A method for calculating a return ore rate of a blast furnace trough

Abstract

The application discloses a blast furnace under-slot return ore rate calculation method, comprising the following steps: obtaining a screening operation time period for a current batch of furnace charges; obtaining first weight data measured on a qualified material conveying path and second weight data measured on a return ore conveying path within the screening operation time period; associating the first weight data and the second weight data as a data group corresponding to the same batch of furnace charges based on the screening operation time period; and calculating the return ore rate of the batch of furnace charges according to return ore rate = second weight data / (first weight data + second weight data) * 100%. The application realizes online, real-time and automatic measurement of the return ore rate, solves the problem that manual methods cannot continuously and accurately measure, and the calculation result can be directly used for production monitoring, abnormal alarm and equipment state diagnosis, thereby improving the intelligent level and stability of blast furnace production control.

Description

Technical Field

[0001] This invention relates to the field of blast furnace ironmaking technology, and in particular to a method for calculating the return ore rate under the blast furnace trough. Background Technology

[0002] Currently, the sintering and pelletizing operations under the blast furnace troughs are conducted. The blast furnace takes material according to the type of material in each trough, requiring a screening result for each sintering and pelletizing trough except for trough #1 on the left and #1 on the right. During the material taking process, 3 seconds after the material from a single sintering trough reaches the sampling point, the blast furnace operator stops the conveyor belt. The head and tail of the material are not collected. A shovel is used to separate the sintered ore from both sides of the sampling port. If large particles roll off during the shoveling process, the sample pile can be retrieved. All sintered ore with a cross-sectional area of ​​15 kg or more is shoveled into an iron bucket. During the screening process, the sintered and pelletizing ore samples are poured into the sieve in one go for screening, passing through 30 times. The ratio of the weight of the undersize material to the original weight reflects the small particle size entering the furnace, indirectly reflecting the return rate.

[0003] Sampling points for manual screening are typically located after the vibrating screen and before the main conveyor belt into the furnace, allowing only the acquisition of "oversize material"—materials of acceptable particle size that are permitted to enter the furnace. Return ore, on the other hand, refers to the undersize material removed by the vibrating screen—powder and excessively small particles. For this, manual screening under the trough can only obtain "particle size information of the oversize material," but cannot simultaneously and synchronously acquire the two crucial weight data points: "total material quantity before screening (A)" and "undersize quantity (B)," thus failing to directly reflect the amount of return ore.

[0004] Blast furnace charging is a continuous or semi-continuous process, and the particle size distribution and powder content of the material are dynamically changing. Manual screening is a discrete, instantaneous activity (e.g., once per hour). It can only provide a "slice" of information at a single point in time and cannot represent the fluctuations in return ore over the entire period. It is possible that a batch of good material is sampled at the time of sampling, with a low return ore rate, but the next batch of material may have a high return ore rate, which will not be captured. Summary of the Invention

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of this invention is to provide a method for calculating the return ore rate under the blast furnace trough.

[0006] The technical solution adopted by this invention to solve its technical problem is: a method for calculating the return ore rate under the blast furnace trough, comprising the following steps:

[0007] Obtain the screening operation time period for the current batch of furnace charge;

[0008] Acquire the first weight data measured on the qualified material conveying path and the second weight data measured on the return ore conveying path during the screening operation period.

[0009] Based on the screening operation time period, the first weight data and the second weight data are associated as a data group corresponding to the same batch of furnace charge;

[0010] The return rate of this batch of furnace charge is calculated based on the formula: return rate = second weight data / (first weight data + second weight data) × 100%.

[0011] As a further improvement of the present invention: the acquisition of the screening operation time period includes: receiving a batch start signal and a batch end signal from the blast furnace charging control system, wherein the time period is between the start signal and the end signal.

[0012] As a further improvement of the present invention: the cumulative weight is obtained from the first electronic scale installed in the qualified material weighing hopper as the first weight data, and the cumulative weight is obtained from the second electronic scale installed in the return ore hopper as the second weight data.

[0013] As a further improvement of the present invention: the first weight data is the difference between the cumulative weight value of the first electronic scale at the end of the screening operation period and at the beginning; the second weight data is the difference between the cumulative weight value of the second electronic scale at the end of the screening operation period and at the beginning.

