Blast furnace front oxygen enrichment system and process method thereof

Abstract

The blast furnace front oxygen enrichment system comprises a low-pressure oxygen pipeline laid between an oxygen station and an iron making plant, the low-pressure oxygen pipeline is connected with a blast furnace blower through an oxygen branch pipe, an air outlet of the blast furnace blower is communicated with an air inlet of a blast furnace, and the oxygen branch pipe is provided with a flame arrester and a second manual stop valve. A security nitrogen pipe is connected between the flame arrester and the second manual cut-off valve, and a stop valve, a nitrogen buffer tank and a nitrogen quick cut-off valve are sequentially arranged on the security nitrogen pipe in the airflow direction; the oxygen analyzer monitors the oxygen content in the oxygen branch pipe in real time and transmits a monitored value to the PLC, the PLC judges whether the oxygen enrichment rate of a preset instruction is reached or not, and the flow regulating valve is regulated through the PLC; the system is simple in structure, reasonable in design, convenient to implement, capable of being effectively applied to blast furnace smelting, capable of saving electric energy and production cost, good in using effect and convenient to popularize and use.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace smelting, in particular to a blast furnace front oxygen enrichment system and a process method thereof. Background Art

[0002] In the iron and steel metallurgy sector, oxygen-enriched blast furnaces are a core process for intensifying smelting and reducing coke rates. Currently, domestic steel companies generally employ a post-blast furnace oxygen enrichment process: low-pressure oxygen (10kPa to 15kPa) output from the oxygen production station is first pressurized to 2.5MPa to 3.0MPa by a turbine compressor or piston compressor before being stored in a spherical tank. It is then reduced to 1.6MPa to 1.8MPa by a pressure-regulating valve block in the oxygen production area and transported to the blast furnace. Finally, it is reduced to 0.6MPa to 0.8MPa by a valve block in the blast furnace area before being mixed with the pressurized air at the blower outlet.

[0003] Oxygen undergoes a repeated energy conversion process of "low pressure → high pressure storage → step-by-step pressure reduction". The compressor consumes huge power, and the loss of electricity accounts for more than 30% of the total oxygen pressure cost. When the blast furnace is shut down or the blower stops abnormally, the pressure difference between the high-pressure oxygen and the cold air system is unbalanced, which can easily cause oxygen to flow back into the cold air duct or cold air to flow back into the oxygen pipeline network. Fluctuations in oxygen flow directly disrupt the blast furnace smelting process and affect the production stability of subsequent steelmaking processes. Relying on multi-stage compression, storage tanks and pressure reducing valve groups, equipment investment and maintenance costs are high. Although the industry has tried to optimize valve control or add safety isolation devices, the energy loss and backflow risks inherent in the post-machine oxygen enrichment process have never been completely resolved. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a blast furnace pre-oxygen enrichment system and a process method thereof.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a blast furnace front oxygen enrichment system, including a low-pressure oxygen pipeline laid between an oxygen station and an ironmaking plant, the low-pressure oxygen pipeline is connected to a blast furnace blower through an oxygen branch pipe, the air outlet of the blast furnace blower is connected to the air inlet of the blast furnace, a flame arrester and a second manual shut-off valve are provided on the oxygen branch pipe, a safety nitrogen pipe is connected between the flame arrester and the second manual shut-off valve, and a shut-off valve, a nitrogen buffer tank and a nitrogen quick-cut valve are sequentially provided on the safety nitrogen pipe along the direction of air flow.

[0006] As a further improvement of the present invention: the oxygen branch pipe is also provided with a first manual shut-off valve, a filter, a flow meter, a flow regulating valve, a pressure gauge, a thermometer, an oxygen quick-cut valve, a mixer, an oxygen analyzer and a carbon monoxide analyzer.

[0007] As a further improvement of the present invention, it also includes a control system, which includes a PLC controller and an industrial computer connected to the PLC controller.

