Total-oxygen hydrogen-rich low-carbon reduction melting ironmaking temperature measurement system and method

Abstract

The system comprises a reduction melting furnace, an indirect reduction area, a soft melting dripping area and a coke combustion and slag iron area are sequentially arranged in the reduction melting furnace from top to bottom, and the system further comprises a high-temperature-resistant pipe, a thermocouple, a compensation wire and a temperature sensor; the high-temperature-resistant pipe downwards extends into the indirect reduction area and the soft melting dripping area from the furnace top of the reduction melting furnace; the plurality of thermocouples are uniformly distributed in the inner cavity of the high-temperature-resistant pipe along the circumference; the hot ends of the thermocouples are arranged in a to-be-measured temperature field area of the reduction melting furnace, and the cold end of each thermocouple is connected with one temperature sensor through one compensation wire. The temperature measuring thermocouple is arranged in the reduction melting furnace, so that the temperature of materials at different sections of an indirect reduction area and a soft melting dripping area can be accurately measured in real time; the delay of temperature measurement is greatly reduced, the ironmaking working condition can be controlled in real time, and a basis is provided for operators to adjust upper and lower systems of a furnace body in time.

Description

Technical Field

[0001] The present invention relates to an ironmaking system and method, in particular to a full-oxygen, hydrogen-rich, low-carbon reduction melting ironmaking temperature measurement system and method. Background Art

[0002] The all-oxygen, hydrogen-rich, low-carbon reduction smelting ironmaking process, through an innovative reduction mode, enables the metallization rate of the indirect reduction zone to reach 85-95%, and reduces the direct reduction to 5-15%, greatly improving the utilization coefficient of the smelting furnace. At the same time, through the top gas circulation method, it completes the recycling of carbon resources; compared with the traditional long process, it can reduce carbon dioxide emissions by more than 40%, realizing truly green and low-carbon smelting.

[0003] During the smelting process, ensuring sufficient stability and permeability of the charge throughout the furnace is crucial. This is especially true in the upper furnace, where the indirect reduction zone is relatively long. The charge remains there for extended periods, constantly exposed to a low-temperature, weakly reducing atmosphere. In such an environment, the pellets must exhibit a low expansion rate. If the temperature rises too quickly, the pellets will expand catastrophically, producing a large amount of powder. This not only compromises the furnace's permeability but also disrupts the airflow and temperature distribution throughout the furnace.

[0004] Currently, in all-oxygen, hydrogen-rich, low-carbon reduction smelting ironmaking systems, temperature-measuring thermocouples are installed on the furnace wall. However, due to the refractory barrier between the furnace wall and the materials inside, heat transfer takes time. Consequently, the thermocouples cannot directly measure the actual temperature of the materials inside the furnace, and the measurement results are significantly delayed. This makes it difficult for operators to accurately and timely determine the actual temperature of the materials inside the furnace. Therefore, it is imperative to develop a system and method that can accurately and timely measure the temperature of the materials inside the furnace. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a full-oxygen hydrogen-rich low-carbon reduction melting ironmaking temperature measurement system with real-time and accurate temperature measurement; the present invention also provides a full-oxygen hydrogen-rich low-carbon reduction melting ironmaking temperature measurement method with real-time and accurate temperature measurement.

[0006] In order to solve the above technical problems, the technical solution adopted by the system of the present invention is: it includes a reduction melting furnace, the interior of the reduction melting furnace is divided into an indirect reduction zone, a soft melt dripping zone and a coke combustion and slag iron zone from top to bottom, and also includes a high-temperature resistant tube, a thermocouple, a compensation wire and a temperature sensor; the high-temperature resistant tube extends downward from the top of the reduction melting furnace into the indirect reduction zone and the soft melt dripping zone; the thermocouple is provided with a plurality of them, which are evenly distributed along the circumference in the inner cavity of the high-temperature resistant tube; the hot end of the thermocouple is placed in the temperature field area to be measured in the reduction melting furnace, and the cold end of each thermocouple is connected to a temperature sensor through a compensation wire.

[0007] Furthermore, the thermocouples are designed with gradient lengths, with the hot ends of one part of the thermocouples extending downward to the indirect reduction zone, and the hot ends of the other part of the thermocouples extending downward to the soft melt droplet landing zone.

