Backflow damping down control method

Abstract

The invention relates to the technical field of blast furnace ironmaking, in particular to a backflow damping-down control method which comprises the following steps: before damping-down, notifying a dispatching room, a hot blast stove, a trough, a blowing station, an air blower station, a TRT control room, a gas plant management room, a soft water pump room and the like to make preparations; when slag iron is basically completely discharged, gradually reducing air and pressure, stopping oxygen enrichment, stopping coal, stopping operation of the TRT, and notifying a water conservancy project to adjust the cooling water amount of a bad tuyere; introducing steam and nitrogen into the furnace top; when high pressure is converted into normal pressure, the pressure difference is lower than the normal level, a cold air gate is closed, air temperature control is changed into manual operation, and a hot blast stove is stopped; and when the air pressure is reduced to about 0.04-0.05 MPa, gas cutting operation is carried out after a management room of a gas plant is contacted, and through standardized operation steps, particularly after a backflow valve is fully opened, hot gas upwards enters a backflow pipe system by virtue of a chimney effect, so that negative pressure in the furnace body is formed, the gas is effectively prevented from overflowing from an air port, and the personal safety of constructors is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace ironmaking, and in particular to a backflow wind-off control method. Background Art

[0002] Blast furnace ironmaking is one of the important processes in modern steel production. In the blast furnace production process, when production needs to be interrupted due to equipment maintenance, accident handling or other reasons, the air supply and smelting are usually stopped. This process is called a wind break. According to the length of the wind break, it can be divided into short-term wind break and long-term wind break. Short-term wind break usually refers to a wind break time of less than 4 hours, which is mainly used for temporary operations such as replacing cooling equipment and repairing equipment; long-term wind break refers to a wind break time of more than 4 hours, involving more complex maintenance tasks.

[0003] Whether it is a short-term or long-term wind stop, as long as it involves the maintenance of the tuyere platform area, backflow operation is required. The main purpose of the backflow operation is to extract the gas generated by the furnace to ensure the safety of the construction workers. At the same time, the temperature control of the backflow system must also be considered to protect the refractory materials at the hot air surrounding pipe and the hot air main pipe to ensure the longevity and efficient operation of the blast furnace.

[0004] Equipment loss: During the backflow wind-off process, if the temperature is not properly controlled, the refractory materials of the hot air main pipe and its connecting parts will crack and peel off due to excessive temperature difference, and may even cause the pipe shell to burn red and collapse, shortening the service life of the equipment.

[0005] Non-standard operation: Different ironmaking plants lack unified standards for backflow wind-down operations, resulting in different operating methods, making it difficult to ensure consistent safety and equipment protection effects. Summary of the invention

[0006] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] In view of the problem that in the above-mentioned backflow wind-off process, the operation is not standardized, which may cause gas to overflow from the air outlet and seriously threaten the life safety of construction workers, the present invention is proposed.

[0008] Therefore, the object of the present invention is to provide a backflow wind control method.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions: a backflow wind stop control method, comprising, before the wind stop, notifying the dispatching room, hot air furnace, trough, blowing station, blower station, TRT control room, gas plant management room, and soft water pump room to prepare;

[0010] When the slag and iron are basically discharged, the air flow and pressure are gradually reduced, oxygen enrichment and coal are stopped, TRT is stopped, and the water engineer is notified to adjust the cooling water volume of the bad tuyere;

[0011] Steam and nitrogen are passed through the furnace top;

[0012] When high pressure is converted to normal pressure, the pressure difference is lower than the normal level, the cold air gate is closed, the air temperature control is changed to manual, and the hot air furnace is stopped;

[0013] When the wind pressure drops to about 0.04-0.05MPa, contact the gas plant management office to cut off the gas, requiring to open the furnace top vent valve first, and then close the dust collector gas cut-off valve;

[0014] While reducing the air pressure, check the working condition of the tuyere, and block the iron outlet after confirming that the slag and iron are completely discharged. After confirming that there is no possibility of slag filling in the tuyere, reduce the air pressure to zero;

[0015] Close the cold air valve and hot air valve of the air supply furnace to release the exhaust gas;

[0016] Open 4-6 small covers of the tuyere viewing holes. Do not open the large cover or the small cover of the tuyere that has been filled with slag.

