Method suitable for online elimination of furnace roller nodules of silicon steel wire

Abstract

The invention discloses a method suitable for online elimination of furnace roller nodules of a silicon steel wire, which comprises a furnace roller partitioning module for averagely dividing a furnace roller into 15 regions according to the total number of the furnace roller and adapting to the control of an existing furnace roller driving system; the speed regulation range covers 80%-120% of the production line speed, rotation speed regulation is achieved through instructions of the grinding control module, and strip steel tension fluctuation caused by sudden rotation speed change is avoided; gas analysis and cleaning quality detection: detecting the pressure, the atmosphere and the dew point in the furnace according to an existing gas analyzer on site, and controlling whether a furnace roller driving module is started or not according to the nodule lower limit in combination with the realization of the on-site cleaning quality; the steps and principle of the grinding method are based on closed-loop control logic of atmosphere pre-judgment, partition grinding and effect feedback. According to the invention, through active control of zoned grinding and atmosphere observation, nodules at the initial stage are removed, continuous production is ensured, and the maintenance cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of silicon steel production equipment technology, and in particular to a method suitable for online elimination of furnace roll nodules in silicon steel production lines. Background Technology

[0002] In the silicon steel production process, the horizontal furnace is a key piece of equipment for annealing and decarburizing strip steel. Under the high temperature environment inside the furnace, residual oil, iron oxide scale, and impurities on the surface of the strip steel are easily attached to the surface of the furnace rollers and gradually form nodules. Nodules on the furnace rollers will cause a series of problems: (1) The nodule protrusions contact the surface of the strip steel, causing pits and scratches on the strip steel, which seriously affects the appearance quality of the product. (2) Nodules will aggravate the wear of the furnace roller surface and shorten the service life of the furnace rollers. The conventional furnace roller replacement cycle is about 6-8 months, and each replacement requires a shutdown of more than 24 hours (the furnace temperature needs to be reduced to near room temperature), which seriously affects the continuity of production. (3) Existing technology cannot automatically detect nodule defects and relies mainly on manual inspection. There are problems of untimely detection of nodules and low efficiency of manual operation.

[0003] Abnormal furnace atmosphere (such as excessively high oxygen concentration or dew point exceeding the standard) is an important cause of rapid nodule formation. Existing grinding roller technology is not effective in reducing nodule formation by detecting the atmosphere. If it is not detected in time, the nodule will grow larger (thickness ≥ 0.5 mm), increasing the difficulty of removal and even requiring shutdown and roller replacement.

[0004] External grinding devices require large-scale modifications to existing production lines, resulting in high costs for new equipment (approximately 50,000 RMB per unit; for example, a 150 furnace rollers on a Baotou Steel silicon steel line would cost 7.5 million RMB). Furthermore, they suffer from poor compatibility with existing production systems, hindering rapid deployment. Therefore, developing a furnace roller grinding technology that eliminates the need for shutdown, can be subjectively triggered, and specifically removes initial furnace roller nodules is crucial for solving the nodule problem in horizontal silicon steel furnaces. Summary of the Invention

[0005] To address the problems of long downtime, untimely removal of nodules, poor production continuity, and lack of an automatic grinding mechanism linked to the furnace atmosphere in existing horizontal silicon steel furnace roller grinding methods, the present invention aims to provide an online regional segmented anti-nodules grinding method for horizontal silicon steel furnace rollers. Through zoned grinding and active control based on atmosphere observation, nodules can be removed in the initial stage, ensuring continuous production and reducing maintenance costs.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This invention provides a method for online elimination of furnace roll nodules suitable for silicon steel wire, comprising:

[0008] Furnace roll partitioning module: Based on the total number of furnace rolls, they are divided into 15 zones on average, each zone is 30 meters long, and is compatible with existing furnace roll drive system control; the speed adjustment range covers 80%-120% of the production line speed, and the speed adjustment is achieved through the grinding control module command to avoid strip tension fluctuations caused by sudden speed changes.

