Porous media off-line baking burner and method adapted to coke oven gas

Abstract

The present application relates to the technical field of metal casting, in particular to a multi-hole medium tundish off-line baking burner and method suitable for coke oven gas. The burner comprises a burner body, a pretreatment unit, a pure silicon carbide multi-hole medium carrier and an intelligent control unit. The burner body adopts a modular structure composed of a main combustion module and a laterally movable side adjustment module, which can flexibly adapt to different ladle types. The pretreatment unit purifies the coke oven gas, the multi-hole medium carrier has the functions of catalysis, filtration and heat storage, ensuring stable and efficient combustion. The method includes ladle type adaptation, gas purification, multi-hole medium combustion and dynamic intelligent regulation based on real-time temperature feedback. The present application solves the problems of poor combustion adaptability of coke oven gas, uneven baking temperature field and insufficient equipment flexibility, realizes the excellent effects of tundish inner wall temperature difference ≤74℃, gas saving 22.6% and nitrogen oxide emission ≤47mg / Nm 3 .

Description

Technical Field

[0001] This invention relates to the field of metal casting technology, specifically to an offline baking burner and method for a porous medium tundish adapted to coke oven gas. Background Technology

[0002] As a critical buffer and refining vessel in continuous casting production, the uniformity and stability of the tundish lining temperature have a decisive impact on the cleanliness of molten steel, smooth continuous casting operation, and billet quality. Offline preheating is a key process to ensure that the tundish reaches the predetermined temperature before being put into use, eliminates moisture in the lining, and avoids secondary contamination of the molten steel and thermal shock. The core technical requirement of this process is to achieve rapid and uniform heating of the three-dimensional temperature field on the inner wall of the tundish. Traditionally, excessive temperature differences can easily lead to cracks or spalling of the refractory material, thereby affecting production safety and the lifespan of the tundish.

[0003] Currently, the tundish baking burners widely used in the industry are mainly divided into two categories: direct-fired and regenerative. Both types have significant technical bottlenecks and common defects when applied to offline baking scenarios using coke oven gas as fuel. 1. Poor fuel compatibility and low operational reliability: Mainstream burner designs are primarily designed for natural gas or blast furnace gas, which have stable calorific value and low impurity content. However, coke oven gas, as a byproduct of coking, has a complex composition, containing impurities such as tar, naphthalene, hydrogen sulfide, and solid particles. Existing burners lack targeted purification and pretreatment measures and anti-coking designs. Tar easily condenses and accumulates in the delivery pipelines, nozzles, and combustion channels, causing blockages; impurity particles exacerbate equipment wear, leading to frequent burner failures, short maintenance cycles, and low effective operating rates, failing to meet the requirements of continuous and stable production.

[0004] 2. Insufficient precision in temperature field uniformity control, making it difficult to guarantee baking quality: Whether it's direct flame combustion or regenerative periodic reversing combustion, the heat release is directional and periodic, making it difficult to form a stable and diffuse temperature field. The area directly impacted by the flame is prone to localized overheating, while other areas heat up slowly, resulting in huge temperature differences (often exceeding 150℃) between the upper, lower, inner, and outer walls of the tundish. This uneven thermal stress is the main cause of refractory lining cracking, and also leads to uneven heat storage in the ladle after baking, causing fluctuations in molten steel temperature during the initial casting stage, which is detrimental to the stable production of high-quality steel grades.

[0005] 3. Limited Equipment Flexibility and Ladle Adaptability: Continuous casting production lines typically need to adapt to various capacities (e.g., 30t to 120t) and shapes (rectangular, trapezoidal). Traditional burners are mostly fixed structures, with their flame jet range and heat flow distribution tied to specific ladle shapes. When changing the type of tundish, it often requires a complete replacement or large-scale modification of the burner, making the adaptation process cumbersome, time-consuming, and labor-intensive, increasing the complexity of equipment investment and production organization.

[0006] 4. Low energy efficiency and excessive emissions: Existing technologies have limited precision in adjusting the air-fuel ratio (typically with an error of ±5%), and the combustion organization methods (such as open flame) themselves have low radiation efficiency, resulting in incomplete combustion of coke oven gas. A large amount of chemical energy is not effectively utilized, leading to persistently high gas consumption. Simultaneously, unstable combustion conditions and localized high temperatures easily generate large amounts of nitrogen oxides (NOx). x） Their emission concentrations generally exceed 100 mg / Nm³. 3 It is difficult to meet the increasingly stringent environmental regulations (such as GB28664-2012 "Emission Standard of Air Pollutants for Iron and Steel Industry").

