Electrostatic filter device

Abstract

The utility model relates to a kind of electrostatic filtration devices.Electrostatic filtration device includes multiple positive electrode plate and multiple negative electrode plate.At least one pair of adjacent first electrode plate exists in multiple positive electrode plate and multiple negative electrode plate, and first electrode plate is insulating electrode plate or high resistance electrode plate, multiple positive electrode plate and multiple negative electrode plate are connected using different support components respectively, and the initial working voltage of electrostatic filtration device is greater than or equal to 2.0kV / mm, to improve initial working efficiency.Electrostatic filtration device further includes first high-voltage power supply, and first high-voltage power supply includes first resistance connected in series at output, and working voltage is first voltage value when working current is first current value, and first voltage value represents the working voltage compatible with the air withstand voltage value between electrodes when pollution degree is high and / or environmental humidity is large.Thus, while ensuring initial working efficiency, the hidden danger of long-term operation discharge sparking of equipment caused by constant high voltage work can be avoided.

Description

Technical Field

[0001] This utility model relates to the field of electrostatic dust removal technology, and in particular to an electrostatic filtration device. Background Technology

[0002] Electrostatic filters have been widely used and developed due to their advantages such as low air resistance and the ability to be repeatedly cleaned and reused.

[0003] An electrostatic filter consists of alternating parallel arrangement of discharge plates and collection plates to create a strong electrostatic field, thus achieving its filtration function. The plates are the core components of an electrostatic filter, and their material and structure determine the filter's purification capacity, cost, lifespan, byproducts, reliability, and safety.

[0004] Air has a pressure withstand limit, which varies with air humidity and is also related to the flatness and surface finish of the electrostatic filter plates. The pressure withstand value of air is generally considered to be 3 kV / mm. When the voltage between the electrodes exceeds this withstand value, the air will break down. In designing electrostatic filters, conductive materials are typically used as electrode plates. However, due to environmental changes, manufacturing processes, and dust adsorption, the voltage that can usually be applied between the plates is only half the air's withstand pressure, meaning it can be less than 1.5 kV / mm.

[0005] Filters using conductive electrode plates encased in insulating material (hereinafter referred to as "high-field solutions") are one of the mainstream electrostatic filter solutions currently available. Because the conductive electrodes are encased in insulating material and not exposed to air, air breakdown can be prevented even when a voltage higher than the air's withstand voltage is applied. Filters where the voltage applied to the air is higher than the air's withstand voltage can be called high-field electrostatic filters. Since the voltage applied to the air is positively correlated with purification efficiency—the higher the voltage, the higher the purification efficiency—high-field electrostatic filters have higher purification efficiency and smaller size. Furthermore, due to the insulating material encapsulation, high-field electrostatic filters have extremely low operating current and do not produce ozone, exhibiting excellent performance characteristics. Long-term high-field solutions, based on the high-field solution, expose the conductive material inside the positive and negative electrodes, ensuring the exposed parts are not aligned, thus maintaining the filter's long-term operating efficiency.

[0006] Using electrodes with high surface resistivity (≥1E6Ω / sq) can also improve the air pressure resistance of electrostatic filters to a certain extent, allowing the initial operating voltage of the filter to reach 2kV / mm or higher.

[0007] Conventional filters are powered directly to a state where they can operate reliably under worst-case conditions. If the initial operating voltage of an electrostatic filter is increased, and the electrodes are contaminated, the air withstand voltage decreases due to the breakdown of the high resistance or insulation properties of the high-resistivity / insulating material surface. If the initial high voltage is still used for driving under these conditions, the current will increase significantly, resulting in discharge and arcing, which in severe cases can even cause a fire.

[0008] Taking a long-lasting, high-electric-field solution as an example, assuming a filter spacing of 1.5mm and an initial operating voltage of 6kV, if the operating voltage remains at 6kV after the filter becomes contaminated, violent discharge and arcing will occur. Therefore, the product's operating voltage cannot be set too high, as this will affect the filter's initial purification efficiency and its efficiency in long-term operation under low humidity conditions.

[0009] If the power supply's load capacity is reduced, the voltage will decrease as the operating current increases. However, due to the leakage current between the electrodes, the output voltage will drop to a very low level after a period of operation, causing the electrostatic filter to fail.

[0010] Meanwhile, the air withstand pressure between the electrodes of electrostatic filters (including strong electric field schemes and high surface resistivity schemes) does not decrease monotonically. The air withstand pressure between the electrodes is strongly correlated with relative humidity. High relative humidity results in low air withstand pressure and increased leakage current between the electrodes. Low relative humidity results in high air withstand pressure and decreased leakage current between the electrodes. Furthermore, it is not possible to simply track the impact of environmental changes on the air withstand pressure between the electrodes using timers or similar methods.

