Double-oxygen-lance blow-in technology suitable for rapid production recovery of blast furnace

Abstract

The invention provides a double-oxygen-lance blow-in technology suitable for rapid production recovery of a blast furnace, and belongs to the field of blast furnace ironmaking. The technology comprises the following steps: (1) adopting a specific blow-in ore blending and charging system; and (2) preheating and melting an iron notch area by adopting a visual intelligent double-oxygen lance device. According to the method, a macroscopic charging heat system design is combined with a microcosmic local iron notch heating channel technology, and precise cooperation is formed in time and space, so that the normal smelting state of the blast furnace is efficiently reconstructed on the premise of ensuring safety. By means of the technology, the blast furnace can rapidly recover production, the normal production state can be achieved within 24 h, the time is shortened from 72 h to 24 h, the blow-in and subsequent production cost is greatly reduced, the labor intensity of workers is reduced, it is ensured that first furnace iron of the blast furnace safely and smoothly passes through a skimmer, and safe blow-in is achieved.

Description

Technical Field

[0001] This application relates to the field of blast furnace ironmaking technology, and in particular to a double oxygen lance start-up technology suitable for rapid blast furnace production recovery. Background Technology

[0002] In ironmaking, the blast furnace is the core equipment that smelts pig iron from iron ore, coke, and flux through high-temperature chemical reactions. In practice, blast furnaces often need to undergo shutdowns of several days or even longer due to planned maintenance, malfunctions, or production scheduling. During this process, the furnace temperature gradually decreases, and the molten slag and iron may re-solidify, especially in the hearth and taphole areas where localized freezing can easily occur. When the blast furnace needs to resume production, the traditional method usually relies on filling the hearth with firewood or coke and gradually heating the entire hearth with hot air supplied from the tuyeres, causing the frozen slag and iron to slowly melt and eventually flow out of the taphole. This process is not only time-consuming, often requiring more than 72 hours to gradually transition to normal production levels, but also suffers from poor furnace stability during prolonged heating, easily leading to problems such as hanging materials and difficulty in movement. Furthermore, workers at the furnace front must repeatedly attempt to tap iron, resulting in high labor intensity and safety risks.

[0003] While macroscopic charging regimes (such as coke ratio setting and segmented charging) can provide overall heat reserves for the upper part of the furnace, they are severely disconnected from the physical unblocking and rapid heating process of the crucial taphole area. This failure to effectively coordinate macroscopic heat transfer to the taphole region, where melting is most critical, and the resulting solidification blockage, in turn, hinders the recovery of the entire smelting process. Therefore, effectively coordinating the overall design of the macroscopic charging thermal regime with the precise and rapid unblocking of the microscopic taphole heating channels, while ensuring the safety of the hearth refractory materials, to significantly shorten the time from ignition and blast to the production of qualified molten iron and the resumption of normal production, has become a core technical challenge that urgently needs to be addressed for the rapid and safe recovery of blast furnace production. Summary of the Invention

[0004] This application provides a double oxygen lance start-up technology suitable for rapid blast furnace production recovery, which precisely coordinates the macroscopic charging heat regime and the microscopic local taphole heating channel required for blast furnace production recovery, thereby significantly shortening the time from ignition and blasting to normal production recovery while ensuring the safety of the blast furnace itself.

[0005] Firstly, this application provides a hydrogen lance start-up technology suitable for rapid blast furnace production recovery, comprising the following steps: (1) A specific ore blending and charging system is adopted: the total coke ratio of the whole furnace is determined to be 2700 kg / t, and the target composition of pig iron is set as [Si] 3%, [Mn] 1.2%, and [Fe] 93%; and the hearth filling wood method is adopted during the charging process, specifically: clean coke is filled in the dead iron layer, hearth and 2 / 3 of the height of the furnace belly; empty coke is filled in the remaining 1 / 3 of the hearth, waist and the lower 3m area of ​​the furnace body; and segmented load material is filled in the area above 3m of the lower part of the furnace body, with the load values ​​of the segmented load material being 2.42, 2.62 and 2.96 respectively. (2) Preheating and melting of the taphole area using a visual intelligent oxygen lance device: The visual intelligent oxygen lance device is sent into the taphole channel of the blast furnace, and the oxygen supply is controlled to continuously supply oxygen for at least 8 hours under the condition that the oxygen supply pressure is not lower than 0.6MPa. At the same time, the combustion status in the furnace is monitored in real time by the camera built into the visual intelligent oxygen lance device, and the temperature of the refractory material in the hearth is monitored by the thermocouple of the visual intelligent oxygen lance device. When the temperature of the thermocouple rises sharply to ≥600℃, the oxygen supply of the visual intelligent oxygen lance device is immediately cut off.