[0007] Porous media combustion technology has shown great potential in the field of industrial heating due to its advantages such as stable combustion, high radiation efficiency, low pollutant emissions, and uniform temperature field. However, there are currently no mature and reliable technical solutions or industrial demonstration applications reported domestically or internationally for applying porous media combustion technology to coke oven gas with tar impurities, and specifically for the offline tundish multi-bundle, high-uniformity baking conditions. This technological gap seriously restricts the efficient and clean resource utilization of by-product coke oven gas by steel enterprises, and also hinders the further improvement of energy efficiency and product quality in continuous casting processes. Summary of the Invention

[0008] To overcome the shortcomings of existing technologies, this invention provides a porous medium tundish offline baking burner and method adapted to coke oven gas, which can fundamentally solve tar blockage and wear, achieve precise and uniform temperature field control, flexibly adapt to various tundish types, and has the advantages of high efficiency, energy saving and ultra-low emissions.

[0009] To achieve the above objectives, the present invention employs the following technical solution: An offline baking burner for a porous medium tundish adapted to coke oven gas includes a burner body, a pretreatment unit, a purified silicon carbide porous medium carrier, and an intelligent control unit. The burner body includes a main combustion module and a side adjustment module. The main combustion module is fixed to the end of the tundish, and the side adjustment module is slidably connected to the main combustion module. The pretreatment unit is connected to the gas inlet of the burner body to purify the coke oven gas. The purified silicon carbide porous medium carrier consists of an upper high-porosity catalytic layer, a middle medium-porosity filter layer, and a lower low-porosity heat storage layer. The surface of the upper high-porosity catalytic layer is coated with a composite catalytic coating. The intelligent control unit is electrically connected to the burner body to achieve precise and uniform temperature control, intelligent self-adaptation, and compatibility.

[0010] Furthermore, the main combustion module and the side adjustment module are slidably connected via a slide rail, and the main combustion module and the side adjustment module are equipped with replaceable fan-shaped nozzle assemblies.

[0011] Furthermore, the nozzle of the fan-shaped nozzle assembly is made of GH4169 high-temperature alloy substrate, with a tungsten carbide wear-resistant layer coated on its inner wall and a spiral cooling water channel provided on its outer wall.

[0012] Furthermore, the pretreatment unit includes a cyclone separator and an electrostatic precipitator. One end of the cyclone separator is connected to the coke oven gas source pipeline, and the other end is connected to the electrostatic precipitator pipeline. The electrostatic precipitator is connected to the gas inlet pipeline of the burner body.

[0013] Furthermore, it also includes a staged mixing system, which includes a Venturi mixer and an annular air distribution channel. The staged mixing system is connected to the pretreatment unit and is configured to premix and finely mix the pretreated coke oven gas with primary air and secondary air in sequence. The mixing ratio is controlled by an electric regulating valve with an adjustment accuracy of ±0.3%.

[0014] Furthermore, the purity of the purified silicon carbide porous medium carrier is ≥99.5%; wherein, the porosity of the upper high-porosity catalyst layer is 35%~45%, the porosity of the middle filter layer is 20%~30%, and the porosity of the lower heat storage layer (33) is 10%~15%.

[0015] Furthermore, the composite catalytic coating is a Ni-Cr-Al-Y composite catalytic coating.

[0016] Furthermore, the intelligent control unit includes a full-area temperature signal acquisition module, an artificial intelligence adaptive temperature control unit, and a system-compatible linkage execution module. The full-area temperature signal acquisition module is equipped with infrared temperature sensors, which are configured at multiple locations on the inner wall of the intermediate bread to be preheated and baked. The artificial intelligence adaptive temperature control unit, based on a PLC and a neural network algorithm, is connected to the temperature signal acquisition module and is used to dynamically adjust the air-fuel ratio, flame intensity, and flame angle of the main combustion module and the side adjustment module according to real-time temperature data. The system-compatible linkage execution module is configured to communicate and coordinate with the existing preheating control system on site.