[0017] Fully open the reverse flow valve to reverse flow;

[0018] Lift the dipstick and give the wind-break signal;

[0019] During the maintenance process, always pay attention to the temperature of the air temperature thermocouple in the hot air main pipe, and control this temperature range between 950-1250℃. When the temperature is high, increase the number of small air vent covers opened; when the temperature is low, reduce the number of small air vent covers opened.

[0020] As a preferred scheme of the backflow air shut-off control method described in the present invention, wherein: 4-6 small covers of the air vent viewing holes are opened, and the amount of air entering the hot air main pipe is adjusted by controlling the number of the small covers of the opened air vents, thereby controlling the temperature in the hot air main pipe to be between 950-1250°C, so as to reduce the impact of the temperature difference on the refractory material in the pipeline and extend the service life of the equipment.

[0021] As a preferred solution of the backflow air shut-off control method described in the present invention, after the backflow valve is fully opened, the hot coal gas is allowed to enter the backflow pipe system upward by relying on the chimney effect, forming a negative pressure inside the furnace body, thereby preventing the coal gas from overflowing from the air outlet and ensuring the personal safety of the construction workers.

[0022] As a preferred scheme of the backflow wind stop control method described in the present invention, the method is particularly suitable for blast furnace ironmaking process, especially the backflow operation involving maintenance of the tuyere platform area. Standardized operation can effectively prevent the safety hazards caused by gas leakage and protect the refractory materials from damage.

[0023] As a preferred scheme of the backflow wind-off control method described in the present invention, the method also includes dynamically adjusting the number of openings of the small tuyere covers according to the change of the temperature in the hot air main pipe during the maintenance process, so as to maintain the temperature in the hot air main pipe within a stable range and reduce the temperature difference with normal production, thereby effectively protecting the refractory materials of the hot air main pipe and its connecting parts and extending the service life of the hot air main pipe.

[0024] As a preferred scheme of the backflow wind stop control method described in the present invention, wherein: while reducing the air flow, check the working condition of the tuyere, and block the iron outlet after confirming that the slag and iron are completely discharged, and after confirming that there is no possibility of slag filling in the tuyere, reduce the air pressure to zero to ensure the safety of the wind stop process.

[0025] As a preferred solution of the backflow wind stop control method described in the present invention, the cold air valve and hot air valve of the air supply furnace are closed to release the exhaust gas, ensuring that there is no residual harmful gas in the furnace, thereby further improving safety.

[0026] As a preferred scheme of the backflow wind-off control method described in the present invention, when the wind pressure is reduced to about 0.04-0.05MPa, the gas cutting operation is carried out after contacting the gas plant management room, requiring to open the furnace top vent valve first and then close the dust collector gas shut-off valve to ensure the safe discharge of gas and prevent gas accumulation from causing safety accidents.

[0027] As a preferred solution of the backflow wind-off control method of the present invention, steam and nitrogen are passed through the furnace top to dilute the coal gas concentration in the furnace to further improve the safety factor.

[0028] As a preferred solution of the backflow wind-off control method described in the present invention, the method also includes regularly checking the status of the small air vent cover during maintenance to ensure that it can be opened or closed in time when needed to adapt to different temperature changes and ensure that the temperature in the hot air main duct is always within the range of 950-1250°C.