[0008] Furthermore, the total number of thermocouples arranged in the indirect reduction zone is 6 to 10, and the number of thermocouples arranged in the soft melt droplet landing zone is 4 to 8.

[0009] Furthermore, it also includes a field bus and a computer; the temperature sensor is connected to the computer via a field bus signal.

[0010] To solve the above technical problems, the method of the present invention adopts the above temperature measurement system, and the technical solution adopted includes the following steps: 1) in the full oxygen hydrogen-rich low carbon reduction melting ironmaking process, the temperature signal measured by the thermocouple is transmitted to the temperature sensor through the compensation wire; 2) The temperature sensor converts the collected multi-channel temperature signals into electrical signals and transmits them to the computer via the field bus; 3) The computer processes, analyzes and stores the received electrical signals, and displays the temperature information in real time on the monitoring interface.

[0011] Furthermore, in step 1), the maximum operating temperature of the high-temperature resistant tube is 1600°C to 1800°C.

[0012] Furthermore, in step 1), the temperature detected by the thermocouple is 200°C to 1400°C.

[0013] The beneficial effects of adopting the above technical solution are: by placing temperature measuring thermocouples in the reduction melting furnace, the present invention can accurately measure the material temperature in different sections of the indirect reduction zone and the soft melt dripping zone in real time; greatly reduces the delay in temperature measurement, can control the ironmaking conditions in real time, and provide a basis for operators to adjust the upper and lower systems of the furnace body in time; at the same time, the temperature measuring device is simple, easy to install and maintain, does not require complicated operations and high costs, and has high economic value.

[0014] The present invention adopts a multi-point distributed temperature measurement method and is equipped with multiple independent thermocouple temperature measurement units. Each temperature measurement unit adopts a gradient length design based on the spatial distribution characteristics of the detection area to ensure accurate coverage of different process areas of the reduction melting furnace; thereby realizing real-time monitoring of the temperature field of each temperature measurement unit, providing reliable data support and technical guarantee for the optimization and control of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0016] Figure 1 It is a structural schematic diagram of the temperature measurement system of the present invention; Figure 2 It is a structural schematic diagram of the thermocouple and the high temperature resistant tube of the present invention.

[0017] In the figure: 1. Reduction melting furnace; 2. Indirect reduction zone; 3. Soft melt dripping zone; 4. Coke combustion and slag iron zone; 5. High-temperature resistant pipe; 6. Flange; 7. Compensating wire; 8. Temperature sensor; 9. Field bus; 10. Computer; 11. Thermocouple. DETAILED DESCRIPTION

[0018] Figure 1 As shown, the present all-oxygen, hydrogen-rich, low-carbon reduction melting and ironmaking temperature measurement system includes a reduction melting furnace 1, a high-temperature resistant tube 5, a thermocouple 11, a compensation wire 7, a temperature sensor 8, a field bus 9, and a computer 10. The interior of the reduction melting furnace 1 is composed, from top to bottom, of an indirect reduction zone 2, a soft melt dripping zone 3, and a coke combustion and slag zone 4. The high-temperature resistant tube 5 extends vertically downward from the roof of the reduction melting furnace 1 through the indirect reduction zone 2 into the soft melt dripping zone 3. The high-temperature resistant tube 5 is fixedly mounted to the roof of the reduction melting furnace 1 via a flange 6. The high-temperature resistant tube 5 is made of silicon carbide, which has excellent high-temperature resistance and a maximum operating temperature of 1600°C to 1800°C. It can withstand the high-temperature environment in the middle and lower parts of the furnace. It also has good chemical stability and thermal shock resistance, effectively protecting the internal thermocouple 11 from the impact of materials in the furnace. The flange 6 is made of A105 steel and is suitable for the medium and low-temperature environments of the furnace roof. The flange 6 used is reasonably designed and has convenient installation and disassembly functions. When the high-temperature resistant tube 5 or the thermocouple 11 reaches its service life and needs to be replaced, it can be quickly opened through the flange 6 and the update can be completed.