[0011] Therefore, how to balance the initial high efficiency and long-term safe operation of electrostatic filters is a problem that needs to be solved. Summary of the Invention

[0012] One objective of this invention is to design an electrostatic filtration device that can balance the initial high efficiency of an electrostatic filter with long-term safe operation.

[0013] According to a first aspect of this utility model, an electrostatic filtration device is provided, comprising: a plurality of positive electrode plates and a plurality of negative electrode plates, wherein the plurality of positive electrode plates and the plurality of negative electrode plates are arranged alternately at equal intervals, the positive electrode plates are connected to the positive terminal of a high-voltage power supply, and the negative electrode plates are connected to the negative terminal of a high-voltage power supply. At least one pair of adjacent first electrode plates exists among the plurality of positive and negative electrode plates. The first electrode plate is an insulating electrode plate or a high-resistivity electrode plate. The insulating electrode plate is composed of an insulating material encasing a conductive material, and the conductive material inside the insulating electrode plate is connected to the high-voltage power supply. The surface resistivity of the high-resistivity electrode plate is greater than or equal to 1E6Ω / sq. If the first electrode plate is an insulating electrode plate, then the insulating electrode plate has exposed conductive material, and the exposed conductive material on two adjacent insulating electrode plates... The multiple positive electrode plates and the multiple negative electrode plates are connected using different support components. The initial operating voltage of the electrostatic filtration device is greater than or equal to 2.0 kV / mm to improve the initial operating efficiency. Here, the unit "kV / mm" refers to the operating voltage per millimeter of electrode spacing. The electrostatic filtration device also includes a first high-voltage power supply. The first high-voltage power supply includes a first resistor connected in series at the output terminal. The positive electrode plate in at least one pair of adjacent first electrode plates is connected to the positive terminal of the first high-voltage power supply, and the negative electrode plate in at least one pair of adjacent first electrode plates is connected to the negative terminal of the first high-voltage power supply. The operating voltage when the operating current is a first current value is a first voltage value. The first voltage value is used to characterize the operating voltage that is compatible with the inter-electrode air resistance value when the pollution level is high and / or the ambient humidity is high.

[0014] Optionally, the first voltage value is 1.5kV / mm. If the electrostatic filter is used to filter indoor air, the first current value is between 20μA and 200μA. Or if the electrostatic filter is used to filter outdoor air, the first current value is between 100μA and 500μA.

[0015] Optionally, the operating voltage of the first high-voltage power supply when the electrostatic filter device is initially working is the second voltage value. If the first electrode plate is the insulating electrode plate, the second voltage value is greater than or equal to 3kV / mm, or if the first electrode plate is the high-resistance electrode plate, the second voltage value is between 2kV / mm and 2.5kV / mm.

[0016] Optionally, the resistance of the first resistor is greater than or equal to 0.5MΩ.

[0017] Optionally,

[0018] Where R is the resistance value of the first resistor, V1′ is the output voltage of the first high-voltage power supply when the first resistor is not connected in series at the output terminal or when the first resistor is short-circuited, and V1 is the first voltage value, and I is the first current value.

[0019] Optionally, the first electrode plate is an insulating electrode plate, and the electrostatic filtration device is used to filter indoor air, with the resistance value of the first resistor ranging from 1.5D to 125D (MΩ); or the first electrode plate is a high-resistance electrode plate, and the electrostatic filtration device is used to filter indoor air, with the resistance value of the first resistor ranging from 1.5D to 50D (MΩ); or the first electrode plate is an insulating electrode plate, and the electrostatic filtration device is used to filter outdoor air, with the resistance value of the first resistor ranging from 0.6D to 25D (MΩ); or the first electrode plate is a high-resistance electrode plate, and the electrostatic filtration device is used to filter outdoor air, with the resistance value of the first resistor ranging from 0.6D to 10D (MΩ), where D represents the electrode spacing, and the unit of D is mm.

[0020] Optionally, the positive terminal of the first high-voltage power supply is connected in series with the first resistor.

[0021] Optionally, all positive electrode plates and all negative electrode plates are the first electrode plates, and each positive electrode plate is connected in series with a second resistor; and / or each negative electrode plate is connected in series with a third resistor; and / or the output terminal of the first high-voltage power supply is connected in series with a fourth resistor, wherein the sum of the parallel value of the second resistors connected in series with all positive electrode plates, the parallel value of the third resistors connected in series with all negative electrode plates, and the resistance value of the fourth resistor is equal to the resistance value of the first resistor.

