A method for dynamic dust control during hot rolling dust removal fan operation

Abstract

This invention discloses a dynamic dust removal control method for hot-rolled strip fans during rolling. It establishes four dust removal modes: a first mode based on a single steel grade, a second mode based on both steel grade and final rolling temperature, a third mode based on both steel grade and target thickness, and a fourth mode based on all three factors (steel grade, final rolling temperature, and target thickness). For each strip entering the finishing rolling zone, the corresponding dust removal airflow is determined based on one of these four modes. This invention addresses the causes of dust generation and influencing dust volume by establishing a real-time dynamic dust removal airflow determination and control method based on three factors: steel grade, target thickness, and target temperature. It forms a method for determining the corresponding dust removal airflow based on the steel grade and rolling properties of the current strip, achieving adaptable control of dust removal airflow for various strips under different rolling process requirements, with the aim of energy saving and consumption reduction.

Description

Technical Field

[0001] This invention belongs to the field of automatic control of metallurgical steel rolling, and specifically relates to a dynamic dust removal control method for hot rolling dust removal fans during rolling. Background Technology

[0002] Baosteel's 1880 hot-rolled steel production line has a diverse product range, including both dust-generating silicon steel and other low-dust steel grades, and involves a variety of rolling processes and alternating rolling operations. On one hand, the finishing mill stands generate a large amount of waste gas containing iron oxide and water vapor in the latter half of the rolling process, forming red smog that seriously affects worker health and the surrounding atmospheric environment. Therefore, effective dust removal is essential. On the other hand, some grades generate very little dust during rolling, but the dust removal capacity is designed for the most severe operating conditions. Currently, considering the lifespan of the high-voltage contactor in the dust collector fan and the impact of long-term high-current startup on the motor and fan, frequent power outages are discouraged. The dust removal system is often kept running at a constant speed, resulting in significant power waste and a substantial reduction in the lifespan of the dust collector fans and motors.

[0003] To optimize dust control on existing hot rolling production lines, energy conservation and consumption reduction are necessary, primarily through the establishment of adjustable airflow dust control. Current variable airflow (VAV) dust collectors mostly employ real-time feedback and VAV adjustment based on actual dust levels under specific on-site conditions. This approach has two main problems: firstly, it impacts the operation of the previously constant-speed power frequency motors and requires significant attention to the frequency converter; secondly, the control process is complex, and the feedback itself is inherently delayed. Combined with the time required for frequency conversion, this creates a cumulative lag effect, failing to achieve the intended effect.

[0004] The invention application with application number CN2020106001427 discloses "a hot rolling dust control system and control method", wherein the system includes: a primary atomizing dust removal module, a secondary atomizing dust removal module, a tertiary negative pressure dust collection module, and a feedforward concentration detection module; the primary atomizing dust removal module is used to start dust removal when the rolling mill starts; the secondary atomizing dust removal module is used to start dust removal when the feedforward concentration detection module detects that the dust concentration is greater than a preset standard concentration; the tertiary negative pressure dust collection module is used to start dust removal after the secondary atomizing dust removal module has started working and when the feedforward concentration detection module detects that the dust concentration is greater than the standard concentration.

[0005] Invention application CN 2020107840744 discloses "a rolling mill dust detection system and method," comprising an environmental dust detector, a rolling mill dust detector, an anemometer, a steel passage detector, a detection controller, and a data processing workstation. The environmental dust detector is installed next to the control room of the rolling mill workshop to measure the dust concentration in the workshop environment. The rolling mill dust detectors are installed on the operating side and drive side of the top of the last stand of the rolling mill, respectively, to measure the dust concentration in the rolling mill area. The anemometer is installed next to the dust detectors on the operating side and drive side of the top of the last stand of the rolling mill, respectively, to measure the wind speed at the top of the rolling mill. The steel passage detector is installed on the last stand of the rolling mill to detect the steel passage status of the last stand. The detection controller collects signals from the environmental dust detector, the rolling mill dust detector, the anemometer, and the steel passage detector, converts them into corresponding data, and transmits them to the data processing workstation. Summary of the Invention

[0006] The purpose of this invention is to provide a method for determining the dust removal air volume based on the steel grade, target thickness, and final rolling target temperature.

[0007] To achieve the above technical objectives, this invention provides a dynamic dust control method for hot rolling dust removal fans during rolling, the specific technical solution of which is as follows:

[0008] A method for dynamic dust control during hot rolling dust removal using a hot rolling dust removal fan.

[0009] A first dust removal mode based on a single steel grade, a second dust removal mode based on two factors: steel grade and final rolling temperature, a third dust removal mode based on two factors: steel grade and target thickness, and a fourth dust removal mode based on three factors: steel grade, final rolling temperature, and target thickness.