[0029] Beneficial effects of the present invention: The present invention uses standardized operating steps, especially after the backflow valve is fully opened, to rely on the chimney effect to allow the hot gas to enter the backflow pipe system upward, forming a negative pressure inside the furnace body, effectively preventing the gas from overflowing from the tuyere, and ensuring the personal safety of the construction personnel. By controlling the number of small tuyere covers opened, the amount of air entering the hot air main is adjusted, and the temperature in the hot air main is controlled between 950-1250°C, reducing the impact of temperature difference on refractory materials, effectively preventing refractory materials from cracking and peeling, and extending the service life of the hot air main and its connecting parts. The backflow wind stop control method of the present invention is simple and efficient to operate, can complete the wind stop operation in a short time, reduce the time of production interruption, and improve production efficiency. The present invention provides a set of standardized backflow wind stop operation procedures to ensure that each ironmaking plant has clear guidance and specifications when performing backflow wind stop operations, thereby improving the consistency and reliability of operations. By accurately controlling the temperature in the hot air main, equipment damage caused by excessive temperature difference is reduced, maintenance costs are reduced, and the service life of the equipment is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without any creative labor.

[0031] Figure 1 The figure is a schematic diagram of the overall process of a backflow wind control method.

[0032] Figure 2 The figure is a schematic diagram of the position structure between the surrounding pipe and the blast furnace in a backflow wind-off control method.

[0033] Figure 3 for Figure 2 The enlarged view of point A in the figure is a schematic diagram of the position structure between the probe and the blast furnace. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0035] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0037] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0038] Example 1, reference Figure 1 to Figure 3 , which is the first embodiment of the present invention. This embodiment provides a backflow wind stop control method, including, this embodiment mainly describes the basic steps of backflow wind stop control, including notification preparation before wind stop, gradual wind reduction and pressure reduction, steam and nitrogen on the furnace top, operation when high pressure turns to normal pressure, gas cutting operation when wind pressure drops to a specific value, reducing wind pressure to zero, closing hot and cold air valves to release exhaust gas, opening the small cover of the air vent sight hole, fully opening the backflow valve for backflow, and lifting the probe to send a wind stop signal. These steps constitute the basic framework of backflow wind stop control, clarify the basic operation process, provide a reliable starting point for subsequent embodiments, and ensure that all necessary safety measures are implemented.

[0039] Step 1: Before the wind is shut down, notify the dispatching room, hot air furnace, trough, injection station, blower station, TRT control room, gas plant management room, and soft water pump room to prepare;

[0040] Step 2: When the slag and iron are basically discharged, start to gradually reduce the air flow and pressure, stop oxygen enrichment and coal, stop TRT operation, and notify the water engineer to adjust the cooling water volume of the bad air outlet;

[0041] Step 3: Pass steam and nitrogen through the furnace top;

[0042] Step 4: When high pressure is converted to normal pressure, the pressure difference is lower than the normal level, close the cold air gate, change the air temperature control to manual, and stop the hot air furnace;

[0043] Step 5: When the wind pressure drops to about 0.04-0.05MPa, contact the gas plant management office to cut off the gas. It is required to open the furnace top vent valve first and then close the dust collector gas cut-off valve;

[0044] Step 6: While reducing the air pressure, check the working condition of the tuyere, confirm that the slag and iron are completely discharged, then block the iron outlet, and after confirming that there is no possibility of slag filling in the tuyere, reduce the air pressure to zero;

[0045] Step 7: Close the cold air valve and hot air valve of the air supply furnace to release the exhaust gas;

[0046] Step 8: Open 4-6 small covers of the tuyere viewing holes. Do not open the large cover or the small cover of the tuyere that has been filled with slag.

[0047] Step 9: Fully open the backflow valve to reverse the flow;

[0048] Step 10: Lift the probe and send out a wind-break signal;

[0049] Step 11: During the inspection, always pay attention to the temperature of the air temperature thermocouple in the hot air main duct, and control this temperature range between 950-1250℃. When the temperature is high, increase the number of small air vent covers opened; when the temperature is low, reduce the number of small air vent covers opened.