[0006] Optionally, the charging system is specifically as follows: a) Clean coke, weighing a total of 235 tons, is packed into the dead iron layer, hearth, and two-thirds of the furnace belly height. This is done in 23.5 batches, corresponding to a charge volume of 360.89 m³. 3 ; b) In the remaining 1 / 3 of the furnace belly, the furnace waist, and the lower 3m of the furnace body, empty coke is filled, with a total weight of 246t, in 20 batches, corresponding to a furnace charge volume of 331.83m³. 3 ; c) In the area above 3m below the furnace body, fill with normal load material, totaling 508.75t, in 23 batches, corresponding to a furnace charge volume of 381.77m³. 3 ; The total charge for the furnace was 956.3 tons, with a total of 66.5 batches and a total charge volume of 1074.49 m³. 3 .

[0007] Optionally, the batching of various furnace charges can be divided into: Net coke: Coke batch weight is 10,000 kg, without added ore; Empty coke: The batch weight of coke is 10,000 kg, with 500 kg of manganese ore and 1,800 kg of dolomite added; Loading material with a load value of 2.42: coke batch weight is 6500kg, ore batch weight is 15000kg, including 10800kg of sinter, 2250kg of pellets, 1950kg of lump ore, 550kg of manganese ore and 600kg of serpentine. Loading material with a load value of 2.62: coke batch weight is 6000kg, ore batch weight is 15000kg, including 11250kg sinter, 1800kg pellets, 1950kg lump ore, 550kg manganese ore, and 450kg serpentine. Loading material with a load value of 2.96: coke batch weight is 5300kg, ore batch weight is 15000kg, including 11250kg sinter, 2100kg pellets, 1650kg lump ore, 550kg manganese ore, and 400kg serpentine.

[0008] Optionally, the coke ratio of the load material is 662 kg / t, and the binary basicity R of the load material is... 2 The basicity of the coke is 0.90, and the total compression rate of the furnace charge is 14%.

[0009] Secondly, this application provides a visualized intelligent hydrogen lance device for the furnace start-up technology described in any one of the first aspects, comprising: The oxygen lance body is composed of an inner tube and an outer tube arranged coaxially. The inner tube and the outer tube are welded together by a connecting tube, and an annular cavity is formed between them. The inner tube forms an oxygen channel, and at least one oxygen inlet is connected to the tail end. The annular cavity forms a compressed air passage, and a compressed air inlet is connected to the tail end. The tail end of the oxygen lance body is coaxially connected to a drill bit for cooperating with the clamping mechanism of the opening machine. An alloy drill bit is installed at the front end of the oxygen lance body, and the alloy drill bit has an injection hole that communicates with the inner tube and the annular cavity. The temperature measuring component includes a thermocouple installed at the rear end of the cavity on the oxygen lance body, used to monitor the temperature at the location of the refractory material in the furnace hearth. The visualization component includes an endoscopic camera installed in the oxygen channel of the inner tube, located in front of the thermocouple, for real-time observation of the combustion status inside the furnace.

[0010] Optionally, the oxygen inlet and the compressed air inlet are located on the same cross-section at the tail end of the oxygen lance body.

[0011] Optionally, there are two oxygen inlets, one of which is oriented at a 45° downward angle and is used as a slag and iron discharge channel after the oxygen supply is cut off.

[0012] Optionally, the shank is a T38 type shank.

[0013] Optionally, the endoscopic camera is an 8mm hard-wired three-in-one high-definition camera, and it is wirelessly connected to an external display terminal via a built-in WiFi module.

[0014] Optionally, the temperature measurement range of the thermocouple is 0~1350℃, and the insertion depth is greater than the thickness of the furnace cylinder refractory material; the camera probe is located 100mm in front of the thermocouple.

[0015] The technical solutions provided in this application have the following advantages compared with the prior art: This application provides a hydrogen lance start-up technology suitable for rapid blast furnace production recovery. By combining macroscopic charging thermal regime design with microscopic localized taphole heating channel technology, precise synergy is achieved in both time and space, thereby efficiently reconstructing the blast furnace to its normal smelting state while ensuring safety. The specific synergy mechanism and implementation path are as follows: At the macro level, the aforementioned ore blending and charging system (step 1) aims to create a top-down, heat-rich, and progressively transitioning initial thermal and metallurgical environment for the blast furnace. First, by setting a high total coke ratio of 2700 kg / t, a massive amount of heat, far exceeding the requirements of conventional production, is stored for the entire furnace body, especially the lower hearth and belly. Second, a layered charging strategy is adopted: clean coke is filled in the lowermost area of ​​the furnace, providing not only an initial heat source but also forming a coke bed with good permeability, creating a physical channel for the future collection and penetration of molten iron; empty coke containing flux is filled in the middle area to pre-form initial slag with appropriate basicity and good fluidity at high temperatures, lubricating the charge column, cleaning the furnace walls, and paving the way for subsequent slag and iron descent; segmented load materials with load values ​​ranging from low to high (2.42, 2.62, 2.96) are filled in the upper part of the furnace body to achieve a gradual and gradient increase in smelting load. The core of this macro-system design lies in its systematic solution to the problem of smooth transition of the heat demand, reduction process and slagging system of the entire blast furnace charge from top to bottom during the process from ignition and air supply to normal production, thus establishing a comprehensive, top-down thermodynamic and kinetic foundation for rapid recovery.

