A method for observing the airtight box at the top of a blast furnace

Abstract

The invention discloses an observation method for a blast furnace top airtight box, relates to the technical field of blast furnace metallurgical equipment, and solves the technical problem that the internal condition of the airtight box can only be checked when the blast furnace is stopped for maintenance in the prior art. The method includes controlling the lubrication, temperature, water temperature difference, positioning in the blast furnace, cross temperature measurement, and sub-center temperature of the airtight box, measuring the operating current of the a-angle tilting motor and the β-angle rotating motor, and measuring the operating current of the current exceeding the predetermined value for a long time. After the online reversal of the spare cabinet and the spare motor and the automatic fault-free inspection, the observation hole on the airtight box is opened during the short air stop time of the blast furnace to check whether the inside of the airtight box is normal, and an imaging device is used to measure the temperature of the a-angle chute tilting gearbox, and observe whether the lubrication and wear of the planetary reducer, the rotating gear transmission, and the tilting gear transmission are normal, so as to judge whether the airtight box can continue to be used or must be planned for replacement. In this way, the service life of the airtight box is improved, and the smooth and stable production of the blast furnace is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace metallurgical equipment, and in particular to an observation method for a blast furnace top airtight box. Background Art

[0002] In the three blast furnaces of Shougang Co., Ltd., the materials are evenly distributed in the furnace according to the required distribution angle and number of turns through the water-cooled airtight transmission gearbox, which is also called the airtight box. As the materials transported into the furnace 24 hours a day are as high as 13,000 tons, which is about 4.55 million tons a year, the working environment of the airtight box equipment is very bad. Once a failure occurs, the blast furnace has to be shut down for a long time to replace the airtight box.

[0003] For example, the average service life of a company's airtight boxes was 2.5 years, which resulted in the blast furnace being forced to stop blowing many times. At the same time, the working conditions at the online replacement site were extremely difficult and harsh, with low construction efficiency and a long construction period.

[0004] Two days after the replacement of the airtight box on the top of the No. 3 blast furnace of a certain company, the current at angle a was high. When the tilting angle of the material distribution chute reached about 34 degrees, it would occasionally become stuck and unable to move. At this time, it was impossible to determine whether it was a fault in the transmission gear inside the airtight box or a fault in the planetary reducer body. The manhole of the airtight box could only be opened for maintenance, and the maintenance cycle was about 5 months. Even a minor repair of 4 hours required steps such as opening the manhole of the furnace throat and ignition. If the manhole of the airtight box is opened when the blast furnace is stopped for a small air change, a large amount of air will be sucked into the furnace and mixed with the coal gas in the furnace, which is easy to reach the explosion limit. Summary of the invention

[0005] The present application provides a method for observing the airtight box at the top of a blast furnace, which solves the technical problem in the prior art that the internal conditions of the airtight box can only be checked when the blast furnace is shut down for maintenance.

[0006] The present application provides an observation method for the airtight box at the top of a blast furnace, comprising: on-the-job personnel observe whether the lubrication condition of the planetary reducer is good every day, and add dry oil lubrication to the lubrication points inside the airtight box at preset intervals; control the temperature of the airtight box not to exceed an alarm value of 40°C, and increase the water volume and nitrogen flow rate as soon as possible when the alarm value is exceeded to stabilize the temperature of the airtight box; control the water temperature difference of the airtight box to be within 15°C, and appropriately increase the water volume according to the situation in the furnace; control the top temperature in the blast furnace to be less than 250°C, the cross temperature measurement to be less than 700°C or 750°C, the sub-center temperature to be less than 600°C or 650°C, and the furnace to be opened after exceeding the alarm value; Use water to cool down; measure whether the operating current of the a angle tilting motor is less than 18A, and whether the operating current of the β angle rotating motor is less than 27A. If the current exceeds this limit for a long time, it means there is a problem. After the spare cabinet and spare motor are turned online and the automation is checked to be fault-free, use the small wind stop time of the blast furnace to open the observation hole on the airtight box to check whether the inside of the airtight box is normal, and use an imaging device to measure the temperature of the a angle chute tilting gearbox. If the temperature exceeds 70℃, it is abnormal. Observe whether the lubrication and wear of the planetary reducer, rotating gear transmission, and tilting gear transmission are normal to determine whether the airtight box can continue to be used or must be planned for replacement.

[0007] In some embodiments, the amount of water can be appropriately increased according to the conditions in the furnace, including the maximum static flow rate of the airtight box test up to 28m 3 / h, including 15m 3 / h.

[0008] In some embodiments, controlling the top temperature of the blast furnace to be less than 250°C includes controlling the top temperature of the blast furnace to be less than 250°C and not less than 230°C.

