Powder brush type discharge electrostatic sensitivity test loading electrode

Abstract

The utility model provides a powder brush type discharge electrostatic sensitivity test loading electrode. A heat conduction coupling unit comprises a metal heating plate, a heat conduction insulating rubber layer and a polytetrafluoroethylene dielectric plate which are sequentially stacked from bottom to top; the polyimide sample groove is fixed in the middle of the upper surface of the polytetrafluoroethylene dielectric plate; a discharge test chamber for placing a powder sample is arranged in the polyimide sample tank; the temperature closed-loop control unit comprises a temperature controller, a voltage adaptation module and an infrared temperature measurement probe; the voltage adaptation module is used for providing multi-gear selectable working voltage for the metal heating plate, and the infrared temperature measurement probe is used for measuring the temperature of a powder sample in the polyimide sample groove in real time; and the temperature controller is used for setting the test temperature of the powder sample and comparing the temperature of the powder sample measured by the infrared temperature measuring probe with the test temperature so as to determine whether the metal heating plate is heated or not. According to the utility model, wide-range temperature coupling and multi-voltage adaptive temperature adjustment of the powder sample can be realized.

Description

Technical Field

[0001] This utility model relates to the field of electrostatic sensitivity evaluation technology under brush discharge conditions of powder materials, and specifically to a loading electrode for testing the electrostatic sensitivity of powder brush discharge. Background Technology

[0002] Electrostatic discharge (ESD), especially brush discharge, is one of the main risk factors for combustion and explosion accidents during the production, storage, and transportation of powder materials. ESD assessment of powders is a crucial means of evaluating their safety, but existing technologies have significant limitations. Traditional ESD testing electrodes are mostly designed for room temperature environments, failing to simulate the dynamic impact of temperature changes on the ESD sensitivity of powders under actual working conditions. Mechanism studies of powder ESD show that increased temperature significantly alters the surface charge distribution of powders and affects the energy release characteristics of brush discharge. For example, powder materials such as explosives may experience a significant decrease in ESD threshold due to increased molecular activity at high temperatures. However, existing electrodes lack sufficient temperature adaptability, exhibiting problems such as low temperature control accuracy and a narrow voltage range. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a loading electrode for testing the electrostatic sensitivity of powder brush discharge in order to overcome the shortcomings of the existing technology. It adopts a wide temperature range control and multi-voltage adaptation design to facilitate the measurement of electrostatic sensitivity of powder brush discharge under different temperature conditions.

[0004] To solve the above-mentioned technical problems, the present invention includes:

[0005] A loading electrode for testing the electrostatic sensitivity of powder brush-type discharge includes:

[0006] The thermal conduction coupling unit includes a metal heating plate, a thermally conductive insulating adhesive layer and a polytetrafluoroethylene dielectric plate stacked sequentially from bottom to top;

[0007] The polyimide sample cell is fixedly positioned at the middle of the upper surface of the polytetrafluoroethylene dielectric plate; and the interior of the polyimide sample cell is a discharge test chamber for placing powder samples.

[0008] The temperature closed-loop control unit includes a temperature controller, a voltage adapter module, and an infrared temperature probe. The voltage adapter module provides a multi-level selectable operating voltage to the metal heating plate. The infrared temperature probe measures the temperature of the powder sample in the polyimide sample chamber in real time. The temperature controller sets the test temperature T of the powder sample and compares the powder sample temperature measured by the infrared temperature probe with the test temperature T to determine whether the metal heating plate should be heated.

[0009] Furthermore, the side of the metal heating plate is provided with a grounding electrode interface and two terminals. The grounding electrode interface is directly grounded through a grounding wire, and the grounding resistance value is ≤0.1Ω. One output terminal of the voltage adapter module is connected to one terminal of the relay of the temperature controller, the other terminal of the relay is connected to a terminal, and the other output terminal of the voltage adapter module is connected to another terminal.

[0010] Furthermore, the infrared temperature probe is positioned above and to the side of the polyimide sample well.

[0011] Furthermore, the voltage adapter module has an output voltage range of 24-440V, specifically configured with five standard voltage output levels: 24V, 110V, 220V, 380V, and 440V, and the switching response time between each level is ≤0.5s.

[0012] Furthermore, the polyimide sample cell is a flat cylindrical shape, and its peripheral wall is fixedly connected to the polytetrafluoroethylene medium plate by multiple polytetrafluoroethylene bolts.

[0013] Furthermore, the height of the polyimide sample well ranges from 0.05 to 1 mm.

[0014] Furthermore, the thickness of the polytetrafluoroethylene dielectric plate ranges from 0.5 to 10 mm.

[0015] Furthermore, the thermally conductive insulating adhesive layer is composed of a silicone rubber-based composite material with a thickness ranging from 0.5 to 2 mm.

