A powder electrostatic elimination method and system based on gas dielectric strength regulation

Abstract

The application discloses a powder electrostatic elimination method and system based on gas dielectric strength regulation, and belongs to the technical field of electrostatic safety control, and comprises the following steps: acquiring the minimum ignition energy of target powder and a powder electrostatic discharge model; selecting a low dielectric strength gas as an initial atmosphere; performing numerical simulation to obtain discharge energy; comparing the discharge energy with the minimum ignition energy; when the discharge energy is smaller than the minimum ignition energy, the initial atmosphere is used as a target electrostatic elimination regulation atmosphere; when the discharge energy is greater than or equal to the minimum ignition energy, a regulation calculation process is repeatedly executed until the new discharge energy is smaller than the minimum ignition energy, and then the atmosphere corresponding to the new discharge energy is used as the target electrostatic elimination regulation atmosphere; and the target electrostatic elimination regulation atmosphere is applied to a powder treatment process. The application realizes effective constraint on the electrostatic discharge process, introduces high dielectric strength gas to regulate the atmosphere composition, and thus realizes collaborative control of powder charging behavior and electrostatic discharge energy.

Description

Technical Field

[0001] This invention relates to a method and system for eliminating static electricity in powders based on the regulation of gas dielectric strength. It belongs to the field of electrostatic safety control technology in powder processing and gas-solid two-phase flow processes, and is applicable to the elimination of static electricity and risk control of powders in processes such as conveying, fluidized bed, drying, mixing, storage and transportation and crushing. Background Technology

[0002] Powder materials are widely used in chemical, energy, military, and pharmaceutical industries. During the production, screening, conveying, fluidization, mixing, crushing, and storage of powders, frequent contact, friction, and separation between particles and between particles and equipment walls are inevitable, leading to the generation and accumulation of electrical charges. Powder charging not only alters the interaction behavior between particles, causing agglomeration, adhesion, and blockage, affecting material flowability and process stability, but may also trigger electrostatic discharge under certain conditions. When the local electric field strength exceeds the breakdown threshold of the gaseous medium, electrostatic discharge phenomena such as spark discharge, brush discharge, or corona discharge can easily occur. For flammable or explosive powder systems, these discharge processes may release sufficient energy to trigger dust explosions, posing serious safety hazards.

[0003] In existing technologies, to reduce the hazards of static electricity in powders, methods such as grounding, using antistatic materials, adding antistatic agents, or adjusting environmental humidity are commonly used to control the charge of the powder. However, the static electricity elimination effect of the above methods is limited, and some methods may adversely affect the properties of the powder itself.

[0004] The dielectric strength of a gaseous medium has a significant impact on the electrostatic behavior of powders. Under certain conditions, powders in low-dielectric-strength atmospheres are more prone to ionization and discharge at lower electric field strengths, thus efficiently promoting charge dissipation and reducing the powder's charge level, while also reducing problems such as powder agglomeration and adhesion. However, such atmospheres may also increase the frequency of discharges and generate enormous discharge energy under high initial charges. Conversely, high-dielectric-strength gases can suppress discharges, but may lead to the continuous accumulation of charge in the powder, thus posing a risk of high-energy discharges under certain conditions.

[0005] Therefore, there is an urgent need to propose a new method for eliminating static electricity in powders, so as to achieve optimized control of gas composition, thereby solving the problems of effectively controlling discharge energy and avoiding the risks of electrostatic discharge ignition and dust explosion while reducing the powder charge level, mitigating powder agglomeration and adhesion, etc. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a method and system for eliminating static electricity in powder based on the control of gas dielectric strength.

[0007] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution.

[0008] In a first aspect, the present invention discloses a method for eliminating static electricity in powders based on the modulation of gas dielectric strength, comprising:

[0009] Obtain the minimum ignition energy of the target powder;

[0010] Obtain a pre-constructed electrostatic discharge model of the powder for the powder processing procedure that requires electrostatic elimination;

[0011] A gas with low dielectric strength was selected as the initial atmosphere;

[0012] Based on the aforementioned powder electrostatic discharge model, the discharge process under the initial atmosphere conditions was numerically simulated to obtain the discharge energy.

