Method for collecting addition amount of scrap steel in electric arc furnace

Abstract

The invention relates to an electric arc furnace scrap steel addition amount acquisition method comprising the following steps: weighing data acquisition: when a material package transport vehicle is in a middle position and is in a motion state, weighing data is acquired according to a fixed frequency, and a weighing data set is formed; judging the weight of the heavy package; judging the weight of an empty ladle; and calculating the weight of the scrap steel entering the furnace: when the electric arc furnace is in a loading state, detecting a position signal and weighing data of a material package transport vehicle, if the material package transport vehicle is in a package hoisting position and the weighing data is smaller than an empty vehicle judgment value, judging that the current material package state is loaded, and meanwhile, calculating a difference value between the weight of a heavy package and the weight of an empty package by utilizing the existing data. The invention relates to the technical field of electric arc furnaces, in particular to a method for collecting the scrap steel adding amount of an electric arc furnace, the weight of scrap steel entering a furnace is calculated through weighing data of a material package transport vehicle in the moving process, automatic collection of the weight of the scrap steel entering the furnace is achieved, data errors are eliminated, and data reliability is improved.

Description

Technical Field

[0001] The invention relates to the technical field of electric arc furnaces, in particular to a method for collecting the amount of scrap steel added to an electric arc furnace. Background Art

[0002] Top-loading electric arc furnaces use baggage to transport scrap to the furnace front and then load it into the furnace via a crane. The weight of the incoming scrap is typically calculated and recorded manually. First, the baggage preparation personnel weigh the baggage before loading and record it as the empty bag weight. After loading is complete, the baggage preparation personnel weigh the baggage again and record it as the heavy bag weight. The personnel then calculate the difference between the recorded empty and heavy bag weights and record this difference as the net weight of the scrap bag. After the furnace issues a charging signal, the personnel confirm the bag number corresponding to the loaded scrap bag. Finally, the personnel look up the corresponding net weight based on the bag number and report this net weight to the furnace operator as the incoming scrap weight.

[0003] The above-mentioned manual calculation and recording of scrap weight is prone to errors, which directly affect the control accuracy and composition stability of the smelting process. The main errors include the following: 1. Weighing Error: Scrap steel is usually weighed by a truck or a transport vehicle. Truck weighing often results in weighing errors due to the difference in the weight of empty and full bags. Transport vehicle weighing often results in weighing errors due to issues like parking positions or vehicle-mounted weighing device jamming. 2. Human error: Manual data reading requires that the material bag be stationary and the instrument data be stable. Reading the weighing data when the material bag is shaking or the material bag transport vehicle is not completely stationary will result in reading errors. Humans often round off when recording weighing data and calculating scrap weight, resulting in calculation errors. When manually looking up the scrap net weight data based on the charging bag number, they may make mistakes and provide incorrect data to the electric arc furnace operator. 3. Loading error: The manually recorded data is the weight of the scrap steel loaded into the bag. During the loading process, some scrap steel falls outside the bag, or some scrap steel remains in the bag after loading is completed, resulting in loading error. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem in the prior art that the weight of scrap steel entering the electric arc furnace is calculated and recorded manually, which easily leads to large errors.

[0005] In order to solve the above technical problems, the present invention provides a method for collecting the amount of scrap steel added to an electric arc furnace, comprising: weighing data collection: when the material bag transport vehicle is in the middle position and in motion, the weighing data is collected at a fixed frequency and a weighing data set is formed; when the material bag transport vehicle is in a stationary state, the weighing data collection is stopped; heavy bag weight determination: when the material bag transport vehicle arrives at the bag hanging position, if the material bag status is displayed as unloaded, the weighing data set is settled, and the result obtained by the data settlement is recorded as the heavy bag weight and the original heavy bag weight data is updated. After the data settlement is completed, the weighing data set is cleared; when the material bag transport vehicle arrives at the bag hanging position, if the material bag status is displayed as loaded, the weighing data set is not settled, and the weighing data set is directly cleared; empty bag weight determination: when the material bag transport vehicle arrives at the material preparation position, if the material bag status is displayed as loaded, the weighing data set is settled. Calculation, the result of data settlement is recorded as the empty bag weight and the original empty bag weight data is updated. After the data settlement is completed, the bag status is restored to unloaded, and the weighing data set is cleared. When the bag transport vehicle arrives at the preparation position, if the bag status is displayed as unloaded, the weighing data set is not settled, and the weighing data set is directly cleared. Calculation of the weight of scrap steel entering the furnace: when the arc furnace is in the loading state, the bag transport vehicle position signal and weighing data are detected. If the bag transport vehicle is in the bag hanging position and the weighing data is less than the empty vehicle judgment value, the current bag status is determined to be loaded. At the same time, the difference between the weight of the heavy bag and the weight of the empty bag is calculated using the existing data, and the difference is added to the weight of the scrap steel entering the furnace. The formula is: The weight of the scrap steel entering the furnace for the Nth time = the weight of the scrap steel entering the furnace for the (N-1)th time + the weight of the heavy bag for the Nth time – the weight of the empty bag for the Nth time; N is a positive integer; when smelting is completed, the weight of the scrap steel entering the furnace is reset to zero. The method for collecting the amount of scrap steel added to an electric arc furnace of the present invention calculates the weight of the scrap steel entering the furnace by using the weighing data of the material bag transport vehicle during movement, thereby realizing automatic collection of the weight of the scrap steel entering the furnace, eliminating data errors, and improving data reliability.