[0009] In some embodiments, during the inspection process of opening the observation hole on the airtight box and checking whether the inside of the airtight box is normal by utilizing the short air stop time of the blast furnace, the process includes: stopping the air of the blast furnace, and after the pressure drops below 0.3 kg, opening the vent valve to release the pressure in the furnace; after the pressure in the furnace is zero, stopping the nitrogen in the airtight box and opening the observation hole; using an imaging device to measure the temperature of the tilting gearbox of the a-angle chute, and a temperature exceeding 70°C is abnormal; observing whether the lubrication and wear of the planetary reducer, rotating gear transmission, and tilting gear transmission are normal, and through this point it can be determined whether it is a fault in the airtight box or a fault in the planetary reducer, and then determining whether the airtight box can continue to be used or must be planned for replacement.

[0010] In some embodiments, an observation hole cover is installed at the observation hole. The observation hole cover is rotatably installed on the box wall of the airtight box through the observation hole shaft, and is equipped with multiple locking mechanisms to enable the observation hole cover to open and close the observation hole.

[0011] In some embodiments, a looped salt water asbestos rope is provided at the interface between the observation hole cover and the airtight box.

[0012] In some embodiments, the locking mechanism includes a pin plate and a pin shaft. The pin shaft is fixed on the wall of the airtight box and is arranged at the outer circle of the observation hole. The pin shaft is provided with a pin hole. The pin plate is wedge-shaped. The pin plate is passed through the pin hole of the pin shaft and the pin plate presses the observation hole cover.

[0013] In some embodiments, the salt water asbestos rope is soaked in saturated concentrated salt water, and the soaking time is controlled within a range of 24 hours to 5 months.

[0014] In some embodiments, the interface of the salt water asbestos rope is overlapped, and the overlap length is 50-70 mm.

[0015] In some embodiments, the diameter of the observation hole is 150±30 mm.

[0016] The beneficial effects of the present application are as follows: a method for observing the airtight box at the top of a blast furnace is provided, by controlling the lubrication, temperature, water temperature difference and positioning in the blast furnace, cross temperature measurement and sub-center temperature of the airtight box, the operating current of the a angle tilting motor and the β angle rotating motor are detected, if the current is too high for a long time, after the online reverse cabinet and the spare motor and the automatic inspection are fault-free, the observation hole on the airtight box is opened during the small wind stop time of the blast furnace to check whether the inside of the airtight box is normal, and the temperature of the a angle chute tilting gearbox is measured by an imaging device, and the temperature measurement is abnormal if it exceeds 70°C, and the lubrication and wear of the planetary reducer, the rotating gear transmission and the tilting gear transmission are observed. Whether the situation is normal, to judge whether the airtight box can continue to be used or must be planned for replacement; this method fully meets the requirements for the standardized and standardized use of blast furnace top airtight boxes. When an abnormal situation is found, it can promptly check whether it is an internal fault, and can meet the daily work of detecting the inside of the airtight box during small air stop and air exchange, thereby ensuring the long-term and stable operation of the airtight box, achieving the goal of increasing the service life of the airtight box, and having a multiplier effect. It is suitable for various large and extra-large blast furnace top airtight box devices, avoiding the serious impact on blast furnace production caused by the blast furnace top airtight box operating for a long time with a disease and no action due to inadequate detection, and ensuring the smooth production of the blast furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention.

[0018] Figure 1 A schematic diagram of the structure of the airtight box in the method for observing the blast furnace top airtight box provided in the present application;

[0019] Figure 2 A schematic diagram of the structure involved in the observation hole in the observation method of the blast furnace top airtight box provided in the present application;

[0020] Figure 3 Schematic diagram of the matching between the pin plate and the pin shaft.

[0021] The attached drawings are marked with: 1- material chute, 2- airtight box, 3- center throat, 4- planetary reducer, 5- rotating gear transmission, 6- tilting gear transmission, 7- observation hole, 7.1- observation hole shaft, 7.2- salt water asbestos rope, 7.3- observation hole cover, 7.4- pin plate, 7.5- pin shaft, 8- chute tilting gearbox, 9- maintenance manhole. DETAILED DESCRIPTION

[0022] Shougang Co., Ltd.'s three blast furnaces use the N1 main belt to convey various ironmaking raw materials through the reversing chute, and enter the left and right receiving ports, upper sealing valves, material tanks, and weighing hoppers for measurement. The upper sealing valve and gas recovery valve are closed, and the equalizing valve is opened to press the material tanks to equal the pressure in the furnace. When the material level in the furnace drops to the specified material line, the probe is raised to its original position, the lower sealing valve and flow regulating valve are opened, and the furnace material passes through the middle funnel, bellows, short section, center throat and water-cooled airtight transmission gearbox, and the material is evenly distributed in the furnace according to the required distribution angle and number of turns. The water-cooled airtight transmission gearbox is also called an airtight box, which is a key equipment for completing the distribution work in the bellless furnace top equipment.