[0014] As a further improvement of the present invention: while acquiring the first weight data and the second weight data, the type identifier of the current batch of furnace charge is also acquired; after calculating the return rate, the method further includes storing the return rate in association with the type identifier.

[0015] As a further improvement of the present invention: within a set statistical period, the sum of the first weight data and the sum of the second weight data of multiple batches corresponding to the same type of furnace charge are accumulated; based on the accumulated sum of weight data, the comprehensive return rate of the furnace charge type within the statistical period is calculated.

[0016] As a further improvement of the present invention, a threshold alarm step is also included:

[0017] Preset return ore rate thresholds for different types of furnace charge;

[0018] The real-time calculated return rate is compared with the preset threshold for the current batch of furnace charge type;

[0019] If the return rate of the current batch exceeds the preset threshold, an audible and visual alarm will be triggered immediately, and alarm details will be displayed on the human-machine interface.

[0020] As a further improvement to the present invention, it also includes:

[0021] The calculated ore return rate data, along with the corresponding batch time and furnace charge type information, are stored in the historical database.

[0022] It provides a human-computer interaction interface for querying and displaying historical trend charts and statistical reports of ore return rate by time and furnace material type.

[0023] As a further improvement of the present invention, it also includes a coordinated step for returning ore discharge metering:

[0024] Monitor the real-time weight value of the second electronic scale;

[0025] When the real-time weight value reaches the preset bucket capacity threshold, the return ore bucket gate is opened to discharge the ore.

[0026] After the gate is closed, the weight value recorded before discharge is included in the second weight data for the current batch.

[0027] As a further improvement of the present invention, it also includes a device status diagnosis step:

[0028] Establish a benchmark range for the return rate of each type of furnace charge under normal production conditions;

[0029] Continuously monitor the return rate of the current batch of furnace charge.

[0030] If the return ore rate continues to deviate from the corresponding benchmark range and the qualified material particle size monitoring data is abnormal, a diagnostic prompt will be generated containing judgment information such as "decreased screening efficiency" or "suspected screen damage".

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] This invention sets up metering devices (such as electronic scales) on the qualified material and return ore path of the blast furnace trough screening system and automatically collects weight data within a specific screening operation period. This enables real-time, automatic, and continuous calculation of the return ore rate, overcoming the shortcomings of traditional manual screening methods, such as being discrete, lagging, and lacking representativeness. It can accurately reflect the real fluctuations in the amount of return ore in each batch or even in continuous production. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the process of the present invention.

[0034] Figure 2 This is a logical schematic diagram of the system of the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0036] In order to solve the technical problems in the prior art, the present invention will now be further described in conjunction with the accompanying drawings and embodiments:

[0037] like Figure 1 As shown in the figure, this invention discloses a method for calculating the return ore rate under the blast furnace trough, including the following steps:

[0038] S1: Obtain the screening operation time period for the current batch of furnace charge;

[0039] In some implementations, obtaining the screening operation time period includes receiving a batch start signal and a batch end signal from the blast furnace charging control system, wherein the time period is between the start signal and the end signal.

[0040] The start and end times of a complete charging batch are defined by standard control signals (start / end) issued by the blast furnace charging control system (PLC). This ensures that the calculation cycle is strictly synchronized with the actual production rhythm of the blast furnace, and that the data calculated each time accurately corresponds to an independent production batch, avoiding subjective errors and asynchrony problems caused by manual division of time periods.

[0041] S2: Obtain the first weight data measured on the qualified material conveying path and the second weight data measured on the return ore conveying path during the screening operation period.

[0042] In some implementations, the cumulative weight is obtained from a first electronic scale installed in the qualified material weighing hopper as the first weight data, and the cumulative weight is obtained from a second electronic scale installed in the return ore hopper as the second weight data.

[0043] The first electronic scale is located at the collection point of qualified materials after screening (weighing hopper) and directly measures the weight of qualified materials; the second electronic scale is located at the return ore collection point (return ore hopper) and directly measures the weight of return ore.

[0044] Furthermore, it also includes coordinated steps for metering and controlling emissions from returned ore:

[0045] Monitor the real-time weight value of the second electronic scale;

[0046] When the real-time weight value reaches the preset bucket capacity threshold, the return ore bucket gate is opened to discharge the ore.

[0047] After the gate is closed, the weight value recorded before discharge is included in the second weight data for the current batch.