[0016] However, macroscopic heat reserves and a good upper process are insufficient to solve the most critical bottleneck after a long blast furnace shutdown—localized freezing in the hearth and taphole areas. To address this, at the microscopic level, this application introduces a visualized intelligent oxygen lance device (step 2) to implement precise and proactive targeted intervention in the taphole area. This device is directly inserted deep into the taphole channel, using high-pressure oxygen (no less than 0.6 MPa) to violently combust with the hearth coke, generating extremely high temperatures (up to 2000°C or higher) locally. This rapidly melts the condensate in the area, physically clearing the vital channel necessary for molten iron flow. The core function of this microscopic operation is to directly overcome the "last mile" problem that macroscopic charging systems cannot solve alone, ensuring that the flow path is unobstructed before the first batch of molten iron is produced.

[0017] The precise synergy between the two is reflected in the following three aspects: First, the timing and functionality are complementary: the preheating operation of the visualized intelligent oxygen lance typically begins before or at the initial stage of blast furnace spurring and continues for at least 8 hours. This prioritizes and centrally addresses the freezing problem in the taphole area of ​​the hearth, providing an "outlet" for the heat and molten material generated under the macro-charging regime. The macro-regulation, in turn, provides a continuous supply of heat and materials for the entire smelting process, enabling the blast furnace to quickly transition to a continuous slag and iron generation and discharge state after the oxygen lance preheating.

[0018] Secondly, a closed-loop safety control system ensures precise and stable operation of the oxygen lance, as the microscopic operation is not performed blindly. Real-time monitoring of the combustion status via a built-in camera visualizes the process. More importantly, real-time monitoring of the hearth refractory temperature using thermocouples and setting a cut-off threshold of ≥600℃ create a direct safety barrier protecting the blast furnace body (hearth carbon bricks). This ensures that while pursuing rapid heating, the significant safety risk of hearth burn-through due to localized overheating is fundamentally eliminated.

[0019] Third, a shared goal orientation: The macro-charging system, by setting targets for high silicon and high manganese pig iron composition, aims to lower the melting point of the initial pig iron and improve its fluidity. The micro-oxygen lance preheating, by directly heating the taphole area, ensures that this area has a sufficiently high temperature to receive and maintain this highly fluid molten iron. The combined effect of these two systems ensures that the first batch of molten iron can be smoothly and safely discharged from the taphole and pass through the skimmer after the furnace is started, marking the significant starting point for the blast furnace to resume normal production cycles.

[0020] In summary, the technical solution of this application is not a simple superposition of isolated measures. The macro-charging system constructs a global and progressive thermal and metallurgical framework for the rapid recovery of the blast furnace; the micro-oxygen lance technology strengthens and monitors the most critical and weakest point within this framework. The two are sequential in time, cover both global and local aspects spatially, and are mutually dependent and supportive in function. Through this systematic synergy, the core bottlenecks of slow hearth heating and difficulty in producing the first batch of iron in traditional furnace start-up are effectively overcome. This achieves the remarkable effect of significantly reducing the recovery time from the traditional 72 hours to less than 24 hours while ensuring the safety of the blast furnace itself. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the visualized intelligent hydrogen peroxide lance device provided in the embodiments of this application; Figure label: 1-Skew shank, 2-Reinforcing connecting plate, 3-Tail end plug, 4-Outer tube, 5-Fixing sleeve, 6-Connecting tube, 7-Inner tube, 8-Temperature measurement and camera cable inlet, 9-Air and oxygen inlet, 10-Alloy drill bit. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0026] This application provides a hydrogen lance start-up technology suitable for rapid production recovery in blast furnaces, comprising the following steps: (1) A specific ore blending and charging system is adopted: the total coke ratio of the whole furnace is determined to be 2700 kg / t, and the target composition of pig iron is set as [Si] 3%, [Mn] 1.2%, and [Fe] 93%; and the hearth filling wood method is adopted during the charging process, specifically: clean coke is filled in the dead iron layer, hearth and 2 / 3 of the height of the furnace belly; empty coke is filled in the remaining 1 / 3 of the hearth, waist and the lower 3m area of ​​the furnace body; and segmented load material is filled in the area above 3m of the lower part of the furnace body, with the load values ​​of the segmented load material being 2.42, 2.62 and 2.96 respectively. (2) Preheating and melting of the taphole area using a visual intelligent oxygen lance device: The visual intelligent oxygen lance device is sent into the taphole channel of the blast furnace, and the oxygen supply is controlled to continuously supply oxygen for at least 8 hours under the condition that the oxygen supply pressure is not lower than 0.6MPa. At the same time, the combustion status in the furnace is monitored in real time by the camera built into the visual intelligent oxygen lance device, and the temperature of the refractory material in the hearth is monitored by the thermocouple of the visual intelligent oxygen lance device. When the temperature of the thermocouple rises sharply to ≥600℃, the oxygen supply of the visual intelligent oxygen lance device is immediately cut off.