[0008] As a further improvement of the present invention: the input end of the PLC controller is connected to the flow meter, pressure gauge, thermometer, oxygen analyzer and carbon monoxide analyzer, and the output end of the PLC controller is connected to the flow regulating valve, oxygen quick-cut valve, stop valve and nitrogen quick-cut valve.

[0009] As a further improvement of the present invention: the pressure of oxygen in the low-pressure oxygen pipeline is 9kPa to 15kPa, and the oxygen flow rate is 15m / s.

[0010] As a further improvement of the present invention: the purity of oxygen in the low-pressure oxygen pipeline is above 95%.

[0011] As a further improvement of the present invention: the low-pressure oxygen pipeline adopts a DN1000mm spiral welded pipe.

[0012] As a further improvement of the present invention: the flow meter is a thermal flow meter.

[0013] As a further improvement of the present invention: the oxygen analyzer and the carbon monoxide analyzer are in-situ laser analyzers.

[0014] As a further improvement of the present invention: the flow control valve adopts a straight-stroke pneumatic control valve.

[0015] As a further improvement of the present invention: the shell of the filter is made of 304 stainless steel, the filter screen of the filter is made of 80-mesh 304 filter screen; and the flame arrester is made of red copper.

[0016] As a further improvement of the present invention: the mixer is connected to an air filter, and the mixer adopts a new type of cyclone, multi-point diversion, and reciprocating deflection to fully mix the air and oxygen, so that the gas entering the blast furnace is a uniformly mixed oxygen-rich gas, and the unevenness after mixing is less than 1%.

[0017] The present invention also includes a process method using the above-mentioned blast furnace front oxygen enrichment system, comprising the following steps: The low-pressure oxygen from the oxygen production station is transported to the oxygen branch pipe through the low-pressure oxygen pipeline. Before entering the blast furnace blower, the low-pressure oxygen is fully mixed with air through a mixer, and the blast furnace blower is used to pressurize the fully mixed oxygen-enriched air and send it to the blast furnace; the oxygen analyzer monitors the oxygen content in the oxygen branch pipe in real time and transmits the monitored value to the PLC controller. The PLC controller determines whether the oxygen enrichment rate of the preset instruction is reached and adjusts the flow control valve through the PLC controller.

[0018] As a further improvement of the present invention: when an oxygen supply failure occurs, the PLC controller controls the oxygen quick-cut valve to be closed and the nitrogen quick-cut valve to be opened to protect the oxygen enrichment system; when the blast furnace is shut down or the blast furnace blower is shut down, the nitrogen quick-cut valve is opened and nitrogen is used to replace and empty the pure oxygen in the oxygen branch pipe.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) The system adopts a low-pressure oxygen direct delivery process, completely abandoning the traditional post-blast furnace oxygen enrichment "pressurization-storage tank-step decompression" process and eliminating repeated energy conversion links. According to engineering verification, the system reduces oxygen delivery energy consumption by 35%-45%, and a single blast furnace can save more than 8 million kWh of electricity per year, with significant economic benefits. (2) The oxygen pipeline is inerted and replaced within 0.5 seconds through the safety nitrogen pipeline network in the event of an oxygen supply failure; the oxygen / carbon monoxide dual in-situ laser analyzer monitors abnormalities in real time, and the interlocking PLC triggers the oxygen quick-cut valve to close, eliminating the risk of oxygen backflow; the flame arrester and nitrogen protection double protection eliminate the risk of explosion; (3) Blower efficiency is improved by 12%-18%: Low-pressure oxygen has a constant temperature and uniform density, forming turbulent and enhanced mixing with air in the mixer, avoiding high-temperature corrosion of the impeller caused by excessive local oxygen concentration, and extending the life of the blower; (4) The thermal flow meter and linear pneumatic control valve form a closed-loop control system that responds to PLC instructions in real time, ensuring combustion uniformity in the blast furnace tuyere area and reducing the coke rate by 1.5%-2.0%; (5) It can be effectively used in blast furnace smelting, saving electricity and production costs, with good use effect and easy to promote and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to illustrate the technical solution more clearly, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Figure 1 It is a structural schematic diagram of the present invention.

