Blast furnace swinging flow nozzle roaster and roasting method

Abstract

The invention discloses a blast furnace swinging flow nozzle roaster and a roasting method, and relates to the technical field of roasting in the steel industry, the blast furnace swinging flow nozzle roaster comprises a roaster shell, a natural gas pipe, a compressed air pipe and a combustor, the inner surface of a main body of the roaster shell is made of a refractory material, and the combustor is installed in a roasting cavity of the roaster shell; the burner is provided with an outer pipe and a burner nozzle arranged in the outer pipe, the burner nozzle is communicated with a natural gas pipe, the outer pipe is communicated with a compressed air pipe, and valves are arranged on the pipe sections, extending out of the roaster shell, of the natural gas pipe and the compressed air pipe respectively. The problems that an existing blast furnace swing flow nozzle roaster is low in production efficiency and large in safety risk are solved.

Description

Technical Field

[0001] The invention relates to the technical field of baking in the steel industry, in particular to a blast furnace swing nozzle baking device and a baking method. Background Art

[0002] The swing nozzle of a blast furnace is a key equipment in blast furnace ironmaking. It is located below the iron ditch in the iron-making yard. Its main function is to flexibly change the flow direction of molten iron and guide the molten iron to flow to the molten iron tank car. By reducing the length of the iron ditch, the swing nozzle optimizes the on-site layout, thereby improving the overall space utilization efficiency; at the same time, mechanized operation reduces the labor intensity of workers, improves the working environment, and improves the comfort and safety of work. In addition, the application of the swing nozzle also significantly reduces the loss of iron ditch, enhances the transportation efficiency of molten iron, and ensures smooth and efficient production. In general, the swing nozzle plays an important role in blast furnace ironmaking and is an indispensable equipment. In order to ensure the continuity of production and the reliability of equipment, the swing nozzle is usually driven by an electric motor and is equipped with a spare chain drive.

[0003] However, in the traditional baking process of the swing nozzle of the blast furnace, the basic baking process is usually carried out by igniting the natural gas transported through the hard pipe to form a torch. This baking method has the following problems: 1. This baking method is mainly an open operation, and the heat is difficult to be effectively gathered and controlled. A large amount of heat energy is dissipated into the surrounding environment unnecessarily, which not only causes a huge waste of energy, but also prolongs the baking time and reduces production efficiency; 2. The increase in baking time brings potential safety risks to the production process and may lead to the loss of spare parts for the swing nozzle, thereby affecting the continuity and stability of production. In order to overcome the problems of the above-mentioned traditional baking methods, it is necessary to explore more efficient and safe baking methods to improve production efficiency and reduce potential risks. Summary of the invention

[0004] The purpose of the present invention is to provide a blast furnace swing nozzle roaster, which can solve the problems of low production efficiency and greater safety risks of the existing blast furnace swing nozzle roaster.

[0005] In order to solve the above problems, the technical solution adopted by the present invention is: this blast furnace swing nozzle roaster includes a roaster shell, a natural gas pipe, a compressed air pipe and a burner, the inner surface of the main body of the roaster shell is made of refractory material, and a burner is installed in the baking chamber of the roaster shell. The burner is provided with an outer tube and a burner disposed in the outer tube, the burner is connected to the natural gas pipe, and the outer tube is connected to the compressed air pipe. Valves are respectively provided on the pipe sections of the natural gas pipe and the compressed air pipe extending out of the roaster shell.

[0006] In the above technical solution of the blast furnace swing nozzle roaster, a more specific technical solution may also be: the burner is installed at the center of the roaster shell, the outer tube is a stainless steel tube, and the burner is provided with a swirl vane.

[0007] In some possible solutions, the side wall of the roaster shell is provided with an inner side plate and an outer side plate, and refractory mud is filled between the inner side plate and the outer side plate.

[0008] In some possible solutions, the inner side plate and the swing flow nozzle are gap-matched.

[0009] In some possible solutions, the compressed air pipe is arranged in multiple circles in the baking chamber.

[0010] Another object of the present invention is to provide a blast furnace swing nozzle baking method, the method using the blast furnace swing nozzle baking device, specifically comprising the following steps: S1. Pre-purge: Open the compressed air valve to purge the inside of the roaster for 5 to 10 minutes to remove impurities. S2. Ignition: Open the natural gas valve, use the ignition device to ignite, observe the flame state, and ensure that the flame is stable; S3, heating stage: cover the baking device on the swing flow nozzle for baking, slowly increase the flow rate of natural gas and compressed air, and heat up at a heating rate of 100℃ / h; S4, constant temperature stage: keep constant temperature baking for 10 to 12 hours, the constant temperature is 800℃; S5, cooling stage: close the natural gas valve and compressed air valve, and cool down naturally to normal temperature.