[0010] For the current strip steel entering the finishing rolling zone, determine the corresponding dust removal air volume based on one of the above four dust removal modes according to its actual situation.

[0011] Furthermore,

[0012] When determining the corresponding dust removal air volume according to the first dust removal mode, the corresponding dust removal air volume is determined according to the composition of the steel grade;

[0013] When determining the corresponding dust removal air volume according to the second dust removal mode, the initial air volume is first determined based on the composition of the steel grade, and then the initial air volume is finely adjusted based on the final rolling temperature to form the final air volume.

[0014] When determining the corresponding dust removal air volume according to the third dust removal mode, the initial air volume is first determined based on the composition of the steel grade, and then the initial air volume is finely adjusted according to the target thickness to form the final air volume determination.

[0015] When determining the corresponding dust removal air volume according to the fourth dust removal mode, the initial air volume is first determined based on the composition of the steel grade, and then fine-tuned according to the target thickness and final rolling temperature to form the final air volume.

[0016] Furthermore,

[0017] When determining the corresponding dust removal air volume according to the first dust removal mode, it is specifically based on the content of C, Ni, Cu, S, Si, Mn, Cr, and Al in the steel composition;

[0018] When determining the corresponding dust removal air volume according to the second dust removal mode, the initial air volume is first determined based on the content of C, Ni, Cu, S, Si, Mn, Cr, and Al in the steel composition. Then, it is finely adjusted according to the final rolling temperature. When the air volume corresponding to the final rolling temperature is consistent with the initial air volume, the initial air volume is used as the final air volume; otherwise, the air volume corresponding to the final rolling temperature is used as the final air volume.

[0019] When determining the corresponding dust removal air volume according to the third dust removal mode, the initial air volume is first determined based on the content of C, Ni, Cu, S, Si, Mn, Cr and Al in the steel composition. Then, it is finely adjusted according to the target thickness. When the air volume corresponding to the target thickness is consistent with the initial air volume, the initial air volume is used as the final air volume; otherwise, the air volume corresponding to the target thickness is used as the final air volume.

[0020] When determining the corresponding dust removal air volume according to the fourth dust removal mode, the initial air volume is first determined based on the C, Ni, Cu, S, Si, Mn, Cr, and Al contents in the steel composition. Then, it is fine-tuned based on the target thickness. When the air volume corresponding to the target thickness is consistent with the initial air volume, the initial air volume is used as the second air volume; otherwise, the air volume corresponding to the target thickness is used as the second air volume. Finally, the second air volume is fine-tuned based on the final rolling temperature. When the air volume corresponding to the final rolling temperature is consistent with the second air volume, the second air volume is used as the final air volume; otherwise, the air volume corresponding to the final rolling temperature is used as the final air volume.

[0021] Furthermore,

[0022] The air volume is determined based on the content of C, Ni, Cu, S, Si, Mn, Cr, and Al in the steel grade composition. Specifically, the steel grade composition of the current strip is first scored according to the following formula, and then the specific air volume is determined based on the score.

[0023] X=a1×C%+a2×Ni%+a3×Cu%+a4×S%+a5×Si%-a6×Mn%-a7×Cr%-a8×Al%,

[0024] In the formula,

[0025] X: Fraction;

[0026] a1-a8: Weighting coefficients;

[0027] C% Ni% Cu% S% Si% Mn% Cr% Al%: Mass percentage of each component.

[0028] Furthermore,

[0029] When determining the corresponding air volume based on the target thickness, the target thickness level is first divided according to the thickness value, then the corresponding air volume is set according to the target thickness level, and finally the air volume for the current strip steel is determined based on which target thickness level the target thickness of the current strip steel corresponds to.

[0030] Furthermore,

[0031] The target thickness levels are divided as follows:

[0032] The first level is defined as the maximum value where the rolling thickness exceeds the set rolling thickness, and the last level is defined as the minimum value where the rolling thickness is less than the set rolling thickness. The target thickness levels are formed by dividing the intervals from the first level to the last level according to the set difference.

[0033] Furthermore,

[0034] When determining the corresponding air volume based on the final rolling temperature, firstly, the corresponding target temperature levels are divided according to the final rolling temperature value. Then, the corresponding air volume is set according to the target temperature level. Finally, the air volume for the current strip at the final rolling temperature is determined by identifying which target temperature level the current strip's final rolling temperature corresponds to.

[0035] Furthermore,

[0036] The target temperature levels are divided as follows:

[0037] The first level is defined as the final rolling target temperature exceeding the set maximum target temperature, and the last level is defined as the final rolling target temperature being less than the set minimum target temperature. The target temperature levels are divided into intervals from the first level to the last level according to the set difference.