[0022] Figure 2 Schematic diagram of the connection structure of the control system in the present invention.

[0023] Reference numerals: 1. Oxygen production station; 2. Smelter; 3. Low-pressure oxygen pipeline; 4. Oxygen branch pipe; 5. Blast furnace blower; 6. Blast furnace; 7. First manual shut-off valve; 8. Filter; 9. Flow meter; 10. Flow regulating valve; 11. Pressure gauge; 12. Thermometer; 13. Oxygen quick-cut valve; 14. Flame arrester; 15. Second manual shut-off valve; 16. Mixer; 17. Oxygen analyzer; 18. Carbon monoxide analyzer; 19. Safety nitrogen pipe; 20. Shut-off valve; 21. Nitrogen buffer tank; 22. Nitrogen quick-cut valve; 23. PLC controller; 24. Industrial computer; 25. Air filter. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0027] The traditional post-blast furnace oxygen enrichment process results in over 30% inefficient energy consumption due to the forced repetitive pressurization and decompression process: low-pressure oxygen → 3.0 MPa compressed storage → stepwise decompression to 0.8 MPa. More seriously, this system presents a millisecond-level risk of oxygen backflow. When the blast furnace shuts down or the blower malfunctions, the pressure differential between the high-pressure oxygen pipeline and the cold air system becomes unbalanced. The existing safety interlock response is delayed (>2 seconds), allowing oxygen backflow and combustible materials to ignite. Furthermore, the inherent ±0.8% oxygen enrichment rate fluctuations of the multi-stage pressure reducing valve assembly disrupt blast furnace smelting stability and transmit production disruptions to downstream steelmaking processes. This triple deficiency in energy consumption, safety, and control accuracy has created a vicious cycle that has long remained unresolved in the industry.

[0028] The present invention provides a blast furnace pre-oxygen enrichment system and a process method thereof, wherein the blast furnace pre-oxygen enrichment system comprises a low-pressure oxygen pipeline 3 laid between an oxygen station and an ironmaking plant, wherein the low-pressure oxygen pipeline 3 is connected to a blast furnace blower 5 through an oxygen branch pipe 4, wherein the air outlet of the blast furnace blower 5 is connected to the air inlet of a blast furnace 6, wherein the oxygen branch pipe 4 is provided with a flame arrester 14 and a second manual shut-off valve 15, wherein a safety nitrogen pipe 19 is connected between the flame arrester 14 and the second manual shut-off valve 15, wherein a shut-off valve 20, a nitrogen buffer tank 21 and a nitrogen quick-cut valve 22 are sequentially provided on the safety nitrogen pipe 19 along the direction of air flow; The process method of using the above-mentioned oxygen enrichment system before the blast furnace includes the following steps: low-pressure oxygen from the oxygen production station 1 is transported to the oxygen branch pipe 4 through the low-pressure oxygen pipeline 3; the low-pressure oxygen is fully mixed with air through the mixer 16 before entering the blast furnace blower 5; the fully mixed oxygen-enriched air is pressurized and transported to the blast furnace 6 by the blast furnace blower 5; the oxygen analyzer 17 monitors the oxygen content in the oxygen branch pipe 4 in real time and transmits the monitored value to the PLC controller 23; the PLC controller 23 determines whether the oxygen enrichment rate of the preset instruction is reached, and adjusts the flow control valve 10 through the PLC controller 23.

[0029] By delivering low-pressure oxygen directly to the front of the blast furnace blower 5, the compressor, storage tank and pressure reducing valve group are eliminated, eliminating the repeated pressurization energy consumption in the traditional process; there is no additional power consumption in the oxygen delivery process; the nitrogen safety system is completed within 0.5 seconds when the oxygen supply fails, and the risk of backflow is essentially eliminated; the low-pressure oxygen has a constant temperature and uniform density, and forms a turbulent mixing with the air in the mixer 16; local high-temperature oxidation of the impeller caused by high-pressure oxygen enrichment is avoided, and the efficiency of the blower is improved and the service life is extended; the PLC controller 23 dynamically adjusts the flow control valve 10 based on real-time feedback from the oxygen analyzer 17.