[0006] In one embodiment of the present invention, the collection method also includes correcting the weight of the scrap steel entering the furnace: if the weight data of the empty package changes, the difference in the weight of the empty package before and after the change is calculated, and the difference is used to correct the weight of the scrap steel entering the furnace. The formula is: the weight of the scrap steel entering the furnace for the Nth time = the weight of the scrap steel entering the furnace for the (N-1)th time + the weight of the empty package after the change - the weight of the empty package before the change.

[0007] In one embodiment of the present invention, the material bag transport vehicle is equipped with an on-board weighing device, and the on-board weighing device is used to measure the weight of the material bag transport vehicle after loading the scrap steel.

[0008] In one embodiment of the present invention, the bag hanging position refers to the bag transport vehicle being in the driving bag hanging area and triggering the bag hanging position limiter.

[0009] In one embodiment of the present invention, the material preparation position refers to the material bag transport vehicle being in the scrap steel yard area and triggering the material preparation position limiter.

[0010] In one embodiment of the present invention, the intermediate position refers to the situation where the material bag transport vehicle is between the scrap steel yard and the bag hanging area and the material preparation position limiter and the bag hanging position limiter are not triggered.

[0011] In one embodiment of the present invention, performing data settlement on the weighing data set refers to using a data processing method to calculate the weighing data set and outputting a calculation result.

[0012] In one embodiment of the present invention, the data processing method is the mean method, the quartile method or the least squares method.

[0013] In one embodiment of the present invention, the empty vehicle determination value is a manually set parameter, which is related to the empty bag weight of the material bag and the weighing data in the empty vehicle state, and is used to determine whether the material bag is lifted by the crane.

[0014] In one embodiment of the present invention, the electric arc furnace is a top-loading electric arc furnace.

[0015] The above technical solution of the present invention has the following beneficial effects compared with the prior art: The method for collecting scrap steel feed into an electric arc furnace, described herein, uses weighing data from a bag transport vehicle during operation to calculate the weight of the incoming scrap steel, eliminating weighing errors. Automating the collection and calculation process eliminates human error. Finally, using weighing data from before and after charging the electric arc furnace to calculate the incoming scrap steel weight eliminates charging errors. The data obtained by this method is reliable and accurate, contributing to improved control accuracy in electric arc furnace smelting. Furthermore, automated control replaces manual operation, reducing the workload of batching personnel. This method requires no additional hardware and can be implemented through programming within the electric arc furnace PLC, primary control system, or secondary control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein: Figure 1 Flow chart of a method for collecting the amount of scrap steel added to an electric arc furnace in a preferred embodiment of the present invention; Figure 2 This is a signal curve diagram of the method for collecting the amount of scrap steel added to an electric arc furnace in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0018] Reference Figure 1 As shown, the method for collecting the amount of scrap steel added to an electric arc furnace of the present invention comprises: (1) Weighing data collection: When the bag transport vehicle is in the middle position and in motion, the weighing data is collected at a fixed frequency and a weighing data set is formed; when the bag transport vehicle is in a stationary state, the weighing data collection is stopped; specifically, the middle position refers to the bag transport vehicle being between the scrap steel yard and the bag hanging area and not triggering the material preparation position limiter and the bag hanging position limiter; according to the actual measurement results, the bag transport vehicle is defined as the running state when it is in motion. Only when the bag transport vehicle is in motion, the weight data of the scrap steel collected will fluctuate less, so that a relatively accurate scrap steel weight information can be obtained in the subsequent data processing. When the bag transport vehicle is in a stationary state, the scrap steel weight information collected will fluctuate more when the bag transport vehicle is in different positions such as the electric arc furnace or the scrap steel yard. The bag transport vehicle is a truck that transports scrap steel.