[0038] Furthermore,

[0039] The dynamic dust removal control method is implemented based on the existing L2 and L1, or based on newly established L2 and L1.

[0040] When implementation is based on the newly established L2 and L1, the newly established L2 obtains strip information by communicating with the original L2.

[0041] Furthermore,

[0042] The dust removal air volume is established according to a frequency conversion system based on the actual air volume or according to a frequency conversion system based on gears.

[0043] Furthermore,

[0044] When the dust removal air volume is established according to the frequency conversion system based on the gear system, two air volume gear adjustment modes are formed: one that is compatible with the frequency conversion system of the power frequency motor and the other that is not compatible with the frequency conversion system of the power frequency motor.

[0045] Furthermore,

[0046] First, a procedure table is established based on historical rolling data for program indexing; then, the strip information is indexed based on the procedure table to determine the current strip information; finally, the corresponding air volume is determined based on the determined information.

[0047] Furthermore,

[0048] The specification table is created in CSV format, forming a sequential order of steel grade, target thickness, and final rolling temperature.

[0049] The indexing process first indexes the steel type, then indexes the target thickness within the constraints of the indexing results, and finally indexes the final rolling temperature within the constraints of the target thickness to complete the indexing and confirmation of the current strip steel information.

[0050] Furthermore,

[0051] The steel grade information is established in a two-level progressive manner, first classifying major steel grades and then minor steel grades.

[0052] Furthermore,

[0053] In L2, a strip steel information index module and a dust removal air volume determination module are established. When the current strip steel information is indexed and confirmed in the strip steel information index module, the dust removal air volume determination module is entered to determine the specific air volume; otherwise, an alarm is issued and the dust removal air volume of the current strip steel is manually adjusted and set.

[0054] This invention discloses a dynamic dust removal control method for hot rolling dust removal fans during rolling. Starting from the causes of dust generation and influencing dust volume, it establishes a real-time dynamic dust removal airflow determination and control method based on three factors: steel grade, target thickness, and final rolling target temperature. It forms a method for determining the corresponding dust removal airflow according to the current strip steel's steel grade and rolling properties, achieving adaptability control of dust removal airflow for various strip steels under different rolling process requirements with the aim of energy saving and consumption reduction. Furthermore, the frequency converter control used to adjust the airflow considers compatibility with industrial frequency motors. Attached Figure Description

[0055] Figure 1This is a schematic diagram of the control execution process of the present invention;

[0056] Figure 2 This is a schematic diagram of the hot rolling production line in this invention. Detailed Implementation

[0057] The following is a detailed description of a dynamic dust removal control method for hot rolling dust removal fans during rolling, based on the accompanying drawings and specific embodiments of the present invention.

[0058] To provide a preliminary understanding of this technical solution, the following is a brief overview of its design and implementation process:

[0059] To establish a dust removal airflow regulation system on a hot rolling production line, the first step is to find the basis for airflow regulation. This basis obviously points to the amount of dust. The amount of dust can be obtained through actual on-site testing, and some existing technologies do this. However, the shortcomings of this regulation method have been briefly described in the background section. To find a solution that differs from obtaining the amount of dust through actual on-site testing, this technical solution starts from the perspective of the causes and influencing factors of dust generation and establishes a real-time dynamic dust removal airflow determination and regulation method based on three factors: steel grade, target thickness, and final rolling target temperature. This forms a method for determining the corresponding dust removal airflow based on the current strip steel grade properties and rolling properties.

[0060] Dust, or iron oxide scale, is related to surface oxidation capacity. Observation, analysis, and summarization revealed the following: 1. Increased carbon, silicon, nickel, copper, and sulfur content in the steel composition increases iron oxide scale formation, while manganese, chromium, and aluminum inhibit it; 2. Oxidation rate increases with temperature; 3. Rolling speed naturally varies with thickness, and thinner rolls with higher speeds and greater metal flow rates result in more iron oxide scale. In other words, the amount of iron oxide scale formed is related to the composition, rolling speed (i.e., thickness), and temperature; this serves as the theoretical basis for this technical solution.

[0061] The practical implementation and production of the above technical concepts will involve the following two aspects: 1. Determining the specific air volume; 2. How to convert it into a form that can be executed by the program and exchange information. The two aspects will be elaborated on below.