[0013] Comparing the discharge energy with the minimum ignition energy includes: when the discharge energy is less than the minimum ignition energy, using the initial atmosphere as the target power-reducing atmosphere; when the discharge energy is greater than or equal to the minimum ignition energy, repeating the control calculation process until a new discharge energy is less than the minimum ignition energy, then using the atmosphere corresponding to the new discharge energy as the target power-reducing atmosphere; the control calculation process includes: adjusting the gas composition of the atmosphere after the previous control, and calculating the atmosphere after the current control based on numerical simulation to obtain the new discharge energy; if the current control is the first control, then the atmosphere after the previous control is the initial atmosphere;

[0014] The target anti-static atmosphere is applied to the powder processing process.

[0015] Furthermore, the process of adjusting the gas composition of the atmosphere after the previous adjustment and calculating the new discharge energy based on numerical simulation for the atmosphere after the current adjustment includes:

[0016] A high dielectric strength gas is introduced into the atmosphere after the previous regulation to form a mixed atmosphere. By adjusting the volume fractions of the low dielectric strength and high dielectric strength gas components, the discharge process under the regulated atmosphere conditions is numerically simulated to obtain a new discharge energy.

[0017] Furthermore, the low dielectric strength gas includes argon, helium, neon, or any combination thereof;

[0018] The high dielectric strength gas includes nitrogen, carbon dioxide, or any combination thereof.

[0019] Furthermore, the target de-energizing atmosphere, under the premise that the discharge energy is lower than the minimum ignition energy, preferentially selects an atmosphere composition that can reduce the powder charge level, reduce powder agglomeration and wall adhesion.

[0020] Furthermore, based on the powder electrostatic discharge model, the discharge process under the initial atmosphere conditions is numerically simulated, and the expression for the discharge energy is obtained as follows:

[0021] ;

[0022] In the formula, E d E is the discharge energy. all,t0 E represents the total electrostatic energy of the system before discharge. all,t1 The total electrostatic energy of the system after discharge; the system is an electrostatic system composed of charged powder, equipment walls and atmospheric medium within the target discharge area.

[0023] Furthermore, the formula for calculating the total electrostatic energy of the system is as follows:

[0024] ;

[0025] In the formula, E is the electric field intensity, and D is the electric displacement vector. It is a volume fraction.

[0026] Furthermore, when the target electrostatic discharge control atmosphere is applied to the powder processing process, the probability of forming local high-risk electrostatic discharge areas is reduced by controlling the uniformity of gas distribution, the pressure state inside the device, and the inlet air flow rate; the device is the powder processing device involved in the powder processing process.

[0027] Furthermore, the control of gas distribution uniformity, internal pressure state, and inlet gas flow rate includes:

[0028] Introducing air into the device through single-point or multi-point air intake can improve the speed of atmosphere formation and uniformity of distribution.

[0029] The pressure state inside the device used to control the target static elimination atmosphere is a positive pressure state;

[0030] The inlet airflow rate is controlled without causing significant powder erosion, enhanced collisional charging, or a significant increase in dust concentration or the formation of a dust cloud. Significant powder erosion refers to the state in which the inlet air causes continuous churning, local voids, or a large amount of powder to be carried away from the original accumulation area on the surface of the powder bed. Enhanced collisional charging refers to the increase in the frequency of collisions and friction between particles or between particles and the wall due to excessively high inlet airflow rate, which increases the powder charge level compared to when no atmosphere is introduced or when the atmosphere is introduced at a low flow rate.

[0031] The significant increase in dust concentration refers to the increase in suspended dust concentration in the device after air intake compared to the state without air intake, exceeding a preset concentration threshold; the formation of a dust cloud refers to the formation of a dust cloud by suspended dust in the device after air intake.

[0032] Furthermore, the powder processing process includes conveying, fluidized bed, mixing, drying, storage and transportation, and crushing processes.

