Method for treating high furnace tuyere coal gas leakage

Abstract

The present application relates to a kind of methods for treating blast furnace tuyere coal gas leakage, it is related to blast furnace field.In the blast furnace during blowing-off period in each tuyere of blast furnace installation gas collection hood;Between the flue end of hot blast stove and each gas collection hood installation flow guide pipe, flow guide pipe includes the branch pipe arranged in front end and the thick pipe arranged in rear end, the number of branch pipe is equal to the number of tuyere, the front end of each branch pipe is connected with single gas collection hood one-to-one, the rear end of each branch pipe is summarized in the thick pipe, thick pipe is connected with the flue end again, and pressure monitoring element is installed on thick pipe;Ejector is installed in thick pipe, and nitrogen is used to enhance negative pressure;Flow regulating valve is installed on the pipeline of thick pipe and each branch pipe.The method directly uses the stable negative pressure suction force formed in the process of hot blast stove flue operation due to waste gas emission to extract tuyere leakage coal gas, and the effect of thoroughly treating tuyere coal gas leakage is achieved.

Description

Technical Field

[0001] This invention relates to the field of blast furnace technology, and specifically to a method for treating gas leakage at the blast furnace tuyeres. Background Technology

[0002] Gas leaks in the blast furnace tuyeres of steel enterprises due to sealing failures have become a key concern in production. Tuyer gas leaks severely deteriorate the on-site working environment, threaten the health of employees and the safety of enterprise production, and have become a pain point and difficulty for the safety production of all steel enterprises.

[0003] Currently, to address the problem of gas leakage at blast furnace tuyeres, enterprises mostly resort to replacing the inner and outer sleeves of the tuyeres, or sealing the leaks with sealing materials. However, replacing tuyeres requires significant manpower and resources, resulting in high labor intensity and necessitating blast furnace shutdowns and reduced production. Sealing the leaks with sealing materials also requires prolonged blast furnace shutdowns, similarly leading to production losses. Furthermore, once the blast furnace resumes normal production, the sealing effect is short-lived under the high temperature and pressure conditions at the tuyeres, only providing a brief respite for safety inspections before the leaks reappear. Frequent tuyere replacements and leak sealing not only increase production costs and labor intensity but also fail to completely resolve the gas leakage problem in the tuyere area. Summary of the Invention

[0004] The purpose of this invention is to provide a method for controlling gas leakage at blast furnace tuyeres, which completely solves the problem of gas leakage at blast furnace tuyeres without affecting the normal operation of the blast furnace and hot blast stove, thus solving the problem that is common in steel enterprises and affects safe production but cannot be eradicated.

[0005] The technical solution adopted by this invention to solve the above problems is: a method for controlling gas leakage at blast furnace tuyeres, characterized in that it includes: Step 1: During the blast furnace shutdown period, install gas collection hoods at each tuyeres of the blast furnace; Step 2: Install a guide pipe between the end of the flue of the hot blast stove and each gas collection hood. The guide pipe includes a branch pipe arranged at the front end and a thick pipe arranged at the rear end. The number of branch pipes is equal to the number of air outlets. The front end of each branch pipe is connected to a single gas collection hood. The rear ends of each branch pipe converge into the thick pipe, which is then connected to the end of the flue. A pressure monitoring element is installed on the thick pipe to monitor the negative pressure in the thick pipe in real time. Step 3: Install an ejector inside the thick tube and use nitrogen to enhance the negative pressure; Step 4: Install flow regulating valves on the main pipe and each branch pipe; Step 5: Start the hot air furnace, operate the regulating valve to adjust the negative pressure in the guide pipe to the design value, calibrate the negative pressure, and verify the suction effect; Step 6: After the hot blast furnace is supplying air normally, gradually adjust the regulating valve on the coarse pipe and monitor the change in suction. If the suction is insufficient, start the ejector to assist in suction. Step 7: Install a CO concentration analyzer on the branch pipe to monitor the CO concentration changes of each vent in real time. When the CO concentration is ≤24ppm, the gas leakage at this vent is small, triggering an interlock to close the regulating valve on the corresponding branch pipe of that vent. Step 8: Take advantage of the blast furnace shutdown to clean the accumulated ash in each gas collecting hood and check the airtightness of the gas collecting hood.

[0006] Preferably, in step five, the design value of the negative pressure inside the coarse pipe is -300 Pa; in step six, insufficient suction means that the negative pressure is less than -200 Pa.

[0007] Preferably, in step one, the gas collection hood is made of a high-temperature resistant fiber material with good flexibility, the material can withstand a temperature of ≥400℃, and the material covers the surface of the air outlet.

[0008] Preferably, in step two, the end of the thicker pipe of the diversion pipe is connected to the flue at a 30-45° angle to prevent backflow of flue gas.