[0062] Determining the specific air volume:

[0063] The basic process is as follows: First, determine the corresponding airflow based on the steel grade composition, target temperature, and target thickness. Then, adjust the airflow accordingly. However, between determining the airflow based on the steel grade composition, target temperature, and target thickness, and adjusting the airflow accordingly, different determination schemes may arise depending on the actual situation and the condition of the on-site motor:

[0064] 1. Determine the corresponding air volume based on the steel grade composition, target temperature, and target thickness. Then, directly set and regulate the specific air volume based on this air volume, i.e., establish the dust removal air volume according to the frequency conversion system based on the actual air volume as mentioned above.

[0065] 2. First, set the air volume level, then determine the corresponding air volume based on the steel composition, target temperature and target thickness. Based on which level the determined air volume belongs to, determine the corresponding air volume level, that is, the dust removal air volume is established according to the frequency conversion based on the level system mentioned above.

[0066] When the first airflow is determined and executed, the motor used is a variable frequency motor. When the second airflow is determined and executed, the specific number of gears can be set according to the specific motor being used. When considering compatibility with a power frequency motor, the corresponding number of gears is set based on the power frequency motor's capacity. When not considering using a power frequency motor, the corresponding number of gears can be determined based on expert experience.

[0067] When determining the appropriate airflow based on steel grade composition, target temperature, and target thickness, it is based on the current strip rolling process requirements. For strips without additional requirements on rolling properties, a first dust removal mode is established, determined solely by the dust removal airflow for the individual steel grade. For strips with additional requirements on rolling properties, three modes can be established according to the specific rolling property requirements: a second dust removal mode based on steel grade and final rolling temperature, a third dust removal mode based on steel grade and target thickness, and a fourth dust removal mode based on steel grade, final rolling temperature, and target thickness. The specific mode chosen depends on the current strip rolling properties.

[0068] To gain a full understanding of this part, the following section will specifically explain the process of determining the dust removal air volume using a frequency conversion dust removal air volume mode based on a gear system, taking the case where all influencing factors are present (i.e., the fourth dust removal mode). For the determination process of other dust removal modes, and for establishing the dust removal air volume of all dust removal modes based on the actual air volume using a frequency conversion system, you can refer to this process and make corresponding technical analogies and processing.

[0069] The process of determining the dust removal air volume of the fourth dust removal mode based on the frequency conversion dust removal air volume mode with gear system:

[0070] First, the initial airflow is determined based on the C, Ni, Cu, S, Si, Mn, Cr, and Al contents of the steel composition. Then, it is fine-tuned based on the target thickness. When the airflow corresponding to the target thickness matches the initial airflow, the initial airflow is used as the second airflow; otherwise, the airflow corresponding to the target thickness is used as the second airflow. Finally, the second airflow is fine-tuned based on the final rolling temperature. When the airflow corresponding to the final rolling temperature matches the second airflow, the second airflow is used as the final airflow; otherwise, the airflow corresponding to the final rolling temperature is used as the final airflow. Once the final airflow is determined, its corresponding speed range is identified, and the appropriate airflow speed range is set accordingly.

[0071] When determining the air volume based on the C, Ni, Cu, S, Si, Mn, Cr, and Al content in the steel grade composition, the specific steps are as follows: First, score the steel grade composition of the current strip steel according to the following formula, and then determine the specific air volume based on the score. The specific air volume determination based on the score is completed according to the expert scoring method.

[0072] X=a1×C%+a2×Ni%+a3×Cu%+a4×S%+a5×Si%-a6×Mn%-a7×Cr%-a8×Al%,

[0073] In the formula, X: fraction; a1-a8: weighting coefficients; C%, Ni%, Cu%, S%, Si%, Mn%, Cr%, Al%: mass percentage of each component. It should be noted that C, Ni, Cu, S, Si, Mn, Cr, and Al listed here are only factors to consider, and not every steel grade contains all of these components. The specific components involved in the calculation are determined based on the specific steel grade; for example, silicon steel contains Si, while other steels do not, so the corresponding weighting coefficient a5 is assigned a value of 0, and so on.

[0074] When determining the corresponding airflow based on the target thickness, the process begins by dividing the target thickness into levels. Then, the corresponding airflow is set according to each target thickness level. Finally, the airflow for the current strip is determined by identifying which target thickness level corresponds to its target thickness. Specifically:

[0075] The first level is defined as the maximum value where the rolled thickness exceeds the set rolled thickness, and the last level is defined as the minimum value where the rolled thickness is less than the set rolled thickness. The target thickness levels are formed by dividing the range from the first level to the last level according to the set difference. The maximum and minimum set rolled thickness values ​​mentioned here are set within the commonly used range of 1.2mm-12mm in the process. Preferably, the specific maximum and minimum values ​​can be determined based on the dust variation. Specifically, the maximum set rolled thickness is determined by taking a value within the range of 5mm-8mm, and the minimum set rolled thickness is determined by taking a value within the range of 1.4-1.7mm. The set difference is determined by taking any value within the range of 1mm-2mm.