[0017] An offline preheating and baking method for intermediate bread includes the following steps: S1: Adjust the lateral position of the side adjustment module and install the fan-shaped nozzle assembly at the corresponding angle according to the shape and volume of the intermediate bread to be baked; S2: Start the pretreatment unit and the staged mixing system to purify the coke oven gas and mix it with air in a set ratio; S3: Ignite the mixed gas to allow it to burn on the surface and inside the purified silicon carbide porous medium carrier; S4: The intelligent control unit collects the temperature at multiple points on the inner wall of the tundish in real time, and dynamically adjusts the gas supply, air ratio, and flame distribution of each combustion module based on artificial intelligence algorithms, so that the maximum temperature difference on the inner wall of the tundish is ≤74℃, and the nitrogen oxide emissions are controlled to ≤47mg / Nm³. 3 .

[0018] Furthermore, in step S4, when a fluctuation in the calorific value of the coke oven gas is detected, the artificial intelligence adaptive temperature control unit adjusts the gas supply and air distribution ratio in coordination within 0.8s to maintain stable heat output.

[0019] Compared with the prior art, the beneficial effects of the present invention are: 1. It fundamentally solved the compatibility problem of coke oven gas combustion and achieved highly reliable operation.

[0020] This invention employs a two-stage pretreatment unit consisting of a cyclone separator and an electrostatic precipitator, combined with a purified silicon carbide porous media carrier featuring a three-layer composite structure comprising a catalytic cracking layer, a filter layer, and a heat storage layer. Particularly noteworthy is the Ni-Cr-Al-Y composite catalytic coating on the surface of the catalytic cracking layer, forming a triple purification and combustion mechanism of "physical interception - electrostatic collection - high-temperature catalytic cracking." This mechanism effectively removes solid particles ≥10μm from coke oven gas and reduces the tar content to 8mg / m³. 3 Furthermore, it can simultaneously catalytically decompose penetrating tar components into small-molecule combustible gases at temperatures above 400℃. This eradicates the industry's chronic problems of tar clogging combustion channels and impurities wearing down key components at the source. Practical applications show that the burner can operate continuously and stably for a year without clogging, with a failure rate reduced by more than 90% compared to traditional burners, maintenance costs reduced by 80%, and service life extended from the traditional 3 years to more than 8 years. This provides a reliable technical guarantee for the stable, efficient, and clean utilization of coke oven gas in offline baking scenarios.

[0021] 2. It achieves precise and uniform control of the temperature field of the intermediate bread, which greatly improves the baking quality and bread life.

[0022] This invention utilizes a planar, diffuse, and highly radiant uniform flame generated during combustion in a porous medium carrier as a heat source, replacing the concentrated point or linear flames of traditional direct-fired or regenerative combustion. More importantly, the closed-loop control logic in step S3 of the method—"real-time monitoring of the temperature at multiple locations on the inner wall of the tundish and dynamic adjustment of combustion parameters based on temperature feedback"—is specifically executed by the full-area temperature signal acquisition module and the artificial intelligence adaptive temperature control unit in the intelligent control unit. This unit, based on a 12-point infrared temperature measurement network and neural network algorithm, can perceive the temperature field distribution in real time. When a local temperature difference is detected, it can dynamically adjust the air-fuel ratio, fuel supply, and flame angle of the main combustion module and the side adjustment module within 0.8 seconds, achieving intelligent heat redistribution. This allows the temperature of the three-dimensional space of the inner wall of the tundish to rise synchronously and evenly during the baking process. Application results show that for different tundish types ranging from 30 to 120 tons, the maximum temperature difference on the inner wall is stably controlled between 62°C and 74°C, a reduction of more than 50% compared to the temperature difference of over 150°C in traditional technologies. A uniform temperature field significantly reduces the thermal stress of refractory materials, extends the service life of tundishes by more than 15%, and creates ideal conditions for the subsequent isothermal casting of high-quality steel.

[0023] 3. It has excellent multi-package flexibility and adaptability, which significantly improves production flexibility and economic efficiency.