[0022] Optionally, the exposed conductive materials on two adjacent insulating electrode plates are at a distance greater than or equal to the electrode plate spacing in the direction perpendicular to the electrode plate spacing, so as to achieve non-alignment; or exposed conductive materials are provided on the electrode plate surfaces on the same side of two adjacent insulating electrode plates, such that an insulating material is spaced between the exposed conductive materials on the two adjacent insulating electrode plates to achieve non-alignment.

[0023] Optionally, the actual voltage value of the operating voltage and / or the actual resistance value of the resistor have a deviation of ±10% from the corresponding calculated value.

[0024] The electrostatic filtration device of this invention is an electrostatic filter that maintains long-term operating efficiency by employing an insulation scheme or a high-resistance scheme. A necessary prerequisite is that the leakage current after contamination between the electrodes is controlled to a relatively low level through electrode-splitting support. Based on this, this invention sets the initial operating voltage to be greater than or equal to 2.0 kV / mm to improve initial operating efficiency. Simultaneously, by connecting a first resistor in series at the output terminal of the first high-voltage power supply, the operating voltage under extreme environments can adaptively adjust to match the air withstand voltage between the electrodes based on its own volt-ampere characteristics, thus avoiding the potential for discharge and arcing during long-term operation due to constant high voltage. Attached Figure Description

[0025] The above and other objects, features and advantages of the present invention will become more apparent from the accompanying drawings, in which like reference numerals generally represent like parts.

[0026] Figure 1 A schematic diagram of an electrostatic filtration device according to an embodiment of the present invention is shown.

[0027] Figure 2A A side cross-sectional view of the insulating electrode plate is shown.

[0028] Figure 2B A top cross-sectional view of the insulating electrode plate is shown.

[0029] Figure 2C A schematic diagram showing the connection between the insulating electrode plate and the power supply is shown.

[0030] Figure 3 A top cross-sectional view of two adjacent insulating electrode plates according to an embodiment of the present invention is shown.

[0031] Figure 4 A top cross-sectional view of two adjacent insulating electrode plates according to another embodiment of the present invention is shown.

[0032] Figure 5A A schematic diagram of the structure of one of the electrode surfaces in an insulating electrode plate is shown.

[0033] Figure 5B A schematic diagram of the structure of another electrode surface in an insulating electrode plate is shown.

[0034] Figure 6 A top cross-sectional view of two adjacent insulating electrode plates according to another embodiment of the present invention is shown. Detailed Implementation

[0035] Preferred embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

[0036] A complete electrostatic filter requires two parts: a charging device and a filtering device. The function of the charging device is to charge fine particulate matter in the air, making it electrically charged. The filtering device uses an electrostatic field to adsorb charged particles, achieving the effect of air purification. This utility model only relates to the improvement of the filtering device, not the improvement of the charging device. Therefore, this utility model does not describe the charging device, but focuses on describing the filtering device (i.e., the electrostatic filtering device). It should be understood that the electrostatic filtering device described in this utility model can be used in conjunction with the charging device to form a complete electrostatic filter. Or, the electrostatic filtering device described in this utility model can also include the charging device to form a complete electrostatic filter. In addition, some test cases mentioned in the text are assumed to be results of tests conducted in conjunction with the charging device. The terms "electrode" and "electrode plate" in the text can be used interchangeably.

[0037] Figure 1 A schematic diagram of an electrostatic filtration device according to an embodiment of the present invention is shown.

[0038] See Figure 1 The electrostatic filtration device includes multiple positive electrode plates 20 and multiple negative electrode plates 10. The positive electrode plates 20 and the negative electrode plates 10 are arranged alternately at equal intervals. That is, any two adjacent electrode plates have different polarities, and the distance between any two adjacent electrode plates (this distance can be called the plate spacing or electrode spacing) is equal. The positive electrode plates 20 are connected to the positive terminal of the high-voltage power supply, and the negative electrode plates 10 are connected to the negative terminal of the high-voltage power supply. For example... Figure 1 As shown, the electrode plate can be connected to a high-voltage power supply on one side via a conductive rod 40.

[0039] At least one pair of adjacent first electrode plates exists among the plurality of positive electrode plates 20 and the plurality of negative electrode plates 10. The first electrode plate is an insulating electrode plate or a high-resistivity electrode plate. For example, all the positive electrode plates 20 and all the negative electrode plates 10 in the electrostatic filtration device are first electrode plates.

[0040] When the first electrode plate is an insulating electrode plate, the electrostatic filtration device can also be called a long-lasting high-electric-field electrostatic filter, or simply an insulating solution. The insulating electrode plate is composed of an insulating material wrapping a conductive material. The insulating material can be, but is not limited to, PP (Polypropylene), PET (Polyethylene Terephthalate), ABS (Acrylonitrile Butadiene Styrene), PC (Polycarbonate), etc.

