area. Currently, there are other ignition methods in the industry, such as gas jet ignition and electronic ignition, but combustion is not ideal in low-temperature and high-wind environments, and the flame is easily extinguished, requiring multiple ignitions, resulting in poor safety. At the same time, once ignited, it is basically a persistent flame that is difficult to turn off, consuming a large amount of energy gases (gas, oxygen, etc.) during non-preheating periods, resulting in significant energy waste.

[0003] In the prior art, Chinese patent CN108397784A, published on August 14, 2018, discloses a blast furnace gas ignition and venting system, which uses a high-altitude ignition and combustion accompaniment device and a catalytic reaction chamber to achieve automatic ignition and combustion through an elevator arc generator. However, its ignition efficiency is not high and it is easy to cause ignition failure. In addition, Chinese patent CN113774185A, published on December 10, 2021, discloses a scrap steel hopper baking device and method based on automatic ignition and gas explosion prevention, which realizes automatic flame monitoring and rapid cut-off of fuel supply. However, it fails to effectively solve the problem of continuous energy consumption caused by the propellant flame, and the overall baking energy efficiency improvement is limited.

[0004] None of the aforementioned existing technologies employ a composite ignition mechanism of 'low-pressure hot rod preheating + high-pressure spark ignition', nor do they achieve dynamic adjustment of electrode spacing based on airflow. Consequently, they cannot simultaneously solve the triple technical problems of low ignition success rate, high energy consumption of the propellant flame, and poor adaptability to operating conditions.

[0005] Therefore, there is an urgent need in this field for an automatic ignition method and system that can significantly improve the success rate of first-time ignition, greatly shorten the ignition time, intelligently adapt to different working conditions, and completely eliminate the non-operational energy consumption of the propellant flame. Summary of the Invention

[0006] The purpose of this invention is to address the problems of low efficiency, high safety risks, and easy extinguishing requiring repeated on-site operation in the manual ignition of molten iron ladle scrap steel baking devices, and to provide an automatic ignition method and system for molten iron ladle scrap steel baking devices.

[0007] This invention relates to an automatic ignition method for a molten iron ladle scrap baking device, characterized by comprising: starting the power supply of the molten iron ladle scrap baking device; preheating the low-pressure heating rod built into the molten iron ladle scrap baking device via a high-temperature resistant ignition cable based on the power supply of the molten iron ladle scrap baking device; when the low-pressure heating rod is preheated and reaches the preset ignition conditions, triggering the gas supply mechanism and compressed air mechanism of the molten iron ladle scrap baking device to respectively deliver gas and compressed air to the ignition area to form a combustible mixture; using an ignition burner to generate a high-pressure spark that acts on the surface of the preheated low-pressure heating rod, igniting the combustible mixture through the combined energy of the hot surface and the electric spark, thereby realizing the automatic ignition of the molten iron ladle scrap baking device.

[0008] Furthermore, the process of preheating the low-pressure heating rod to achieve the preset ignition conditions includes: adjusting the heating power through temperature control at the initial stage of ignition so that the low-pressure heating rod reaches a reference temperature of 800°C within a set time of 3 seconds; after the low-pressure heating rod reaches the reference temperature, it enters an ignition window period of 5-8 seconds and waits for a preset time of 3 seconds to trigger the gas supply mechanism and compressed air mechanism to deliver gas to the ignition area for the low-pressure heating rod to ignite.

[0009] Furthermore, the above method also includes: if ignition fails three times consecutively by the low-pressure heating rod within the ignition window, then switch to the backup high-pressure discharge ignition mode.

[0010] Furthermore, in the standby high-voltage discharge ignition mode, the electrode spacing is dynamically adjusted according to the air flow.

[0011] Furthermore, gas is supplied to the ignition area through a gas supply mechanism and a compressed air mechanism, including: the gas supply mechanism adjusts the valve opening according to a preset gas flow rate parameter of 5 m³ / min, and delivers the gas to the ignition area after the gas is stabilized to 0.05 MPa by a pressure reducing valve; at the same time, the compressed air mechanism compresses the air to 0.6 MPa ± 0.05 MPa by a pressure reducing valve and delivers the compressed air to the ignition area; the gas and compressed air are mixed in the ignition area to form a combustible mixture.