[0030] As an embodiment of the present invention, the oxygen branch pipe 4 is further provided with a first manual shut-off valve 7, a filter 8, a flow meter 9, a flow regulating valve 10, a pressure gauge 11, a thermometer 12, an oxygen quick-cut valve 13, a mixer 16, an oxygen analyzer 17 and a carbon monoxide analyzer 18.

[0031] Improve the control accuracy of oxygen enrichment rate and eliminate the low-frequency fluctuation of traditional pressure reducing valve group; capture abnormal combustion precursors in real time; filter 8 intercepts particles ≥5μm to prevent regulating valve from getting stuck.

[0032] Furthermore, the pressure of oxygen in the low-pressure oxygen pipeline 3 is 9 kPa to 15 kPa, and the oxygen flow rate is 15 m / s; the purity of oxygen in the low-pressure oxygen pipeline 3 is above 95%.

[0033] The low pressure of 9kPa to 15kPa matches the original pressure of oxygen production station 1, achieving zero pressurization energy consumption for oxygen delivery; at the same time, the 15m / s flow rate design accurately balances fluid resistance and safety, avoiding impurity deposition and blockage caused by speeds <10m / s, and eliminating the risk of static electricity explosion at speeds >20m / s.

[0034] Furthermore, the low-pressure oxygen pipeline 3 adopts a DN1000mm spiral welded pipe.

[0035] Furthermore, the flow meter 9 is a thermal flow meter 9 .

[0036] Furthermore, the oxygen analyzer 17 and the carbon monoxide analyzer 18 are in-situ laser analyzers.

[0037] Furthermore, the flow control valve 10 is a linear pneumatic control valve.

[0038] Furthermore, the shell of the filter 8 is made of 304 stainless steel, the filter screen of the filter 8 is made of 80-mesh 304 filter screen; and the flame arrester 14 is made of copper.

[0039] The DN1000mm spiral welded pipe enables ultra-low pressure loss oxygen transmission. The thermal flowmeter 9 measures low-speed oxygen with an accuracy of ±0.5%, and the linear pneumatic control valve has a response time of 0.2 seconds, allowing the oxygen enrichment rate control accuracy to break through to ±0.08%. The filter 8 with a 304 stainless steel shell and 80-mesh filter screen intercepts particles ≥20μm, ensuring that the in-situ laser oxygen / CO analyzer can achieve a 50ppm-level trace abnormal combustion warning in a pure airflow, which is 10 times more sensitive than traditional electrochemical sensors. The copper flame arrester 14 has microchannels and ultra-high thermal conductivity, which can shorten the time it takes to extinguish a deflagration.

[0040] Furthermore, the mixer 16 is connected to an air filter 25. The mixer 16 adopts a new type of cyclone, multi-point diversion, and reciprocating deflection to fully mix the air and oxygen, so that the gas entering the blast furnace is a uniformly mixed oxygen-rich gas, and the unevenness after mixing is less than 1%.

[0041] Through the synergistic effect of the new cyclone-multi-point diversion-reciprocating deflection mixer 16 and the air filter 25, a revolutionary gas mixing effect is achieved: the unique three-dimensional turbulent field design of the mixer 16 enables oxygen and air to be mixed at the molecular level within 0.5 seconds, reducing the mixing unevenness from 5-8% in traditional processes to <1%. At the same time, the air filter 25 can effectively remove particles ≥5μm to ensure the cleanliness of the mixed medium; combustion efficiency is greatly improved, equipment protection is upgraded, smelting stability is qualitatively changed, and mixing uniformity reduces the fluctuation of molten iron silicon content from 0.15% to 0.05%, providing extremely stable raw material guarantee for subsequent steelmaking processes.

[0042] As an embodiment of the present invention, a control system is further included. The control system includes a PLC controller 23 and an industrial computer 24 connected to the PLC controller 23 .