[0019] Figure 1 、 2As shown, in the present full oxygen hydrogen-rich low carbon reduction melting ironmaking temperature measurement system, the thermocouples 11 are provided in a plurality, which are vertically penetrated from top to bottom into the inner cavity of the high temperature resistant tube 5 and are evenly distributed along the circumference in the inner cavity of the high temperature resistant tube 5. The cold end of the thermocouple 11 is located at the upper part and the hot end is located at the lower part; the hot end is placed in the temperature field area to be measured in the reduction melting furnace 1, namely the indirect reduction zone 2 and the soft melt droplet zone 3. In order to accurately grasp the temperature change of the material before melting, the thermocouples are designed with a gradient length. The hot end of one part of the thermocouples extends downward to the indirect reduction zone 2, and the hot end of the other part of the thermocouples passes through the indirect reduction zone 2 and extends downward to the soft melt droplet zone 3. These two parts are also designed with a gradient length. In this way, the thermocouple 11 can detect the temperature at different heights of the indirect reduction zone 2 and the soft melt droplet zone 3. It is preferred to arrange 6 to 10 thermocouples 11 in the indirect reduction zone 2, where the temperature distribution is relatively complex, i.e., 6 to 10 thermocouples with their hot ends extending into the indirect reduction zone 2; and to arrange 4 to 8 thermocouples 11 in the soft melt droplet landing zone 3, i.e., 4 to 8 thermocouples with their hot ends extending into the soft melt droplet landing zone 3. The temperature range measured by these thermocouples is 200°C to 1400°C. Alumina protective tubes are installed outside the thermocouples 11 to extend the service life of the temperature measuring element.

[0020] Figure 1 、 2 As shown, in this all-oxygen, hydrogen-rich, low-carbon reduction melting ironmaking temperature measurement system, the number of compensation wires 7 and temperature sensors 8 is the same as the number of thermocouples 11; the cold end of each thermocouple 11 is connected to a temperature sensor 8 via a compensation wire 7, and the temperature sensor 8 is connected to the computer 10 via the field bus 9 signal; thus, the temperature sensor 8 transmits the collected multi-channel temperature signals via the field bus 9 to the computer 10 for processing, analysis, and storage, and the temperature information is displayed in real time on the monitoring interface. The external surface of the compensation wire 7 is wrapped with a high-performance insulation layer, which can effectively prevent signal interference and leakage, ensuring the accurate transmission of the temperature signal. The temperature sensor 8 can sense the temperature signal in real time and convert it into a usable output signal. When the temperature is abnormal, the sensor will promptly trigger the alarm system. The field bus 9 has high-speed and stable data transmission capabilities, which can ensure the real-time and accurate transmission of large amounts of temperature data. The computer 10 can promptly process the received electrical signals and perform data storage and analysis.

[0021] Figure 1 、 2As shown, the installation process of the thermocouple 11 in the present all-oxygen, hydrogen-rich, low-carbon reduction melting ironmaking temperature measurement system is as follows: First, select thermocouples 11 of different lengths and arrange them evenly along the circumference of the inner cavity of the high-temperature resistant tube 5; during the installation process, ensure that the thermocouples 11 are stable and secure to prevent loosening or position shifting. Next, the high-temperature resistant tube 5 equipped with multiple thermocouples 11 is fixed to the top of the reduction melting furnace 1 via the flange 6. During installation, the end of the high-temperature resistant tube 5 should be aligned with the indirect reduction zone 2 or the soft melt droplet zone 3 within the reduction melting furnace 1 to ensure that the thermocouple can accurately monitor the temperature changes in these key areas.

[0022] The all-oxygen, hydrogen-rich, low-carbon reduction melting ironmaking process is as follows: oxidized pellets are evenly distributed into a reduction melting furnace 1, hydrogen-rich gas is sprayed into the furnace for reduction, and the materials are gradually melted into molten iron during coke combustion and heating in the slag iron zone 3; the oxidized pellets have a total iron content of ≥65wt%, a compressive strength of ≥2000N, and a proportion of solid particles with a particle size of 6.5mm to 31.8mm of ≥90%.