[0041] Figure 2A A side cross-sectional view of the insulating electrode plate is shown; Figure 2B A top cross-sectional view of the insulating electrode plate is shown.

[0042] like Figure 2A , Figure 2B As shown, the insulating electrode plate consists of two layers, an inner and an outer layer. The inner layer is a conductive layer 110 made of conductive material, and the outer layer is an insulating layer 120 made of insulating material.

[0043] Figure 2C A schematic diagram showing the connection between the insulating electrode plate and the power supply is shown.

[0044] like Figure 2C As shown, the conductive layer 110 extends a section of conductive material in at least one direction for connecting to a power source.

[0045] If the first electrode plate is an insulating electrode plate, then there is still exposed conductive material in the effective ventilation area of ​​the insulating electrode plate (not shown in the figure), and the exposed conductive material in the effective ventilation area on two adjacent insulating electrode plates is not aligned.

[0046] The effective ventilation area, also known as the effective working area, refers to the region between two adjacent electrode plates through which unpurified gas can flow. The exposed conductive material is connected to the conductive layer inside the insulating electrode plate. By placing exposed conductive material within the effective working area, conductive contaminants on the electrode plate surface can be connected to the power source through the exposed conductive material, thus enabling the electrostatic precipitator to operate efficiently over the long term. Simultaneously, due to the high voltage applied to the conductive material of adjacent insulating electrode plates, normal operation is only possible when protected by insulation. Therefore, when both adjacent insulating electrode plates have exposed conductive material, setting the exposed conductive material on the two adjacent insulating electrode plates to be non-aligned can prevent direct discharge and arcing.

[0047] The exposed conductive material can be misaligned in the following two ways.

[0048] The first method involves arranging the exposed conductive material on two adjacent insulating electrode plates such that the distance between them in the direction perpendicular to the electrode spacing is greater than or equal to the electrode spacing, thus achieving non-alignment. In other words, the exposed conductive material on two adjacent insulating electrode plates is not aligned in the direction perpendicular to the electrode spacing (e.g., the length direction of the electrodes).

[0049] Each electrode plate includes two surfaces, two sides, a connecting surface, and a facing surface. The distance between the two adjacent surfaces (i.e., the electrode plate surfaces) of two adjacent electrode plates is called the electrode plate spacing. The connecting surface is the surface where the electrode plate connects to the high-voltage power supply, and the facing surface is the surface parallel to the connecting surface. For example, the electrode plate on... Figure 1 The dimension along the x-axis can be called the electrode length. Figure 1 The dimension along the y-axis can be called the electrode thickness. Figure 1 The dimension along the z-axis can be called the electrode width. The surface where the electrode plate connects to the high-voltage power supply (i.e., the connection surface) can be a surface composed of the width and thickness of the electrode plate. The side surface refers to the surface composed of the length and thickness of the electrode plate. The electrode surface refers to the surface composed of the length and width of the electrode plate.

[0050] Figure 3 A top cross-sectional view of two adjacent insulating electrode plates according to an embodiment of the present invention is shown.

[0051] See Figure 3 A row of exposed conductive material 330 can be drawn from different sides of two adjacent insulating electrode plates (e.g., sides located within the effective working area). The number of exposed conductive material 330 drawn can be set as needed, with a minimum number of 1. Figure 3 In this case, the distance between the exposed conductive material 330 of two adjacent insulating electrode plates is equal to the width of the electrode plates. That is, Figure 3 It utilizes the width of the electrode plates to ensure sufficient offset between the exposed conductive materials on two adjacent insulating electrode plates.

[0052] Figure 4 A top cross-sectional view of two adjacent insulating electrode plates according to another embodiment of the present invention is shown.

[0053] See Figure 4At least one segment of exposed conductive material can be derived from the same side of two adjacent insulating electrode plates. For example, one or more segments of exposed conductive material can be derived from both sides of each of the two adjacent insulating electrode plates. Furthermore, the exposed conductive materials derived from the same side of two adjacent insulating electrode plates can be staggered by a certain distance along the length of the electrode plates to satisfy the non-alignment condition. That is, the distance along the length of the electrode plates between the exposed conductive materials derived from the same side of two adjacent insulating electrode plates is greater than or equal to the minimum electrode spacing. For the exposed conductive materials derived from different sides of two adjacent insulating electrode plates, the non-alignment condition can be naturally satisfied by utilizing the width of the electrode plates.