[0033] Secondly, the present invention also discloses a powder electrostatic elimination system based on gas dielectric strength regulation, used to implement the powder electrostatic elimination method based on gas dielectric strength regulation described in the first aspect, the system comprising:

[0034] The parameter acquisition and modeling module is used to acquire the minimum ignition energy of the target powder, the dielectric strength of different gases and the initial atmosphere type parameters, and to establish a powder electrostatic discharge model for the powder processing process that requires electrostatic elimination.

[0035] The numerical simulation module is used to perform numerical simulations of the discharge process under different atmospheres.

[0036] The discharge energy post-processing calculation module is used to post-process the results obtained from the numerical simulation module and calculate the total electrostatic energy of the system under different atmospheres.

[0037] The electrostatic elimination gas assessment and control module is used to adjust the volume fraction of low dielectric strength and high dielectric strength gases and input them into the numerical simulation module. The discharge energy post-processing calculation module calculates the discharge energy under different atmospheres. Based on the discharge energy under different atmospheres and the minimum ignition energy of the target powder, the target electrostatic elimination control atmosphere for the powder treatment process that requires electrostatic elimination is determined.

[0038] The beneficial effects achieved by this invention are as follows:

[0039] This invention uses the minimum ignition energy of powder as a safety criterion. By constructing a powder electrostatic discharge model and combining it with numerical simulation, the discharge energy under different atmospheric conditions is quantitatively evaluated, thus achieving effective constraint on the electrostatic discharge process. On this basis, low dielectric strength gas is preferentially used to reduce the powder charge level, thereby mitigating adverse phenomena such as powder agglomeration, adhesion, and blockage. At the same time, when the discharge energy may exceed the safety threshold, high dielectric strength gas is introduced to regulate the atmosphere composition, so that the discharge energy is reduced to below the minimum ignition energy of powder, thereby achieving coordinated control of powder charge behavior and electrostatic discharge energy.

[0040] Compared to traditional methods that rely solely on grounding or antistatic measures, this invention can effectively suppress the risk of ignition and dust explosion caused by electrostatic discharge while reducing powder charge, mitigating or eliminating adverse phenomena such as powder agglomeration and wall adhesion. It also has good controllability and can provide a reliable technical basis for static elimination and explosion prevention in different powder processing processes. Attached Figure Description

[0041] Figure 1This is a schematic flowchart of a powder electrostatic elimination method based on gas dielectric strength regulation provided by the present invention. Detailed Implementation

[0042] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention. Here, the illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0043] It should also be noted that, in order to avoid obscuring the invention with unnecessary details, only the structures and / or processing steps closely related to the solution according to the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0044] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0045] It should be emphasized here that the step markers mentioned below are not a limitation on the order of the steps, but should be understood as meaning that the steps can be executed in the order mentioned in the embodiments, or in a different order than in the embodiments, or several steps can be executed simultaneously.

[0046] Example 1: This invention introduces a method for eliminating static electricity in powders based on the control of gas dielectric strength, comprising:

[0047] Obtain the minimum ignition energy of the target powder;

[0048] Obtain a pre-constructed electrostatic discharge model of the powder for the powder processing procedure that requires electrostatic elimination;

[0049] A gas with low dielectric strength was selected as the initial atmosphere;

[0050] Based on the aforementioned powder electrostatic discharge model, the discharge process under the initial atmosphere conditions was numerically simulated to obtain the discharge energy.

[0051] Comparing the discharge energy with the minimum ignition energy includes: when the discharge energy is less than the minimum ignition energy, using the initial atmosphere as the target power-reducing atmosphere; when the discharge energy is greater than or equal to the minimum ignition energy, repeating the control calculation process until a new discharge energy is less than the minimum ignition energy, then using the atmosphere corresponding to the new discharge energy as the target power-reducing atmosphere; the control calculation process includes: adjusting the gas composition of the atmosphere after the previous control, and calculating the atmosphere after the current control based on numerical simulation to obtain the new discharge energy; if the current control is the first control, then the atmosphere after the previous control is the initial atmosphere;

[0052] The target anti-static atmosphere is applied to the powder processing process.