[0024] This invention achieves a unified approach of rapid hardware adjustment and automatic software adaptation by combining modular structural design with a built-in intelligent control model. On the hardware side, according to step S1, operators only need to adjust the lateral position of the side adjustment module (adjustable from 0 to 3 meters, with an accuracy of ±10 mm) via a slide rail, based on the width of the tundish to be baked, and replace the fan-shaped nozzle assembly with the corresponding spray angle (30°, 45°, 60° selectable). This allows for a switch from one ladle type to another within 1 hour, without requiring a complete burner replacement, improving adaptation efficiency by over 80%. On the software side, the AI-adaptive temperature control unit incorporates optimized control models for different volumes and shapes of tundishes. After changing the ladle type, the system automatically calls the corresponding model, achieving "ready to use after replacement." This innovation solves the rigid "one burner per ladle" model of traditional burners, enabling a single set of equipment to cover most tundish types in steel plants, reducing equipment investment costs by approximately 60%, and significantly improving the flexibility of continuous casting production organization.

[0025] 4. Significant energy savings and ultra-low pollutant emissions have been achieved, resulting in a win-win situation for both economic and environmental benefits.

[0026] This invention achieves a 99.3% combustion efficiency for coke oven gas by combining three technologies: "pretreatment to ensure fuel cleanliness," "a staged mixing system to achieve ±0.3% air-fuel ratio control," and "porous media low-temperature combustion with AI dynamic optimization." Among these, porous media combustion inherently possesses characteristics of complete combustion and high radiation efficiency, while the AI ​​control system can adjust based on calorific value fluctuations (15-19 MJ / m³). 3 This method precisely matches the optimal air-fuel ratio in real time, avoiding heat loss caused by improper air coefficient. Actual operating data shows that compared to traditional coke oven gas baking methods, this method can achieve a 22.6% reduction in gas consumption. Based on an annual production of 1200 intermediate batches, this translates to an annual gas saving of approximately 1.8 million cubic meters, equivalent to an energy cost of approximately 9.2 million yuan. In terms of environmental protection, uniform and stable low-temperature combustion effectively suppresses the formation of thermal NOx. Combined with precise air-fuel ratio control, this keeps the NOx emission concentration in the flue gas stable at 47 mg / Nm³. 3 The following carbon monoxide (CO) emissions are ≤35 mg / Nm³. 3 It reduces emissions by more than 55% compared to traditional burners, far exceeding the limits set by the national "Emission Standard for Air Pollutants from the Iron and Steel Industry" (GB28664-2012), thus achieving cleaner production.

[0027] 5. It has good system compatibility and intelligence, reducing upgrade and transformation costs and operational difficulties.

[0028] By employing a standard PROFINET industrial Ethernet interface through a system-compatible linkage execution module, the burner and method described in this invention can achieve seamless data integration and command coordination with the existing tundish preheating and baking control system in steel plants. The existing central control room can receive the burner's real-time temperature curves and fault alarms without modification, and issue unified heating rate commands (e.g., 100℃ / h), achieving synchronous start-up and coordinated control between the old and new systems. This significantly reduces the complexity and implementation cost of technical upgrades. Simultaneously, the artificial intelligence adaptive control unit automates and intelligently manages the complex multivariable temperature field control process, reducing reliance on operator experience and improving the accuracy and repeatability of overall process control. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the present invention.

[0030] Figure 2 This is a schematic diagram of the main structure of the modular burner of the present invention.

[0031] Figure 3 This is a schematic diagram of the purified silicon carbide porous media carrier structure of the present invention.

[0032] Figure 4 This is the core control logic diagram of the present invention.

[0033] In the diagram: 1. Burner body; 2. Pretreatment unit; 3. Purified silicon carbide porous media carrier; 4. Intelligent control unit; 11. Main combustion module; 12. Slide rail; 13. Side adjustment module; 14. Fan-shaped nozzle assembly; 21. Cyclone impurity remover; 22. Electrostatic precipitator; 31. Upper high-porosity catalytic layer; 32. Middle medium-porosity filter layer; 33. Lower low-porosity heat storage layer; 51. Venturi mixer; 52. Annular air distribution channel. Detailed Implementation

[0034] This invention discloses a porous medium tundish offline baking burner and method adapted to coke oven gas. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments, and those skilled in the art can obviously make modifications or appropriate changes and combinations to the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0035] This invention provides a porous medium tundish offline baking burner and method adapted to coke oven gas, aiming to systematically solve industry problems such as poor coke oven gas combustion adaptability, uneven tundish baking temperature field, insufficient equipment flexibility, and high energy consumption and emissions. The following description uses a preferred embodiment. The described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0036] Example: An offline baking system for porous media tundish adapted to coke oven gas and its working method I. Overall System Composition like Figure 1 As shown, the system in this embodiment mainly includes four core components: a burner body 1, a pretreatment unit 2, a purified silicon carbide porous media carrier 3, and an intelligent control unit 4. This system is installed at the offline preheating station of the tundish in the continuous casting workshop of an iron and steel enterprise, and is used to uniformly heat the tundish lining to a predetermined temperature (e.g., 1100°C) before casting.