[0054] It should be noted that, Figure 3 , Figure 4 It is only used to illustrate how to place exposed conductive material on two adjacent electrode plates. Figure 3 , Figure 4 This is not intended to represent the actual arrangement of two adjacent electrode plates. For the actual arrangement of the electrode plates, please refer to [link / reference needed]. Figure 1 As shown.

[0055] The second method refers to the fact that two adjacent insulating electrode plates can have exposed conductive material on the surface of the plates on the same side, so that the exposed conductive material on the two adjacent insulating electrode plates is separated by an insulating material to achieve non-alignment.

[0056] Figure 5A A schematic diagram of the structure of one of the electrode surfaces in an insulating electrode plate is shown.

[0057] Figure 5B A schematic diagram of the structure of another electrode surface in an insulating electrode plate is shown.

[0058] Can Figure 5A The surface of the electrode shown is called the front side, and... Figure 5B The surface of the electrode shown is called the reverse side.

[0059] See Figure 5A , Figure 5B The insulating electrode plate has a groove 350 on only one of its electrode surfaces. The groove 350 can be understood as removing the outer insulating material to form a recess, thereby exposing the conductive material inside the insulating electrode plate 1 at the groove 350. It should be understood that although the term "groove" is used here, this does not mean that a groove must exist. For example, replacing part of the insulating material on the electrode surface with exposed conductive material (or the high-resistivity material described below) can also be considered a grooved structure; in this case, the entire electrode plate surface is flat, and there is actually no groove.

[0060] Both adjacent insulating electrode plates can be used Figure 5A , Figure 5B The structure is shown. Furthermore, the two adjacent insulating electrode plates, after assembly, have exposed conductive material on their same side surface. For example, each electrode plate includes two electrode plate surfaces; the left side surface can be defined as the front, and the right side surface as the back.

[0061] Assuming the first and second insulating electrode plates are adjacent, if the first insulating electrode plate has a slot 350 on its front side, then the second insulating electrode plate should also have a slot 350 on its front side. Since the first and second insulating electrode plates have slots on the same side of their electrode surfaces, and the other side of the electrode surfaces of the first and second insulating electrode plates is made of insulating material (without slots), the exposed conductive material on the electrode surfaces of the first and second insulating electrode plates will be blocked by the insulating material on the other side of one insulating electrode plate. This can be considered as a misalignment at another angle, and it also avoids the risk of discharge arcing that would occur if they were directly aligned.

[0062] Figure 6 A top cross-sectional view of two adjacent insulating electrode plates according to another embodiment of the present invention is shown.

[0063] See Figure 6 An insulating electrode plate can expose a row of exposed conductive material 330 on each of its two sides. An adjacent insulating electrode plate can have several through holes 360 in its center to expose the internal conductive material.

[0064] When the first electrode plate is a high-resistivity electrode plate, the electrostatic filtration device can also be called a high-resistivity electrostatic filter, or simply a high-resistivity solution. The surface resistivity of the high-resistivity electrode plate is greater than or equal to 1E6 Ω / sq. Here, 1E6 refers to 10 to the power of 6, and Ω / sq refers to ohms per square meter.

[0065] In some embodiments, a conductive electrode plate and a first electrode plate may coexist in the electrostatic filtration device. The electrode surface of the conductive electrode plate is made of a conductive material.

[0066] In some embodiments, all electrode plates in the electrostatic filtration device are insulated electrode plates.

[0067] In some embodiments, all electrode plates in the electrostatic filtration device are high-resistance electrode plates.

[0068] In some embodiments, an insulating electrode plate and a high-resistance electrode plate may coexist in the electrostatic filtration device.

[0069] From a usage perspective, electrostatic filtration devices can be divided into indoor and outdoor products. Indoor products refer to electrostatic filtration devices whose input air source is indoors, and are used to filter indoor air. Outdoor products refer to electrostatic filtration devices whose input air source is outdoors, or partially outdoors, and are used to filter outdoor air.

[0070] Electrostatic filtration devices employing either insulation or high-resistance solutions operate in two different states during initial use and after prolonged contamination. The operating voltage of an electrostatic filtration device is related to the electrode spacing. To accommodate designs with varying electrode spacings, the following descriptions are based on the operating voltage per millimeter of electrode spacing. That is, the unit of operating voltage is kV / mm.

[0071] During initial operation, the electrostatic filter can be considered a clean filter, and the air withstand pressure between the electrodes is determined by the electrode materials themselves. Because the electrode surfaces are made of insulating or high-resistivity materials, the air withstand pressure between the electrodes is relatively high, allowing the electrostatic filter to operate at a higher voltage and a relatively lower operating current initially.