[0053] In this embodiment, the process of adjusting the gas composition of the atmosphere after the previous adjustment and calculating the new discharge energy based on numerical simulation for the atmosphere after the current adjustment includes:

[0054] A high dielectric strength gas is introduced into the atmosphere after the previous regulation to form a mixed atmosphere. By adjusting the volume fractions of the low dielectric strength and high dielectric strength gas components, the discharge process under the regulated atmosphere conditions is numerically simulated to obtain a new discharge energy.

[0055] In this embodiment, the low dielectric strength gas includes argon, helium, neon, or any combination thereof;

[0056] The high dielectric strength gas includes nitrogen, carbon dioxide, or any combination thereof.

[0057] In this embodiment, the target de-energizing atmosphere is selected based on the premise that the discharge energy is lower than the minimum ignition energy, and the atmosphere composition is preferably selected to reduce the powder charge level, reduce powder agglomeration and wall adhesion.

[0058] In this embodiment, based on the powder electrostatic discharge model, the discharge process under the initial atmosphere conditions is numerically simulated, and the expression for the discharge energy is obtained as follows:

[0059] ;

[0060] In the formula, E d E is the discharge energy. all,t0 E represents the total electrostatic energy of the system before discharge. all,t1 The total electrostatic energy of the system after discharge; the system is an electrostatic system composed of charged powder, equipment walls and atmospheric medium within the target discharge area.

[0061] In this embodiment, the formula for calculating the total electrostatic energy of the system is:

[0062] ;

[0063] In the formula, E is the electric field intensity, and D is the electric displacement vector. It is a volume fraction.

[0064] In this embodiment, when the target electrostatic discharge control atmosphere is applied to the powder processing process, the probability of forming local high-risk electrostatic discharge areas is reduced by controlling the uniformity of gas distribution, the pressure state inside the device, and the inlet air flow rate; the device is the powder processing device involved in the powder processing process.

[0065] In this embodiment, controlling the uniformity of gas distribution, the pressure state within the device, and the inlet gas flow rate includes:

[0066] Introducing air into the device through single-point or multi-point air intake can improve the speed of atmosphere formation and uniformity of distribution.

[0067] The pressure state inside the device used to control the target static elimination atmosphere is a positive pressure state;

[0068] The inlet airflow rate is controlled without causing significant powder erosion, enhanced collisional charging, or a significant increase in dust concentration or the formation of a dust cloud. Significant powder erosion refers to the state in which the inlet air causes continuous churning, local voids, or a large amount of powder to be carried away from the original accumulation area on the surface of the powder bed. Enhanced collisional charging refers to the increase in the frequency of collisions and friction between particles or between particles and the wall due to excessively high inlet airflow rate, which increases the powder charge level compared to when no atmosphere is introduced or when the atmosphere is introduced at a low flow rate.

[0069] The significant increase in dust concentration refers to the increase in suspended dust concentration in the device after air intake compared to the state without air intake, exceeding a preset concentration threshold; the formation of a dust cloud refers to the formation of a dust cloud by suspended dust in the device after air intake.

[0070] In this embodiment, the powder processing process includes conveying, fluidized bed, mixing, drying, storage and transportation, and crushing processes.

[0071] Example 2, based on the same inventive concept as Example 1, introduces a method for eliminating static electricity in powders based on the control of gas dielectric strength. The following provides a detailed step-by-step description of the method, such as... Figure 1 As shown, it includes the following steps:

[0072] Step (1) Obtain the minimum ignition energy E of the target powder 0.01 And serve as the electrostatic safety threshold;

[0073] In this invention, the minimum ignition energy of the powder is... The results were obtained through national standard experimental methods, namely GB / T 16428-2026 (Method for Determination of Minimum Ignition Energy of Dust Cloud) or GB / T 16428-1996 (Method for Determination of Minimum Ignition Energy of Dust Cloud).