[0023] The airtight box is driven by two AC variable frequency motors. After being decelerated by the planetary reducer, water-cooled transmission gearbox, chute tilting reducer, etc., the distribution chute can swing and rotate. After the various raw materials flow through the central throat and fall into the distribution chute, the raw materials fall to different positions in the furnace under the combined action of the swing and rotation of the distribution chute. The distribution chute works according to the ɑ angle and β angle data required by the production process, and various distribution methods such as single ring, multi-ring, spiral, fan-shaped, fixed point, etc. can be formed on the material surface in the furnace, thereby meeting various distribution requirements. Since the material transported to the furnace 24 hours a day is as high as about 13,000 tons, it reaches about 4.55 million tons a year. The working environment of the airtight box equipment is very harsh. Once a failure occurs, the blast furnace has to be stopped for a long time to replace the airtight box.

[0024] For example, the average service life of a company's airtight boxes was 2.5 years, which resulted in the blast furnace being forced to stop blowing many times. At the same time, the working conditions at the online replacement site were extremely difficult and harsh, with low construction efficiency and a long construction period.

[0025] Two days after the replacement of the airtight box on the top of the No. 3 blast furnace of a certain company, the current at angle a was high. When the tilting angle of the material distribution chute reached about 34 degrees, it would occasionally become stuck and unable to move. At this time, it was impossible to determine whether it was a fault in the transmission gear inside the airtight box or a fault in the planetary reducer body. The manhole of the airtight box could only be opened for maintenance, and the maintenance cycle was about 5 months. Even a minor repair of 4 hours required steps such as opening the manhole of the furnace throat and ignition. If the manhole of the airtight box is opened when the blast furnace is stopped for a small air change, a large amount of air will be sucked into the furnace and mixed with the coal gas in the furnace, which is easy to reach the explosion limit.

[0026] How to extend the service life of the airtight box in daily operation? The time for stopping the air and changing the air vents is usually 30 minutes. When a fault occurs, using the time for stopping the air and changing the air vents to detect the internal situation of the airtight box has become a problem that needs to be solved urgently.

[0027] The theoretical design service life of the blast furnace water-cooled airtight box is 5 years. If it is used and maintained properly in the later stage, the service life of the water-cooled airtight box will be extended; however, factors such as furnace temperature, pressure, cooling water quality, lubrication, bearing fatigue wear, equipment lubricant replacement cycle, etc. will affect the equipment life. By controlling the center temperature not to exceed 700℃ and the duration not to exceed 30 minutes, the support shaft bending degree is avoided, and the operation method is specially formulated in combination with production operations.

[0028] Therefore, based on Figure 1 The disclosed blast furnace involves an airtight box 2-related structure, specifically including a distribution chute 1, an airtight box 2, a central throat 3, a planetary reducer 4, a rotating gear transmission 5, a tilting gear transmission 6, an observation hole 7, a chute tilting gearbox 8 and a maintenance manhole 9. This embodiment discloses a method for observing the airtight box on the top of a blast furnace, and an observation hole 7 is opened on the wall of the airtight box 2. Figure 2 and Figure 3 The structure of the observation hole 7 is disclosed, including an observation hole rotating shaft 7.1, a salt water asbestos rope 7.2, an observation hole cover 7.3, a pin plate 7.4 and a pin shaft 7.5.

[0029] The observation method of the blast furnace top airtight box disclosed in the present embodiment specifically includes: the post personnel observe whether the thin oil lubrication condition of the planetary reducer 4 is good every day, and automatically add dry oil lubrication to the lubrication points inside the airtight box 2 at preset time intervals; control the temperature of the airtight box 2 not to exceed the alarm value of 40°C, and increase the water volume and nitrogen flow rate as soon as possible when the alarm value is exceeded to stabilize the temperature of the airtight box 2; control the water temperature difference of the airtight box 2 to be within 15°C, and the water volume can be appropriately increased according to the situation in the furnace. The static maximum flow rate of the airtight box 2 test can reach 28m 3 / h, including 15m 3 / h; control the top temperature of the blast furnace to be less than 250℃. For large blast furnaces, control the cross temperature measurement to be less than 700℃ and the secondary center temperature to be less than 600℃; control the top temperature of the blast furnace to be less than 250℃. For extra large blast furnaces such as 4000m 3 When the cross temperature is controlled to be less than 750℃, the sub-center temperature is controlled to be less than 650℃. When the corresponding values ​​are exceeded, water is added to the furnace to cool it down.