[0011] In the technical solution of the above-mentioned blast furnace swing nozzle baking method, a more specific technical solution can also be: the ambient temperature of the baking operation is 5-35°C, the natural gas pressure is 0.1-0.2MPa, and the compressed air pressure is 0.3-0.5MPa.

[0012] In some possible solutions, multiple temperature sensors are arranged in the swing flow nozzle for temperature monitoring.

[0013] In some possible solutions, flame status monitoring is performed during the baking process to observe the flame color, shape and stability. A normal flame is blue, stable and has no obvious jumping or flameout phenomenon.

[0014] Among the possible solutions, pressure monitoring is performed during the baking process to continuously monitor the pressure of natural gas and compressed air to ensure that they fluctuate within the specified range.

[0015] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art: 1. The blast furnace swing nozzle roaster is equipped with a roaster shell made of refractory materials, and is equipped with a dual pipeline of natural gas pipe and compressed air pipe and burner. Then, the heat reverse heating technology is used to effectively reduce heat loss and natural gas consumption, and improve energy utilization efficiency; the burner and burner design ensure that the natural gas burns more fully and stably, effectively avoiding the occurrence of flameout, thereby ensuring the continuity and stability of the combustion process, achieving the highest calorific value, and accurately controlling the air-fuel ratio through the valve to further optimize the combustion effect. In addition, its structure is simple and reliable, which reduces the manufacturing cost and maintenance difficulty, ensures the stability of equipment operation, and reduces safety risks. The heat of the roaster is concentrated, not easy to dissipate, saves energy, and has a short baking time.

[0016] 2. The burner is installed in the center of the roaster shell to ensure uniform heat distribution and improve the consistency of the roasting effect; the outer tube of the burner is made of stainless steel, which enhances durability and corrosion resistance, extends the service life of the equipment and reduces maintenance costs; the burner is equipped with swirl vanes to accelerate the premixing of fuel and air and shorten the ignition delay time. The outer tube is filled with compressed air low-temperature medium to form an "air film cooling" effect, which protects the burner head from high-temperature ablation, while reducing the outer wall temperature and extending the service life.

[0017] 3. The structural design of the roaster shell significantly reduces the heat loss to the outside, ensures the heat concentration in the baking chamber, and improves the energy utilization efficiency; at the same time, the high temperature resistance and thermal shock resistance of the refractory clay enhance the structural stability and durability of the shell, extend the service life of the equipment, and reduce the loss and maintenance cost caused by high temperature erosion.

[0018] 4. The compressed air pipe in the baking chamber is arranged in multiple circles, which can use the heat of the cavity to heat the gas in the pipe during the heating process, effectively increase the temperature of the compressed air, thereby improving the combustion efficiency and reducing fuel consumption.

[0019] 5. The blast furnace swing nozzle baking method first effectively removes impurities inside the baking device through pre-purge to ensure the cleanliness and safety of the baking process; ensures flame stability during ignition to improve operational safety; slowly heats up at a rate of 100℃ / h during the heating stage to avoid equipment damage or material deformation; maintains a constant temperature baking for 10 to 12 hours during the constant temperature stage to ensure that the material is evenly heated and improves the baking quality and consistency; and adopts a natural cooling method during the cooling stage to reduce equipment stress and extend the service life of the equipment. These steps and parameters work together to improve the efficiency, safety and quality of the baking process, while extending the service life of the equipment.

[0020] 6. The baking operation is carried out at an ambient temperature of 5 to 35°C, which can adapt to a wide range of ambient temperature conditions to ensure the stability and reliability of the baking process. At the same time, the pressure of natural gas and compressed air is controlled within a reasonable range to ensure combustion efficiency and safety.

[0021] 7. During baking, real-time monitoring and adjustment of temperature, flame state and pressure can ensure the consistency of the baking process and improve product quality and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the blast furnace swing nozzle roaster.