[0012] Furthermore, the above method also includes: performing three-level flame verification sequentially after ignition, including: detecting the initial ignition flame through an ultraviolet flame sensor, detecting the rate of change of the combustion chamber temperature gradient through a K-type thermocouple, and identifying the flame shape through an infrared vision system. When the proportion of flame pixels in the preset ROI area is >60%, it is determined that the shape is normal.

[0013] Furthermore, the above-mentioned flame verification process also includes: when two or more levels of the three-level verification show abnormalities, shutting off the gas supply and power supply within ≤3 seconds, issuing an audible and visual alarm, and simultaneously pushing a fault code to the remote control system.

[0014] This invention relates to an automatic ignition system for a molten iron ladle scrap baking device, characterized in that it comprises:

[0015] Control Unit: Based on a PLC, integrating a PID temperature control module, a dynamic spacing adjustment algorithm module, and a safety interlock logic module; Execution Unit: Ignition high-temperature resistant cable, connecting the power supply and the low-pressure heating rod, transmitting electrical energy to the low-pressure heating rod built into the molten iron ladle scrap baking device for preheating; Low-pressure heating rod, located inside the molten iron ladle scrap baking device, receives electrical energy for preheating via the ignition high-temperature resistant cable; Gas supply mechanism, connected to the ignition area, supplies gas to the ignition area when the low-pressure heating rod reaches the preset ignition conditions; Compressed air mechanism, connected to the ignition area, supplies compressed air to the ignition area when the low-pressure heating rod reaches the preset ignition conditions. Compressed air; Dual-mode igniter, integrating an igniter burner that generates a high-voltage spark and a high-voltage discharge device with dynamically adjustable electrode spacing, and an electrode spacing adjustment servo mechanism for precise control of electrode position and optimization of heating effect; The igniter burner generates a high-voltage spark that acts on the surface of the preheated low-pressure hot rod, igniting the combustible mixture of gas and compressed air; Sensing and verification unit: including an ultraviolet flame sensor, a K-type thermocouple, an infrared vision camera, and an air flow meter, used to collect ignition process parameters and perform flame verification; Safety unit: including an emergency shut-off valve, an audible and visual alarm, and a remote fault push module, used for safety protection under abnormal operating conditions.

[0016] Furthermore, the aforementioned gas supply mechanism includes: a gas manual valve, normally open, used to shut off the gas supply during maintenance; a gas pneumatic ball valve with switch feedback, used to control the on / off state of the gas passage; and a pressure reducing valve, used to stabilize the gas pressure to 0.05 MPa.

[0017] Furthermore, the aforementioned compressed air mechanism includes: a normally open manual compressed air valve for controlling the supply of compressed air; a pneumatic compressed air ball valve for controlling the opening and closing of the compressed air passage and adjusting the air flow to a set value after the high-pressure spark stabilizes; and a pressure reducing valve for stabilizing the compressed air pressure to 0.6MPa±0.05.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. This invention solves the problems of low efficiency, high safety risk, easy extinguishing and need for repeated on-site operation of scrap steel baking equipment by manual ignition. It achieves rapid and uniform heating, reduces energy consumption caused by the continuous flame, improves baking efficiency, reduces on-site manual operation, reduces operational risks, and improves the overall safety of operation.

[0020] 2. Ignition efficiency and success rate are significantly improved:

[0021] First-time ignition success rate: The dual-mode collaborative intelligent algorithm of this invention achieves an overall ignition success rate of ≥99.5% (test conditions: ambient temperature -20℃~40℃, gas pressure 0.03~0.08MPa, air flow 6~12m³ / min), which is much higher than traditional electric spark ignition (about 60%) or single automatic ignition method (about 85%).

[0022] Average ignition time: From receiving the command to the stable establishment of the flame, the average time is ≤10 seconds (excluding system self-test time). Compared with traditional manual ignition (usually requiring 1-2 minutes, including preparation and trial time), the efficiency is improved by more than 80%; compared with ordinary automatic ignition devices (approximately 30-45 seconds), the efficiency is improved by more than 50%.