[0023] Figure 1 、 2 As shown, the temperature measurement method for all-oxygen hydrogen-rich low-carbon reduction smelting ironmaking includes the following steps: 1) Oxidized Pellets Reduction: During the reduction process, the quality of the oxidized pellets must be strictly controlled. The raw materials for production primarily consist of iron ore fines, a composite binder, and dust ash. During the production process, qualified green pellets with a particle size range of 8mm to 16mm are selected as the base raw material. After preheating, these green pellets are placed in a roasting kiln and oxidatively roasted at a high temperature of 1250±20°C to produce finished oxidized pellets. The finished oxidized pellets must meet quality standards of a total iron content of at least 65wt% and a compressive strength of at least 2000N. Only pellets meeting these requirements are fed into the reduction melting furnace 1 for further processing. During the distribution stage, the distribution equipment evenly distributes the oxidized pellets that meet quality standards into the reduction melting furnace 1. High-temperature hydrogen-rich gas is then injected into the furnace, maintaining a temperature of 1000°C to 1050°C, with a hydrogen content exceeding 70 vol%. Under these high-temperature conditions, the hydrogen-rich gas undergoes a strong reduction reaction with the oxidized pellets. At the same time, the combustion of coke in the furnace generates a large amount of heat energy, which causes the coke to burn and the materials in the slag iron area 4 to gradually melt under the action of high temperature, and finally form molten iron to be discharged from the slag iron outlet.

[0024] 2) Temperature Signal Transmission: After thermocouple 11 measures the temperature signal in indirect reduction zone 2 or soft melt droplet zone 3, it is transmitted via the cold-end compensation wire 7. The main function of the compensation wire 7 is to eliminate interference with the measurement results caused by temperature fluctuations at the cold end of the thermocouple, thereby ensuring the accuracy of the temperature signal. When selecting the compensation wire 7, it is necessary to match it according to the specific type of thermocouple and its operating environment to ensure good compatibility between the two. In addition, during the installation process of the compensation wire 7, it should be protected from factors such as high temperature environments to ensure the stability and reliability of signal transmission. The compensation wire 7 then transmits the temperature signal to the temperature sensor 8.

[0025] 3) Signal Conversion: After receiving temperature signals from multiple channels, temperature sensor 8 utilizes its advanced sensing technology and signal processing circuitry to rapidly convert these temperature signals into corresponding electrical signals. These converted electrical signals are then transmitted to computer 10 via fieldbus 9. As an industrial data bus, fieldbus 9 offers high reliability and high-speed transmission, ensuring the accuracy and timeliness of electrical signals during transmission. When setting up fieldbus 9, careful wiring planning is crucial to ensure stable connections between nodes and avoid issues such as signal attenuation and interruptions. Through fieldbus 9, the electrical signals converted by temperature sensor 8 are quickly and accurately transmitted to computer 10 for subsequent data processing and analysis.

[0026] 4) Data Processing and Display: When computer 10 receives electrical signals transmitted via fieldbus 9, it immediately activates data processing software to perform preliminary processing on these signals. This software effectively removes noise and interference by filtering, amplifying, and calibrating the electrical signals. Computer 10 then conducts further in-depth analysis of the processed electrical signals, using pre-set algorithms and models to calculate specific temperature values ​​and evaluate temperature trends. This processed and analyzed temperature data is stored in a dedicated database for subsequent querying. Finally, computer 10 displays real-time temperature information on a monitoring interface, allowing operators to intuitively understand the temperature conditions within reduction melting furnace 1. Based on the temperature changes displayed on the monitoring interface, operators can promptly adjust production parameters to ensure the safety and stability of the entire production process.

[0027] The present invention has the following advantages: (1) Reasonable structural design: The system consists of various components such as high-temperature resistant tubes, thermocouples, and compensation wires. Different functional areas are set up in the reduction melting furnace. The high-temperature resistant tubes are fixed to the furnace top through flanges and extend into specific areas, so that the temperature measurement system can be closely integrated with the structure of the ironmaking process, providing basic conditions for accurate temperature measurement.

[0028] (2) Accurate and effective temperature measurement: The thermocouples are evenly distributed along the circumference of the high-temperature resistant tube, which can comprehensively and evenly collect the temperature of the temperature field area to be measured, avoiding the limitations of single-point temperature measurement and more accurately reflecting the temperature distribution in the furnace. Thermocouples with gradient length design are arranged in different numbers in the indirect reduction zone and the soft melt droplet zone according to different needs, which can make more accurate measurements based on the temperature characteristics of different areas and improve the pertinence of temperature measurement.