[0074] Step (2) Construct a powder electrostatic discharge model for the powder processing process that requires electrostatic elimination;

[0075] In this invention, the powder processing process includes, but is not limited to, processes such as conveying, fluidized bed, mixing, drying, storage and transportation, and crushing.

[0076] Step (3) Select a low dielectric strength gas as the initial atmosphere;

[0077] In this invention, the low dielectric strength gas includes, but is not limited to, argon, helium, neon, or any combination thereof.

[0078] Step (4) Based on the powder electrostatic discharge model, the discharge process under the initial atmosphere conditions is numerically simulated to obtain the discharge energy E. d ;

[0079] In this invention, the discharge energy E d The total electrostatic energy E of the system before and after discharge can be calculated. all The difference is determined by the following expression:

[0080] ;

[0081] Where E all,t0 E represents the total electrostatic energy of the system before discharge. all,t1 The total electrostatic energy of the system after discharge; the system is an electrostatic system composed of charged powder, equipment walls and atmospheric medium within the target discharge area.

[0082] In this invention, the total electrostatic energy E of the system all Calculate using the following formula or its equivalent variation:

[0083] ;

[0084] Where E is the electric field intensity and D is the electric displacement vector. It is a volume fraction.

[0085] Step (5) discharges the energy E d With the minimum ignition energy E 0.01 Comparison:

[0086] When the discharge energy E d Less than the minimum ignition energy E 0.01 At that time, the initial atmosphere is used as the target atmosphere for power elimination and control.

[0087] When the discharge energy E d Greater than or equal to minimum ignition energy E 0.01 At that time, the gas composition of the initial atmosphere was adjusted, and the adjusted atmosphere was evaluated based on numerical simulation.

[0088] In this invention, the gas composition of the initial atmosphere is controlled, and the controlled atmosphere is evaluated based on numerical simulation, including:

[0089] A high dielectric strength gas was introduced into the initial atmosphere to form a mixed atmosphere. By adjusting the volume fractions of the low and high dielectric strength gas components, the discharge process under the adjusted atmosphere conditions was numerically simulated to achieve the desired discharge energy E. d Reduce to less than the minimum ignition energy E 0.01 ;

[0090] In this invention, the high dielectric strength gas includes, but is not limited to, nitrogen, carbon dioxide, or any combination thereof.

[0091] Step (6) Determine the target power-dissipating control atmosphere that satisfies the requirement that the discharge energy is lower than the minimum ignition energy, and apply it to the powder processing process.

[0092] In this invention, when the target electrostatic discharge control atmosphere is applied to the powder processing process, it reduces the probability of forming local high-risk electrostatic discharge areas by controlling the uniformity of gas distribution, the pressure state inside the device, and the inlet air flow rate.

[0093] In this invention, the pressure state inside the device for applying the target anti-static atmosphere control is a positive pressure state to suppress the entry of external gas into the device; the device is a powder processing device involved in the powder processing process, including equipment for powder conveying, fluidized bed, mixing, drying, storage and crushing; preferably, the powder processing device includes pipelines, fluidized bed, mixer, drying device, silo, and crushing device.

[0094] In this invention, the inlet airflow velocity control for the target electrostatic control atmosphere application includes controlling the airflow velocity within a range that does not cause significant powder erosion, additional collision electrification, or dust generation. This aims to prevent excessive mechanical impact on the powder due to airflow disturbance, suppress violent collisions between particles and between particles and the wall surface, and simultaneously prevent a significant increase in suspended dust concentration or the formation of high-concentration dust clouds. This reduces the risk of enhanced powder electrostatic discharge, mechanical impact-induced ignition, and dust explosions. Significant powder erosion refers to the continuous agitation, localized voids, or significant removal of powder from its original accumulation area caused by the airflow. A significant increase in dust concentration refers to a substantial increase in suspended dust concentration within the device after airflow compared to the state without airflow, increasing the risk of dust cloud formation or expansion. Enhanced additional collision electrification refers to an increase in the frequency of collisions and friction between particles or between particles and the wall surface due to excessively high inlet airflow velocity, resulting in a higher powder charge level compared to when no atmosphere was introduced or when an atmosphere was introduced at a low flow rate.