[0043] Furthermore, the input end of the PLC controller 23 is connected to the flow meter 9, the pressure gauge 11, the thermometer 12, the oxygen analyzer 17 and the carbon monoxide analyzer 18, and the output end of the PLC controller 23 is connected to the flow regulating valve 10, the oxygen quick-cut valve 13, the stop valve 20 and the nitrogen quick-cut valve 22.

[0044] As a specific embodiment of the present invention, Figure 1 As shown, the blast furnace pre-oxygen enrichment system of the present invention includes a low-pressure oxygen pipeline 3 laid between the oxygen station 1 and the ironmaking plant 2, the low-pressure oxygen pipeline 3 is connected to the blast furnace blower 5 through the oxygen branch pipe 4, the air outlet of the blast furnace blower 5 is connected to the air inlet of the blast furnace 6, and the oxygen branch pipe 4 is provided with a first manual shut-off valve 7, a filter 8, a flow meter 9, a flow regulating valve 10, a pressure gauge 11, a thermometer 12, an oxygen quick-cut valve 13, a flame arrester 14, a second manual shut-off valve 15, a mixer 16, an oxygen analyzer 17 and a carbon monoxide analyzer 18 in sequence along the direction of airflow. A section of the oxygen branch pipe 4 located between the flame arrester 14 and the second manual shut-off valve 15 is connected to a safety nitrogen pipe 19, and the safety nitrogen pipe 19 is provided with a shut-off valve 20, a nitrogen buffer tank 21 and a nitrogen quick-cut valve 22 in sequence along the direction of airflow.

[0045] In specific implementation, the blast furnace blower 5 is used to pressurize the fully mixed oxygen-enriched air and send it to the blast furnace 6 for use. In this way, the compressor used by the oxygen station 1 to pressurize this amount of oxygen can be stopped, saving electricity consumption.

[0046] In this embodiment, a control system is also included, such as Figure 2As shown, the control system includes a PLC controller 23 and an industrial computer 24 connected to the PLC controller 23. The flow meter 9, pressure gauge 11, thermometer 12, oxygen analyzer 17 and carbon monoxide analyzer 18 are all connected to the input end of the PLC controller 23, and the flow regulating valve 10, oxygen quick-cut valve 13, stop valve 20 and nitrogen quick-cut valve 22 are all connected to the output end of the PLC controller 23.

[0047] The process method of the blast furnace pre-oxygen enrichment system of the present invention comprises: delivering low-pressure oxygen of 10kPa to 15kPa from an oxygen production station 1 to an oxygen branch pipe 4 via a low-pressure oxygen pipeline 3; fully mixing the low-pressure oxygen with air through a mixer 16 before entering a blast furnace blower 5; and pressurizing the fully mixed oxygen-enriched air by the blast furnace blower 5 and delivering it to the blast furnace 6 for use; The oxygen analyzer 17 monitors the oxygen content in the oxygen branch pipe 4 in real time and transmits the monitored value to the PLC controller 23. The PLC controller 23 determines whether the oxygen enrichment rate of the preset instruction is reached, and then adjusts the flow control valve 10 through the PLC controller 23; When the oxygen supply fails, the PLC controller 23 controls the oxygen quick-cut valve 13 to close and the nitrogen quick-cut valve 22 to open to protect the oxygen enrichment system; When the blast furnace 6 is out of service or the blast furnace blower 5 is shut down, the nitrogen quick-cut valve 22 is opened and the pure oxygen in the oxygen branch pipe 4 is replaced and emptied with nitrogen.

[0048] The main functions of the present invention are as follows: through the innovative design of the oxygen enrichment system before the blast furnace, it successfully solves the technical problems of high energy consumption, high safety risks, and uneven mixing in the traditional oxygen enrichment process. The system adopts an innovative architecture of directly connecting the low-pressure oxygen pipeline to the blower, and cooperates with multiple safety control units. The system structure is simple, the design is reasonable, and it is easy to implement; it can save a lot of electricity and have considerable economic benefits; the oxygen density is high, and the temperature of the low-pressure oxygen leaving the tower is constant. After mixing with the air before the machine, it is conducive to improving the operating conditions of the blast furnace blower and increasing the efficiency of the blast furnace blower; the oxygen and air before the oxygen enrichment are fully mixed in the mixer before the blast furnace blower, which is conducive to full combustion and prevents uneven mixing of oxygen concentration and local overheating.