[0023] 3. Energy consumption has been significantly reduced:

[0024] Ignition Energy Consumption: This invention consumes electrical energy only briefly during the ignition window to heat the heating rod, and overheating is avoided through precise PID control. The energy consumption for each ignition is approximately 0.00075 kWh. In traditional continuous flame mode, only in standby mode does it consume approximately 15-20 m³ of gas per hour. Based on 16 hours of non-operating time per day, a single unit can save over 80,000 cubic meters of gas annually (calculated based on 16 hours of non-operating time per day, 15 m³ of gas consumption per standby hour, and 330 operating days per year: 16 × 15 × 330 = 79,200 m³ ≈ 80,000 m³).

[0025] Overall Energy Efficiency: Due to rapid and precise ignition, the temperature control during the baking process is more stable, resulting in improved overall baking thermal efficiency. Actual test data shows that this system can reduce gas consumption by approximately 18-22% when baking the same tonnage of scrap steel to the target temperature.

[0026] 4. Intelligent self-adaptation and high reliability:

[0027] Through the `Q_air-d` dynamic adjustment algorithm, the system can automatically adapt to different ambient air pressures and fan operating conditions, ensuring that the backup ignition mode can maintain a high success rate under a wide airflow range of 6-12m³ / min.

[0028] The three-level flame verification and ≤3-second emergency shutdown system construct an active safety protection system, minimizing safety risks.

[0029] 5. High degree of automation and safety:

[0030] It achieves full-process automation, reduces manual intervention, and lowers operational risks and labor intensity. Safety interlocks respond quickly, and fault information is remotely pushed, facilitating maintenance and management. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the method flow according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the automatic ignition procedure according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the structure of an embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of the system of the present invention;

[0035] In the diagram: 1. 24V power supply; 2. Ignition high-temperature resistant cable; 3. Low-voltage heating rod; 4. Gas supply mechanism; 5. Compressed air mechanism; 6. Ignition burner (including high-voltage discharge unit); 11. Iron ladle scrap steel baking device; 12. PLC; 13. Flame sensor group; 13.1. Ultraviolet sensor; 13.2. K-type thermocouple; 13.3. Infrared vision system; 14. Electrode spacing adjustment servo mechanism. Detailed Implementation

[0036] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] In the description of this invention, it should be noted that the terms "middle", "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0038] like Figure 1As shown, this embodiment of the invention provides an automatic ignition method for a scrap steel baking device 11 applied to a molten iron ladle, comprising: an operator issuing a baking start command via an HMI interface in a remote control room, and a PLC... 12. Upon power-on, the system first performs a self-test. After passing the self-test, it enters the main ignition mode, i.e., the power supply of the molten iron ladle scrap baking device 11 is started. Based on the power supply of the molten iron ladle scrap baking device 11, the low-pressure heating rod 3 (the low-pressure heating rod is an industrial-grade dry-burning single-head electric heating tube, such as the HY-DR-G series dry-burning heating rod produced by Zhenjiang Huyang Electric Complete Equipment Co., Ltd.) built into the molten iron ladle scrap baking device 11 is preheated through the ignition high-temperature resistant cable 2. When the low-pressure heating rod 3 has completed preheating and reached the preset ignition conditions, the gas supply mechanism 4 and the compressed air mechanism 5 of the molten iron ladle scrap baking device 11 are triggered to deliver gas and compressed air to the ignition area respectively, forming a combustible mixture. The high-pressure spark generated by the ignition burner 6 acts on the surface of the low-pressure heating rod 3, igniting the combustible mixture. The ultraviolet sensor 13-1 immediately detects the flame, and the first-level verification is passed. If ignition fails 3 times in the main mode, the PLC... 12 automatically switches to the backup high-voltage discharge ignition mode, outputting a control signal to the electrode spacing adjustment servo mechanism 14 to precisely adjust the discharge electrode spacing (specifically, the electrode spacing adjustment servo mechanism 14 may include one relatively fixed electrode and another relatively movable electrode, the movable electrode being moved by a servo motor-driven screw and nut mechanism or an electric push cylinder). After adjustment, the igniter generates a high-voltage spark for ignition, successfully igniting the gas. After successful ignition, the flame verification group 13 operates, and the PLC stops discharging after receiving a stable signal. This achieves automatic ignition of the molten iron ladle scrap baking device 11.

