Homogeneity risk control method for box-type graphitization furnace

Abstract

The present invention provides a method for controlling the homogeneity hidden dangers of a box-type graphitization furnace, and relates to the technical field of graphitization furnace hidden danger control. The present invention utilizes the characteristic that the box-type graphitization furnace is filled with uniform and symmetrical graphite conductors before and after filling, and uses the uniformity of adjacent voltages to measure the resistance uniformity of the graphite rods as the core heating components of the graphitization furnace, as well as the entire furnace body after filling. The uneven resistance is used to determine the presence of homogeneity hidden dangers, thereby achieving timely discovery and approximate positioning of homogeneity hidden dangers. At the same time, the elimination method is used to perform homogeneity hidden danger detection in three steps: before filling, before production begins, and during production. It is determined whether the cause of the homogeneity hidden danger is the quality of the graphite rods, uneven filling, or various factors in the production process, such as high temperature, and then guide the production line to take appropriate intervention measures.

Description

Technical Field

[0001] The present invention relates to the technical field of hidden danger control of graphitization furnaces, and in particular to a method for controlling homogeneity hidden dangers of a box-type graphitization furnace. Background Art

[0002] In the production process of negative electrode carbon materials for automotive power batteries, the graphitization process mostly uses a box-type graphitization furnace. A single furnace can produce about 100 tons of carbon materials, and the furnace temperature exceeds 3000 degrees Celsius.

[0003] The following technical solutions are currently available for monitoring and controlling the working conditions of this production process: an invention application with publication number CN115355727A and a utility model application with publication number CN202305665U. The former uses the current of the graphitization furnace heating module as the key parameter to determine and control the heating conditions; the latter comprehensively monitors the power transmission parameters at the front end of the graphitization furnace to determine and analyze the working conditions of the graphitization furnace. In addition, at this stage, the actual production line usually manually measures the temperature and other parameters at several locations on the furnace body from the measurement points reserved on the outside of the furnace body as an auxiliary judgment basis for working condition monitoring.

[0004] However, monitoring parameters such as current at the front end of the graphitization furnace or its heating module essentially only indirectly monitors the overall power changes of the graphitization furnace, and does not directly monitor the actual state of the carbon material being heated in the furnace. This inevitably leads to poor representativeness of the monitoring results, low accuracy, and inability to detect potential homogeneity problems. Manual monitoring of parameters such as temperature of the carbon material in the furnace has the disadvantages of long monitoring sampling cycles, low accuracy, and difficulty in detecting minor homogeneity risks. The causes of such homogeneity risks are diverse, such as problems with the heating module or surface flatness defects and internal porosity and cavitation problems that occur when the carbon material is loaded, which can lead to uneven temperature in the graphitization furnace during the production process. Once this occurs, it can affect product quality at the very least, or even lead to serious production safety accidents such as furnace spraying.

[0005] Therefore, there is an urgent need to provide a control method that can promptly determine the location and cause of homogeneity hazards in box-type graphitizing furnaces. Summary of the Invention

[0006] (1) Technical problems solved

[0007] In response to the shortcomings of the existing technology, the present invention provides a method for controlling homogeneity hazards of a box-type graphitization furnace, which solves the technical problem of being unable to promptly determine the location and cause of the homogeneity hazards of a box-type graphitization furnace.

[0008] (2) Technical solution

[0009] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0010] A method for controlling homogeneity hazards in a box-type graphitizing furnace, comprising:

[0011] S1. A plurality of graphite walls are provided longitudinally inside the box-type graphitization furnace as support surfaces, wherein the support surfaces divide a plurality of graphite rods uniformly distributed longitudinally as core heating components into segments at equal intervals;

[0012] S2. Set voltage sampling points on each support surface, furnace head end surface and furnace tail end surface respectively;

[0013] S3. Before filling the box-type graphitization furnace with carbon material, detect the voltage between each two adjacent voltage sampling points to obtain a first voltage set; if all voltages in the first voltage set are statistically consistent, proceed to S4; otherwise, determine that the graphite rod segment between the two voltage sampling points corresponding to the first abnormal voltage has a homogeneity risk, and perform risk control;