[0037] II. Detailed Structure and Function of Each Component 1. Burner body 1 The burner body 1 is the system's execution terminal, employing an innovative modular and adjustable design. For example... Figure 2 As shown, it mainly consists of a main combustion module 11, a slide rail 12, and a side adjustment module 13.

[0038] Main combustion module 11: It is fixedly installed at the center of one end of the intermediate bread to be baked via a bracket, serving as the basic heat source and main control unit.

[0039] Side adjustment module 13: It is mechanically connected to the main combustion module 11 via a high-precision slide rail 12. It can slide laterally according to the width of the tundish (usually between 2m and 5m), with an adjustment range of 0-3m and a positioning accuracy of ±10mm. This design allows a single burner to flexibly adapt to rectangular or trapezoidal tundishes of different widths.

[0040] Fan-shaped nozzle assembly 14: The flame outlet end of the main combustion module 11 and each side adjustment module 13 is equipped with a quick-detachable fan-shaped nozzle assembly 14. The nozzle assembly offers nozzles with various spray angles such as 30°, 45°, and 60° for selection. By changing the nozzles, the coverage and shape of the flame can be further adjusted to match the three-dimensional thermal requirements of tundishes with different volumes (30t to 120t).

[0041] To further enhance durability, the fan-shaped nozzle is forged from GH4169 high-temperature alloy. Its inner wall is plasma-sprayed with a 1.5mm thick tungsten carbide wear-resistant layer to resist the scouring of impurity particles in coke oven gas. The outer wall is machined with a spiral cooling water channel, which is connected to the industrial cooling water circulation in the plant area to control the nozzle's working temperature below 250℃, effectively preventing high-temperature sulfide corrosion and thermal deformation.

[0042] 2. Preprocessing Unit 2 Pretreatment unit 2 is connected in series between the coke oven gas main and the gas inlet of burner body 1, and is specifically used for purifying coke oven gas. It adopts a two-stage series purification process: First stage: Cyclone separator 21. Coke oven gas first enters the cyclone separator 21 tangentially. Under the action of centrifugal force, heavy impurities such as solid dust and iron filings with a particle size greater than or equal to 10µm are separated and collected into the bottom ash hopper.

[0043] Second stage: Electrostatic precipitator 22. The pre-treated coal gas then enters the electrostatic precipitator 22. Under the action of a high-voltage electrostatic field, tar droplets, naphthalene, and other light liquid impurities in the coal gas are adsorbed and captured, reducing the tar content in the outlet coal gas to 8 mg / m³. 3 the following.

[0044] After passing through this pretreatment unit, the cleanliness of the coke oven gas is greatly improved, laying the foundation for subsequent stable and blockage-free combustion.

[0045] 3. Purified silicon carbide porous media carrier like Figure 3As shown, this is one of the core technical features of the present invention. The carrier 3 is a silicon carbide ceramic plate integrally sintered, with a purity of over 99.5% (purification treatment), few impurities, and good high-temperature stability. This carrier is not a homogeneous structure, but rather a carefully designed three-layer composite structure with functional gradients along the thickness direction (i.e., the gas flow direction): Upper high-porosity catalytic layer 31: facing the flame, with a porosity of 35%~45%. The surface of this layer is firmly coated with a Ni-Cr-Al-Y composite catalytic coating (bonding force ≥60MPa) through high-temperature sintering. When the gas flows through, the coating can catalytically decompose the residual trace tar components into small molecule combustible gases at temperatures above 400℃, achieving "clean combustion".

[0046] The middle layer of the medium-porosity filter layer 32 has a porosity of 20%~30%. Its pore size distribution can effectively intercept extremely fine particles that may remain after penetrating the pretreatment unit and the catalyst layer, thus protecting the subsequent flow channels.