[0039] Specifically, the embodiments of the present invention also provide the structural components in the automatic ignition process, which consist of a low-pressure heating rod 3, an ignition burner 6, a 24V power supply 1, a gas pipeline, a gas manual valve, a gas pneumatic ball valve, a compressed air pipeline, a compressed air manual valve, a compressed air pneumatic ball valve, a compressed air pressure reducing valve, and an ignition high-temperature resistant cable 2.

[0040] The automatic ignition system of the present invention applied to the scrap steel baking device of molten iron ladle includes:

[0041] 1. Control Unit: Based on PLC, it integrates PID temperature control module, dynamic spacing adjustment algorithm module, and safety interlock logic module.

[0042] 2. Execution Unit:

[0043] Ignition high-temperature resistant cable and low-voltage heating rod: used for preheating.

[0044] Gas supply mechanism: including, in sequence, a gas manual valve (normally open, for maintenance), a gas pneumatic ball valve (with feedback), and a pressure reducing valve (stabilizing pressure to 0.05MPa).

[0045] Compressed air mechanism: including, in sequence, a compressed air manual valve (normally open), a compressed air pneumatic ball valve, and a pressure reducing valve (stabilizing pressure to 0.6MPa±0.05).

[0046] Dual-mode igniter: integrates an ignition burner that generates a high-voltage spark (acting on the heating rod) and a high-voltage discharge device with dynamically adjustable electrode spacing; the electrode spacing adjustment servo mechanism is used to precisely control the electrode position and optimize the heating effect.

[0047] 3. Sensing and verification unit: ultraviolet flame sensor, K-type thermocouple, infrared vision camera, air flow meter.

[0048] 4. Safety Units: Emergency shut-off valve, audible and visual alarm, remote fault push module.

[0049] The present invention relates to a method for operating an automatic ignition system of a molten iron ladle scrap baking device, comprising:

[0050] S1: The system performs a power-on self-test, starts the power supply and PLC control system of the molten iron ladle scrap baking device, and initializes and self-tests all sensors and actuators.

[0051] S2: Low-pressure incinerator preheating. Power is supplied to the built-in nickel-chromium alloy low-pressure incinerator via a high-temperature resistant ignition cable to start the main ignition mode. A PID temperature closed-loop control algorithm is used to rapidly increase the heating power in the early stage of ignition, so that the surface temperature of the incinerator reaches the reference ignition temperature of 800℃ within 3 seconds. The overall temperature response time is ≤10 seconds. This reference ignition temperature is set to about 1.5 times the typical ignition point of coal gas (about 530℃) to ensure reliable ignition capability.

[0052] S3: Combustible gas mixture delivery and dual-mode ignition. After the low-pressure heating rod reaches the preset temperature, the system enters an ignition window of 5-8 seconds. During this window:

[0053] The PLC synchronously triggers the gas supply mechanism and the compressed air mechanism. The gas is stabilized to 0.05MPa by the pressure reducing valve and then delivered at a flow rate of 5m³ / min. The compressed air is delivered at a preset flow rate, and the two mix in the ignition zone.

[0054] Main mode ignition: The igniter generates a high-pressure spark, which acts on the surface of the preheated low-pressure hot rod, and uses the combined energy of "hot surface + electric spark" to instantly ignite the gas mixture.

[0055] Backup mode switching and intelligent adjustment: If ignition fails three times consecutively within the main mode window, the system automatically switches to the backup high-voltage discharge ignition mode. The core innovation in this mode lies in the dynamic adjustment of the spacing (d) of the high-voltage discharge electrodes based on real-time monitored compressed air flow (Q_air). This adjustment relationship is based on a combination of an experimentally established mathematical model and a lookup table method.