[0027] In some embodiments, the charging system specifically includes: a) Clean coke, weighing a total of 235 tons, is packed into the dead iron layer, hearth, and two-thirds of the furnace belly height. This is done in 23.5 batches, corresponding to a charge volume of 360.89 m³. 3 ; b) In the remaining 1 / 3 of the furnace belly, the furnace waist, and the lower 3m of the furnace body, empty coke is filled, with a total weight of 246t, in 20 batches, corresponding to a furnace charge volume of 331.83m³. 3 ; c) In the area above 3m below the furnace body, fill with normal load material, totaling 508.75t, in 23 batches, corresponding to a furnace charge volume of 381.77m³. 3 ; The total charge for the furnace was 956.3 tons, with a total of 66.5 batches and a total charge volume of 1074.49 m³. 3 .

[0028] In some implementations, the batching of various furnace charges becomes: Net coke: Coke batch weight is 10,000 kg, without added ore; Empty coke: The batch weight of coke is 10,000 kg, with 500 kg of manganese ore and 1,800 kg of dolomite added; Loading material with a load value of 2.42: coke batch weight is 6500kg, ore batch weight is 15000kg, including 10800kg of sinter, 2250kg of pellets, 1950kg of lump ore, 550kg of manganese ore and 600kg of serpentine. Loading material with a load value of 2.62: coke batch weight is 6000kg, ore batch weight is 15000kg, including 11250kg sinter, 1800kg pellets, 1950kg lump ore, 550kg manganese ore, and 450kg serpentine. Loading material with a load value of 2.96: coke batch weight is 5300kg, ore batch weight is 15000kg, including 11250kg sinter, 2100kg pellets, 1650kg lump ore, 550kg manganese ore, and 400kg serpentine.

[0029] In some embodiments, the coke ratio of the load material is 662 kg / t, and the binary basicity R of the load material is... 2 The basicity of the coke is 0.90, and the total compression rate of the furnace charge is 14%.

[0030] The core of the dual-oxygen lance start-up technology for rapid blast furnace production recovery provided in this application lies in the synergistic effect of a precisely designed start-up batching system and an innovative oxygen lance device application method, which aims to enable the blast furnace to safely and quickly return to normal production status after a long-term shutdown or major overhaul.

[0031] The specific implementation of this technology first relies on the scientific design of the furnace start-up ore blending and charging system. This step aims to establish an ideal initial state for the blast furnace restart from top to bottom and from heat to metallurgy. Its core function is to provide sufficient heat reserves, ensure smooth slag formation and discharge, and achieve a smooth transition of furnace conditions.

[0032] The extremely high initial total coke ratio of the entire furnace, reaching 2700 kg / ton of iron, is designed to accumulate a large heat reserve for the entire furnace body, especially the lower hearth and belly areas, during the initial start-up phase. A layered charging strategy is employed. Pure coke, known as clean coke, is filled into the dead iron layer, hearth, and two-thirds of the belly height. Its primary function is to provide the hearth and taphole areas with the most direct and intense initial heat source through coke combustion, rapidly increasing the temperature in these areas and melting any frozen material. Secondly, the coke bed's excellent permeability creates channels for the subsequent penetration and accumulation of molten iron. The remaining one-third of the belly, waist, and the lower three meters of the furnace body are filled with coke mixed with fluxes such as dolomite, known as empty coke, with a designed basicity of 0.90. As this portion of the material descends to the high-temperature zone, the added flux reacts with the coke ash and the small amount of initial slag that follows, forming initial slag with suitable basicity and good fluidity in advance. This effectively cleans the furnace walls, lubricates the charge column, protects the furnace lining, and prepares for the smooth descent of the metal and slag produced by the subsequent load charge into the hearth. In the area above three meters in the lower part of the furnace, the loading load value gradually increases, with segmented ore loads of 2.42, 2.62, and 2.96 respectively. This serves to achieve a gradient increase in smelting load. The lower initial load allows the upper region to begin indirect reduction under relatively gentle conditions, gradually producing metallic iron and initial slag, avoiding a sharp deterioration in the permeability of the charge column due to sudden heavy load. The stepwise increase in load, matched with sufficient heat reserves in the lower part, ensures a balance in the blast furnace's heat balance and achieves a stable and controllable transition in furnace temperature.

[0033] In designing key process parameters, the target silicon content of pig iron was set at 3% and the manganese content at 1.2%. The main purpose was to lower the melting point of the pig iron and improve its fluidity, ensuring that the first batch of molten iron has good fluidity in the early stages before the temperature reaches its peak. This facilitates smooth discharge from the taphole and safe passage through the skimmer, a crucial guarantee for successful start-up. The coke ratio in the load section was designed at 662 kg / ton of iron, with a binary basicity set at 1.19. This coke ratio ensures sufficient heat for ore reduction and slag melting after the ore is introduced. The set basicity aims to form slag with moderate basicity, good fluidity, and appropriate desulfurization capacity, ensuring smooth initial slag-iron separation and high-quality pig iron. In addition, a total charge compression ratio of 14% is used for charging calculations. This parameter reflects the volume shrinkage ratio of the charge from a loose state to its actual packed state in the blast furnace. This is to more accurately predict and control the actual filling height and distribution of different charges in the furnace, ensuring that the intended charging structure is accurately realized in actual operation, thereby ensuring that the thermal regime and slagging regime can be established as designed.