[0014] S4. After the box-type graphitizing furnace is filled with carbon material and before production begins, the voltage between each two adjacent voltage sampling points is detected to obtain a second voltage set; if all voltages in the second voltage set are statistically consistent, the process proceeds to S5; otherwise, it is determined that the carbon material segment between the two voltage sampling points corresponding to the second abnormal voltage has a homogeneity risk, and risk control is performed;

[0015] S5. After the box-type graphitizing furnace is powered on and production begins, the voltage between each two adjacent voltage sampling points is detected at predetermined time intervals to obtain a plurality of third voltage sets; if all voltages in each of the third voltage sets are statistically consistent, production is terminated and the processed carbon material is removed; otherwise, it is determined that a homogeneity risk exists in the production process during the time period of the third abnormal voltage, and risk control is performed.

[0016] Preferably, all voltages in the first, second and third voltage sets are statistically consistent, specifically:

[0017] Define and set M-1 sections of support surface, then set M+1 voltage sampling points in total; let the voltage set U * The mean of If any If M∈[1,M] is a positive integer and satisfies the following conditions, then all elements in the voltage set are said to be statistically consistent:

[0018]

[0019] Where * represents the voltage set index, and 1, 2, and 3 represent the first, second, and third voltage sets respectively; α is a preset parameter, and its value is between (0, 1).

[0020] Preferably, all voltages in the first, second and third voltage sets are statistically consistent, specifically:

[0021] Define and set M-1 sections of support surface, then set M+1 voltage sampling points in total; let the voltage set U * The mean of The standard deviation is If any If X∈[1,M] is a positive integer and satisfies the following conditions, then all elements in the voltage set are said to be statistically consistent:

[0022]

[0023] Where * represents the voltage set index, and 1, 2, and 3 represent the first, second, and third voltage sets, respectively. β is a preset parameter and its value cannot be negative.

[0024] Preferably, in said S2, a plurality of voltage sampling points are set on each supporting surface, furnace head end surface and / or furnace tail end surface.

[0025] (3) Beneficial effects

[0026] The present invention provides a method for controlling homogeneity hazards in a box-type graphitization furnace. Compared with the existing technology, it has the following beneficial effects:

[0027] 1. The present invention utilizes the characteristic of the box-type graphitization furnace that the graphite conductors before and after the filling are uniform and symmetrical. The uniformity of adjacent voltages is used to measure the resistance uniformity of the graphite rods as the core heating components of the graphitization furnace, as well as the entire furnace body after filling. The uneven resistance is used to determine the presence of homogeneity risks, thereby achieving timely discovery and approximate location of homogeneity risks.

[0028] 2. The present invention uses the elimination method to conduct homogeneity risk detection in three steps: before filling, before production, and during production. It can determine whether the cause of the homogeneity risk lies in the quality of graphite rods, uneven filling, or various factors in the production process such as high temperature, thereby guiding the production line to take appropriate intervention measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 Three views of a box-type graphitization furnace provided in an embodiment of the present invention;

[0031] Figure 2 A block diagram of a method for controlling homogeneity hazards in a box-type graphitization furnace provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0033] The embodiment of the present application solves the technical problem of being unable to promptly determine the location and cause of the homogeneity hidden danger of a box-type graphitization furnace by providing a method for controlling the homogeneity hidden danger of a box-type graphitization furnace.

[0034] The technical solution in the embodiments of the present application is to solve the above technical problems, and the overall idea is as follows:

[0035] In response to the problems pointed out in the background technology, the applicant has realized that there are three main reasons for the homogeneity hidden dangers:

[0036] One is the surface flatness defects, internal porosity and cavitation problems when the carbon material is filled.

[0037] Secondly, there are quality risks in the graphite rods, which are the core components of the heating module. This is because the standards currently followed in domestic production were generally compiled between 2000 and 2005, such as YB / T4088-2000, YB / T 2818-2005, etc., which are relatively old. In addition to the appearance size, surface quality and density, their quality requirements only require the resistivity to be tested. There are no requirements and testing methods for the intrinsic homogeneity of the product. As a result, the current graphite rod products in my country are difficult to meet the quality requirements for use in box-type graphitization furnaces in terms of homogeneity, and there is a high possibility of homogeneity quality risks.