[0056] Mathematical model (empirical formula): d = d_base k * (Q_air Q_base). Where d_base is the reference spacing (e.g., 3mm), Q_base is the reference airflow (e.g., 8m³ / min), and k is the adjustment coefficient (calibrated experimentally, e.g., 0.1mm·min / m³). This model ensures that when the airflow increases, the electrode spacing is appropriately reduced to maintain the arc intensity and overcome the airflow extinguishing effect.

[0057] Lookup table method: The PLC pre-stores a table of correspondence between `Q_air-d` that has been optimized through a large number of experiments (see the table below for an example). The control system looks up the table based on the real-time `Q_air` to obtain the optimal `d` value and adjusts the electrode position through the servo mechanism.

[0058] Compressed air flow rate Q_air (m³ / min) Electrode spacing d (mm) 6 3.2 7 3.1 8 (Base Flow Rate) 3.0 (reference spacing) 9 2.9 10 2.8 11 2.7 12 2.6

[0059] Experimental data support: Laboratory and field tests show that, within the airflow range of 6-12 m³ / min, the dynamic adjustment algorithm can increase the high-voltage discharge ignition success rate from approximately 65% ​​under static spacing to over 99%.

[0060] S4: Multi-level flame verification and safety interlock. After successful ignition, the system immediately initiates a three-level flame verification sequence with a response time of <100ms.

[0061] Level 1 verification: Ultraviolet flame sensor detects the initial ignition flame;

[0062] Secondary verification: K-type thermocouples monitor the rate of change of the combustion chamber temperature gradient;

[0063] Level 3 verification: The infrared vision system performs pattern recognition on the flame shape. When the percentage of flame pixels in the preset ROI (region of interest) is >60%, it is judged as normal.

[0064] If two or more abnormalities are found in the three-level verification, the system will immediately trigger the emergency shutdown logic, cut off the gas and power supply within ≤3 seconds, and activate the audible and visual alarm. This response time is about 60% faster than the industry standard.

[0065] The sensor installation location and requirements for Level 3 verification are as follows:

[0066] Sensor type Sensor installation location Sensor installation parameter requirements Ultraviolet flame sensor The upper part of the combustion chamber side wall, facing the intersection of the ignition electrode and the gas nozzle. With a protection rating of ≥IP65, the detection range is 0.8~1.5m from the flame core, covering 100% of the ignition area, and avoiding direct obstruction by smoke and dust. K-type thermocouple The temperature sensor should be inserted 150-200mm into the combustion chamber from the top center, avoiding the area directly burned by the flame. Temperature measurement range 0~1200℃, using high-temperature resistant ceramic protective sleeve, with sealed and heat-insulated treatment at the contact point with the furnace wall. Infrared vision system Near the observation port of the baking device, the lens is pointed towards the surface of the scrap metal pile. Equipped with a high-temperature resistant and dustproof lens cover, featuring compressed air purging function, and a viewing distance of 0.3~0.5m from the observation port, the field of view covers the entire scrap steel loading area.

[0067] S5: Intelligent control and energy efficiency management during the baking process. After the flame stabilizes, the system enters the PID temperature closed-loop baking control stage, dynamically adjusting the gas and air ratio according to the set temperature. After the baking task is completed, the system completely shuts off, achieving "zero persistent flame" standby.

[0068] The core objective of the automatic ignition method and system of the present invention applied to the scrap steel baking device of molten iron ladle is as follows:

[0069] 1. Improved ignition performance: Through a dual-mode collaborative ignition mechanism of "low-pressure hot rod preheating + high-pressure spark ignition" and combined with intelligent dynamic adjustment algorithm, an ultra-high first-time ignition success rate and an extremely short ignition time are achieved.

[0070] 2. Achieve intelligent control: Introduce an algorithm for dynamic adjustment of electrode spacing based on airflow, precise PID temperature control, and multi-level flame verification logic to enable the system to have adaptability, high reliability, and precise control capabilities.

[0071] 3. Significant energy savings: By igniting on demand, quick start-stop, and eliminating the persistent flame, and by making a quantitative comparison with traditional ignition methods, the gas and electricity consumption per unit baking load is significantly reduced.

[0072] 4. Ensure inherent safety: The integrated multi-sensor fusion flame verification and emergency shutdown system achieves millisecond-level anomaly response, minimizing safety risks.