[0076] When determining the corresponding air volume based on the final rolling temperature, the process begins by first dividing the strip into target temperature levels according to the final rolling temperature value. Then, the corresponding air volume is set based on the target temperature level. Finally, the air volume for the current strip at the final rolling temperature is determined by identifying which target temperature level it corresponds to. Specifically:

[0077] The first level is defined as the final rolling target temperature exceeding the set maximum target temperature, and the last level is defined as the final rolling target temperature being less than the set minimum target temperature. The target temperature levels are divided into intervals from the first level to the last level based on the set difference. The set maximum and minimum target temperatures mentioned here are typically set within the range of 840-920℃, commonly used in the process. Preferably, the specific maximum and minimum values ​​can be determined by considering dust variation. Specifically, the maximum target temperature is determined by taking a value within the range of 850-860℃, the minimum target temperature is determined by taking a value within the range of 880-890℃, and the set difference is determined by taking any value within the range of 25-35℃.

[0078] How to transform it into a part that can be executed by the program and exchange information:

[0079] This involves the following technical processes and settings: 1. How to establish a control system; 2. How to quickly confirm strip steel information and determine the corresponding dust removal air volume based on the confirmed strip steel information; 3. How to properly establish the frequency conversion timing.

[0080] Regarding the question of how to establish a control system, this technical solution can be implemented based on the existing L2 and L1, or based on a newly established L2 and L1. When implemented based on a newly established L2 and L1, the newly established L2 obtains strip information by communicating with the existing L2. The determination of the specific air volume mentioned above is triggered by the L2 receiving the current strip information.

[0081] Regarding the issue of how to properly establish the frequency conversion timing, this technical solution considers the factor that frequency conversion requires a transition time to change from the current frequency to the target frequency and thus achieve the desired airflow. Therefore, a scheme using the flying shear signal as the frequency conversion trigger signal is established. Alternatively, the specific setting of the corresponding trigger signal position can be determined based on the actual frequency conversion speed. That is, the timing of the frequency conversion trigger signal is determined according to the specific frequency conversion speed, and reaching the flying shear position is merely one scheme determined based on this setting guideline.

[0082] The following section focuses on how to quickly confirm strip steel information and determine the corresponding dust removal air volume based on the confirmed strip steel information:

[0083] The corresponding technical setup for handling this problem can be conceptually summarized as follows: it is accomplished through the strip information index module and the dust removal airflow determination module set in L2. The strip information index module contains a procedure table, while the determination of the specific airflow mentioned above is completed in the dust removal airflow determination module. The basic execution steps are as follows: when the current strip information is indexed and confirmed in the strip information index module, the dust removal airflow determination module is entered to determine the specific airflow; otherwise, an alarm is issued, and the dust removal airflow for the current strip is manually adjusted. See [link to relevant documentation]. Figure 1 This means that a DI node is set up in L1.

[0084] The establishment of the procedure index follows a tree-structured search approach. Specifically, it indexes and confirms the information of the current strip steel by first indexing the steel grade, then the target thickness within the constraints of the indexed results, and finally the final rolling temperature within the constraints of the target thickness. To further improve indexing efficiency, a two-level progressive classification system is established under the steel grade entries, first classifying major steel grades and then minor steel grades. This facilitates the progressive indexing of major steel grades first, and then minor steel grades within the defined range. The establishment of the specific procedure table is to adapt to the determination process of the specific air volume mentioned above, and also to form a statistical record of existing steel grades and rolling processes. Therefore, the procedure table is ultimately established based on the sequential order of steel grade, target thickness, and final rolling temperature, and is completed based on historical rolling data. When the indexing of the procedure table fails to complete the indexing and confirmation, an alarm is issued. This means that new data not yet entered into the procedure table has been generated. After the alarm is processed accordingly, the corresponding data for this alarm needs to be added to the procedure table. To facilitate the handling of this matter, the procedure table is created in CSV format to accommodate switching to Excel, data changes, and program execution.

[0085] To provide a more intuitive understanding of the above explanation, the following is a description of specific implementation steps. The control described below is based on the newly established L2 and L1 (i.e., IHTL1 mentioned below). The newly established L2 (i.e., IHTL2 mentioned below) obtains strip information by establishing communication with the existing L2. The specific steps, such as using the flying shear signal as the trigger signal, and the upper and lower limits of the target thickness and target temperature, as well as the layer division difference, are all for illustrative purposes and are settings made within the scope of the above explanation. These settings are not the only ones that can be defined.