[0019] (2) Determination of the weight of the heavy bag (i.e., the weight of the scrap steel on the bag transport vehicle): When the bag transport vehicle arrives at the bag lifting position, if the bag status is displayed as unloaded, the weighing data set is settled, and the result of the data settlement is recorded as the weight of the heavy bag and the original weight of the heavy bag is updated. After the data settlement is completed, the weighing data set is cleared; when the bag transport vehicle arrives at the bag lifting position, if the bag status is displayed as loaded, the weighing data set is not settled, and the weighing data set is directly cleared; specifically, the bag lifting position refers to the bag transport vehicle being in the driving bag lifting area and the bag lifting position limiter is triggered. The bag is a container for holding scrap steel on the truck transporting scrap steel. The scrap steel is loaded in this container and unloaded at the electric arc furnace side.

[0020] (3) Determination of empty bag weight (i.e., the weight of the bag transport vehicle when there is no scrap steel on it): When the bag transport vehicle arrives at the material preparation position, if the bag status is displayed as loaded, the weighing data set is settled, and the result of the data settlement is recorded as the empty bag weight and the original empty bag weight data is updated. After the data settlement is completed, the bag status is restored to unloaded, and the weighing data set is cleared; when the bag transport vehicle arrives at the material preparation position, if the bag status is displayed as unloaded, the weighing data set is not settled, and the weighing data set is directly cleared; specifically, the material preparation position refers to the bag transport vehicle being in the scrap steel yard area and the material preparation position limiter is triggered.

[0021] (4) Calculation of the weight of scrap steel entering the furnace: When the electric arc furnace is in the loading state, the position signal of the material bag transport vehicle and the weighing data are detected. If the material bag transport vehicle is in the bag hanging position and the weighing data is less than the empty vehicle judgment value, the current material bag state is determined to be loaded. At the same time, the difference between the weight of the heavy bag and the weight of the empty bag is calculated using the existing data, and the difference is added to the weight of the scrap steel entering the furnace. The formula is: The weight of the scrap steel entering the furnace for the Nth time = the weight of the scrap steel entering the furnace for the (N-1)th time + the weight of the heavy bag for the Nth time – the weight of the empty bag for the Nth time; N is a positive integer. The calculation method is used because new scrap steel will be continuously added to the electric arc furnace in the smelting process in multiple times during the scrap steel smelting process in the electric arc furnace.

[0022] (5) Correction of the weight of scrap steel entering the furnace: If the weight data of the empty ladle changes, calculate the difference between the weights of the empty ladle before and after the change, and use the difference to correct the weight of the scrap steel entering the furnace. The formula is: Weight of scrap steel entering the furnace for the Nth time = Weight of scrap steel entering the furnace for the (N-1)th time + Weight of empty ladle after the change - Weight of empty ladle before the change.

[0023] (6) When smelting is completed, the weight of the scrap steel entering the furnace returns to zero.

[0024] The above-mentioned material bag transport vehicle is equipped with an on-board weighing device, which is used to measure the weight of the material bag transport vehicle after loading the scrap steel.

[0025] The aforementioned data settlement of the weighing dataset refers to the use of data processing methods to calculate and output the results of the weighing dataset. The data processing methods are designed by process engineers based on the distribution characteristics of the benchmark data and test data for the material bag transport vehicles, and may include, but are not limited to, the mean method, the quartile method, and the least squares method. Specifically, the data collection frequency is 1 time per second; the empty vehicle threshold is 30 tons; the data settlement method for empty bag weight determination is to use the quartile method to calculate the upper quartile of the weighing dataset; the data settlement method for heavy bag weight determination is to use the quartile method to calculate the median of the weighing dataset.

[0026] The above empty car judgment value is a manually set parameter (i.e., a parameter manually input into the system), which is related to the empty bag weight of the material bag and the weighing data under the empty car state, and is used to determine whether the material bag is lifted by the crane.

[0027] The electric arc furnace used in the method for collecting the amount of added scrap steel in an electric arc furnace of the present invention is specifically a top-loading electric arc furnace.