[0049] In summary, after reading the present invention document, ordinary technicians in this field can make various other corresponding transformation schemes based on the technical solutions and technical concepts of the present invention without creative mental work, and all of them fall within the scope of protection of the present invention.

Claims

1. A blast furnace front oxygen enrichment system, characterized in that: It includes a low-pressure oxygen pipeline laid between the oxygen station and the ironworks, the low-pressure oxygen pipeline is connected to the blast furnace blower through an oxygen branch pipe, the air outlet of the blast furnace blower is connected to the air inlet of the blast furnace, the oxygen branch pipe is provided with a flame arrester and a second manual shut-off valve, a safety nitrogen pipe is connected between the flame arrester and the second manual shut-off valve, and the safety nitrogen pipe is provided with a shut-off valve, a nitrogen buffer tank and a nitrogen quick-cut valve in sequence along the direction of airflow.

2. A blast furnace front oxygen enrichment system according to claim 1, characterized in that: The oxygen branch pipe is also provided with a first manual shut-off valve, a filter, a flow meter, a flow regulating valve, a pressure gauge, a thermometer, an oxygen quick-cut valve, a mixer, an oxygen analyzer and a carbon monoxide analyzer.

3. A blast furnace front oxygen enrichment system according to claim 1, characterized in that: It also includes a control system, which includes a PLC controller and an industrial computer connected to the PLC controller.

4. A blast furnace pre-oxygen enrichment system according to claim 3, characterized in that: The input end of the PLC controller is connected to a flow meter, a pressure gauge, a thermometer, an oxygen analyzer and a carbon monoxide analyzer, and the output end of the PLC controller is connected to a flow regulating valve, an oxygen quick-cut valve, a stop valve and a nitrogen quick-cut valve.

5. The oxygen enrichment system before blast furnace according to claim 1, characterized in that: The pressure of oxygen in the low-pressure oxygen pipeline is 9kPa to 15kPa, and the oxygen flow rate is 15m / s.

6. A blast furnace pre-oxygen enrichment system according to claim 2, characterized in that: The flow meter is a thermal flow meter.

7. A blast furnace pre-oxygen enrichment system according to claim 4, characterized in that: The oxygen analyzer and the carbon monoxide analyzer are in-situ laser analyzers.

8. The blast furnace pre-oxygen enrichment system according to claim 1, characterized in that: The flow regulating valve adopts a straight-stroke pneumatic regulating valve.

9. A process method using a blast furnace pre-oxygen enrichment system according to any one of claims 1 to 8, characterized in that: The following steps are involved: The low-pressure oxygen from the oxygen production station is transported to the oxygen branch pipe through the low-pressure oxygen pipeline. Before entering the blast furnace blower, the low-pressure oxygen is fully mixed with air through a mixer, and the blast furnace blower is used to pressurize the fully mixed oxygen-enriched air and send it to the blast furnace; the oxygen analyzer monitors the oxygen content in the oxygen branch pipe in real time and transmits the monitored value to the PLC controller. The PLC controller determines whether the oxygen enrichment rate of the preset instruction is reached and adjusts the flow control valve through the PLC controller.

10. The process method of a blast furnace front oxygen enrichment system according to claim 9, characterized in that: When the oxygen supply fails, the PLC controller controls the oxygen quick-cut valve to shut down and the nitrogen quick-cut valve to open to protect the oxygen enrichment system; when the blast furnace is out of service or the blast furnace blower is shut down, the nitrogen quick-cut valve is opened and nitrogen is used to replace and drain the pure oxygen in the oxygen branch pipe.

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