[0086] 1.1 Material tracking of strip position:

[0087] This technical solution uses strip steel location to correspond to material information and employs multiple excitation methods to ensure the accuracy of material location and information. Specifically, the material tracking program sends a coil information message to the dust removal system interface service program when HSB, R1 ON, CS ON, and F1 ON, thus establishing a strip steel object. (See also...) Figure 2 The process diagram of the hot rolling production line is shown.

[0088] When the L2 (process control) system (dust removal service system) receives messages from different locations on the server, it generates a strip tracking status (TRACK STATUS event) and performs corresponding processing.

[0089] TRACK STATUS event definition:

[0090]

[0091] 1.2 Flying shear position signal

[0092] After the strip arrives at the flying shear (CS ON), L2 sends the strip data to IHT L2 (Dust Removal Service System).

[0093] 1.3 Establishment of a dust removal procedure index;

[0094] 1.3.1 Establishment of a multi-dimensional classification procedure table:

[0095] This technical solution takes into account the characteristics of the production site, namely the need for efficient output of the current product's dust removal mode. Therefore, the procedures involved in this technology need to be efficient and accurate. To this end, this technical solution adopts a multi-dimensional classification method to ensure the accuracy of the dust removal mode.

[0096] The specific classification methods are as follows: classification is based on hot-rolled steel grades, then major and minor classifications are made according to the steel tapping mark, and finally, multi-dimensional classification is made by grade division according to strip thickness and temperature, so as to achieve the purpose of efficient indexing;

[0097] For example, a production line might categorize hot-rolled steel grades into five main categories: carbon steel, alloy steel, hot-rolled high-strength steel, cold-rolled high-strength steel, and pipeline steel. Each main category could be further divided into approximately ten subcategories. Special products (such as silicon steel, which could be categorized into low-to-medium grade and high-grade non-oriented and oriented silicon steel) could then be classified. Finally, for each main category, a special steel subcategory could be added. This would allow for the direct classification of one or more steel output marks into a subcategory, which would then become a special steel subcategory within the main category.

[0098] In practical application, a certain production line produces over 500 steel tapping marks with more than 930 specifications. After adopting this technology, the dust removal procedure table index, divided into 7 thickness layers and 3 temperature layers, achieved a complete dust removal procedure table with over 20,000 layer records. The following is an example of the index classification:

[0099] Specifically, the procedure index level classification is as follows:

[0100] SFC: Steel Grade Classification (SFCO1+SFC02)

[0101] SFC01: Major Categories of Steel Production Marks

[0102] SFC02: Subcategories of Steel Discharge Marks

[0103] ThickClass: Target Thickness Grade

[0104] TempClass: Target Temperature Class

[0105] • Target thickness CH distinction:

[0106] Floor number Layer distinction 1 CH<1.5 2 1.5<=CH<2.0 3 2.0<=CH<3.0 4 3.0<=CH<4.0 5 4.0<=CH<5.0 6 5.0<=CH<6.0 7 CH>=6.0

[0107] • Target temperature FT distinction:

[0108] Floor number Layer distinction 1 FT<850 2 850<=FT<880 3 FT >= 880

[0109] 1.3.2 After receiving the strip data, the dust removal system (module) determines the reading procedure strategy based on the strip steel type, thickness grade, and temperature grade. Simultaneously, it sets the dust removal motor power setting (Power Mode X0~X4) to L1 (basic automation) to achieve differentiated control of the dust removal airflow. No dust removal settings are applied to virtual strip steel.

[0110] The table below shows the strip data sent from L2 to IHT L2 (Dust Removal Service System):

[0111]

[0112] Note: After receiving the strip data, the L2 (dust removal service system) establishes an index for the strip based on its steel family, target thickness, and target final rolling temperature. Then, it determines the airflow and corresponding motor opening based on the index results. If the indexing and confirmation are not completed, an alarm is issued, and the airflow is manually determined.

[0113] 1.4. Procedure Data Control

[0114] 1.4.1 Establishment of the structure of the procedure document

[0115]

[0116] Based on the dust removal procedure levels, the power opening of the dust removal motor can be divided into multiple levels according to the model. Taking the five levels (0 to 4) as an example, the dust collector is given four air volume settings: 0%, 30%, 50%, 80%, and 100%. At the same time, the setting value can be adjusted on the dust collector HMI.

[0117] 1.4.2 Establishing the Stratification Data Search Order:

[0118] Due to the massive amount of data, it is impossible to create an index for every product specification of all steel grades. Therefore, based on the tree search concept, a specific specification table was constructed, and a corresponding specific indexing method was implemented, using a priority indexing method. The following is a detailed implementation of the priority indexing method used in this technical solution:

[0119]

[0120] In the table, 1 represents data that exists, and 0 represents the default value. For example, the production steel coil index information is: SFC01=9; SFC02=3; ThickClass=3; TempClass=3. First, SFC01 is indexed. If SFC01=9 is found in the database, SFC02 is indexed from there. If 3 is found in SFC02, ThickClass is searched in SFC02=3. If 3 is not found, ThickClass is searched in the default value 0; and so on.