[0095] In this invention, the control of gas distribution uniformity in the target electrostatic control atmosphere application includes introducing gas into the device through single-point or multi-point gas intake to improve the atmosphere formation speed and distribution uniformity.

[0096] In this invention, the powder processing process includes, but is not limited to, processes such as conveying, fluidized bed, mixing, drying, storage and transportation, and crushing.

[0097] In this invention, the target de-energizing atmosphere, under the premise that the discharge energy is lower than the minimum ignition energy, preferentially selects an atmosphere composition that can reduce the powder charge level, reduce powder agglomeration and wall adhesion.

[0098] Example 3, as a specific implementation of the present invention, provides a detailed description of the powder electrostatic elimination method based on gas dielectric strength regulation proposed in Example 2, as follows:

[0099] In this embodiment, the powder electrostatic elimination method based on gas dielectric strength regulation of the present invention is implemented in the mixing process of a highly sensitive powder in a mixing device. The specific implementation steps are as follows:

[0100] (1) Obtain the minimum ignition energy E of the target powder 0.01 And serve as the electrostatic safety threshold;

[0101] In this embodiment, the minimum ignition energy of the powder was measured to be E using standard experimental methods. 0.01 (For example, 39.13mJ), as the electrostatic safety threshold.

[0102] (2) For powder processing processes that require static electricity elimination, a powder electrostatic discharge model is constructed;

[0103] In this embodiment, an electrostatic discharge model of powder is constructed for the mixing process of powder in the mixing device.

[0104] (3) Select a gas with low dielectric strength as the initial atmosphere;

[0105] In this embodiment, argon, a gas with low dielectric strength, is selected as the initial atmosphere. The dielectric strength of argon at standard atmospheric pressure is 0.6 MV / m, which is far lower than the dielectric strength of air (3 MV / m).

[0106] (4) Based on the electrostatic discharge model of the powder, the discharge process under the initial atmosphere conditions is numerically simulated to obtain the discharge energy E. d ;

[0107] In this embodiment, based on the constructed powder electrostatic discharge model within the mixing device, the discharge process under low dielectric strength argon atmosphere conditions is numerically analyzed, and the discharge energy E is calculated using the following formula. d,0 (For example, 39.13 mJ).

[0108] ;

[0109] ;

[0110] (5) Discharge energy E d With the minimum ignition energy E 0.01 Comparison:

[0111] In this embodiment, the powder discharge energy E d,0 Greater than the minimum ignition energy of the powder E 0.01 Therefore, the gas composition of the initial atmosphere is controlled.

[0112] A high-dielectric-strength gas was introduced into the initial argon atmosphere to form a mixed atmosphere. Nitrogen was selected as the high-dielectric-strength gas, with a dielectric strength of 3.4 MV / m at standard atmospheric pressure. The volume fractions of the low-dielectric-strength and high-dielectric-strength gas components were adjusted, with the high-dielectric-strength gas being added to the total gas volume by 10% each time. Numerical simulations were performed on the discharge process under the adjusted atmosphere conditions. The discharge energy of the mixed atmosphere consisting of 10% high-dielectric-strength gas and 90% low-dielectric-strength gas was E. d,1 (For example, 42.2 mJ), the discharge energy of a mixed atmosphere consisting of 20% high dielectric strength gas and 80% low dielectric strength gas is E. d,2 (For example, 35.0 mJ), discharge energy E d,2 Less than the minimum ignition energy E 0.01 .

[0113] (6) Determine the target power-dissipating control atmosphere that meets the requirement that the discharge energy is lower than the minimum ignition energy, and apply it to the powder processing process.