[0034] Another core component of this technology is the targeted preheating and status monitoring of the visualized intelligent oxygen lance. This step directly addresses the freezing risk in the hearth and taphole areas, which are the most vulnerable parts of the blast furnace after a long-term shutdown, providing an active and controllable local heating solution.

[0035] The specific operation involves directly inserting the oxygen lance into the depths of the blast furnace taphole channel. Its fundamental function is to target and heat the taphole area and the dead material column in front of the hearth before and during the initial blasting process. The oxygen injected through the lance reacts violently with the coke in the hearth, generating temperatures far exceeding those achievable with conventional blasting. This rapidly and efficiently melts the condensate in that area, clears the molten iron channel, and significantly increases the local heat reserve in the hearth. During this process, the oxygen supply pressure must be maintained at no less than 0.6 MPa. This higher pressure ensures sufficient penetration and velocity of the oxygen jet, allowing it to reach deep into the coke layer and maintain a stable combustion reaction intensity. Simultaneously, a continuous oxygen supply for at least eight hours is required. This is based on calculations of the amount of frozen material in the hearth and the heat balance, ensuring sufficient total heat input to fully preheat and melt the channel from the taphole area to the hearth, laying a solid foundation for the safe and successful opening of the first taphole. Thermocouples installed at the tail end of the oxygen lance are used to monitor the temperature of the refractory backing material or adjacent areas of the hearth in real time. When the monitored temperature rises sharply to 600℃ or above, it indicates that the oxygen lance's combustion point is very close to or threatens the safety limit of the hearth's carbon bricks. Immediately cutting off the oxygen supply at this point is crucial to prevent overheating and damage to the expensive hearth refractory material, avoiding a major safety accident such as hearth burn-through. This is a critical safety interlock control point. Simultaneously, the built-in endoscope camera in the oxygen lance allows direct observation of the state and color of the combustion flame and the melting of coke inside the furnace, achieving process visualization. Operators can remotely and intuitively judge whether the oxygen lance has successfully ignited, whether combustion is sufficient and stable, and the expansion of the preheating zone, providing a basis for real-time operational adjustments. This transforms traditional blind operation into precise, visualized operation, greatly improving the safety and reliability of process control.

[0036] In summary, this rapid blast furnace production recovery technology establishes a gradual and well-prepared initial metallurgical state for the blast furnace through a scientific charging system at the top. Simultaneously, the lower-level visualized intelligent oxygen lance technology provides proactive and enhanced localized heating and unblocking of key bottleneck areas. These two technologies work in close coordination in both time and space to overcome the core challenges of slow hearth heating and difficulty in smoothly discharging the first batch of molten iron in traditional furnace start-up methods, thus achieving the overall goal of rapid and safe production recovery. All technical parameters were designed around the core principles of ensuring sufficient heat supply, optimizing slag metallurgical properties, ensuring operational safety, and achieving full-process controllability.

[0037] Based on a general inventive concept, this application provides a visualized intelligent oxygen lance device for any of the above-described furnace start-up techniques, comprising: The oxygen lance body is composed of an inner tube 7 and an outer tube 4 arranged coaxially. The inner tube 7 and the outer tube 4 are welded and fixed by a connecting pipe 6, and an annular cavity is formed between them. The inner tube 7 forms an oxygen channel, and at least one oxygen inlet is connected to its tail end. The annular cavity forms a compressed air passage, and a compressed air inlet is connected to the tail end. The tail end of the oxygen lance body is coaxially connected to a drill bit 1 for cooperating with the clamping mechanism of the opening machine; An alloy drill bit 10 is installed at the front end of the oxygen lance body, and the alloy drill bit 10 has an injection hole that communicates with the inner tube 7 and the annular cavity. The temperature measuring component includes a thermocouple installed at the rear end of the cavity on the oxygen lance body, used to monitor the temperature at the location of the refractory material in the furnace hearth. The visualization component includes an endoscopic camera installed in the oxygen channel of the inner tube 7, located in front of the thermocouple, for real-time observation of the combustion status inside the furnace.

[0038] In some embodiments, the oxygen inlet and the compressed air inlet are located on the same cross-section at the tail end of the oxygen lance body.

[0039] In some embodiments, there are two oxygen inlets, one of which is oriented at a 45° downward angle and is used as a slag and iron discharge channel after the oxygen supply is cut off.

[0040] In some embodiments, the shank 1 is a T38 type shank.

[0041] In some implementations, the endoscopic camera is an 8mm hard-wired three-in-one high-definition camera, and it is wirelessly connected to an external display terminal via a built-in WiFi module.

[0042] In some embodiments, the thermocouple has a temperature measurement range of 0~1350℃ and an insertion depth greater than the thickness of the furnace cylinder refractory material; the camera probe is located 100mm in front of the thermocouple.