[0009] Gas analysis and cleaning quality inspection: Based on the existing gas analyzer on site, the furnace pressure, atmosphere and dew point are detected. Combined with the on-site cleaning quality, the furnace roller drive module is controlled to start based on the lower limit of nodule formation.

[0010] The grinding method and its principles are based on a closed-loop control logic of "atmosphere prediction - zoned grinding - effect feedback". The specific steps and principles are as follows:

[0011] 1) Initialization settings: When the production line starts, the gas composition of the furnace area is detected and the feedback data is analyzed. Combined with the on-site cleaning quality, if any limit is exceeded, the furnace roller grinding will start. The grinding sequence is selected by default as an interval skipping type. The furnace roller speed in each area is different from the actual production speed. Through the mutual friction between the furnace roller and the strip, the iron powder and impurities formed in the early stage of nodule formation will be removed in the early stage to avoid the nodule from growing and affecting the surface quality of the steel strip.

[0012] 2) Production operation phase: By starting the initialization settings, the furnace roller nodule rate is reduced by 90%, with a significant preventive effect, and stable continuous production is basically achieved throughout the month.

[0013] Furthermore, each furnace roller is equipped with an individual variable frequency motor and gearbox.

[0014] Furthermore, the fluctuation range of strip tension should be controlled to ≤5%.

[0015] Furthermore, for the furnace rolls that still show signs of caking after the initial setup of the production line, the operators can quickly locate the caking furnace rolls by shortening the grinding time of each area of ​​the furnace rolls. The caking furnace rolls will leave long scratches on the strip by grinding with a speed mismatch with the strip speed. After the caking area is identified, the initial setup is stopped, and the furnace rolls in this area are ground separately at a differential speed to finally identify the caking furnace rolls. Stubborn caking areas are treated according to the treatment procedures.

[0016] Furthermore, the minimum range for furnace roll nodule formation in silicon steel lines is set at an oxygen concentration of ≤20ppm, a dew point of ≤15℃, and a residual iron content of 50mg / ㎡ during on-site cleaning.

[0017] Furthermore, by controlling the minimum range of nodule formation, the grinding program is started when the range is exceeded. The grinding starts in a random area and then performs zone grinding in an interval-jumping manner. The initial grinding period is mostly the nodule budding stage. After the grinding starts, the nodule budding stage is destroyed, and the nodule nucleation conditions cannot be met, thus eliminating furnace roller nodules.

[0018] Furthermore, the production line runs continuously during the grinding process, with the maximum fluctuation of the strip steel being ±3%, and there are no deviations or wrinkles on the production line; the initial nodules on the surface of the furnace rollers are completely removed, and the production line can achieve long-term non-stop production. The strip steel scratch rate has been reduced from 4.2% to 0.3%, and the monthly output has increased by 15%.

[0019] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0020] 1. High production continuity: Utilizing a zoned grinding method, speed is reduced only in a single zone while the remaining zones operate normally. Strip tension fluctuations are controlled to ≤5%, eliminating downtime. Compared to traditional offline grinding, this reduces downtime losses by 7.5 million RMB per year. Production efficiency is increased by 15-30%.

[0021] 2. Timely removal of nodules: By detecting the furnace atmosphere in advance, the risk of nodules can be predicted and eliminated in the initial stage, avoiding strip scratches caused by nodules growing larger, and increasing the product qualification rate to over 99.5%.

[0022] 3. High degree of automation: From atmosphere detection and grinding triggering to zoned execution, the entire process is completed automatically. Operators only need to check the equipment status periodically, which reduces the labor intensity and avoids delays in nodule treatment caused by missed or misjudged inspections.