[0028] like Figure 2 As shown at point A, the material bag is loaded and the status is loaded. At this time, the material bag transport vehicle leaves the bag hanging position and runs towards the preparation position. Before arriving at the preparation position, the arc furnace PLC collects the weighing data at a frequency of 1 time / second through the on-board weighing system and uploads it to the arc furnace secondary control system.

[0029] like Figure 2 As shown at point B, the bag transport vehicle arrives at the material preparation location. Weighing data collection stops, and the bag status is displayed as loaded, meeting the empty bag weight determination criteria. The arc furnace's secondary control system settles the weighing data set using the quartile method to calculate the upper quartile of the weighing data set. The result of the data settlement is 58.45 tons, which is recorded as the empty bag weight in the arc furnace's secondary control system and replaces the original empty bag weight data. After the data settlement is completed, the bag status returns to unloaded, and the weighing data set is cleared.

[0030] like Figure 2 As shown at point C in the middle, the material bag has been prepared and leaves the preparation position and moves towards the bag hanging position. Before reaching the bag hanging position, the arc furnace PLC collects the weighing data at a frequency of 1 time / second through the on-board weighing system and uploads it to the arc furnace secondary control system.

[0031] like Figure 2 As shown at point D, the bag transport vehicle arrives at the bag lifting position, weighing data collection stops, and the bag status display shows unloaded, meeting the heavy bag weight determination criteria. The electric arc furnace secondary control system settles the weighing data set, specifically using the quartile method to calculate the median of the weighing data set. The result of the data settlement is 105.75 tons, which is recorded as the heavy bag weight in the electric arc furnace secondary control system and replaces the original heavy bag weight data. After the data settlement is completed, the weighing data set is cleared.

[0032] like Figure 2 As shown at point E in the middle, the electric arc furnace begins to be loaded. The material bag transport vehicle is at the bag lifting position at this time and the weighing data shows 1.74 tons, which is less than the empty vehicle judgment value of 30 tons, indicating that the material bag transport vehicle is empty. It is determined that the material bag status at this time is loaded and the material bag has been lifted by the crane for loading operation, which meets the conditions for calculating the weight of scrap steel entering the furnace. According to the heavy bag weight and empty bag weight data recorded in the electric arc furnace secondary control system, the weight of the scrap steel entering the furnace is calculated to be 47.3 tons.

[0033] like Figure 2 As shown at point F, the material bag is loaded and the material bag status is displayed as loaded. At this time, the material bag transport vehicle leaves the bag hanging position and runs towards the material preparation position. Before arriving at the material preparation position, the arc furnace PLC collects the weighing data at a frequency of 1 time / second through the on-board weighing system and uploads it to the arc furnace secondary control system.

[0034] like Figure 2As shown at point G in the middle, the bag transport vehicle arrives at the material preparation location, weighing data collection stops, and the bag status is displayed as loaded, meeting the empty bag weight determination criteria. The arc furnace secondary control system settles the weighing data set, specifically using the quartile method to calculate the upper quartile of the weighing data set. The result of the data settlement is 57.99 tons, which is recorded as the empty bag weight in the arc furnace secondary control system and replaces the original empty bag weight data of 58.45 tons. The change in the empty bag weight data is detected, meeting the conditions for the correction of the incoming scrap weight. The arc furnace secondary control system corrects the incoming scrap weight based on the difference between the empty bag weight data before and after the change, resulting in a corrected weight of 47.76 tons.

[0035] After smelting is completed, the weight of the scrap steel entering the furnace returns to zero.

[0036] The specific steps of the method for collecting the amount of scrap steel added to the electric arc furnace of the present invention are: S1, the material bag transport vehicle drives to the material preparation position. The initial weight of the material bag transport vehicle is M1. Scrap steel is loaded onto the material bag transport vehicle at the material preparation position. S2, the material bag transport vehicle is loaded with scrap steel and moves toward the bag hanging position. During the movement of the material bag transport vehicle, the material bag transport vehicle and the scrap steel loaded thereon are weighed multiple times to collect data to form a weighing data set. The weight M2 of the material bag transport vehicle and the scrap steel loaded thereon is obtained through data processing; S3. The scrap steel on the bag transport vehicle is hoisted into the electric arc furnace by a driving crane. After unloading the scrap steel into the electric arc furnace, the bag transport vehicle moves from the bag hoisting position to the material preparation position. During the movement of the bag transport vehicle, the bag transport vehicle and the scrap steel remaining on it are weighed multiple times to collect data to form a weighing data set. The weight M3 of the bag transport vehicle and the scrap steel remaining on it is obtained through data processing; S4, replace M1 in step S1 with weight M3, where M1 is the weight of the material bag transport vehicle at the new material preparation position; S5. Load the scrap steel again on the bag transport vehicle with a weight of M3, repeat steps S1 to S4, and continuously load or unload the scrap steel back and forth between the material preparation position and the bag hanging position through the bag transport vehicle.