[0043] The visualized intelligent oxygen lance device is a specialized piece of equipment designed to meet the needs of rapid blast furnace start-up and resumption of production. Its core function is to achieve safe, efficient, and controllable targeted preheating and status monitoring of the taphole area of ​​the blast furnace. Through a series of carefully designed structures and components working together, this device overcomes the problems of uneven heating, blind operation, and high safety risks inherent in traditional start-up methods.

[0044] The main structure of the device is the oxygen lance body, which consists of an inner tube and an outer tube coaxially mounted and fixed by a welded connecting pipe, thus forming an annular cavity between the inner and outer tubes. This dual-tube coaxial design is the basis for achieving multi-functional integration. Specifically, the inner tube forms a direct core oxygen channel, whose core function is to deliver high-pressure oxygen deep into the furnace hearth, providing a reactant for the intense combustion of coke, which is fundamental to generating a high-temperature heat source. The outer tube serves as a protective structure and cooling channel, and the annular cavity between it and the inner tube is used as a compressed air channel. The introduced compressed air has a dual key function: first, as it flows through the annular cavity, it continuously cools the inner tube, preventing it from burning out under the extreme high temperatures inside the furnace and ensuring the structural integrity of the oxygen lance during long-term operation; second, after the compressed air is ejected from the lance head, it mixes with oxygen, playing a role in assisting combustion, adjusting the flame pattern, and further cooling and protecting the lance head.

[0045] To ensure the oxygen lance is installed accurately and securely and delivered to its intended position, a specially designed drill bit is coaxially connected to the tail end of the device. This drill bit's structure perfectly matches the clamping mechanism of the blast furnace tappet. Its function is to reliably mount the oxygen lance on the tappet and, with the help of the tappet's feeding mechanism, smoothly and precisely push the oxygen lance along the taphole channel to the preset depth in the hearth, much like a drill rod. At the very tip of the oxygen lance, a specially designed alloy drill bit is installed. Its primary function is to use its high hardness and wear resistance to break through any residual slag, iron, or coke fragments that may exist in the taphole channel during the advancement process, ensuring the oxygen lance reaches the target area smoothly. Simultaneously, the drill bit has injection holes that connect to the inner tube oxygen channel and the annular compressed air channel. Their function is to ensure that the oxygen-air mixture is injected into the coke layer in the hearth with optimal flow and direction, triggering a highly efficient and concentrated combustion reaction.

[0046] The intelligence and safety of this device are reflected in its integrated temperature measurement and visualization components. The temperature measurement component includes thermocouples installed in the rear cavity of the oxygen lance body, with a temperature measurement range covering 0 to 1350℃. Their insertion depth is calculated to ensure monitoring of the temperature at the refractory backing of the hearth. Its core function is to perceive the thermal state of the hearth carbon bricks in real time and directly. When the oxygen lance's combustion point gets too close to the refractory, causing its temperature to rise sharply to 600℃ or higher, the system can provide timely and accurate early warning signals. This is a key monitoring method to prevent hearth burn-through and ensure the safety of the blast furnace body. The visualization component includes an endoscopic camera installed in the inner tube oxygen channel. Its probe is located approximately 100 mm in front of the thermocouple, using an 8 mm hard-wired three-in-one high-definition standard, and transmits signals through a built-in wireless network module. Its fundamental function is to achieve remote visual monitoring of the process. Operators can observe the color, shape, size of the flame in the furnace and the melting of coke in real time on an external display terminal, thereby intuitively judging the preheating effect, combustion stability and oxygen lance working status, transforming traditional experience-based inference into precise operation based on real-time images.

[0047] In terms of specific implementation details, the oxygen inlet and compressed air inlet are located on the same cross-section at the tail end of the oxygen lance body. This layout simplifies the connection of external pipelines and promotes the initial mixing of the two gases before ejection. Furthermore, two oxygen inlets are provided, with one of the pipes angled downwards at 45 degrees. This design gives this inlet an extended function: when oxygen needs to be cut off after preheating, this angled inlet can be converted into an emergency or planned discharge channel for molten slag and iron, using gravity to draw out any molten material that may accumulate, thereby extending the overall effective time of the oxygen lance and helping to reduce heat loss. The use of a T38 type tappet is to match the industry-standard tappet opening equipment, ensuring the device's wide applicability and ease of installation.

[0048] In summary, the visualized intelligent oxygen lance device, with its unique dual-tube structure, robust drilling and feeding front end, integrated temperature measurement and visual sensing system, and user-friendly interface design, constitutes a comprehensive system integrating drilling and feeding, high-pressure oxygen supply, cooling protection, temperature monitoring, video observation, and emergency slag removal. Each component performs its specific function while working closely together to achieve the precise preheating goal of "visible, controllable, and safe" operation in the blast furnace hearth area, providing crucial technical equipment support for the rapid and safe resumption of blast furnace production.