[0073] Example 1: System startup and main mode ignition

[0074] refer to Figure 1 , 2 3. The operator issues the baking start command via the HMI interface in the control room. PLC12 is powered on and first performs a system self-test. After the self-test passes, it enters the main ignition mode. The PLC uses a PID algorithm to control the 24V power supply 1 to rapidly heat the low-pressure heating rod 3 via the ignition high-temperature resistant cable 2, bringing its surface to 800°C within 3 seconds. Once the temperature is reached, the PLC simultaneously opens the gas pneumatic ball valve and the compressed air pneumatic ball valve within a 5-second ignition window. Gas (pressure 0.05MPa, flow rate 5m³ / min) mixes with compressed air. Immediately, the ignition burner 6 generates a high-pressure spark that acts on the surface of the incandescent low-pressure heating rod 3, instantly igniting the gas mixture. The ultraviolet sensor 13-1 immediately detects the flame, and the first-level verification passes.

[0075] Example 2: Standby Mode Triggering and Intelligent Adjustment

[0076] Continuing the previous example, if the main mode fails to ignite three times consecutively due to extreme humidity or airflow disturbance, the PLC automatically switches to the backup high-voltage discharge ignition mode. At this time, the air flow meter detects a current compressed air flow rate of 10 m³ / min. The PLC uses its built-in `Q_air-d` lookup table (e.g., 8 m³ / min corresponds to 3.0 mm, 10 m³ / min to 2.8 mm, and 12 m³ / min to 2.6 mm) to output a control signal to the electrode spacing adjustment servo mechanism 14, precisely adjusting the discharge electrode spacing to 2.8 mm. After adjustment, the igniter generates a high-voltage spark for ignition, successfully igniting the gas. After successful ignition, the flame verification group 13 operates, and the PLC stops discharging after receiving a stable signal.

[0077] Example 3: Safety Interlock Trigger

[0078] During the baking process, the infrared vision system 13-3 suddenly detected that the flame coverage within the ROI dropped to 40% (below the 60% threshold), while the K-type thermocouple 13-2 detected an abnormal decrease in the temperature gradient. These two-level verification anomalies triggered the safety interlock. Within 2 seconds, the PLC issued a shutdown command, the emergency gas shut-off valve closed, the power was cut off, the on-site audible and visual alarms sounded, and the fault code "F102 (Abnormal Flame Pattern and Temperature)" was pushed to the remote control system HMI interface. The system entered protection mode, awaiting troubleshooting.

[0079] Example 4: Ignition under boundary conditions

[0080] When the ambient temperature is -15℃ and the compressed air flow rate is 12m³ / min, the PLC adjusts the electrode spacing to 2.6mm according to the Q_air-d correspondence table. Ignition in standby mode is successful on the first try, and the flame stabilization time is 9 seconds.

[0081] To ensure safety during the baking process, a comprehensive safety control system is in place. For example, an ion signal collector can be used to monitor the flame on the lid in real time. Once the flame goes out, the supply of combustion-supporting gases such as coal gas and oxygen is immediately shut off to prevent gas spills and potential safety hazards. Simultaneously, multiple alarms are installed in the surrounding area to promptly alert workers and allow for rapid evacuation from the danger zone in case of any abnormalities.

[0082] Specifically, electrode materials are usually made of materials such as tungsten and platinum. These materials are resistant to high temperatures, do not easily oxidize, and have good conductivity, which can ensure the stability and continuity of the electric arc.

[0083] Specifically, the scrap steel baking device involved in the embodiments of the present invention has significant innovations compared with traditional methods, which will be described in detail below through specific embodiments.

[0084] Traditional scrap metal baking equipment mostly uses manual ignition or electric spark ignition. Manual ignition is inefficient and poses safety hazards, while electric spark ignition has a success rate of about 60%. The low-pressure heating rod 3 automatic ignition system of this invention utilizes low-pressure technology to achieve automatic ignition. During implementation, upon receiving an ignition command, the PLC control system precisely controls the heating power of the low-pressure heating rod 3, enabling it to reach a reference temperature of 800℃ within 3 seconds. Subsequently, after reaching the target temperature, the gas is ignited within 5-8 seconds, using radiant heat to ignite the gas.