[0050] Furthermore, 4-6 small covers of the tuyere viewing holes are opened, and the amount of air entering the hot air main duct is adjusted by controlling the number of small covers opened, thereby controlling the temperature in the hot air main duct between 950-1250°C to reduce the impact of temperature difference on the refractory material in the pipeline and extend the service life of the equipment.

[0051] Furthermore, after the backflow valve is fully opened, the hot gas is allowed to flow upward into the backflow pipe system by relying on the chimney effect, forming a negative pressure inside the furnace body, thereby preventing the gas from overflowing from the tuyere and ensuring the personal safety of the construction workers.

[0052] Furthermore, the method is particularly suitable for blast furnace ironmaking process, especially the backflow operation involving the maintenance of the tuyere platform area. Standardized operation can effectively prevent the safety hazards caused by gas leakage and protect the refractory materials from damage.

[0053] Furthermore, the method also includes dynamically adjusting the number of openings of the small tuyere covers according to the temperature changes in the hot air main pipe during the maintenance process to maintain the temperature in the hot air main pipe within a stable range and reduce the temperature difference with normal production, thereby effectively protecting the refractory materials of the hot air main pipe and its connecting parts and extending the service life of the hot air main pipe.

[0054] Furthermore, while reducing the air flow, check the working condition of the tuyere, confirm that all the slag and iron are out and then block the iron outlet. After confirming that there is no possibility of slag filling in the tuyere, reduce the air pressure to zero to ensure the safety of the air stop process.

[0055] Furthermore, close the cold air valve and hot air valve of the air supply furnace to release the exhaust gas and ensure that there is no residual harmful gas in the furnace, further improving safety.

[0056] Furthermore, when the wind pressure drops to about 0.04-0.05MPa, contact the gas plant management office and cut off the gas. It is required to open the furnace top vent valve first and then close the dust collector gas shut-off valve to ensure the safe discharge of gas and prevent gas accumulation from causing safety accidents.

[0057] Furthermore, steam and nitrogen are passed through the furnace top to dilute the gas concentration in the furnace and further improve the safety factor.

[0058] Furthermore, the method also includes periodically checking the status of the tuyere cover during the maintenance process to ensure that it can be opened or closed in time when needed to adapt to different temperature changes and ensure that the temperature in the hot air main pipe is always within the range of 950-1250°C.

[0059] Example 2, reference Figure 1 to Figure 3 , which is the second embodiment of the present invention. This embodiment is different from the first embodiment in that: this embodiment is different from embodiment 1 in that the safety-enhanced backflow air shut-off control method ensures that gas does not leak through a series of specific steps to prevent accidents.

[0060] Notice before the shutdown: Before the shutdown, notify the dispatching room, hot air furnace, trough, injection station, blower station, TRT control room, gas plant management room, and soft water pump room to be ready.

[0061] Gradually reduce air flow and pressure: When the slag and iron are basically discharged, start to gradually reduce air flow and pressure, stop oxygen enrichment and coal, stop TRT operation, and notify the water engineer to adjust the cooling water volume of the bad air outlet.

[0062] Steam and nitrogen are introduced into the furnace top to dilute the gas concentration in the furnace and further improve the safety factor.

[0063] High pressure to normal pressure: When high pressure is converted to normal pressure, the pressure difference is lower than the normal level, the cold air valve is closed, the air temperature control is changed to manual, and the hot air furnace is stopped.

[0064] Wind pressure drops to 0.04-0.05MPa: When the wind pressure drops to about 0.04-0.05MPa, contact the gas plant management office to cut off the gas. It is required to open the furnace top vent valve first and then close the dust collector gas shut-off valve to ensure safe gas discharge and prevent gas accumulation from causing safety accidents.

[0065] Check the working condition of the tuyere: check the working condition of the tuyere while reducing the air flow, block the iron outlet after confirming that the slag and iron are all out, and reduce the air pressure to zero after confirming that there is no possibility of slag filling in the tuyere to ensure the safety of the air stop process.