[0114] The target discharge control atmosphere, which satisfies the requirement that the discharge energy is lower than the minimum ignition energy, is a mixture of 20% high dielectric strength gas nitrogen and 80% low dielectric strength gas argon, and this mixture is applied to the powder mixing process.

[0115] In practical applications, the internal pressure of the device is maintained at a positive pressure to prevent external gas from entering the device. The inlet gas flow rate is controlled at v. gas (For example, within 0.15 m / s) to avoid excessive mechanical impact on the powder due to airflow or violent collisions between particles and between particles and the wall surface, thereby reducing the risk of enhanced electrostatic discharge of the powder and mechanical impact-induced ignition. A four-point air intake method is used to introduce air into the device to improve the atmosphere formation speed and distribution uniformity.

[0116] Example 4, based on the same inventive concept as Example 1, introduces a powder electrostatic elimination system based on gas dielectric strength regulation, comprising:

[0117] The parameter acquisition and modeling module is used to acquire parameters such as the minimum ignition energy of the target powder, the dielectric strength of different gases, and the type of initial atmosphere, and to establish a powder electrostatic discharge model for the powder processing process that requires electrostatic elimination.

[0118] The numerical simulation module is used to perform numerical simulations of the discharge process under different atmospheres.

[0119] The discharge energy post-processing calculation module is used to post-process the results obtained from the numerical simulation module and calculate the total electrostatic energy of the system under different atmospheres.

[0120] The electrostatic elimination gas assessment and control module is used to adjust the volume fraction of low dielectric strength and high dielectric strength gases and input them into the numerical simulation module. The discharge energy post-processing calculation module calculates the discharge energy under different atmospheres. Based on the discharge energy under different atmospheres and the minimum ignition energy of the target powder, the target electrostatic elimination control atmosphere for the powder treatment process that requires electrostatic elimination is determined.

[0121] The modules described above work together to implement the gas dielectric strength control method disclosed in the above embodiments.

[0122] It is worth noting that the system embodiment corresponds to the above method embodiment. The implementation methods of the above method embodiments are all applicable to the system embodiment and can achieve the same or similar technical effects, so they will not be described in detail here.

[0123] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0124] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0125] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0126] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0127] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for eliminating static electricity in powders based on the control of gas dielectric strength, characterized in that, include: Obtain the minimum ignition energy of the target powder; Obtain a pre-constructed electrostatic discharge model of the powder for the powder processing procedure that requires electrostatic elimination; A gas with low dielectric strength was selected as the initial atmosphere; Based on the aforementioned powder electrostatic discharge model, the discharge process under the initial atmosphere conditions was numerically simulated to obtain the discharge energy. Comparing the discharge energy with the minimum ignition energy includes: when the discharge energy is less than the minimum ignition energy, using the initial atmosphere as the target power-reducing atmosphere; when the discharge energy is greater than or equal to the minimum ignition energy, repeating the control calculation process until a new discharge energy is less than the minimum ignition energy, then using the atmosphere corresponding to the new discharge energy as the target power-reducing atmosphere; the control calculation process includes: adjusting the gas composition of the atmosphere after the previous control, and calculating the atmosphere after the current control based on numerical simulation to obtain the new discharge energy; if the current control is the first control, then the atmosphere after the previous control is the initial atmosphere; The target anti-static atmosphere is applied to the powder processing process.

2. The method for eliminating static electricity in powders based on gas dielectric strength regulation according to claim 1, characterized in that, The process of adjusting the gas composition of the atmosphere after the previous adjustment and calculating the new discharge energy based on numerical simulation for the atmosphere after the current adjustment includes: A high dielectric strength gas is introduced into the atmosphere after the previous regulation to form a mixed atmosphere. By adjusting the volume fractions of the low dielectric strength and high dielectric strength gas components, the discharge process under the regulated atmosphere conditions is numerically simulated to obtain a new discharge energy.

3. The method for eliminating static electricity in powders based on gas dielectric strength regulation according to claim 2, characterized in that, The low dielectric strength gas includes argon, helium, neon, or any combination thereof; The high dielectric strength gas includes nitrogen, carbon dioxide, or any combination thereof.