[0009] Compared with the prior art, the advantages of the present invention are as follows: The present invention proposes a method for treating gas leakage at the blast furnace tuyere. It directly utilizes the stable negative pressure suction formed by the exhaust gas emission during the operation of the hot blast stove flue to extract the leaking gas at the tuyere. Without affecting the normal operation of the blast furnace and hot blast stove, it comprehensively considers multiple aspects such as collection, transportation, and monitoring to completely solve the problem of gas leakage at the blast furnace tuyere. Subsequently, it is not necessary to force the blast furnace to shut down to replace the tuyere sleeve and the small sleeve or frequently seal the leak point, which would affect production and cost. Attached Figure Description

[0010] Figure 1 This is a flowchart illustrating the implementation process of the method for controlling gas leakage at the blast furnace tuyeres in an embodiment of the present invention. Detailed Implementation

[0011] The present invention will be further described in detail below with reference to the embodiments. The embodiments are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0012] like Figure 1 As shown in this embodiment, a method for controlling gas leakage at the blast furnace tuyeres includes the following steps: Step 1: During the blast furnace shutdown period, install gas collection hoods at each tuyer of the blast furnace. The gas collection hoods are made of high-temperature resistant (temperature resistance ≥400℃) fiber material with good flexibility, which can be wrapped around the surface of the tuyer.

[0013] Step 2: Install guide pipes between the end of the flue and each gas collection hood. The guide pipes include branch pipes distributed at the front end and thick pipes distributed at the rear end. The number of branch pipes is equal to the number of air outlets. The front end of each branch pipe is connected to a single gas collection hood. The rear end of the guide pipe is a thick pipe that enters the flue at a 30-45° angle. The rear ends of the branch pipes converge into the thick pipe. A pressure monitor is installed on the thick pipe to monitor the negative pressure in the thick pipe in real time.

[0014] Step 3: Install an ejector inside the thick tube and use nitrogen to enhance the negative pressure.

[0015] Step 4: Install regulating valves on the main pipe and each branch pipe of the diversion pipeline to regulate the flow rate in the pipe.

[0016] Step 5: Start the hot air furnace and adjust the negative pressure of the guide pipe to the design value of -300 Pa through the regulating valve on the thick pipe. Calibrate the negative pressure and verify the suction effect.

[0017] Step 6: After the hot air furnace is supplying air normally, gradually open the regulating valve on the thick pipe of the guide pipe and monitor the change in suction. If the suction is insufficient: the negative pressure is lower than -200 Pa, start the ejector to assist in suction.

[0018] Step 7: Install CO concentration analyzers on each branch of the diversion pipeline to monitor CO concentration changes in real time. When the CO concentration is ≤24ppm, it indicates that the gas leakage at this vent is small, triggering the interlock to close the regulating valve on the corresponding branch of the vent.

[0019] Step 8: Take advantage of the blast furnace shutdown to clean the ash accumulation in the gas collecting hood and check the airtightness of the gas collecting hood.

[0020] This embodiment utilizes the stable negative pressure suction generated by the exhaust gas during the operation of the hot blast stove flue to extract leaked tuyere gas. Without affecting the normal operation of the blast furnace and hot blast stove, it comprehensively considers multiple aspects such as collection, transportation, and monitoring to completely solve the problem of blast furnace tuyere gas leakage.

[0021] In addition to the above embodiments, the present invention also includes other embodiments. All technical solutions formed by equivalent transformation or equivalent substitution should fall within the protection scope of the claims of the present invention.

Claims

1. A method for controlling gas leakage at blast furnace tuyeres, characterized in that: include, Step 1: During the blast furnace shutdown period, install gas collection hoods at each tuyeres of the blast furnace; Step 2: Install a guide pipe between the end of the flue of the hot blast stove and each gas collection hood. The guide pipe includes a branch pipe arranged at the front end and a thick pipe arranged at the rear end. The number of branch pipes is equal to the number of air outlets. The front end of each branch pipe is connected to a single gas collection hood. The rear ends of each branch pipe converge into the thick pipe, which is then connected to the end of the flue. A pressure monitoring element is installed on the thick pipe. Step 3: Install an ejector inside the thick tube and use nitrogen to enhance the negative pressure; Step 4: Install flow regulating valves on the main pipe and each branch pipe; Step 5: Start the hot air furnace, operate the regulating valve to adjust the negative pressure in the guide pipe to the design value, calibrate the negative pressure, and verify the suction effect; Step 6: After the hot blast furnace is supplying air normally, gradually adjust the regulating valve on the coarse pipe and monitor the change in suction. If the suction is insufficient, start the ejector to assist in suction. Step 7: Install a CO concentration analyzer on the branch pipe to monitor the CO concentration changes of each vent in real time. When the CO concentration is ≤24ppm, the gas leakage at this vent is small, triggering an interlock to close the regulating valve on the corresponding branch pipe of that vent. Step 8: Take advantage of the blast furnace shutdown to clean the accumulated ash in each gas collecting hood and check the airtightness of the gas collecting hood.

2. The method for controlling gas leakage at the blast furnace tuyeres according to claim 1, characterized in that: In step five, the design value for the negative pressure inside the thick pipe is -300 Pa; in step six, insufficient suction means that the negative pressure is less than -200 Pa.

3. The method for controlling gas leakage at the blast furnace tuyeres according to claim 1, characterized in that: In step one, the gas collection hood is made of high-temperature resistant and flexible fiber material with a temperature resistance of ≥400℃, and the material is wrapped around the surface of the air outlet.

4. The method for controlling gas leakage at the blast furnace tuyeres according to claim 1, characterized in that: In step two, the end of the thicker pipe of the diversion pipe is connected to the flue at an angle of 30-45°.

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