[0023] 4. Low furnace roll wear: Targeted removal of initial furnace roll nodules prevents nodules from growing and causing severe wear on the furnace roll surface. At the same time, load protection logic prevents furnace roll overload, extending furnace roll service life by 30-50% and saving 800,000-1,200,000 yuan in furnace roll replacement costs annually. Detailed Implementation

[0024] A method suitable for online elimination of furnace roll nodules in silicon steel wire includes:

[0025] Furnace roll zoning module: Based on the total number of furnace rolls (taking Baotou Steel's silicon steel wire as an example, there are 150 rolls in total), they are divided into 15 zones, each zone is 30 meters long. It is compatible with the existing furnace roll drive system control (each furnace roll is a separate variable frequency motor and gearbox). The speed adjustment range covers 80%-120% of the production line speed. The speed can be adjusted through the grinding control module command to avoid strip tension fluctuations caused by sudden speed changes (control fluctuation amplitude ≤5%).

[0026] Gas analysis and cleaning quality inspection: Based on the existing gas analyzer on site, the furnace pressure, atmosphere and dew point are detected. Combined with the on-site cleaning quality, the furnace roller drive module is controlled to start based on the lower limit of nodule formation (residual iron content 50mg / m2).

[0027] The grinding method and its principles are based on a closed-loop control logic of "atmosphere prediction - zoned grinding - effect feedback". The specific steps and principles are as follows:

[0028] 1. Initialization settings: When the production line starts, the system analyzes the feedback data of the gas composition detection in the furnace area (taking Baogang silicon steel line as an example, oxygen concentration ≤20ppm, dew point ≤15℃), and combines this with the on-site cleaning quality (residual iron content 50mg / m2). If any of these limits are exceeded, the furnace roller grinding will start. The grinding sequence is set to interval skipping by default. The furnace roller speed in each area differs from the actual production speed. Through the mutual friction between the furnace roller and the strip, the iron powder and impurities formed in the early stage of nodule formation will be removed in the early stage, preventing the nodules from growing and affecting the surface quality of the steel strip.

[0029] 2. Production Operation Phase: Initial setup can reduce the furnace roll nodule rate by 90%, demonstrating a significant preventative effect and enabling stable continuous production throughout the month. However, on-site production is subject to chance. For furnace roll nodules that persist after initial setup, operators must quickly locate the nodule-forming rolls by shortening the grinding time for each area (changing the initial 10 min / area to 5 min / area). (Nodule-forming rolls leave long scratches on the strip due to grinding mismatched with the strip speed). Once the nodule area is identified, initial setup is stopped, and the rolls in that area undergo individual differential speed grinding to definitively pinpoint the nodule-forming roll. Stubborn nodules are then treated according to the established procedures.

[0030] The present invention will be described in more detail below through specific embodiments. These embodiments are merely descriptions of the best mode of implementation and do not limit the scope of the invention in any way.

[0031] Example 1

[0032] Equipment configuration: Based on data feedback from existing furnace area gas analyzers, hydrogen-oxygen analyzers, oxygen content metering devices, and dew point analyzers, combined with cleaning quality information feedback from the cleaning section outlet, the furnace roller frequency converter motors are modularly grouped, and the rotation speed after module startup is adjusted (80%-120% speed difference from the production line).

[0033] Parameter settings: Based on actual production conditions and theoretical knowledge, the minimum range for furnace roller nodule formation on Baogang silicon steel line is set as follows: oxygen concentration ≤ 20ppm, dew point ≤ 15℃, and residual iron content after on-site cleaning 50mg / ㎡. The grinding sequence is an intermittent skip pattern (1→3→5→7→9→11→2→4→6→8→10→12→13→14→15); grinding time is 10min / area.

[0034] Operation process: The grinding program is started when the minimum limit of nodule formation is exceeded. The grinding starts in a random area and then proceeds in a zoned grinding manner with intervals. The initial grinding period is mostly the nodule budding stage. After the grinding starts, the nodule budding stage is destroyed and the conditions for nodule nucleation cannot be met, thus eliminating nodule formation on the furnace roller.