[0047] The lower low-porosity heat storage layer 33 is located near the unexposed surface and has a porosity of 10%-15%. This layer is dense and has a strong heat storage capacity. It can uniformly store the heat generated by combustion and slowly and stably release it in the form of radiation, thereby forming a planar, uniform, flameless radiant heat source, which fundamentally solves the problem of local overheating caused by direct flame impact.

[0048] 4. Graded mixing system 5 To ensure thorough mixing of the purified gas and air, this system also includes a staged mixing system 5 (see [link]). Figure 1 , 2 The system consists of a Venturi mixer 51, an annular air distribution channel 52, and a high-precision electric regulating valve.

[0049] Primary premixing: The purified coke oven gas is initially mixed with approximately 60% of the total primary air (primary primary air) in the Venturi mixer 51.

[0050] Secondary fine mixing: The premixed gas enters the burner head and undergoes secondary fine mixing with the remaining 40% secondary air (secondary secondary air) through the annular air distribution channel 52 to ensure that a highly homogeneous combustible premixed gas is formed before entering the porous medium carrier 3.

[0051] Precise control: The flow rates of gas and primary and secondary air are controlled by high-precision electric regulating valves, and the air-fuel ratio adjustment accuracy of the system can reach ±0.3%, providing a key guarantee for efficient and low-pollution combustion.

[0052] 5. Intelligent Control Unit 4 like Figure 4As shown in the core control logic diagram, the intelligent control unit is the brain of the system, realizing closed-loop intelligent control from perception and decision-making to execution. It consists of three core modules: Full-area temperature signal acquisition module: 12 high-precision infrared temperature sensors (temperature measurement accuracy ±2℃) are arranged at different heights (bottom, middle, and top) and different positions (center and edge) on the inner wall of the intermediate bread to be baked, to monitor the temperature field distribution in real time, with data acquisition and transmission delay ≤30ms.

[0053] Artificial Intelligence Adaptive Temperature Control Unit: Using an industrial PLC as the main controller, this unit embeds a temperature field control model based on a neural network algorithm. It receives temperature data from the modules in real time and dynamically analyzes the temperature field uniformity. When a region is detected to be too cold, it automatically calculates and outputs commands to adjust the opening of the gas valve and air valve (i.e., air-fuel ratio and flame intensity) of the corresponding main combustion module 11 or side adjustment module 13, and even changes the heat flow distribution by adjusting the angle of the nozzles in the side modules. For real-time fluctuations in the calorific value of coke oven gas (15~19 MJ / m³), this system can complete the coordinated adjustment of the gas volume ratio within 0.8 seconds to maintain stable heat output.

[0054] System-compatible linkage execution module: Adopting the PROFINET industrial Ethernet communication protocol, it has a standard interface. This module is responsible for data exchange and command coordination with the steel plant's existing tundish preheating and baking central control system. The new burner can upload temperature curves, equipment status, and alarm information to the original control room, while receiving overall heating rate commands (such as 100℃ / h) from the original system, achieving seamless integration and synchronous operation of the old and new systems without the need to modify the original control cabinet, greatly saving on transformation costs.

[0055] III. System Working Methods and Processes The method for offline baking of intermediate packages using this system includes the following steps: Step S1: Package type adaptation and initial settings.

[0056] Depending on the specific model of the intermediate loaf to be baked (e.g., a 60t trapezoidal loaf), the operator moves the side adjustment modules 13 on both sides to a position approximately 2.2m from the main module 11 using the slide rail 12. Then, the nozzles on the main module 11 and the side modules 13 are replaced with 45° fan-shaped nozzle assemblies 14. On the human-machine interface of the intelligent control unit 4, the corresponding "60t trapezoidal loaf" baking process model is selected.

[0057] Step S2: Fuel purification and mixing preparation.

[0058] The coke oven gas supply is activated, and the gas flows sequentially through the cyclone separator 21 and the electrostatic precipitator 22 in the pretreatment unit 2 for purification. Subsequently, the purified gas enters the staged mixing system 5, where it is thoroughly mixed with proportionally supplied air in the Venturi mixer 51 and the annular air distribution channel 52 to form a uniform combustible premixed gas. The system automatically sets the initial air-fuel ratio based on the real-time calorific value of the gas (e.g., 17 MJ / m³).