[0048] Normal metering is performed before the return ore hopper is full. Discharge is controlled when the threshold is reached, and metering continues after discharge to ensure a complete record of the weight of the entire batch of return ore. This ensures that even if the return ore is discharged multiple times during continuous production, its total weight can be accurately and continuously accumulated, ensuring the completeness and accuracy of the return ore rate calculation.

[0049] S3: Based on the screening operation time period, associate the first weight data and the second weight data into a data group corresponding to the same batch of furnace charge;

[0050] In some implementations, the first weight data is the difference between the cumulative weight value of the first electronic scale at the end of the screening operation period and at the beginning; the second weight data is the difference between the cumulative weight value of the second electronic scale at the end of the screening operation period and at the beginning.

[0051] The difference in cumulative weight values ​​within a time window (batch time period) is used to obtain the net increase in qualified material weight and return ore weight for that batch.

[0052] S4: Calculate the return rate of this batch of furnace charge based on the return rate = second weight data / (first weight data + second weight data) × 100%.

[0053] Some implementations also include a threshold alarm step:

[0054] Preset return ore rate thresholds for different types of furnace charge;

[0055] The real-time calculated return rate is compared with the preset threshold for the current batch of furnace charge type;

[0056] If the return rate of the current batch exceeds the preset threshold, an audible and visual alarm will be triggered immediately, and alarm details will be displayed on the human-machine interface.

[0057] A dynamic monitoring mechanism is set up for the calculated return ore rate, with reasonable thresholds preset for different types of furnace materials. When the real-time calculated return ore rate exceeds the threshold, an alarm is immediately triggered. The data is converted into directly executable monitoring signals, which can alert operators in the first instance to deterioration of raw material quality or malfunction of screening equipment (such as screen breakage), transforming passive analysis into proactive early warning.

[0058] In some implementations, while acquiring the first weight data and the second weight data, the type identifier of the current batch of furnace charge is also acquired; after calculating the return rate, the method further includes storing the return rate in association with the type identifier.

[0059] The "furnace material type identifier" is acquired simultaneously during weight data collection, and the return rate is bound to this identifier after calculation and stored to realize hierarchical and classified management of return rate data. This can distinguish the return status of different furnace material types such as sinter and pellets, and meet the needs of refined production management.

[0060] Furthermore, within a set statistical period, the sum of the first weight data and the sum of the second weight data of multiple batches corresponding to the same type of furnace charge are accumulated; based on the accumulated sum of weight data, the comprehensive return rate of the furnace charge type within the statistical period is calculated.

[0061] Furthermore, the weight data of multiple batches of the same variety within a longer statistical period (such as shift, day, month) are accumulated, and the overall return rate of the period is calculated. This method can stably reflect the overall screening efficiency or quality status of a certain furnace material within a certain period, and is suitable for production performance evaluation, cost accounting and long-term trend analysis.

[0062] Some implementations also include: storing the calculated return rate data, along with the corresponding batch time and furnace charge type information, into a historical database; and providing a human-computer interaction interface for querying and displaying historical trend charts and statistical reports of the return rate by time and furnace charge type.

[0063] The main impacts of the return ore rate on the blast furnace: Too high a rate worsens permeability, increases air pressure, makes operation difficult, raises the fuel ratio, and leads to unstable furnace conditions; too low a rate can be even more dangerous! It indicates that powder entering the furnace will drastically worsen the permeability inside the furnace, and the problem is more insidious. Malfunction of the under-trough screening equipment (screen breakage) results in severely insufficient screening efficiency. The return ore rate is a crucial monitoring indicator; its abnormal fluctuations (especially sudden increases) are a strong signal to the blast furnace foreman: "There is a problem with the raw material quality or the screening equipment is malfunctioning, requiring immediate attention and adjustment!" Controlling the return ore rate by stabilizing sinter quality, reducing breakage during transport, and ensuring under-trough screening efficiency is a key link in achieving efficient, low-consumption, and stable operation of the blast furnace.

[0064] Some implementations also include a device status diagnostic step:

[0065] Establish a benchmark range for the return rate of each type of furnace charge under normal production conditions;

[0066] Continuously monitor the return rate of the current batch of furnace charge.

[0067] If the return ore rate continues to deviate from the corresponding benchmark range and the qualified material particle size monitoring data is abnormal, a diagnostic prompt will be generated containing judgment information such as "decreased screening efficiency" or "suspected screen damage".