[0030] It also includes: measuring whether the operating current of the a-angle tilting motor is less than 18A, and whether the operating current of the β-angle rotating motor is less than 27A. If the former exceeds 18A for a long time, and the latter exceeds 27A for a long time, it means that there is a problem. After the online backup cabinet and backup motor are turned over and the automation is checked to be fault-free, it is necessary to use the blast furnace's small wind stop time to open the observation hole 7 on the airtight box 2 to check whether the inside of the airtight box 2 is normal, and use an imaging device to measure the temperature of the a-angle chute tilting gearbox 8. The temperature measurement is abnormal if it exceeds 70°C. Observe whether the lubrication and wear of the planetary reducer 4, the rotating gear transmission 5, and the tilting gear transmission 6 are normal to determine whether the airtight box 2 can continue to be used or must be planned for replacement. Among them, the diameter of the observation hole is 150±30mm, and about 150mm is appropriate, which can effectively avoid a large amount of air from mixing with the coal gas in the furnace, and can meet the observation needs.

[0031] The observation method of the present embodiment fully complies with the normalized and standardized use requirements of the blast furnace top airtight box. Through the observation method of the present embodiment, it is possible to timely check whether it is an internal fault when an abnormal situation is found, and it is possible to meet the work of detecting the inside of the airtight box at the daily small air stop and air exchange port, thereby ensuring the longevity and stable operation of the airtight box 2, achieving the goal of improving the service life of the airtight box, and having a multiplier effect. And the method is applicable to various large and extra-large blast furnace top airtight box devices, avoiding the serious impact on blast furnace production caused by the blast furnace top airtight box due to long-term operation with illness and no action due to inadequate detection, and ensuring the smooth and stable production of the blast furnace.

[0032] Regarding the above-mentioned control of the top temperature of the blast furnace to be less than 250°C, in some embodiments, when the top temperature is greater than 250°C, the top water pumping for cooling is promptly opened; when the top temperature is less than 230°C, the top water pumping for cooling is promptly closed.

[0033] The above involves measuring the operating current of the a-angle tilting motor and the β-angle rotating motor. Taking the three blast furnaces of Shougang Co., Ltd. as an example, the furnace master control post is required to pay close attention to the current situation in the table below and promptly feedback if the current increases abnormally. When the current increases abnormally, it is necessary to eliminate the electrical fault online and reconfirm it in the spare electrical cabinet. If there is no abnormality, it is necessary to use the blast furnace's small wind stop time to detect whether there is any abnormality inside the airtight box. The operating current is detailed in the table below:

[0034]

[0035] Regarding the inspection of whether the inside of the airtight box is normal, the specific inspection steps include: stop the blast furnace, wait until the pressure drops below 0.3 kg, open the vent valve to release the pressure in the furnace; after the pressure in the furnace is zero, stop the nitrogen in the airtight box 2, open the observation hole 7, and if the gas is large during the inspection, you need to wear a long tube respirator; use an imaging device to measure the temperature of the a-angle chute tilting gearbox 8, and the measured temperature value exceeds 70°C, which is abnormal. Observe whether the lubrication and wear of the planetary reducer 4, the rotating gear transmission 5, and the tilting gear transmission 6 are normal. Through this point, it can be determined whether it is a fault in the airtight box 2 or the planetary reducer 4, and then determine whether the airtight box 2 can continue to be used or must be planned for replacement.

[0036] Regarding the observation hole 7 opened on the airtight box 2, it is used for observation when it is opened, and for maintaining the function of the airtight box 2 when it is closed. Figure 2 An observation hole cover 7.3 is installed at the observation hole 7. The observation hole cover 7.3 is rotatably installed on the box wall of the airtight box 2 through the observation hole rotating shaft 7.1, and is equipped with multiple locking mechanisms. When the observation hole cover 7.3 covers the observation hole 7, the locking mechanisms lock the observation hole cover 7.3 on the airtight box 2 to realize the opening and closing of the observation hole 7 by the observation hole cover 7.3.

[0037] In some embodiments, see Figure 2 A ring-shaped salt water asbestos rope 7.2 is arranged at the interface between the observation hole cover 7.3 and the airtight box 2. The salt water asbestos rope 7.2 is soaked in saturated concentrated brine. The soaking time can be controlled between 24 hours and 5 months. If the soaking time is less than 24 hours, it cannot be used. If the soaking time exceeds 5 months, it must be replaced with a new one. The salt water asbestos rope 7.2 arranged in a ring shape can be overlapped at the interface, and the overlap length is controlled to be 50-70mm.