[0066] Close relevant valves: close the cold air valve and hot air valve of the air supply furnace, release the exhaust gas, ensure that there is no residual harmful gas in the furnace, and further improve safety.

[0067] Fully open the backflow valve: After the backflow valve is fully opened, the chimney effect is used to allow the hot gas to flow upward into the backflow pipe system, forming a negative pressure inside the furnace body, thereby preventing the gas from overflowing from the tuyere and ensuring the personal safety of the construction workers.

[0068] Regularly check the status of the tuyere cover: During the maintenance process, regularly check the status of the tuyere cover to ensure that it can be opened or closed in time when needed to adapt to different temperature changes and ensure that the temperature in the hot air main duct is always within the range of 950-1250℃.

[0069] The rest of the structure is the same as that of Example 1.

[0070] Example 3, reference Figure 1 to Figure 3 , which is the third embodiment of the present invention. This embodiment is different from the above embodiments in that: the difference between this embodiment and embodiment 2 is that the backflow wind-off control method for equipment protection and life extension is to reduce the influence of temperature difference on refractory materials by accurately controlling the temperature in the hot air main pipe.

[0071] Notice before the shutdown: Before the shutdown, notify the dispatching room, hot air furnace, trough, injection station, blower station, TRT control room, gas plant management room, and soft water pump room to be ready.

[0072] Gradually reduce air flow and pressure: When the slag and iron are basically discharged, start to gradually reduce air flow and pressure, stop oxygen enrichment and coal, stop TRT operation, and notify the water engineer to adjust the cooling water volume of the bad air outlet.

[0073] Steam and nitrogen are introduced into the furnace top to dilute the gas concentration in the furnace and further improve the safety factor.

[0074] High pressure to normal pressure: When high pressure is converted to normal pressure, the pressure difference is lower than the normal level, the cold air valve is closed, the air temperature control is changed to manual, and the hot air furnace is stopped.

[0075] Wind pressure drops to 0.04-0.05MPa: When the wind pressure drops to about 0.04-0.05MPa, contact the gas plant management office to cut off the gas. It is required to open the furnace top vent valve first and then close the dust collector gas shut-off valve to ensure safe gas discharge and prevent gas accumulation from causing safety accidents.

[0076] Open the small covers of the tuyere sight holes: Open 4-6 small covers of the tuyere sight holes, and adjust the amount of air entering the hot air main duct by controlling the number of small covers opened, thereby controlling the temperature in the hot air main duct between 950-1250℃, so as to reduce the impact of temperature difference on the refractory materials in the pipeline and extend the service life of the equipment.

[0077] Dynamically adjust the number of small tuyere covers opened: During the maintenance process, always pay attention to the temperature of the air temperature thermocouple in the hot air main duct, and control this temperature range between 950-1250℃. When the temperature is high, increase the number of small tuyere covers opened; when the temperature is low, reduce the number of small tuyere covers opened.

[0078] Regularly check the status of the tuyere cover: During the maintenance process, regularly check the status of the tuyere cover to ensure that it can be opened or closed in time when needed to adapt to different temperature changes and ensure that the temperature in the hot air main duct is always within the range of 950-1250℃.

[0079] Close relevant valves: close the cold air valve and hot air valve of the air supply furnace, release the exhaust gas, ensure that there is no residual harmful gas in the furnace, and further improve safety.

[0080] Fully open the backflow valve: After the backflow valve is fully opened, the chimney effect is used to allow the hot gas to flow upward into the backflow pipe system, forming a negative pressure inside the furnace body, thereby preventing the gas from overflowing from the tuyere and ensuring the personal safety of the construction workers.

[0081] Through these two embodiments, Example 2 and Example 3, the application and advantages of the backflow wind control method in different aspects can be more clearly demonstrated.