[0085] During ignition, the heating power of the low-pressure heating rod 3 is precisely controlled through a PID temperature control algorithm, ensuring a temperature response time of ≤10 seconds and avoiding energy waste caused by overheating. Simultaneously, the ignition window is optimized, shortening the gas supply time while ensuring successful ignition and improving baking efficiency. Compared to traditional devices, more scrap steel can be baked in the same amount of time, with energy consumption reduced by approximately 99%.

[0086] This system is closely integrated with the intelligent control system, enabling remote monitoring and management. Operators can remotely send commands to start and stop the baking process via terminal devices, and obtain real-time information such as equipment operating status and temperature data. Furthermore, the system features automatic fault diagnosis and alarm functions, reducing the difficulty and risk of manual operation and improving the overall automation level of the equipment. The low-pressure heating rod 3 automatic ignition system is highly adaptable to fuels and operating conditions. Regardless of the calorific value of the gas or the shape and size of the scrap steel, the system can ensure baking quality and production efficiency by adjusting ignition parameters and baking strategies.

[0087] The implementation of the various embodiments of the present invention is based on programmed processing by a device with processor functionality. Therefore, in practical engineering, the technical solutions and functions of the various embodiments of the present invention are encapsulated into various modules. Based on this reality, and building upon the above embodiments, the embodiments of the present invention provide an automatic ignition system for a molten iron ladle scrap baking device 11, which is used to execute an automatic ignition method for a molten iron ladle scrap baking device 11 as described in the above method embodiments.

[0088] This invention provides an automatic ignition system for a molten iron ladle scrap steel baking device 11. Existing technologies often suffer from low efficiency, high safety risks, and the tendency for manual ignition to extinguish, requiring repeated on-site operations. This system employs several modules to achieve rapid and uniform heating, reducing energy consumption from persistent flames, improving baking efficiency, reducing on-site manual operation, lowering operational risks, and enhancing overall operational safety. It also improves the reliability and safety of ignition. Furthermore, the low-pressure heating rod 3 is designed and used with a focus on energy conservation and high efficiency. Through precise control of the ignition process, energy waste is reduced. This system can handle different types of scrap steel and baking requirements, ensuring baking quality and production efficiency.

[0089] Finally, it should be noted that the above specific embodiments are merely representative examples of the present invention. Obviously, the present invention is not limited to the above specific embodiments and many variations are possible. Any simple modifications, equivalent changes, and alterations made to the above specific embodiments based on the technical essence of the present invention are protected.

Claims

1. An automatic ignition method for a scrap steel baking device for molten iron ladles, characterized in that, include: Start the power supply to the molten iron ladle scrap baking device; Based on the power supply of the molten iron ladle scrap baking device, the low-pressure heating rods built into the molten iron ladle scrap baking device are preheated through the ignition high-temperature resistant cable. When the low-pressure heating rod is preheated and reaches the preset ignition conditions, the gas supply mechanism and compressed air mechanism of the molten iron ladle scrap steel baking device are triggered to deliver gas and compressed air to the ignition area respectively, forming a combustible mixture. The high-pressure spark generated by the ignition burner acts on the surface of the preheated low-pressure hot bar, and the combustible mixture is ignited by the combined energy of the hot surface and the electric spark, thus realizing the automatic ignition of the molten iron ladle scrap steel baking device.

2. The automatic ignition method for a scrap steel baking device for molten iron ladles according to claim 1, characterized in that, The process of preheating the low-pressure heating rod to achieve the preset ignition conditions includes: In the initial stage of ignition, the heating power is adjusted by temperature control so that the low-pressure heating rod reaches the reference temperature of 800°C within a set time of 3 seconds. After the low-pressure heating rod reaches the reference temperature, it enters an ignition window period of 5-8 seconds and waits for a preset time of 3 seconds to trigger the gas supply mechanism and compressed air mechanism to deliver gas to the ignition area for the low-pressure heating rod to ignite.