[0049] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to industry standards. If there is no corresponding industry standard, then common international standards, conventional conditions, or conditions recommended by the manufacturer are followed. Example

[0050] This application provides a hydrogen lance start-up technology suitable for rapid production recovery in blast furnaces, comprising the following steps: (1) A scientifically sound and reasonable ore blending ratio for furnace start-up: The total coke ratio of the entire furnace is 2700 kg / t, the pig iron composition is [Si] 3% + [Mn] 1.2% + [Fe] 93%, the normal feed coke ratio is 662 kg / t, the normal feed R2=1.19, the basicity of the empty coke is 0.90, and the total compression rate is 14%. The main method of filling the hearth with wood is adopted, that is, the area below the tuyere is filled with sleepers, the area from the tuyere to 2 / 3 of the furnace belly is filled with clean coke, the 1 / 3 of the furnace belly, the furnace waist and the lower 3 meters of the furnace body are filled with empty coke, and the area above the lower 3 meters of the furnace body is filled with light load material. The load material is loaded in three sections with loads of 2.42 (load 1), 2.62 (load 2) and 2.96 (load 3). The specific loading sequence and composition are shown in Tables 1 and 2.

[0051]

[0052] (2) A visual intelligent hydrogen peroxide gun device: Each oxygen lance in a dual-fuel lance consists of an inner tube 7 and an outer tube 4, which are welded together via a connecting pipe 6. During welding, it is ensured that the inner and outer tubes are coaxial, forming a cavity between them. Oxygen is supplied to the inner tube for combustion, while compressed air is supplied to the cavity for cooling and auxiliary combustion. A T38 probe 1 is installed at the tail end for easy feeding into the furnace using an opening machine. A thermocouple is installed at the rear end of the cavity near the refractory material of the furnace hearth. When the oxygen lance burns down to the refractory material of the furnace hearth, the thermocouple temperature rises sharply, at which point oxygen supply must be stopped immediately. An oxygen inlet and a compressed air inlet are installed on the outer tube, located on the same cross-section to facilitate oxygen-air mixing. To increase oxygen pressure and flow rate, the oxygen lance body is equipped with dual oxygen inlets at the tail end, one of which is angled downwards at 45°. When the thermocouple temperature rises sharply to ≥600° or exceeds the range, it indicates that the oxygen lance has burned to the refractory material position in the hearth. The oxygen is immediately cut off without removing the lance. Slag and iron are discharged from the 45° angled air inlet pipe of the oxygen lance, controlling and extending the tapping time and reducing heat loss from the hearth.

[0053] The installation of traditional oxygen lances on the opening machine is relatively difficult. To solve this problem, the rear end of the oxygen lance body is coaxially equipped with the opening machine's shank. The opening machine's shank serves to install the oxygen lance on the opening machine, and the oxygen lance is buried in the hearth by the opening machine's feeding mechanism.

[0054] An alloy drill bit 10 is installed at the very front of the oxygen lance body. The drill bit's placement allows the oxygen lance body to be smoothly drilled into the preset position, reducing obstruction from residual slag, iron, and coke fragments during the oxygen lance's entry into the taphole channel. The drill bit is connected to the mixed gas channel, ensuring that the mixed gas is injected into the furnace hearth through the four holes of the drill bit. An endoscope camera is installed in the oxygen channel of the inner tube to monitor the success of oxygen lance ignition and the combustion status inside the furnace, enabling real-time monitoring of oxygen combustion. The camera is located in front of the thermocouple. The endoscope camera is an 8mm hard wire (three-in-one high-definition version). A mobile app is downloaded and connects to the phone via built-in Wi-Fi to display the combustion status in real time.

[0055] After application, the system enabled the blast furnace to resume production within 51 minutes by introducing coal gas, 10 hours and 28 minutes by direct water and slag flow for iron tapping, and 12 hours and 44 minutes by fully opening the tuyeres to restore normal production.

[0056] Therefore, this embodiment provides a scientific and reasonable ore blending ratio for furnace start-up and a visual intelligent oxygen lance device. Combining the above two points, it enables the blast furnace to quickly resume production and reach normal production status within 24 hours, shortening the original 72 hours to 24 hours. This significantly reduces the start-up and subsequent production costs, reduces the labor intensity of workers, and ensures the safe and smooth passage of the first batch of iron through the skimmer, thus achieving safe furnace start-up.

[0057] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A hydrogen lance start-up technology suitable for rapid blast furnace production recovery, characterized in that, Includes the following steps: (1) A specific ore blending and charging system is adopted: the total coke ratio of the whole furnace is determined to be 2700 kg / t, and the target composition of pig iron is set as [Si] 3%, [Mn] 1.2%, and [Fe] 93%; and the hearth filling wood method is adopted during the charging process, specifically: clean coke is filled in the dead iron layer, hearth and 2 / 3 of the height of the furnace belly; empty coke is filled in the remaining 1 / 3 of the hearth, waist and the lower 3m area of ​​the furnace body; and segmented load material is filled in the area above 3m of the lower part of the furnace body, with the load values ​​of the segmented load material being 2.42, 2.62 and 2.96 respectively. (2) Preheating and melting of the taphole area using a visual intelligent oxygen lance device: The visual intelligent oxygen lance device is sent into the taphole channel of the blast furnace, and the oxygen supply is controlled to continuously supply oxygen for at least 8 hours under the condition that the oxygen supply pressure is not lower than 0.6MPa. At the same time, the combustion status in the furnace is monitored in real time by the camera built into the visual intelligent oxygen lance device, and the temperature of the refractory material in the hearth is monitored by the thermocouple of the visual intelligent oxygen lance device. When the temperature of the thermocouple rises sharply to ≥600℃, the oxygen supply of the visual intelligent oxygen lance device is immediately cut off.