[0023] Explanation of the accompanying figures: 1. Roaster shell; 2. Outer side plate; 3. Refractory clay; 4. Inner side plate; 5. Roaster cavity; 6. Natural gas pipe; 7. Natural gas valve; 8. Compressed air pipe; 9. Compressed air valve; 10. Burner; 11. Outer pipe; 12. Burner. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings: Figure 1 The blast furnace swing nozzle roaster shown mainly includes a roaster shell 1, a natural gas pipe 6, a compressed air pipe 8 and a burner 10. The main body of the roaster shell 1 is made of refractory material, which can withstand the high temperature baking environment, avoid deformation or damage of the shell due to high temperature baking, and ensure the stability and durability of the equipment under long-term high temperature operation. The burner 10 is installed in the baking cavity 5 of the roaster shell 1, and fuel and combustion-supporting gas are provided through the natural gas pipe 6 and the compressed air pipe 8 respectively to achieve efficient combustion.

[0025] The side wall of the roaster shell 1 is designed as a multi-layer structure, and the side wall is provided with an inner side plate 4 and an outer side plate 2 made of steel plates, and refractory mud is filled between the inner side plate 4 and the outer side plate 2. The refractory mud has good thermal insulation performance, which can effectively reduce the heat transfer to the outside and improve the utilization rate of thermal energy. The inner side plate 4 of the roaster shell 1 and the swing flow nozzle adopt a clearance fit design, which not only ensures the effective transfer of heat, but also avoids equipment damage caused by thermal expansion.

[0026] The burner 10 is installed at the center of the baking chamber 5 to ensure uniform heat distribution. The burner 10 consists of an outer tube 11 and a burner 12. The burner 12 is arranged in the outer tube. The outer tube 11 is made of a stainless steel tube, which has the characteristics of high temperature resistance and corrosion resistance and can adapt to long-term high temperature working environment. The burner 12 is fed with natural gas, and the outer tube 11 introduces compressed air. The gradient mixing of fuel and combustion-supporting agent is achieved through layered injection, avoiding the problem of uneven concentration of traditional single-tube mixing. At the same time, the flow rate and pressure of the pipeline are adjusted to achieve segmented control of the combustion reaction, improve the combustion efficiency and reduce the generation of local high-temperature areas. The burner 12 is provided with a swirl plate, which can fully mix the natural gas and compressed air to form a stable swirl flame and improve the combustion efficiency; in addition, the swirl plate can also accelerate the premixing of fuel and air and shorten the ignition delay time. The burner 12 is connected to the natural gas pipe 6 to provide fuel; the outer tube 11 is connected to the compressed air pipe 8 to provide combustion-supporting gas. The two work together to ensure the stability and efficiency of the combustion process. The compressed air introduced into the outer tube 11 can be used as a low-temperature medium to form an "air film cooling" effect, thereby protecting the head of the burner 12 from high-temperature ablation, while reducing the temperature of the outer wall and extending the service life.

[0027] The natural gas pipe 6 and the compressed air pipe 8 are used to transport natural gas and compressed air respectively. Valves are provided on the pipe sections of both extending out of the roaster housing 1. The two valves are natural gas valve 7 and compressed air valve 9, respectively, which are used to control the corresponding gas flow. The natural gas pipe 6 provides fuel, and the compressed air pipe 8 provides combustion-supporting gas. The two work together through the burner 10 to achieve efficient combustion. The compressed air pipe 8 is arranged in multiple circles in the roasting chamber 5 to extend the length of the compressed air pipeline in the roasting chamber 5, so that the heat generated during the heating process can fully heat the combustion-supporting gas in the pipeline, increase the temperature of the compressed air, thereby improving the combustion efficiency and reducing fuel consumption.

[0028] The following is a baking method for baking a blast furnace swing nozzle using the above-mentioned baking device, and the specific steps of the method are as follows: S1. Pre-purge: Open the compressed air valve, and the compressed air enters the roaster to purge the inside of the roaster. The purge time is 5 to 10 minutes to remove impurities inside the roaster and ensure the cleanliness of the ignition environment. S2. Ignition: Open the natural gas valve, and the natural gas enters the burner through the burner nozzle. At the same time, the compressed air enters the burner through the outer pipe. The two are mixed at the burner nozzle. Use the ignition device to ignite. The mixed gas ignites to form a flame. Observe the flame state to ensure that the flame is blue, stable, and has no obvious jumps or flameouts. S3, heating stage: Cover the baking machine on the swinging nozzle for baking, slowly increase the flow of natural gas and compressed air, and heat up at a heating rate of 100℃ / h. This heating rate can avoid excessive thermal stress or material deformation of the equipment caused by sudden temperature rise, and ensure the safety of the equipment during the heating process; S4, constant temperature stage: keep constant temperature baking for 10 to 12 hours, the constant temperature is 800℃, so that the material can fully absorb the heat and achieve the ideal baking effect; S5, Cooling stage: Close the natural gas valve and compressed air valve, and cool down naturally to room temperature to prepare for the next baking operation. Natural cooling can avoid equipment stress concentration caused by rapid cooling and extend the service life of the equipment.