[0121] Assume the data in the database is:

[0122]

[0123] The information retrieved by the steel coil index is SFC01=9; SFC02=0; ThickClass=3; TempClass=0; therefore, the output mode is MODE=3.

[0124] 1.4.3 Determine the frequency of the dust collector fan

[0125] The L2 dust removal service system presets multiple speed settings and corresponding fan frequencies. The L2 dust removal service system transmits the fan frequency set according to the indexed motor power opening speed to the L1 dust removal execution system. Multiple speed settings can be set for the airflow corresponding to the production conditions, and adjustments can be made based on actual conditions during operation. Taking the production line involved in this technical solution as an example, five speed settings are configured.

[0126] The specific production conditions and the corresponding set air volume are shown in the table below:

[0127] Set mode 0 1 2 3 4 Preset air volume 0％ 30％ 50％ 80％ 100％ Fan frequency OHZ 20Hz 30Hz 40Hz 50Hz

[0128] 1.4.4 Data Archiving

[0129] During steel coil production, IHT L1 will send the actual dust removal data back to the IHT L2 system in real time. After receiving the dust removal data, the strip steel data temporarily stored in the IHT L2 system will be transferred to the database for persistence and later query.

[0130] The database tables include:

[0131] coil_dust_info basic data table for strip steel (primary key: strip steel grade)

[0132] coil_dust_actual strip dust removal performance data table (primary key: strip grade)

[0133] 1.4 Feedback Value Output

[0134] Based on the current strip steel information in section 1.3, output the current dust removal mode;

[0135] 1.5 Send dust collector fan control:

[0136] The IHT L2 dust removal service system presets multiple gear positions and corresponding fan frequencies. The IHT L2 dust removal service system transmits the fan frequency set according to the indexed motor power opening gear to the IHT L1 dust removal execution system.

[0137] 1.6 Dust removal procedure:

[0138] The L1 dust removal system operates according to the fan frequency set by the L2 dust removal service system based on the indexed motor power opening level.

Claims

1. A method for dynamic dust control during hot rolling dust removal using a hot rolling dust removal fan, characterized in that: A first dust removal mode based on a single steel grade, a second dust removal mode based on two factors: steel grade and final rolling temperature, a third dust removal mode based on two factors: steel grade and target thickness, and a fourth dust removal mode based on three factors: steel grade, final rolling temperature, and target thickness. For the current strip steel entering the finishing rolling zone, determine the corresponding dust removal air volume based on one of the above four dust removal modes according to its actual situation. When determining the corresponding dust removal air volume according to the first dust removal mode, the corresponding dust removal air volume is determined according to the composition of the steel grade; When determining the corresponding dust removal air volume according to the second dust removal mode, the initial air volume is first determined based on the composition of the steel grade, and then the initial air volume is finely adjusted based on the final rolling temperature to form the final air volume. When determining the corresponding dust removal air volume according to the third dust removal mode, the initial air volume is first determined based on the composition of the steel grade, and then the initial air volume is finely adjusted according to the target thickness to form the final air volume determination. When determining the corresponding dust removal air volume according to the fourth dust removal mode, the initial air volume is first determined based on the composition of the steel grade, and then fine-tuned according to the target thickness and final rolling temperature to form the final air volume determination. When determining the corresponding dust removal air volume according to the first dust removal mode, it is specifically based on the content of C, Ni, Cu, S, Si, Mn, Cr, and Al in the steel composition; When determining the corresponding dust removal air volume according to the second dust removal mode, the initial air volume is first determined based on the content of C, Ni, Cu, S, Si, Mn, Cr, and Al in the steel composition. Then, it is finely adjusted based on the final rolling temperature. When the air volume corresponding to the final rolling temperature is consistent with the initial air volume, the initial air volume is used as the final air volume; otherwise, the air volume corresponding to the final rolling temperature is used as the final air volume. When determining the corresponding dust removal air volume according to the third dust removal mode, the initial air volume is first determined based on the content of C, Ni, Cu, S, Si, Mn, Cr and Al in the steel composition. Then, it is finely adjusted according to the target thickness. When the air volume corresponding to the target thickness is consistent with the initial air volume, the initial air volume is used as the final air volume; otherwise, the air volume corresponding to the target thickness is used as the final air volume. When determining the corresponding dust removal air volume according to the fourth dust removal mode, the initial air volume is first determined based on the content of C, Ni, Cu, S, Si, Mn, Cr, and Al in the steel composition. Then, it is fine-tuned according to the target thickness. When the air volume corresponding to the target thickness is consistent with the initial air volume, the initial air volume is used as the second air volume; otherwise, the air volume corresponding to the target thickness is used as the second air volume. Finally, the second air volume is fine-tuned according to the final rolling temperature. When the air volume corresponding to the final rolling temperature is consistent with the second air volume, the second air volume is used as the final air volume. Otherwise, the air volume corresponding to the final rolling temperature shall be used as the final air volume.