[0038] The third is the hidden danger of homogeneity caused by various factors in the production process, such as high temperature.

[0039] Based on this, the embodiment of the present invention provides a box-type graphitization furnace homogeneity hidden danger control method, which relies on the following Figure 1The box-type graphitization furnace shown in the figure utilizes the characteristic of a box-type graphitization furnace with uniform and symmetrical graphite conductors before and after filling. The uniformity of adjacent voltages is measured to measure the resistance uniformity of the graphite rods, the core heating components of the graphitization furnace, and the entire furnace body after filling. Resistance unevenness is used to identify homogeneity risks, thereby enabling the timely discovery and approximate location of homogeneity risks. Simultaneously, using the elimination method, homogeneity risk detection is conducted in three steps: before filling, before production begins, and during production. The cause of the homogeneity risk is determined to be the quality of the graphite rods, uneven filling, or various factors in the production process, such as high temperature. This can then guide the production line to take appropriate intervention measures.

[0040] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0041] Example:

[0042] like Figure 2 As shown, an embodiment of the present invention provides a method for controlling homogeneity hazards of a box-type graphitization furnace, comprising:

[0043] S1. A plurality of graphite walls are provided longitudinally inside the box-type graphitization furnace as support surfaces, wherein the support surfaces divide a plurality of graphite rods uniformly distributed longitudinally as core heating components into segments at equal intervals;

[0044] S2. Set voltage sampling points on each support surface, furnace head end surface and furnace tail end surface respectively;

[0045] S3. Before filling the box-type graphitization furnace with carbon material, detect the voltage between each two adjacent voltage sampling points to obtain a first voltage set; if all voltages in the first voltage set are statistically consistent, proceed to S4; otherwise, determine that the graphite rod segment between the two voltage sampling points corresponding to the first abnormal voltage has a homogeneity risk, and perform risk control;

[0046] S4. After the box-type graphitizing furnace is filled with carbon material and before production begins, the voltage between each two adjacent voltage sampling points is detected to obtain a second voltage set; if all voltages in the second voltage set are statistically consistent, the process proceeds to S5; otherwise, it is determined that the carbon material segment between the two voltage sampling points corresponding to the second abnormal voltage has a homogeneity risk, and risk control is performed;

[0047] S5. After the box-type graphitizing furnace is powered on and production begins, the voltage between each two adjacent voltage sampling points is detected at predetermined time intervals to obtain a plurality of third voltage sets; if all voltages in each of the third voltage sets are statistically consistent, production is terminated and the processed carbon material is removed; otherwise, it is determined that a homogeneity risk exists in the production process during the time period of the third abnormal voltage, and risk control is performed.

[0048] The present invention utilizes the characteristic of a box-type graphitization furnace with uniform and symmetrical graphite conductors before and after filling. The uniformity of adjacent voltages is measured to measure the resistance uniformity of the graphite rods, the core heating components of the graphitization furnace, and the entire furnace body after filling. Resistance non-uniformity is used to determine the presence of homogeneity risks, thereby enabling the timely discovery and approximate location of homogeneity risks. Simultaneously, a process of elimination is employed to conduct homogeneity risk detection in three steps: before filling, before production begins, and during production. The cause of the homogeneity risk is determined to be the quality of the graphite rods, uneven filling, or various factors during the production process, such as high temperature. This allows guidance on appropriate intervention measures for production lines.

[0049] The following are the steps of the above technical solution:

[0050] In step S1, M-1 graphite walls are longitudinally arranged inside the box-type graphitization furnace as a support surface, and the support surface divides N graphite rods uniformly distributed longitudinally as the core heating component into M segments at equal intervals.

[0051] In step S2, M+1 voltage sampling points are respectively set on the M-1 blocking support surface, the furnace head end surface and the furnace tail end surface.

[0052] In step S3, before filling the box-type graphitization furnace with carbon material, the voltage between each two adjacent voltage sampling points is detected to obtain a first voltage set; if all voltages in the first voltage set are consistent at the statistical level, then proceed to S4; otherwise, it is determined that there is a homogeneity risk in the graphite rod segment between the two voltage sampling points corresponding to the first abnormal voltage, and the risk control is performed.