[0029] Preferably, before baking, multiple temperature sensors are arranged in the swinging nozzle to monitor the temperature changes in the baking chamber in real time. The data of the temperature sensor can provide accurate temperature feedback for the heating, constant temperature and cooling stages to ensure the temperature control accuracy of the baking process. During the baking process, the color, shape and stability of the flame are continuously observed from the nozzles at both ends of the swinging nozzle. A normal flame should be blue, stable and without obvious jumping or flameout. Monitoring of the flame state can detect combustion abnormalities in a timely manner and avoid baking quality problems caused by unstable flames.

[0030] During the baking process, the pressure of natural gas and compressed air is continuously monitored to ensure that the natural gas pressure is maintained at 0.1-0.2MPa and the compressed air pressure is maintained at 0.3-0.5MPa. Pressure monitoring can ensure the stability and safety of the combustion process and avoid the decrease in combustion efficiency or safety hazards caused by abnormal pressure. The entire baking process is carried out within the ambient temperature range of 5-35℃ to ensure the stability and controllability of baking.

[0031] The blast furnace swing nozzle roaster can achieve efficient, stable and controllable roasting effect with high thermal energy utilization. During roasting, the safety of the roasting process and the consistency of the roasting quality are ensured through the reasonable control of the pre-purge, ignition, heating, constant temperature and cooling stages.

Claims

1. A blast furnace swing nozzle roaster, characterized in that: The invention comprises a roaster shell, a natural gas pipe, a compressed air pipe and a burner. The inner surface of the main body of the roaster shell is made of refractory material. The burner is installed in the roasting cavity of the roaster shell. The burner is provided with an outer tube and a burner disposed in the outer tube. The burner is connected with the natural gas pipe, and the outer tube is connected with the compressed air pipe. Valves are respectively arranged on the pipe sections of the natural gas pipe and the compressed air pipe extending out of the roaster shell.

2. The blast furnace swing nozzle roaster according to claim 1, characterized in that: The burner is installed at the center of the roaster shell, the outer tube is a stainless steel tube, and the burner is provided with a swirl sheet.

3. The blast furnace swing nozzle roaster according to claim 2, characterized in that: The side wall of the roaster shell is provided with an inner side plate and an outer side plate, and refractory mud is filled between the inner side plate and the outer side plate.

4. The blast furnace swing nozzle roaster according to claim 3, characterized in that: The inner side plate is clearance-matched with the swing flow nozzle.

5. The blast furnace swing nozzle roaster according to claim 4, characterized in that: The compressed air pipe is arranged in a plurality of circles in the baking chamber.

6. A method for baking a blast furnace swing nozzle, characterized in that: The method uses the blast furnace swing nozzle roaster according to any one of claims 1 to 4, and specifically comprises the following steps: S1. Pre-purge: Open the compressed air valve to purge the inside of the roaster for 5 to 10 minutes to remove impurities. S2. Ignition: Open the natural gas valve, use the ignition device to ignite, observe the flame state, and ensure that the flame is stable; S3, heating stage: cover the baking device on the swing flow nozzle for baking, slowly increase the flow rate of natural gas and compressed air, and heat up at a heating rate of 100℃ / h; S4, constant temperature stage: keep constant temperature baking for 10 to 12 hours, the constant temperature is 800℃; S5, cooling stage: close the natural gas valve and compressed air valve, and cool down naturally to normal temperature.

7. The baking method of the blast furnace swing nozzle according to claim 6, characterized in that: The ambient temperature for baking operation is 5-35°C, the natural gas pressure is 0.1-0.2MPa, and the compressed air pressure is 0.3-0.5MPa.

8. The baking method of the swing nozzle of a blast furnace according to claim 7, characterized in that: A plurality of temperature sensors are arranged in the swing flow nozzle for temperature monitoring.

9. The baking method of the blast furnace swing nozzle according to claim 8, characterized in that: Monitor the flame status during the baking process and observe the flame color, shape and stability. A normal flame is blue, stable and has no obvious jumping or flameout.

10. The baking method of the swing nozzle of a blast furnace according to claim 9, characterized in that: During the baking process, pressure monitoring is carried out to continuously monitor the pressure of natural gas and compressed air to ensure that it fluctuates within the specified range.

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