3. The automatic ignition method for a scrap steel baking device for molten iron ladles according to claim 2, characterized in that, The method further includes: If ignition fails three times consecutively using the low-pressure heating rod within the ignition window, the system will switch to the backup high-pressure discharge ignition mode.

4. The automatic ignition method for a scrap steel baking device for molten iron ladles according to claim 3, characterized in that, In the standby high-voltage discharge ignition mode, the electrode spacing is dynamically adjusted according to the air flow.

5. The automatic ignition method for a scrap steel baking device for molten iron ladles according to claim 2, characterized in that, Gas is supplied to the ignition zone through a gas supply system and a compressed air system, including: The gas supply unit adjusts the valve opening according to the preset gas flow rate parameter of 5 m³ / min, and delivers the gas to the ignition area after the pressure is stabilized to 0.05 MPa by the pressure reducing valve; at the same time, the compressed air unit compresses the air to 0.6 MPa ± 0.05 MPa by the pressure reducing valve and delivers the compressed air to the ignition area. The fuel gas and compressed air mix in the ignition zone to form a combustible mixture.

6. The automatic ignition method for a scrap steel baking device for molten iron ladles according to claim 1, characterized in that, The method further includes: performing three-level flame verification after ignition, including: detecting the initial ignition flame through an ultraviolet flame sensor, detecting the rate of change of the combustion chamber temperature gradient through a K-type thermocouple, and identifying the flame shape through an infrared vision system. When the proportion of flame pixels in the preset ROI area is >60%, it is determined that the shape is normal.

7. An automatic ignition method for a scrap steel baking device for molten iron ladles according to claim 6, characterized in that, Flame verification is performed sequentially, and also includes: If two or more of the three levels of verification fail, the gas supply and power supply will be shut off within ≤3 seconds, and an audible and visual alarm will be issued. At the same time, a fault code will be pushed to the remote control system.

8. An automatic ignition system for a scrap steel baking device for molten iron ladles, characterized in that, include: Control unit: Based on PLC, it integrates PID temperature control module, dynamic spacing adjustment algorithm module, and safety interlock logic module; Execution unit: Ignition high-temperature resistant cable, connects power supply and low-voltage heating rod, transmits electrical energy to the low-voltage heating rod built into the molten iron ladle scrap baking device and preheats it; The low-pressure heating rod is placed inside the iron ladle scrap steel baking device and receives electrical energy through an ignition high-temperature resistant cable for preheating. The gas supply system is connected to the ignition zone and supplies gas to the ignition zone when the low-pressure heating rod reaches the preset ignition conditions. The compressed air mechanism is connected to the ignition zone and delivers compressed air to the ignition zone when the low-pressure heated rod reaches the preset ignition conditions. The dual-mode igniter integrates an ignition burner that can generate high-voltage sparks and a high-voltage discharge device with dynamically adjustable electrode spacing. The ignition burner generates a high-voltage spark that acts on the surface of a preheated low-pressure hot rod, igniting the combustible mixture of gas and compressed air. The electrode spacing adjustment servo mechanism is used to precisely control the electrode position and optimize the heating effect; Sensing and verification unit: including ultraviolet flame sensor, K-type thermocouple, infrared vision camera and air flow meter, used to collect ignition process parameters and perform flame verification; Safety Unit: Includes emergency shut-off valve, audible and visual alarm, and remote fault push module, used for safety protection under abnormal operating conditions.

9. An automatic ignition system for a scrap steel baking device for molten iron ladles according to claim 8, characterized in that, The gas supply mechanism includes: a gas manual valve, normally open, used to shut off the gas supply during maintenance; a gas pneumatic ball valve with switch feedback, used to control the on / off state of the gas passage; and a pressure reducing valve, used to stabilize the gas pressure to 0.05 MPa.

10. An automatic ignition system for a scrap steel baking device for molten iron ladles according to claim 8, characterized in that, The compressed air mechanism includes: a normally open manual compressed air valve for controlling the supply of compressed air; a pneumatic compressed air ball valve for controlling the opening and closing of the compressed air passage and adjusting the air flow to a set value after the high-pressure spark stabilizes; and a pressure reducing valve for stabilizing the compressed air pressure to 0.6MPa±0.05.

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