[0082] The rest of the structure is the same as that of Example 2.

[0083] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A backflow wind control method, characterized in that: The method comprises the following steps: Before stopping the wind, notify the dispatching room, hot air furnace, trough, injection station, blower station, TRT control room, gas plant management room, and soft water pump room to prepare; When the slag and iron are basically discharged, the air flow and pressure are gradually reduced, oxygen enrichment and coal are stopped, TRT is stopped, and the water engineer is notified to adjust the cooling water volume of the bad tuyere; Steam and nitrogen are passed through the furnace top; When high pressure is converted to normal pressure, the pressure difference is lower than the normal level, the cold air gate is closed, the air temperature control is changed to manual, and the hot air furnace is stopped; When the wind pressure drops to about 0.04-0.05MPa, contact the gas plant management office to cut off the gas, requiring to open the furnace top vent valve first, and then close the dust collector gas cut-off valve; While reducing the air pressure, check the working condition of the tuyere, and block the iron outlet after confirming that the slag and iron are completely discharged. After confirming that there is no possibility of slag filling in the tuyere, reduce the air pressure to zero; Close the cold air valve and hot air valve of the air supply furnace to release the exhaust gas; Open 4-6 small covers of the tuyere viewing holes. Do not open the large cover or the small cover of the tuyere that has been filled with slag. Fully open the reverse flow valve to reverse flow; Lift the dipstick and give the wind-break signal; During the maintenance process, always pay attention to the temperature of the air temperature thermocouple in the hot air main pipe, and control this temperature range between 950-1250℃. When the temperature is high, increase the number of small air vent covers opened; when the temperature is low, reduce the number of small air vent covers opened.

2. The backflow wind control method according to claim 1, characterized in that: The 4-6 tuyere viewing hole covers are opened, and the amount of air entering the hot air main pipe is adjusted by controlling the number of the opened tuyere viewing hole covers, thereby controlling the temperature in the hot air main pipe to be between 950-1250° C. to reduce the temperature difference.

3. The backflow wind control method according to claim 2, characterized in that: After the backflow valve is fully opened, the hot coal gas flows upward into the backflow pipe system by relying on the chimney effect, forming a negative pressure inside the furnace body.

4. The backflow wind control method according to claim 3, characterized in that: The method is particularly suitable for blast furnace ironmaking processes, especially backflow operations involving maintenance of the tuyere platform area.

5. The backflow wind control method according to claim 4, characterized in that: The method also includes dynamically adjusting the number of openings of the tuyere covers according to the temperature change in the hot air main pipe during the maintenance process to maintain the temperature in the hot air main pipe within a stable range and reduce the temperature difference with normal production.

6. The backflow wind control method according to claim 5, characterized in that: During the described air reduction, in the process of gradually reducing the air, the working condition of each tuyere is continuously checked to ensure that the iron outlet is sealed after the slag and iron are completely discharged, and after confirming that there is no risk of slag and iron backflow at the tuyere, the air pressure is reduced to zero.

7. The backflow wind control method according to claim 6, characterized in that: The cold air valve and hot air valve of the blast furnace are closed to release the exhaust gas and ensure that no harmful gas remains in the furnace.

8. The backflow wind control method according to claim 7, characterized in that: When the wind pressure drops to about 0.04-0.05MPa, contact the gas plant management office to cut off the gas. It is required to open the furnace top vent valve first and then close the dust collector gas shut-off valve to ensure safe gas discharge.

9. The backflow wind control method according to claim 8, characterized in that: Steam and nitrogen are passed through the furnace top to dilute the coal gas concentration in the furnace.

10. The backflow wind control method according to claim 9, characterized in that: The method also includes regularly checking the status of the tuyere cover during the maintenance process to ensure that it can be opened or closed in time when needed to adapt to different temperature changes and ensure that the temperature in the hot air main pipe is always within the range of 950-1250°C.

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