4. The method for eliminating static electricity in powders based on gas dielectric strength regulation according to claim 3, characterized in that, The target de-energizing atmosphere, under the premise that the discharge energy is lower than the minimum ignition energy, shall preferentially select an atmosphere composition that can reduce the powder charge level, reduce powder agglomeration and wall adhesion.

5. The method for eliminating static electricity in powders based on gas dielectric strength regulation according to claim 1, characterized in that, Based on the powder electrostatic discharge model, the discharge process under the initial atmosphere conditions is numerically simulated, and the expression for the discharge energy is obtained as follows: ； In the formula, E d E is the discharge energy. all,t0 E represents the total electrostatic energy of the system before discharge. all,t1 This represents the total electrostatic energy of the system after discharge. The system is an electrostatic system composed of charged powder, equipment walls, and atmospheric medium within the target discharge area.

6. The method for eliminating static electricity in powders based on gas dielectric strength regulation according to claim 5, characterized in that, The formula for calculating the total electrostatic energy of the system is: ； In the formula, E is the electric field intensity, and D is the electric displacement vector. It is a volume fraction.

7. The method for eliminating static electricity in powders based on gas dielectric strength regulation according to claim 1, characterized in that, When the target electrostatic discharge control atmosphere is applied to the powder processing process, the probability of forming local high-risk electrostatic discharge areas is reduced by controlling the uniformity of gas distribution, the pressure state inside the device, and the inlet air velocity; the device is the powder processing device involved in the powder processing process.

8. The method for eliminating static electricity in powders based on gas dielectric strength regulation according to claim 7, characterized in that, The control of gas distribution uniformity, internal pressure state, and inlet gas flow rate includes: Introducing air into the device through single-point or multi-point air intake can improve the speed of atmosphere formation and uniformity of distribution. The pressure state inside the device used to control the target static elimination atmosphere is a positive pressure state; The inlet airflow rate is controlled without causing significant powder erosion, enhanced collisional charging, or a significant increase in dust concentration or the formation of a dust cloud. Significant powder erosion refers to the state in which the inlet air causes continuous churning, local voids, or a large amount of powder to be carried away from the original accumulation area on the surface of the powder bed. Enhanced collisional charging refers to the increase in the frequency of collisions and friction between particles or between particles and the wall due to excessively high inlet airflow rate, which increases the powder charge level compared to when no atmosphere is introduced or when the atmosphere is introduced at a low flow rate. The significant increase in dust concentration refers to the increase in suspended dust concentration in the device after air intake compared to the state without air intake, exceeding a preset concentration threshold; the formation of a dust cloud refers to the formation of a dust cloud by suspended dust in the device after air intake.

9. The method for eliminating static electricity in powders based on gas dielectric strength regulation according to claim 1, characterized in that, The powder processing includes conveying, fluidized bed, mixing, drying, storage and transportation, and crushing.

10. A powder electrostatic elimination system based on gas dielectric strength regulation, characterized in that, The system is used to implement the powder electrostatic elimination method based on gas dielectric strength regulation as described in any one of claims 1-9, the system comprising: The parameter acquisition and modeling module is used to acquire the minimum ignition energy of the target powder, the dielectric strength of different gases and the initial atmosphere type parameters, and to establish a powder electrostatic discharge model for the powder processing process that requires electrostatic elimination. The numerical simulation module is used to perform numerical simulations of the discharge process under different atmospheres. The discharge energy post-processing calculation module is used to post-process the results obtained from the numerical simulation module and calculate the total electrostatic energy of the system under different atmospheres. The electrostatic elimination gas assessment and control module is used to adjust the volume fraction of low dielectric strength and high dielectric strength gases and input them into the numerical simulation module. The discharge energy post-processing calculation module calculates the discharge energy under different atmospheres. Based on the discharge energy under different atmospheres and the minimum ignition energy of the target powder, the target electrostatic elimination control atmosphere for the powder treatment process that requires electrostatic elimination is determined.

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