[0072] Specifically, when the electrostatic filtration device employs an insulation scheme, the initial operating voltage between the electrodes can be stabilized at, for example, 3kV / mm. This initial operating voltage is largely unaffected by materials and the environment; as long as the material has sufficient withstand voltage, the initial operating voltage between the electrodes remains relatively stable. When the electrostatic filtration device employs a high-resistivity scheme, the initial operating voltage between the electrodes can be stabilized at, for example, ≥2kV / mm. This initial operating voltage is affected by the resistivity of the material itself and the ambient humidity. The higher the material resistivity, the higher the initial operating voltage. The lower the relative humidity of the environment, the higher the initial operating voltage.

[0073] After a period of operation, an electrostatic filter can be considered a dirty filter. At this point, the electrodes become conductors composed of both the electrode material itself and the contaminants. Because the contaminants typically contain a certain proportion of carbon, their resistivity is relatively low. Especially at high relative humidity (e.g., above 60%), the surface resistivity of the contaminants will be less than 1E6Ω / sq, therefore, the resistivity of the contaminants usually dominates on the contaminated electrodes. Simultaneously, since the contaminants adsorbed on the electrodes are a stack of many fine particles, the surface of the contaminants is rough and granular. Compared to a smooth electrode surface, this rough surface is more prone to discharge, thus further reducing the air pressure resistance between the electrodes.

[0074] When the resistivity of the electrodes in an electrostatic filter gradually decreases due to contamination, and rough particles appear on the electrode surface, the withstand voltage that the air between the electrodes can withstand decreases. If the electrostatic filter is still powered by the same voltage at this time, air breakdown discharge will occur.

[0075] In this invention, D represents the electrode spacing, with the unit being mm (millimeters). The table below lists the initial ignition voltage under different humidity conditions when D = 1.5 mm and the electrostatic filter is contaminated. It should be noted that the table below is only an example, and the initial ignition voltage will vary under different contamination conditions.

[0076] 30% humidity 4 60% humidity 3.3 80% humidity 3.0

[0077] Therefore, the power supply for the electrostatic filtration device needs to be able to automatically adjust the operating voltage according to the actual working state of the electrostatic filtration device, so as to avoid the risk of arcing caused by the operating voltage exceeding the air withstand pressure value between the electrodes.

[0078] Meanwhile, the resistivity of contaminants on the electrode surface is not constant. It changes with ambient humidity. At high humidity, the contaminant resistivity is low, and the air pressure resistance between the electrodes decreases. In this case, the power supply needs to be adjusted to lower the operating voltage, and the efficiency of the electrostatic filtration device will correspondingly decrease. At low humidity, the contaminant resistivity is high, and the air pressure resistance between the electrodes increases. In this case, the voltage needs to be adjusted to increase, allowing the electrostatic filtration device to operate at high performance.

[0079] Through extensive practical testing, the inventors of this invention summarized the pressure resistance of filters employing insulation (i.e., electrostatic filtration devices) and filters employing high-resistance solutions under different operating conditions. The test results are shown in the table below.

[0080]

[0081] Based on the test results shown in the table above, it can be roughly understood that for electrostatic filter devices with insulating or high-resistance electrode surfaces, the power supply for them needs to meet two conditions: First, the initial operating voltage of the electrostatic filter device should be high enough, such as at least greater than or equal to 2.0kV / mm, to improve the initial operating efficiency; Second, when the environmental conditions are harsh after long-term operation of the electrostatic filter device (such as high pollution levels and / or high ambient humidity), the operating voltage should be adapted to the environment so as not to exceed the air withstand pressure value between the electrodes.

[0082] The first condition can be met by setting the initial operating voltage of the electrostatic filter. For example, the initial operating voltage can be set to greater than or equal to 2.0 kV / mm to improve initial operating efficiency. For insulation schemes, the initial operating voltage can be set relatively higher, for example, greater than or equal to 3 kV / mm; for high-resistance schemes, the initial operating voltage can be set relatively lower, for example, between 2 kV / mm and 2.5 kV / mm. From an engineering perspective, the actual operating voltage of the insulation scheme should be ≤12 kV.

[0083] Regarding the second condition, this utility model proposes to connect a resistor in series with the high-voltage power supply that powers the electrostatic filtration device (more specifically, the first electrode plate in the electrostatic filtration device) to configure the volt-ampere characteristics of the high-voltage power supply so that the configured volt-ampere characteristics (i.e., the relationship between the configured operating current and operating voltage) are compatible with the harsh environment (such as high pollution and / or high humidity) after the electrostatic filtration device has been in operation for a long time.