[0053] The fact that all voltages in the first voltage set are statistically consistent may specifically mean that:

[0054] Assume that the first voltage set U 1 The mean of If any If X∈[1,M] is a positive integer and satisfies the following conditions, then all elements in the voltage set are said to be statistically consistent:

[0055]

[0056] Among them, α is a preset parameter, and its value is between (0, 1).

[0057] Or it can specifically refer to:

[0058] Assume that the first voltage set U 1 The mean of The standard deviation is If any If X∈[1,M] is a positive integer and satisfies the following conditions, then all elements in the voltage set are said to be statistically consistent:

[0059]

[0060] Among them, β is a preset parameter and its value cannot be negative.

[0061] At this time, in this step, it is determined that the graphite rod segment between the two voltage sampling points corresponding to the first abnormal voltage has a homogeneity risk, specifically: N graphite rods have quality defects or cracks, and the quality defects or cracks are located in the Xth segment of graphite rods.

[0062] In step S4, after the box-type graphitization furnace is filled with carbon material and before production begins, the voltage between each two adjacent voltage sampling points is detected to obtain a second voltage set; if all voltages in the second voltage set are consistent at the statistical level, the process proceeds to S5; otherwise, it is determined that there is a homogeneity risk in the carbon material segment between the two voltage sampling points corresponding to the second abnormal voltage, and the risk control is performed.

[0063] The fact that all voltages in the second voltage set are statistically consistent may specifically refer to:

[0064] Assume that the second voltage set U 2 The mean of If any If X∈[1,M] is a positive integer and satisfies the following conditions, then all elements in the voltage set are said to be statistically consistent:

[0065]

[0066] Among them, α is a preset parameter, and its value is between (0, 1).

[0067] Or it can specifically refer to:

[0068] Assume that the second voltage set U 2 The mean of The standard deviation is If any If X∈[1,M] is a positive integer and satisfies the following conditions, then all elements in the voltage set are said to be statistically consistent:

[0069]

[0070] Among them, β is a preset parameter and its value cannot be negative.

[0071] At this time, in this step, it is determined that there is a homogeneity risk in the carbon material segment between the two voltage sampling points corresponding to the second abnormal voltage, specifically: it is determined that there are surface defects or internal looseness and cavitation problems in the filling process, and the defects or problems are located in the Xth segment of carbon material.

[0072] In step S5, after the box-type graphitization furnace is powered on and production begins, the voltage between each two adjacent voltage sampling points is detected every predetermined time period (for example, 1 hour) to obtain several third voltage sets; if all the voltages in each of the third voltage sets are consistent at the statistical level, the production is terminated and the processed carbon material is taken out; otherwise, it is determined that there is a homogeneity risk in the production process during the time period where the third abnormal voltage is located, and the risk control is carried out.

[0073] The fact that all voltages in the third voltage set are statistically consistent may specifically mean that:

[0074] Assume that the third voltage set U 3 The mean of If any If X∈[1,M] is a positive integer and satisfies the following conditions, then all elements in the voltage set are said to be statistically consistent:

[0075]

[0076] Among them, α is a preset parameter, and its value is between (0, 1).

[0077] Or it can specifically refer to:

[0078] Assume that the third voltage set U 3 The mean of The standard deviation is If any If X∈[1,M] is a positive integer and satisfies the following conditions, then all elements in the voltage set are said to be statistically consistent:

[0079]

[0080] Among them, β is a preset parameter and its value cannot be negative.

[0081] At this time, in this step, it is determined that a homogeneity hidden danger occurs in the production process during the time period of the third abnormal voltage, and the hidden danger is located in the Xth section.

[0082] In particular, when the voltage set U * When a voltage element is inconsistent at the statistical level, * represents the voltage set index, and 1, 2, and 3 represent the first, second, and third voltage sets respectively. For example, the following approach can be taken:

[0083] 1. If it is determined that the existing homogeneity hidden danger will have a serious impact on product quality and production safety, the production process can be stopped and rectification can be started. After the rectification is completed, the process can be restarted from step S1;

[0084] 2. If it is determined that the existing homogeneity risk will not have a serious impact on product quality and production safety, production can continue, and in subsequent production processes, more attention should be paid to the inconsistency of voltage parameters at corresponding locations;

[0085] In addition, in order to further improve the credibility of the judgment results, in an optional embodiment, multiple voltage sampling points are set on each support surface, furnace head end surface and / or furnace tail end surface in step S2, and the voltage between each two adjacent support surfaces and the furnace head and furnace tail end surfaces is repeatedly tested multiple times, and the mean or median is taken to reduce the interference of detection errors and abnormal data on the results.