[0035] Implementation results: The production line runs continuously during the grinding process, with the maximum fluctuation of the strip steel being ±3%. There are no deviations or wrinkles on the production line. The initial nodules on the surface of the furnace rollers are completely removed. The production line can achieve long-term non-stop production. The strip steel scratch rate has been reduced from 4.2% to 0.3%, and the monthly output has increased by 15%.

[0036] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for online elimination of furnace roll nodules suitable for silicon steel wire, characterized in that: include: Furnace roller partitioning module: Based on the total number of furnace rollers, they are divided into 15 zones on average, which is compatible with the existing furnace roller drive system control; The speed regulation range covers 80%-120% of the production line speed. The speed regulation is achieved through the grinding control module command to avoid strip tension fluctuations caused by sudden speed changes. Gas analysis and cleaning quality inspection: Based on the existing gas analyzer on site, the furnace pressure, atmosphere and dew point are detected. Combined with the on-site cleaning quality, the furnace roller drive module is controlled to start based on the lower limit of nodule formation. The grinding method and its principles are based on a closed-loop control logic of "atmosphere prediction - zoned grinding - effect feedback". The specific steps and principles are as follows: 1) Initialization settings: When the production line starts, the gas composition of the furnace area is detected and the feedback data is analyzed. Combined with the on-site cleaning quality, if any limit is exceeded, the furnace roller grinding will start. The grinding sequence is selected by default as an interval skipping type. The furnace roller speed in each area is different from the actual production speed. Through the mutual friction between the furnace roller and the strip, the iron powder and impurities formed in the early stage of nodule formation will be removed in the early stage to avoid the nodule from growing and affecting the surface quality of the steel strip. 2) Production operation phase: By starting the initialization settings, the furnace roller nodule rate is reduced by 90%, with a significant preventive effect, and stable continuous production is basically achieved throughout the month.

2. The method for online elimination of furnace roll nodules suitable for silicon steel wire according to claim 1, characterized in that: Each furnace roller has its own variable frequency motor and gearbox.

3. The method for online elimination of furnace roll nodules suitable for silicon steel wire according to claim 1, characterized in that: The fluctuation range of strip tension should be controlled to ≤5%.

4. The method for online elimination of furnace roll nodules suitable for silicon steel wire according to claim 1, characterized in that: For furnace roll lumps that persist after initial setup, operators can quickly locate the lumped furnace rolls by shortening the grinding time for each area. The lumped furnace rolls, through grinding that is not matched to the strip speed, will leave long scratches on the strip. Once the lumped area is identified, the initial setup is stopped, and the furnace rolls in this area are ground separately at differential speed to finally pinpoint the lumped furnace rolls. Stubborn lumps are then treated according to the treatment procedures.

5. The method for online elimination of furnace roll nodules suitable for silicon steel wire according to claim 1, characterized in that: The minimum range for furnace roll nodule formation on silicon steel lines is set at an oxygen concentration of ≤20ppm, a dew point of ≤15℃, and a residual iron content of 50mg / ㎡ during on-site cleaning.

6. The method for online elimination of furnace roll nodules suitable for silicon steel wire according to claim 5, characterized in that: By controlling the minimum range of nodule formation, the grinding program is started when the range is exceeded. Grinding begins in a random area and then proceeds in a zoned grinding manner with intervals. The initial grinding stage is mostly the nodule budding stage. After grinding begins, the nodule budding stage is destroyed, and the conditions for nodule nucleation cannot be met, thus eliminating nodule formation on the furnace roller.

7. The method for online elimination of furnace roll nodules suitable for silicon steel wire according to claim 1, characterized in that: During the grinding process, the production line runs continuously with a maximum strip steel fluctuation of ±3%, and there are no deviations or wrinkles on the production line. The initial nodules on the surface of the furnace rollers are completely removed, and the production line can achieve long-term non-stop production. The strip steel scratch rate has been reduced from 4.2% to 0.3%, and the monthly output has increased by 15%.