[0016] The beneficial effects of this utility model are:

[0017] This invention employs a wide-range temperature coupling and multi-voltage adaptation design, which significantly improves the accuracy of powder electrostatic sensitivity testing. Through the synergistic effect of the metal heating plate and the thermally conductive insulating adhesive layer, the temperature of the powder sample can be continuously adjusted within the range of room temperature (25℃) to 350℃ to simulate the real electrostatic risks of high-temperature industrial conditions (such as chemical reactors and drying equipment). A voltage adaptation module provides the metal heating plate with multiple selectable operating voltages. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the electrode for testing the electrostatic sensitivity of powder brush-type discharge.

[0019] In the figure: 1. Polyimide sample cell, 2. Polytetrafluoroethylene dielectric plate, 3. Thermally conductive insulating adhesive layer, 4. Metal heating plate, 5. Grounding electrode interface, 6. Terminal block, 7. Infrared temperature probe, 8. Discharge ball electrode. Detailed Implementation

[0020] To facilitate understanding of this utility model, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments. Those skilled in the art should understand that the described embodiments are merely illustrative and should not be construed as limiting the scope of this utility model.

[0021] like Figure 1 As shown, this utility model provides a powder brush-type discharge electrostatic sensitivity test loading electrode, comprising:

[0022] The thermal conduction coupling unit includes a metal heating plate 4, a thermally conductive insulating adhesive layer 3, and a polytetrafluoroethylene dielectric plate 2 stacked sequentially from bottom to top;

[0023] The polyimide sample cell 1 is fixedly positioned at the middle of the upper surface of the polytetrafluoroethylene dielectric plate 2; and the interior of the polyimide sample cell 1 is a discharge test chamber for placing powder samples.

[0024] The temperature closed-loop control unit includes a temperature controller, a voltage adapter module, and an infrared temperature probe 7. The voltage adapter module provides a multi-level selectable operating voltage to the metal heating plate 4. The infrared temperature probe 7 is located above the side of the polyimide sample cell 1 and is used to measure the temperature of the powder sample in the polyimide sample cell 1 in real time. The temperature controller is used to set the test temperature T of the powder sample and compare the temperature of the powder sample measured by the infrared temperature probe 7 with the test temperature T to determine whether the metal heating plate 4 should be heated.

[0025] The metal heating plate 4 supports the entire device and is grounded. It heats the powder sample in the polyimide sample tank 1 on the polytetrafluoroethylene dielectric plate 2 to reach the set test temperature T. The middle thermally conductive and insulating adhesive layer 3 is used to bond and fix the polytetrafluoroethylene dielectric plate 2 to the metal heating plate 4, and to achieve thermal conductivity and insulation. The top polytetrafluoroethylene dielectric plate 2 cannot be metal or other conductive plates, so that brush discharge can occur when the discharge ball electrode 8 discharges after the powder sample is charged. This sandwich-type thermal conduction coupling structure can achieve both efficient heating of the powder sample and reliable insulation and brush discharge.

[0026] The metal heating plate 4 has a grounding electrode interface 5 and two terminals 6 on its side. The grounding electrode interface 5 is directly grounded through a grounding wire, and the grounding resistance value is ≤0.1Ω to effectively suppress stray current. One output terminal of the voltage adapter module is connected to one terminal of the relay of the temperature controller, and the other terminal of the relay is connected to one terminal 6. The other output terminal of the voltage adapter module is connected to another terminal 6.

[0027] The relay of the temperature controller acts as the heating switch for the metal heating plate 4. When the infrared temperature probe 7 detects that the temperature of the powder sample has not reached the test temperature T, the two terminals of the relay of the temperature controller will automatically connect. In this way, the voltage adapter module is connected to the metal heating plate 4 and provides it with working voltage, and the metal heating plate 4 is in the heating state. When the infrared temperature probe 7 detects that the temperature of the powder sample has reached the test temperature T, the relay of the temperature controller will automatically disconnect, that is, the voltage adapter module is disconnected from the metal heating plate 4, and the metal heating plate 4 stops heating.

[0028] The voltage adapter module has an output voltage range of 24-440V, specifically configured with five standard voltage output levels: 24V, 110V, 220V, 380V, and 440V, and the switching response time between each level is ≤0.5s.

[0029] The polyimide sample cell 1 is a flat cylindrical shape, and its peripheral wall is fixedly connected to the polytetrafluoroethylene medium plate 2 by multiple polytetrafluoroethylene bolts.

[0030] The height of the polyimide sample well 1 ranges from 0.05 to 1 mm. This height is positively correlated with the particle size of the powder sample being tested. The height of the polyimide sample well 1 depends on the particle size of the powder sample being tested; larger particles require a greater height, while smaller particles can require a lower height.

[0031] The thickness of the PTFE dielectric plate 2 ranges from 0.5 to 10 mm. This thickness is positively correlated with the explosive force of the powder sample being tested. The thickness of the PTFE dielectric plate 2 is determined by the explosive force of the powder sample being tested; if the explosive force of the powder sample is large, the PTFE dielectric plate 2 should be thicker, otherwise it can be thinner.