[0084] It should be understood that high-voltage power supplies inherently possess certain volt-ampere characteristics. This invention aims to adjust the volt-ampere characteristics of the high-voltage power supply by connecting a resistor (i.e., the first resistor mentioned below) in series at the output terminal, making it suitable for the harsh environment after long-term operation of the electrostatic filtration device. In other words, the series-connected resistor is used to adjust the volt-ampere characteristics of the high-voltage power supply itself to adapt to the harsh environment after long-term operation of the electrostatic filtration device.

[0085] Furthermore, the operating state of an electrostatic filter is not solely determined by the withstand voltage between the electrodes; the operating current also plays a crucial role. For electrostatic filters with contaminated surfaces, a larger operating current can result in a higher operating voltage and improved filtration efficiency. For example, for an electrostatic filter employing a high-resistance design, the relationship between operating current and efficiency at different voltages in an initially clean state can be summarized as follows: the higher the voltage, the greater the operating current, and consequently, the higher the filtration efficiency.

[0086] 4.0 167 90.3％ 3.75 (2.5 / mm) 124 90.2％ 3.3 (2.2 / mm) 70 88.7％ 3.2 28 84.6％ 3.1 14 83.3％ 3.0 (2.0 / mm) 10 80.0％ 2.9 6 77.0％ 2.7 (1.8 / mm) 2 75.5％

[0087] The above table shows the operating current and filtration efficiency of the high-resistivity (D) scheme with a diameter of 1.5 mm at different operating voltages. It can be seen that below 2.5 kV / mm, increasing the operating voltage increases the operating current and significantly improves the filtration efficiency. When the operating voltage is increased above 2.5 kV / mm, increasing the operating voltage significantly increases the current, but the improvement in filtration efficiency is extremely limited.

[0088] As shown in the table above, the normal operating current of an electrostatic filter is approximately a few microamps to tens of microamps. Of course, this depends on the size of the electrostatic filter and the application scenario. When used indoors, the operating current of the electrostatic filter needs to be kept lower to ensure greater safety. When used outdoors, due to the higher level of pollution, the operating current of the electrostatic filter can be more relaxed (i.e., higher). For example, when used indoors, the operating current of an electrostatic filter should ideally be less than or equal to 20 μA; when used indoors, the operating current should ideally be less than or equal to 200 μA.

[0089] Another factor affecting the operating current needs to be considered: the leakage current between the positive and negative electrodes during long-term operation of the filter. This varies greatly depending on the environment. Indoor electrostatic filters typically have low leakage currents, in the tens of microamps range. Outdoor filters, on the other hand, may have leakage currents reaching hundreds of microamps, or even milliamps.

[0090] As shown in the table above, the typical operating current is only in the hundreds of microamps range, therefore, excessive leakage current between the electrodes cannot be tolerated. This is because excessive leakage current between the electrodes makes it impossible to distinguish between the power supply output current and the leakage current, thus making it impossible to accurately configure the volt-ampere characteristics of the high-voltage power supply by connecting a series resistor.

[0091] Therefore, leakage current between electrodes must be limited. Specific limiting methods can include two aspects: firstly, by using positive and negative electrode separation support to prevent the power supply from short-circuiting through the support structure; secondly, by using pre-coating to prevent foreign objects such as lint and large particles from entering.

[0092] Separate positive and negative electrode support means that the positive and negative electrode plates in an electrostatic filter are connected using different support components. That is, the support components connecting the individual positive electrode plates are different from the support components connecting the individual negative electrode plates. See also... Figure 1 , Figure 1 The blue line 210 in the diagram represents a support component used to connect an electrode plate of one polarity (such as all positive electrode plates 20). Figure 1 The red line 220 indicates a support component used to connect electrode plates of another polarity (such as all negative electrode plates 10). This polarity-separated support method is called a polarity-separated support method. Figure 1 As shown, multiple groove-shaped support structures 320 can be provided on the electrode plate to fix the polarity of the electrode plate to be connected to its different support components. Figure 1 As shown, multiple grooved support structure clearance positions 310 can also be provided on the electrode plate to avoid the polarity of the electrode plate to be connected from the support component with a different polarity. The groove depth of the support structure clearance position 310 is greater than that of the support structure fixing position 320. Exposed conductive material 330 can be provided near the support structure fixing position 320.

[0093] By using a positive and negative electrode separation support method, short circuits through the support structure can be prevented. With this method, direct short circuits caused by contamination of the support structure can be fundamentally avoided. However, direct short circuits between electrodes caused by lint and particulate matter deposits are unavoidable and can only be minimized. Strengthening the pre-filter can significantly reduce direct short circuits between electrodes. Furthermore, direct short circuits caused by lint usually result in relatively small short-circuit currents. Therefore, leakage current can be reduced to a sufficiently low level by controlling leakage current or regularly cleaning the filter. This improves the accuracy of configuring the volt-ampere characteristics of the high-voltage power supply by adding a series resistor.