[0029] (3) Reliable equipment performance: The high-temperature resistant tube is made of silicon carbide and has high-temperature resistance. The maximum operating temperature can reach 1600℃~1800℃. It can work stably in the high-temperature environment of ironmaking, ensuring the stability and reliability of the temperature measurement system. The outer layer of the thermocouple is equipped with an alumina protective tube, and the outer layer of the compensation wire is wrapped with a high-performance insulation layer. These measures can effectively protect the thermocouple and compensation wire from factors such as high temperature and friction, extend the service life of the equipment, and ensure the long-term stable operation of the temperature measurement system.

[0030] (4) Helping to save energy and reduce emissions: In traditional ironmaking processes, excessive energy consumption is often caused by inaccurate temperature monitoring. However, this temperature measurement system can measure the temperature of each area in the reduction melting furnace with extremely high accuracy. By obtaining temperature data in real time and accurately, operators can precisely adjust the operating parameters of the equipment according to the actual temperature conditions, avoiding energy waste caused by excessively high or low temperatures. For example, when the temperature in the furnace approaches the target temperature, the heating power can be adjusted in time to stabilize the temperature within the appropriate range. This not only improves energy utilization efficiency, but also effectively reduces carbon emissions caused by excessive energy consumption.

Claims

1. A full oxygen hydrogen-rich low carbon reduction melting ironmaking temperature measurement system, comprising a reduction melting furnace (1), wherein the interior of the reduction melting furnace (1) is sequentially divided into an indirect reduction zone (2), a soft melt dripping zone (3) and a coke combustion and slag iron zone (4) from top to bottom, characterized in that: It also includes a high-temperature resistant tube (5), a thermocouple (11), a compensation wire (7) and a temperature sensor (8); the high-temperature resistant tube (5) extends downward from the top of the reduction melting furnace (1) into the indirect reduction zone (2) and the soft melt droplet zone (3); a plurality of the thermocouples (11) are uniformly distributed along the circumference in the inner cavity of the high-temperature resistant tube (5); the hot end of the thermocouple (11) is placed in the temperature field area to be measured in the reduction melting furnace (1), and the cold end of each thermocouple (11) is connected to a temperature sensor (8) through a compensation wire (7).

2. The full oxygen, hydrogen-rich, low carbon reduction smelting ironmaking temperature measurement system according to claim 1 is characterized in that: The thermocouple (11) is designed with a gradient length, with the hot ends of one portion of the thermocouple (11) extending downward to the indirect reduction zone (2), and the hot ends of another portion of the thermocouple (11) extending downward to the soft melt droplet landing zone (3).

3. The full oxygen hydrogen-rich low carbon reduction melting ironmaking temperature measurement system according to claim 2 is characterized in that: The number of thermocouples arranged in the indirect reduction zone (2) is 6 to 10, and the number of thermocouples arranged in the soft melt droplet zone (3) is 4 to 8.

4. A full oxygen, hydrogen-rich, low carbon reduction smelting ironmaking temperature measurement system according to claim 1, 2 or 3, characterized in that: It also includes a field bus (9) and a computer (10); the temperature sensor (8) is connected to the computer (10) via a field bus (9) signal.

5. A temperature measurement method for full oxygen hydrogen-rich low carbon reduction smelting ironmaking, using the temperature measurement system according to claim 4, characterized in that: The method comprises the following steps: 1) in a full oxygen, hydrogen-rich, low carbon reduction melting ironmaking process, transmitting a temperature signal measured by a thermocouple (11) to a temperature sensor (8) via a compensation wire (7); 2) The temperature sensor (8) converts the collected multi-channel temperature signals into electrical signals and transmits them to the computer (10) via the field bus (9); 3) The computer (10) processes, analyzes and stores the received electrical signals, and displays the temperature information on the monitoring interface in real time.

6. The temperature measurement method for full oxygen, hydrogen-rich, low carbon reduction smelting ironmaking according to claim 5, characterized in that: In the step 1), the maximum operating temperature of the high temperature resistant tube (5) is 1600°C to 1800°C.

7. A temperature measurement method for full oxygen, hydrogen-rich, low carbon reduction smelting ironmaking according to claim 5 or 6, characterized in that: In the step 1), the temperature detected by the thermocouple (11) is 200°C to 1400°C.

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