[0059] Step S3: Ignition and combustion of porous media.

[0060] The ignition device is activated to ignite the premixed gas. The flame rapidly spreads and stabilizes inside and on the surface of the porous medium carrier 3, heating the carrier to an incandescent state (e.g., initial preheating to 350°C), radiating a uniform and stable high-intensity infrared heat flow outward, thus baking the intermediate ladle from all directions.

[0061] Step S4: Intelligent closed-loop baking control.

[0062] The baking process enters the intelligent control stage. Twelve infrared sensors in the full-area temperature signal acquisition module continuously monitor the temperature inside the bag. The artificial intelligence adaptive temperature control unit dynamically adjusts the temperature based on the deviation between the real-time temperature data and the preset heating curve (e.g., heating from 80℃ / h to 1100℃).

[0063] For example, during the middle of baking, the system detected that the temperature at the bottom of the bread was 65°C higher than that at the top. The control unit immediately issued a command to appropriately reduce the gas supply of the main combustion module 11 by about 10%, while simultaneously increasing the flame injection angle of the two regulating modules 13 to 50° and slightly increasing their gas flow. After about 30 minutes, the temperature difference decreased to 42°C.

[0064] For example, if the calorific value of coke oven gas fluctuates from 17 MJ / m³ to 15.2 MJ / m³ during operation, the system responds within 0.7 seconds, increasing the total gas supply by 12% and simultaneously adjusting the air distribution ratio to the new optimal value to ensure a stable heating rate.

[0065] Throughout the baking process, the system continuously performs such fine-tuning to ensure that the maximum temperature difference between various points on the inner wall of the intermediate bread never exceeds the set threshold of 74°C. Furthermore, by optimizing the combustion conditions, it reduces nitrogen oxides (NOx). x Emission concentrations should be controlled below 47 mg / Nm³.

[0066] Step S5: End and Switch.

[0067] Once the intermediate package reaches the predetermined temperature and completes the heat preservation process, the system sequentially shuts off the gas and air to stop baking. If another type of package (such as a 30t rectangular package) needs to be baked, simply replace the nozzle with a 30° nozzle, adjust the side module spacing to 1.5m, and select the corresponding model in the control system. The entire changeover preparation time can be shortened to less than 1 hour.

[0068] IV. Implementation Results In practical application at the steelmaking plant of Benxi Beiying Iron & Steel (Group) Co., Ltd., this system has been running stably for over a year, completing over 2000 heats of tundish baking. Practice shows that: 1. Excellent temperature uniformity: During baking of three typical ladle types (30t rectangular, 60t trapezoidal, and 120t rectangular), the maximum temperature difference on the inner wall is stable at 62℃, 74℃, and 68℃ respectively, which is more than 50% lower than the traditional technology (>150℃). This fully meets the production requirements of high-quality steels such as ultra-low carbon steel, and the service life of the refractory lining of the tundish is expected to be extended by 15%.

[0069] Stable and reliable operation: No tar blockage of the combustion channel occurred, the wear-resistant coating of the nozzle remained intact, the number of annual failures decreased by more than 90% compared to previous equipment, and maintenance costs were reduced by about 80%.

[0070] 2. Significant energy conservation and environmental protection: The combustion efficiency of coke oven gas has been increased to 99.3%, achieving a gas saving of 22.6%, and nitrogen oxide emissions have been stably kept below 47 mg / Nm³. 3 It saves nearly 10 million yuan in energy costs annually, and its environmental protection indicators far exceed national standards.

[0071] 3. Flexible and efficient: Modular design improves package type change efficiency by more than 80%, significantly enhancing the flexibility of production organization.

[0072] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An offline baking burner for a porous medium tundish adapted to coke oven gas, characterized in that, It includes a burner body (1), a pretreatment unit (2), a purified silicon carbide porous medium carrier (3), and an intelligent control unit (4). The burner body (1) includes a main combustion module (11) and a side adjustment module (13). The main combustion module (11) is fixed to the end of the intermediate tumbler, and the side adjustment module (13) is slidably connected to the main combustion module (11). The pretreatment unit (2) is connected to the gas inlet of the burner body (1) to purify the coke oven gas; The purified silicon carbide porous media carrier (3) is composed of an upper high porosity catalyst layer (31), a middle medium porosity filter layer (32) and a lower low porosity heat storage layer (33). The surface of the upper high porosity catalyst layer (31) is coated with a composite catalyst coating. The intelligent control unit (4) is electrically connected to the burner body (1) to achieve precise and uniform temperature control, intelligent self-adaptation and compatibility.