[0032] The thermally conductive insulating adhesive layer 3 is composed of a silicone rubber-based composite material, with a thickness ranging from 0.5 to 2 mm. The thickness of the thermally conductive insulating adhesive layer 3 depends on the thermal conductivity and adhesive viscosity of the insulating adhesive used, ensuring both good thermal conductivity and strong adhesion.

[0033] The operation method of the above-mentioned loading electrode for powder brush type discharge electrostatic sensitivity test includes the following steps:

[0034] S1. Fill the discharge test chamber of the polyimide sample 1 with the powder sample to be tested;

[0035] S2. Set the target test temperature T through the temperature controller and select the working voltage level of the voltage adapter module. Then, energize the metal heating plate 4 to heat the powder sample in the discharge test chamber.

[0036] S3. The temperature data of the powder sample in the discharge test chamber is collected in real time by the infrared temperature probe 7. When the temperature of the powder sample reaches the target temperature T, the temperature controller disconnects the voltage adapter module from the metal heating plate 4 and stops heating the powder sample.

[0037] In the electrostatic sensitivity test, the powder sample is heated after the electrostatic spraying process. The powder sample in the discharge test chamber is charged by electrostatic spraying using a corona spray brush connected to a high-voltage power supply; then the powder sample is heated by a metal heating plate 4 to simulate the real electrostatic risks under high-temperature industrial conditions.

[0038] Finally, brush discharge is achieved by the discharge ball electrode 8 positioned directly above the polyimide sample cell 1, while voltage and current data during the discharge process are collected using a data acquisition card connected to the discharge ball electrode 8.

[0039] The target test temperature T is: 25℃ ≤ T ≤ 350℃. During electrostatic sensitivity testing, a temperature controller is used to set the test temperature T of the powder sample, with a temperature control accuracy of ±1℃. Typically, the process begins at a lower temperature, where discharge is performed, data is collected, and sensitivity values ​​are calculated. Then, the temperature is gradually increased by a step, and the discharge, data collection, and sensitivity calculation are repeated until the desired highest temperature is reached, at which point data collection and calculation are also completed.

[0040] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A loading electrode for a powder brush discharge electrostatic sensitivity test, characterized by include: The thermal conduction coupling unit includes a metal heating plate (4), a thermally conductive insulating adhesive layer (3), and a polytetrafluoroethylene dielectric plate (2) stacked sequentially from bottom to top. The polyimide sample cell (1) is fixedly positioned at the middle of the upper surface of the polytetrafluoroethylene dielectric plate (2); and the interior of the polyimide sample cell (1) is a discharge test chamber for placing powder samples. The temperature closed-loop control unit includes a temperature controller, a voltage adapter module, and an infrared temperature probe (7); the voltage adapter module is used to provide a multi-level selectable working voltage to the metal heating plate (4); the infrared temperature probe (7) is used to measure the temperature of the powder sample in the polyimide sample tank (1) in real time; the temperature controller is used to set the test temperature T of the powder sample and compare the temperature of the powder sample measured by the infrared temperature probe (7) with the test temperature T to determine whether the metal heating plate (4) is heated.

2. The powder brush discharge electrostatic sensitivity test loading electrode according to claim 1, wherein The metal heating plate (4) is provided with a grounding electrode interface (5) and two terminals (6) on its side. The grounding electrode interface (5) is directly grounded through a grounding wire and the grounding resistance value is ≤0.1Ω. One output terminal of the voltage adapter module is connected to one terminal of the relay of the temperature controller. The other terminal of the relay is connected to one terminal (6), and the other output terminal of the voltage adapter module is connected to another terminal (6).

3. The powder brush-type discharge electrostatic sensitivity test loading electrode according to claim 1, wherein The infrared temperature probe (7) is positioned above and to the side of the polyimide sample tank (1).

4. The powder brush-type discharge electrostatic sensitivity test loading electrode according to claim 1, wherein The voltage adapter module has an output voltage range of 24-440V, specifically configured with five standard voltage output levels: 24V, 110V, 220V, 380V, and 440V, and the switching response time between each level is ≤0.5s.

5. The powder brush-type discharge electrostatic sensitivity test loading electrode according to claim 1, wherein The polyimide sample tank (1) is a flat cylindrical shape, and its peripheral wall is fixedly connected to the polytetrafluoroethylene medium plate (2) by multiple polytetrafluoroethylene bolts.

6. The powder brush-type discharge electrostatic sensitivity test loading electrode according to claim 1, wherein The height range of the polyimide sample well (1) is 0.05-1 mm.

7. The powder brush-type discharge electrostatic sensitivity test loading electrode according to claim 1, wherein The thickness of the polytetrafluoroethylene dielectric plate (2) ranges from 0.5 to 10 mm.

8. The loading electrode for powder brush-type discharge electrostatic sensitivity testing according to claim 1, characterized in that, The thermally conductive insulating adhesive layer (3) is composed of a silicone rubber-based composite material with a thickness ranging from 0.5 to 2 mm.

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