[0068] Based on ore return rate data, combined with historical benchmarks and related signals (such as particle size data), a simple diagnostic model is constructed. When the ore return rate remains abnormal, the system automatically generates diagnostic prompts pointing to the status of the screening equipment.

[0069] Implementation Case 1:

[0070] The blast furnace trough return ore rate is an important technical and economic indicator in blast furnace ironmaking. It reflects the proportion of ore returned from the blast furnace trough to raw material processing steps such as sintering or pelletizing, relative to the total amount of sintered ore, pellets, and other finished ores in the blast furnace feed. The return ore rate reflects the particle size distribution of the raw materials entering the furnace and plays a crucial role in the stable and smooth operation of the blast furnace.

[0071] This embodiment discloses a method for calculating the return ore rate under the blast furnace trough. A return ore hopper gate is added to the existing return ore hopper under the trough, and an electronic scale is added to the return ore hopper. The weight of the return ore is measured by closing the return ore hopper gate.

[0072] The daily return rate can be calculated using the following formula: Return rate = Cumulative weight of returned ore / (Cumulative weight of returned ore + Cumulative weight of weighing hopper) * 100%.

[0073] First, the calculation object is clearly defined as the return ore rate: it refers to the percentage of powder (return ore) that is screened out during the screening, weighing and conveying process of sintered ore, pellets, lump ore and other furnace materials from the bottom of the trough to the total weight of the furnace material (qualified material + return ore).

[0074] Computational hierarchy:

[0075] 1. Single feeding: For the feeding cycle of one vibrating screen (open and close the gate according to the upper limit weight of the return ore hopper not exceeding 3 tons).

[0076] 2. Single type of furnace charge: statistics are compiled separately according to the type (e.g., sintered ore A, sintered ore B, pellets).

[0077] 3. Class / Day / Month Summary: Statistics are compiled according to time periods.

[0078] like Figure 2 As shown, an automated ore return rate calculation system requires support in the following three areas:

[0079] 1. Perception Layer (Data Acquisition)

[0080] This is the foundation of the system, and reliable automated instruments need to be installed.

[0081] Core equipment:

[0082] Weighing scale: installed on two key small hoppers.

[0083] Qualified material hopper scale: Installed after the vibrating screen, it measures the weight of qualified furnace material that enters the main conveyor belt and finally enters the furnace.

[0084] Return ore bucket scale: Installed on the return ore bucket, it measures the weight of the powder that is sieved.

[0085] Material identification signal: Information is obtained from the blast furnace charging PLC system to determine the type of furnace material being transported (such as sintered ore or pellets).

[0086] Operating status signals: Acquire start and stop signals of the vibrating screen and related belts to determine the metering period.

[0087] 2. Transport Layer (Data Communication)

[0088] Agreement: Data from the small bucket scales on site will be uploaded in real time to the server in the central control room via PLC and other equipment.

[0089] Network: Ensure the stability and reliability of industrial networks and avoid data packet loss.

[0090] 3. Application Layer (Data Processing and Presentation)

[0091] Based on the material identification signal, the weight data of qualified material and return ore of the same batch and the same type of furnace charge are aligned and matched in time.

[0092] The formula for calculating the return rate is executed in real time.

[0093] The blast furnace trough return ore rate is an important technical and economic indicator in blast furnace ironmaking. It reflects the proportion of ore returned from the blast furnace trough to raw material processing steps such as sintering or pelletizing, relative to the total amount of sinter, pellets, and other finished ores in the blast furnace feed. The return ore rate not only reflects changes in the quality of raw materials but also the powder content in the furnace feed, directly affecting the permeability of the blast furnace burden and playing a crucial role in the long-term stable operation of the blast furnace.

[0094] In this embodiment, in the automated under-tank system, each weighing hopper and return conveyor is usually equipped with a weighing scale to record the "pre-screen weight" and "post-screen return weight" of each batch of material in real time and continuously, thereby accurately calculating the instantaneous return rate and cumulative return rate.

[0095] The main functions of this invention are:

[0096] 1. This invention achieves real-time, automatic, and continuous calculation of the return ore rate by setting metering devices (such as electronic scales) on the qualified material and return ore path of the blast furnace trough screening system and automatically collecting weight data within a specific screening operation period.