2. The dynamic dust control method for hot rolling dust removal fans during rolling as described in claim 1, characterized in that: The air volume is determined based on the content of C, Ni, Cu, S, Si, Mn, Cr, and Al in the steel grade composition. Specifically, the steel grade composition of the current strip is first scored according to the following formula, and then the specific air volume is determined based on the score. X=a1×C%+a2×Ni%+a3×Cu%+a4×S%+a5×Si%-a6×Mn%-a7×Cr%-a8×Al%, In the formula, X: Fraction; a1-a8: Weighting coefficients; C% Ni% Cu% S% Si% Mn% Cr% Al%: Mass percentage of each component.

3. The dynamic dust control method for hot rolling dust removal fans during rolling as described in claim 1, characterized in that: When determining the corresponding air volume based on the target thickness, the target thickness level is first divided according to the thickness value, then the corresponding air volume is set according to the target thickness level, and finally the air volume for the current strip steel is determined based on which target thickness level the target thickness of the current strip steel corresponds to.

4. The dynamic dust control method for hot rolling dust removal fans during rolling as described in claim 3, characterized in that: The target thickness levels are divided as follows: The first level is defined as the maximum value where the rolling thickness exceeds the set rolling thickness, and the last level is defined as the minimum value where the rolling thickness is less than the set rolling thickness. The target thickness levels are formed by dividing the intervals from the first level to the last level according to the set difference.

5. The dynamic dust control method for hot rolling dust removal fans during rolling as described in claim 1, characterized in that: When determining the corresponding air volume based on the final rolling temperature, firstly, the corresponding target temperature levels are divided according to the final rolling temperature value. Then, the corresponding air volume is set according to the target temperature level. Finally, the air volume for the current strip at the final rolling temperature is determined by identifying which target temperature level the current strip's final rolling temperature corresponds to.

6. The dynamic dust control method for hot rolling dust removal fan during rolling as described in claim 5, characterized in that: The target temperature levels are divided as follows: The first level is defined as the final rolling target temperature exceeding the set maximum target temperature, and the last level is defined as the final rolling target temperature being less than the set minimum target temperature. The target temperature levels are divided into intervals from the first level to the last level according to the set difference.

7. The dynamic dust control method for hot rolling dust removal fans during rolling as described in claim 1, characterized in that: The dust removal air volume is established according to a frequency conversion system based on the actual air volume or according to a frequency conversion system based on gears.

8. The dynamic dust control method for hot rolling dust removal fans during rolling as described in claim 7, characterized in that: When the dust removal air volume is established according to the frequency conversion system based on the gear system, two air volume gear adjustment modes are formed: one that is compatible with the frequency conversion system of the power frequency motor and the other that is not compatible with the frequency conversion system of the power frequency motor.

9. The dynamic dust control method for hot rolling dust removal fans according to claim 1, characterized in that: First, a procedure table is established based on historical rolling data for program indexing; then, the strip information is indexed based on the procedure table to determine the current strip information; finally, the corresponding air volume is determined based on the determined information.

10. A dynamic dust control method for hot rolling dust removal fans during rolling according to claim 9, characterized in that: The specification table is created in CSV format, forming a sequential order of steel grade, target thickness, and final rolling temperature. The indexing process first indexes the steel type, then indexes the target thickness within the constraints of the indexing results, and finally indexes the final rolling temperature within the constraints of the target thickness to complete the indexing and confirmation of the current strip steel information.

11. The dynamic dust control method for hot rolling dust removal fans according to claim 10, characterized in that: The steel grade information is established in a two-level progressive manner, first classifying major steel grades and then minor steel grades.

12. The dynamic dust control method for hot rolling dust removal fan during rolling as described in claim 10, characterized in that: Establish a strip steel information index module and a dust removal air volume determination module. When the current strip steel information is indexed and confirmed in the strip steel information index module, the dust removal air volume determination module is entered to determine the specific air volume; otherwise, an alarm is issued and the dust removal air volume of the current strip steel is manually adjusted and set.

Images