2. The oxygen lance start-up technology for rapid blast furnace production recovery according to claim 1, characterized in that, The specific loading system is as follows: a) Clean coke, weighing a total of 235 tons, is packed into the dead iron layer, hearth, and two-thirds of the furnace belly height. This is done in 23.5 batches, corresponding to a charge volume of 360.89 m³. 3 ; b) In the remaining 1 / 3 of the furnace belly, the furnace waist, and the lower 3m of the furnace body, empty coke is filled, with a total weight of 246t, loaded in 20 batches, corresponding to a furnace charge volume of 331.83m³. 3 ; c) In the area above 3m below the furnace body, fill with normal load material, totaling 508.75t, in 23 batches, corresponding to a furnace charge volume of 381.77m³. 3 ; The total charge for the furnace was 956.3 tons, with a total of 66.5 batches and a total charge volume of 1074.49 m³. 3 .

3. The oxygen lance start-up technology for rapid blast furnace production recovery according to claim 1, characterized in that, The batching of various furnace materials becomes: Net coke: Coke batch weight is 10,000 kg, without added ore; Empty coke: The batch weight of coke is 10,000 kg, with 500 kg of manganese ore and 1,800 kg of dolomite added; Loading material with a load value of 2.42: coke batch weight is 6500kg, ore batch weight is 15000kg, including 10800kg of sinter, 2250kg of pellets, 1950kg of lump ore, 550kg of manganese ore and 600kg of serpentine. Loading material with a load value of 2.62: coke batch weight is 6000kg, ore batch weight is 15000kg, including 11250kg sinter, 1800kg pellets, 1950kg lump ore, 550kg manganese ore, and 450kg serpentine. Loading material with a load value of 2.96: coke batch weight is 5300kg, ore batch weight is 15000kg, including 11250kg sinter, 2100kg pellets, 1650kg lump ore, 550kg manganese ore, and 400kg serpentine.

4. The oxygen lance start-up technology for rapid blast furnace production recovery according to claim 3, characterized in that, The coke ratio of the load feed is 662 kg / t, and the binary basicity R of the load feed is... 2 The basicity of the coke is 0.90, and the total compression rate of the furnace charge is 14%.

5. A visualized intelligent hydrogen lance device for the furnace start-up technology according to any one of claims 1 to 4, characterized in that, include: The oxygen lance body is composed of an inner tube (7) and an outer tube (4) arranged coaxially. The inner tube (7) and the outer tube (4) are welded and fixed by a connecting pipe (6), and an annular cavity is formed between them. The inner tube (7) forms an oxygen channel, and at least one oxygen inlet is connected to the tail end; The annular cavity forms a compressed air passage, and a compressed air inlet is connected to the tail end. The tail end of the oxygen lance body is coaxially connected to a drill bit (1) for cooperating with the clamping mechanism of the opening machine; An alloy drill bit (10) is installed at the front end of the oxygen lance body. The alloy drill bit (10) has an injection hole that communicates with the inner tube (7) and the annular cavity. The temperature measuring component includes a thermocouple installed at the rear end of the cavity on the oxygen lance body, used to monitor the temperature at the location of the refractory material in the furnace hearth. The visualization component includes an endoscope camera located in the oxygen channel of the inner tube (7), the camera being positioned in front of the thermocouple for real-time observation of the combustion status inside the furnace.

6. The visualized intelligent hydrogen peroxide gun device according to claim 5, characterized in that, The oxygen inlet and the compressed air inlet are located on the same cross-section at the tail end of the oxygen lance body.

7. The visualized intelligent hydrogen peroxide gun device according to claim 5 or 6, characterized in that, There are two oxygen inlets, one of which has its pipe angled downwards at 45° to serve as a slag and iron discharge channel after the oxygen supply is cut off.

8. The visualized intelligent hydrogen peroxide gun device according to claim 5, characterized in that, The drill bit (1) is a T38 type drill bit.

9. The visualized intelligent hydrogen peroxide gun device according to claim 5, characterized in that, The endoscopic camera is an 8mm hard-wired three-in-one high-definition camera, and it is wirelessly connected to an external display terminal via a built-in WiFi module.

10. The visualized intelligent hydrogen peroxide gun device according to claim 5, characterized in that, The thermocouple has a temperature measurement range of 0~1350℃ and an insertion depth greater than the thickness of the furnace cylinder refractory material; the camera probe is located 100mm in front of the thermocouple.

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