2. The porous medium tundish offline baking burner adapted to coke oven gas according to claim 1, characterized in that, The main combustion module (11) and the side adjustment module (13) are slidably connected by a slide rail (12), and the main combustion module (11) and the side adjustment module (13) are equipped with replaceable fan-shaped nozzle assemblies (14).

3. The porous medium tundish offline baking burner adapted to coke oven gas according to claim 2, characterized in that, The nozzle of the fan-shaped nozzle assembly (14) is made of GH4169 high-temperature alloy substrate, with tungsten carbide wear-resistant layer coated on its inner wall and spiral cooling water channel provided on its outer wall.

4. The porous medium tundish offline baking burner adapted to coke oven gas according to claim 1, characterized in that, The pretreatment unit (2) includes a cyclone separator (21) and an electrostatic precipitator (22). One end of the cyclone separator (21) is connected to the coke oven gas source pipeline, and the other end is connected to the electrostatic precipitator (22) pipeline. The electrostatic precipitator (22) is connected to the gas inlet pipeline of the burner body (1).

5. The porous medium tundish offline baking burner adapted to coke oven gas according to claim 4, characterized in that, It also includes a graded mixing system (5), which includes a Venturi mixer (51) and an annular air distribution channel (52). The graded mixing system (5) is connected to the pretreatment unit (2) and is configured to premix and finely mix the pretreated coke oven gas with primary air and secondary air in sequence. The mixing ratio is controlled by an electric regulating valve with an adjustment accuracy of ±0.3%.

6. The porous medium tundish offline baking burner adapted to coke oven gas according to claim 1, characterized in that, The purity of the purified silicon carbide porous medium carrier (3) is ≥99.5%; wherein the porosity of the upper high porosity catalyst layer (31) is 35%~45%, the porosity of the middle filter layer (32) is 20%~30%, and the porosity of the lower heat storage layer (33) is 10%~15%.

7. The porous medium tundish offline baking burner adapted to coke oven gas according to claim 1, characterized in that, The composite catalytic coating is a Ni-Cr-Al-Y composite catalytic coating.

8. The porous medium tundish offline baking burner adapted to coke oven gas according to claim 1, characterized in that, The intelligent control unit (4) includes a full-area temperature signal acquisition module, an artificial intelligence adaptive temperature control unit, and a system-compatible linkage execution module; The full-area temperature signal acquisition module is equipped with infrared temperature sensors, which are configured at multiple locations on the inner wall of the intermediate bread to be preheated and baked. The artificial intelligence adaptive temperature control unit, based on PLC and neural network algorithm, is connected to the temperature signal acquisition module and is used to dynamically adjust the air-fuel ratio, flame intensity and flame angle of the main combustion module (11) and the side adjustment module (13) according to real-time temperature data. The system-compatible linkage execution module is configured to communicate and coordinate with the existing preheating control system on site.

9. A preheating and baking method based on the porous medium tundish offline baking burner adapted to coke oven gas as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: Adjust the lateral position of the side adjustment module (13) and install the fan-shaped nozzle assembly (14) at the corresponding angle according to the shape and volume of the intermediate bread to be baked. S2: Start the pretreatment unit (2) and the graded mixing system (5) to purify the coke oven gas and mix it with air in a set ratio; S3: Ignite the mixed gas to make it burn on the surface and inside of the purified silicon carbide porous medium carrier (3); S4: The intelligent control unit (4) collects the temperature of multiple points on the inner wall of the tundish in real time, and dynamically adjusts the gas supply, air ratio and flame distribution of each combustion module based on artificial intelligence algorithms, so that the maximum temperature difference on the inner wall of the tundish is ≤74℃, and the nitrogen oxide emission is controlled to ≤47mg / Nm³. 3 .

10. The offline intermediate batch preheating and baking method according to claim 9, characterized in that, In step S4, when a fluctuation in the calorific value of coke oven gas is detected, the artificial intelligence adaptive temperature control unit adjusts the gas supply and air distribution ratio in coordination within 0.8s to maintain stable heat output.

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