[0097] 2. Overcoming the shortcomings of traditional manual screening methods, such as dispersion, lag, and insufficient representativeness, this method can accurately reflect the true fluctuations in the amount of returned ore in each batch and even in continuous production. By linking the returned ore rate data with furnace charge type and time information, and setting alarm and diagnostic functions, it not only provides blast furnace operators with accurate and timely key indicators, enabling them to quickly respond to changes in raw material quality or screening equipment failures, but also provides reliable data support for the refined management and long-term optimization of the production process.

[0098] In summary, after reading this invention document, those skilled in the art can make various other corresponding modifications to the technical solutions and concepts based on this invention without creative mental effort, and all of these modifications fall within the scope of protection of this invention.

Claims

1. A method for calculating the return ore rate under the blast furnace trough, characterized in that, Includes the following steps: Obtain the screening operation time period for the current batch of furnace charge; Acquire the first weight data measured on the qualified material conveying path and the second weight data measured on the return ore conveying path during the screening operation period. Based on the screening operation time period, the first weight data and the second weight data are associated as a data group corresponding to the same batch of furnace charge; The return rate of this batch of furnace charge is calculated based on the formula: return rate = second weight data / (first weight data + second weight data) × 100%.

2. The method for calculating the return ore rate under the blast furnace trough according to claim 1, characterized in that, The acquisition of the screening operation time period includes: receiving batch start signal and batch end signal from the blast furnace charging control system, wherein the time period is between the start signal and the end signal.

3. The method for calculating the return ore rate under the blast furnace trough according to claim 1, characterized in that, The cumulative weight is obtained from the first electronic scale installed in the qualified material weighing hopper as the first weight data, and the cumulative weight is obtained from the second electronic scale installed in the return ore hopper as the second weight data.

4. The method for calculating the return ore rate under the blast furnace trough according to claim 3, characterized in that, The first weight data is the difference between the cumulative weight value of the first electronic scale at the end of the screening operation period and at the beginning; the second weight data is the difference between the cumulative weight value of the second electronic scale at the end of the screening operation period and at the beginning.

5. The method for calculating the return ore rate under the blast furnace trough according to claim 1, characterized in that, While acquiring the first weight data and the second weight data, the type identifier of the current batch of furnace charge is also acquired; after calculating the return rate, the process also includes storing the return rate in association with the type identifier.

6. The method for calculating the return ore rate under the blast furnace trough according to claim 5, characterized in that, Within a set statistical period, the sum of the first weight data and the sum of the second weight data of multiple batches corresponding to the same type of furnace charge are accumulated; based on the accumulated sum of weight data, the comprehensive return rate of the furnace charge type within the statistical period is calculated.

7. The method for calculating the return ore rate under the blast furnace trough according to claim 1, characterized in that, It also includes threshold alarm steps: Preset return ore rate thresholds for different types of furnace charge; The real-time calculated return rate is compared with the preset threshold for the current batch of furnace charge type; If the return rate of the current batch exceeds the preset threshold, an audible and visual alarm will be triggered immediately, and alarm details will be displayed on the human-machine interface.

8. The method for calculating the return ore rate under the blast furnace trough according to claim 1, characterized in that, Also includes: The calculated ore return rate data, along with the corresponding batch time and furnace charge type information, are stored in the historical database. It provides a human-computer interaction interface for querying and displaying historical trend charts and statistical reports of ore return rate by time and furnace material type.

9. The method for calculating the return ore rate under the blast furnace trough according to claim 1, characterized in that, It also includes the coordinated steps for metering and controlling emissions from returned ore: Monitor the real-time weight value of the second electronic scale; When the real-time weight value reaches the preset bucket capacity threshold, the return ore bucket gate is opened to discharge the ore. After the gate is closed, the weight value recorded before discharge is included in the second weight data for the current batch.

10. The method for calculating the return ore rate under the blast furnace trough according to claim 1, characterized in that, It also includes equipment status diagnostic steps: Establish a benchmark range for the return rate of each type of furnace charge under normal production conditions; Continuously monitor the return rate of the current batch of furnace charge. If the return ore rate continues to deviate from the corresponding benchmark range and the qualified material particle size monitoring data is abnormal, a diagnostic prompt containing judgment information such as "decreased screening efficiency" or "suspected screen damage" will be generated.

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