[0086] In summary, compared with the existing technology, the present invention has the following beneficial effects:

[0087] 1. The accuracy, precision and efficiency of the operating condition monitoring of the box-type graphitization furnace have been greatly improved. It can timely and efficiently discover and locate homogeneity hazards, and can distinguish whether the homogeneity hazards are caused by quality defects or cracks in the graphite rods as the core components of the heating module, or by surface defects or internal porosity and cavitation problems in the filling process, or by factors such as high temperature in the production process. This guides the production line to take appropriate intervention measures in a timely manner, thereby improving the level of production intelligence and production management efficiency.

[0088] 2. Improved the quality control level of the box-type graphitization furnace production process and improved product quality.

[0089] 3. It reduces the possibility of production safety accidents such as furnace spraying during the production process of box-type graphitization furnace, and improves the production safety level.

[0090] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0091] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for controlling homogeneity hazards of a box-type graphitizing furnace, characterized in that: include: S1. A plurality of graphite walls are provided longitudinally inside the box-type graphitization furnace as support surfaces, wherein the support surfaces divide a plurality of graphite rods uniformly distributed longitudinally as core heating components into segments at equal intervals; S2. Set voltage sampling points on each support surface, furnace head end surface and furnace tail end surface respectively; S3. Before filling the box-type graphitization furnace with carbon material, detect the voltage between each two adjacent voltage sampling points to obtain a first voltage set; if all voltages in the first voltage set are statistically consistent, proceed to S4; otherwise, determine that the graphite rod segment between the two voltage sampling points corresponding to the first abnormal voltage has a homogeneity risk, and perform risk control; S4. After the box-type graphitizing furnace is filled with carbon material and before production begins, the voltage between each two adjacent voltage sampling points is detected to obtain a second voltage set; if all voltages in the second voltage set are statistically consistent, the process proceeds to S5; otherwise, it is determined that the carbon material segment between the two voltage sampling points corresponding to the second abnormal voltage has a homogeneity risk, and risk control is performed; S5. After the box-type graphitizing furnace is powered on and production begins, the voltage between each two adjacent voltage sampling points is detected at predetermined time intervals to obtain a plurality of third voltage sets; if all voltages in each of the third voltage sets are statistically consistent, production is terminated and the processed carbon material is removed; otherwise, it is determined that a homogeneity risk exists in the production process during the time period of the third abnormal voltage, and risk control is performed.

2. The method for controlling homogeneity hazards of a box-type graphitizing furnace according to claim 1, characterized in that: All voltages in the first, second, and third voltage sets are statistically consistent, specifically: Define and set M-1 sections of support surface, then set M+1 voltage sampling points in total; let the voltage set U * The mean of If any If X∈[1,M] is a positive integer and satisfies the following conditions, then all elements in the voltage set are said to be statistically consistent: Where * represents the voltage set index, and 1, 2, and 3 represent the first, second, and third voltage sets respectively; α is a preset parameter, and its value is between (0, 1).

3. The method for controlling homogeneity hazards of a box-type graphitizing furnace according to claim 1, wherein: All voltages in the first, second, and third voltage sets are statistically consistent, specifically: Define and set M-1 sections of support surface, then set M+1 voltage sampling points in total; let the voltage set U * The mean of The standard deviation is If any If X∈[1,M] is a positive integer and satisfies the following conditions, then all elements in the voltage set are said to be statistically consistent: Where * represents the voltage set index, and 1, 2, and 3 represent the first, second, and third voltage sets, respectively. β is a preset parameter and its value cannot be negative.

4. The method for controlling homogeneity hazards of a box-type graphitizing furnace according to any one of claims 1 to 3, characterized in that: In the above S2, a plurality of voltage sampling points are set on each supporting surface, furnace head end surface and / or furnace tail end surface.

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