[0037] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for collecting the amount of scrap steel added to an electric arc furnace, characterized in that: include: Weighing data collection: When the bag transport vehicle is in the middle position and in motion, the weighing data is collected at a fixed frequency and a weighing data set is formed; when the bag transport vehicle is stationary, the weighing data collection is stopped; Determination of heavy bag weight: When the bag transport vehicle arrives at the bag hanging position, if the bag status shows that it is not loaded, the weighing data set will be settled. The result of the data settlement will be recorded as the heavy bag weight and the original heavy bag weight data will be updated. After the data settlement is completed, the weighing data set will be cleared. When the bag transport vehicle arrives at the bag hanging position, if the bag status shows that it is loaded, the weighing data set will not be settled and will be cleared directly. Empty bag weight determination: When the bag transport vehicle arrives at the material preparation location, if the bag status is displayed as loaded, the weighing data set will be settled. The result of the data settlement will be recorded as the empty bag weight and the original empty bag weight data will be updated. After the data settlement is completed, the bag status will be restored to unloaded and the weighing data set will be cleared. When the material bag transport vehicle arrives at the material preparation location, if the material bag status is displayed as unloaded, the weighing data set will not be settled and the weighing data set will be cleared directly; Calculation of scrap steel weight entering the furnace: When the electric arc furnace is in the charging state, the position signal of the material bag transport vehicle and the weighing data are detected. If the material bag transport vehicle is in the bag hanging position and the weighing data is less than the empty vehicle judgment value, the current material bag status is determined to be loaded. At the same time, the difference between the weight of the heavy bag and the weight of the empty bag is calculated using the existing data, and the difference is added to the weight of the scrap steel entering the furnace. The formula is: Nth scrap steel weight entering the furnace = (N-1)th scrap steel weight entering the furnace + Nth heavy bag weight – Nth empty bag weight; N is a positive integer; When smelting is completed, the weight of the scrap steel entering the furnace returns to zero.

2. The method for collecting the amount of scrap steel added to an electric arc furnace according to claim 1, wherein: The collection method also includes weight correction of scrap steel entering the furnace: if the weight data of the empty package changes, calculate the difference between the weights of the empty package before and after the change, and use the difference to correct the weight of the scrap steel entering the furnace. The formula is: The weight of the scrap steel entering the furnace for the Nth time = the weight of the scrap steel entering the furnace for the (N-1)th time + the weight of the empty package after the change - the weight of the empty package before the change.

3. The method for collecting the amount of scrap steel added to an electric arc furnace according to claim 1 or 2, characterized in that: The material bag transport vehicle is equipped with an on-board weighing device, which is used to measure the weight of the material bag transport vehicle after loading the scrap steel.

4. The method for collecting the amount of scrap steel added to an electric arc furnace according to claim 1, wherein: The bag hanging position refers to the bag transport vehicle being in the driving bag hanging area and triggering the bag hanging position limiter.

5. The method for collecting the amount of scrap steel added to an electric arc furnace according to claim 5, characterized in that: The material preparation position refers to the material bag transport vehicle being in the scrap steel yard area and triggering the material preparation position limiter.

6. The method for collecting the amount of scrap steel added to an electric arc furnace according to claim 5, characterized in that: The intermediate position refers to the situation where the material bag transport vehicle is between the scrap steel yard and the bag hanging area and the material preparation position limiter and the bag hanging position limiter are not triggered.

7. The method for collecting the amount of scrap steel added to an electric arc furnace according to claim 1, wherein: The data settlement of the weighing data set refers to using a data processing method to calculate the weighing data set and output a calculation result.

8. The method for collecting the amount of scrap steel added to an electric arc furnace according to claim 7, wherein: The data processing method is the mean method, the quartile method or the least squares method.

9. The method for collecting the amount of scrap steel added to an electric arc furnace according to claim 1, wherein: The empty vehicle judgment value is a manually set parameter, which is related to the empty bag weight and the weighing data in the empty vehicle state. It is used to determine whether the bag is lifted by the crane.

10. The method for collecting the amount of scrap steel added to an electric arc furnace according to claim 1, characterized in that: The electric arc furnace is a top-loading electric arc furnace.

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