[0038] In some embodiments, please refer to Figure 2 and Figure 3 The locking mechanism includes a pin plate 7.4 and a pin shaft 7.5. The pin shaft 7.5 is fixed on the wall of the airtight box 2 and is arranged at the outer circle of the observation hole 7. The pin shaft 7.5 is provided with a pin hole. The pin plate 7.4 is wedge-shaped. The pin plate 7.4 is inserted into the pin hole of the pin shaft 7.5 and the pin plate 7.4 presses the observation hole cover 7.3. In addition, the locking mechanism can also adopt other forms such as bolt connection.

[0039] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0040] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for observing a blast furnace top airtight box, characterized in that: include: The personnel on duty observe whether the planetary reducer's thin oil lubrication condition is good every day, and add dry oil lubrication to the lubrication points inside the airtight box at preset intervals; Control the temperature of the airtight box not to exceed the alarm value of 40°C. If it exceeds the alarm value, increase the water volume and nitrogen flow rate as soon as possible to stabilize the temperature of the airtight box; The water temperature difference of the airtight box is controlled within 15°C, and the water volume can be appropriately increased according to the situation in the furnace; Control the top temperature of the blast furnace to be less than 250℃, the cross temperature measurement to be less than 750℃, and the secondary center temperature to be less than 650℃. If the temperature exceeds the limit, water will be added to cool the furnace down. Measure whether the operating current of the a-angle tilting motor is less than 18A, and whether the operating current of the β-angle rotating motor is less than 27A. If the current exceeds this limit for a long time, it means there is a problem. After the spare cabinet and spare motor are turned online and the automation is checked to be fault-free, use the small wind stop time of the blast furnace to open the observation hole on the airtight box to check whether the inside of the airtight box is normal, and use an imaging device to measure the temperature of the a-angle chute tilting gearbox. If the temperature exceeds 70℃, it is abnormal. Observe whether the lubrication and wear of the planetary reducer, rotating gear transmission, and tilting gear transmission are normal to determine whether the airtight box can continue to be used or must be planned for replacement.

2. The method for observing the blast furnace top airtight box according to claim 1, wherein: Controlling the top temperature of the blast furnace to be less than 250°C includes controlling the top temperature of the blast furnace to be less than 250°C and not less than 230°C.

3. The method for observing the blast furnace top airtight box according to claim 1, characterized in that: During the inspection process of opening the observation hole on the airtight box during the short-term air stop of the blast furnace to check whether the inside of the airtight box is normal, the following steps are included: Stop the blast furnace and wait until the pressure drops below 0.3 kg, then open the relief valve to release the pressure in the furnace; After the pressure in the furnace reaches zero, stop the nitrogen in the airtight box and open the observation hole; Use an imaging device to measure the temperature of the tilting gearbox in the A angle chute. If the temperature exceeds 70°C, it is abnormal. Observe whether the lubrication and wear of the planetary reducer, rotating gear transmission, and tilting gear transmission are normal. Through this point, it can be determined whether it is an airtight box failure or a planetary reducer failure, and then determine whether the airtight box can continue to be used or must be replaced.

4. The method for observing the blast furnace top airtight box according to claim 1, characterized in that: An observation hole cover is installed at the observation hole. The observation hole cover is rotatably installed on the box wall of the airtight box through an observation hole rotating shaft, and is equipped with multiple locking mechanisms to realize the opening and closing of the observation hole by the observation hole cover.

5. The method for observing the blast furnace top airtight box according to claim 4, characterized in that: A ring-shaped salt water asbestos rope is arranged at the interface between the observation hole cover and the airtight box.

6. The method for observing the blast furnace top airtight box according to claim 4, characterized in that: The locking mechanism includes a pin plate and a pin shaft, the pin shaft is fixed on the box wall of the airtight box and is arranged at the outer circle of the observation hole, the pin shaft is provided with a pin hole, the pin plate is wedge-shaped, the pin plate is passed through the pin hole of the pin shaft and the pin plate presses the observation hole cover.

7. The method for observing the blast furnace top airtight box according to claim 5, characterized in that: The salt water asbestos rope is soaked in saturated concentrated salt water, and the soaking time is controlled within a range of 24 hours to 5 months.

8. The method for observing the blast furnace top airtight box according to claim 5, characterized in that: The interface of the salt water asbestos rope is overlapped, and the overlap length is 50-70mm.

9. The method for observing the blast furnace top airtight box according to claim 1, characterized in that: The diameter of the observation hole is 150±30 mm.

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