[0094] In summary, the electrostatic filtration device of this invention is an electrostatic filter that can maintain long-term working efficiency by adopting an insulation scheme or a high-resistance scheme; furthermore, a necessary prerequisite for configuring the volt-ampere characteristics of the high-voltage power supply by connecting a series resistor to the high-voltage power supply is that the leakage current between the electrodes is limited to a relatively low level by using a polarity support.

[0095] The following data demonstrates the gradual contamination process of a new electrostatic filter. Data is provided for both the insulation and high-resistance schemes, operating indoors and outdoors respectively. The electrostatic filter dimensions are 600*300*50mm, with D=1.5mm. The measured data are as follows.

[0096]

[0097]

[0098] The data above shows a significant difference in the initial operating states of the insulation scheme and the high-resistance scheme. Initially, the air withstand voltage between the electrodes in the insulation scheme is higher than that in the high-resistance scheme. Therefore, the insulation scheme can operate at a higher voltage. In other words, the high-resistance scheme can be understood as an insulation scheme operating under conditions of shallow contamination.

[0099] After long-term operation, the overall working conditions of the two solutions are similar. As contaminants accumulate, the insulation or high-resistance properties of the electrode surface will gradually be damaged, and the products will enter a working state dominated by contaminants on the electrode surface.

[0100] As pollutants gradually increase, the air withstand voltage between the electrodes gradually decreases, and the leakage current between the electrodes gradually increases. Since the power supply cannot distinguish between the operating current and the leakage current of the device, the power supply design no longer differentiates between these two types of current; it only considers the comprehensive output current, which is the sum of all currents. That is, the operating current mentioned in this invention can refer to the comprehensive output current, including the air leakage current between the electrodes and the leakage current between the electrodes through the support structure.

[0101] The following provides further illustrative examples of the details involved in this utility model.

[0102] In some embodiments, the electrostatic filtration device further includes a first high-voltage power supply. The first high-voltage power supply is used to power at least one pair of adjacent first electrode plates. That is, the positive electrode plate of at least one pair of adjacent first electrode plates is connected to the positive terminal of the first high-voltage power supply, and the negative electrode plate of at least one pair of adjacent first electrode plates is connected to the negative terminal of the first high-voltage power supply.

[0103] It should be understood that in an electrostatic filtration device where both conductive electrode plates with conductive surface materials and first electrode plates with insulating or high-resistivity surface materials exist, the high-voltage power supply powering the conductive electrode plates and the high-voltage power supply powering the first electrode plates can be different high-voltage power supplies. This invention aims to configure the volt-ampere characteristics of the first high-voltage power supply powering the first electrode plates. Furthermore, the operating voltage mentioned in this invention refers to the voltage between two adjacent first electrode plates. The operating current mentioned in this invention refers to the total output current of the high-voltage power supply powering the first electrode plates (including air leakage current between the first electrode plates and leakage current between the first electrode plates through the support structure).

[0104] The first high-voltage power supply includes a first resistor connected in series at the output terminal. Based on the first resistor, the volt-ampere characteristic of the first high-voltage power supply is configured such that the operating voltage gradually decreases from an initial operating voltage to a first voltage value as the operating current increases. The first voltage value is used to characterize the operating voltage adapted to the inter-electrode air withstand voltage under conditions of high pollution levels and / or high ambient humidity. The first voltage value can be considered as the operating voltage of the electrostatic filtration device under extremely harsh environments (such as high pollution and high humidity). The first voltage value can be close to but not exceed the inter-electrode air withstand voltage of the electrostatic filtration device under extremely harsh environments. For example, the first voltage value is 1.5 kV / mm. The operating current corresponding to the first voltage value is the first current value.

[0105] On the one hand, the first resistor can be used to adjust the volt-ampere characteristics of the first high-voltage power supply, so that the operating voltage is the first voltage value when the operating current is the first current value. The first current value can be regarded as the operating current of the electrostatic filter device in extremely harsh environments, that is, the operating current when the operating voltage is the first voltage value. On the other hand, the first high-voltage power supply usually contains energy storage components such as capacitors and inductors. Therefore, the instantaneous current output by the first high-voltage power supply will be very high. By connecting the first resistor in series at the output terminal of the first high-voltage power supply, high-intensity discharge caused by power supply short circuit can also be prevented.

[0106] For example, the resistance of the first resistor is greater than or equal to 0.5MΩ.

[0107] When selecting the first high-voltage power supply, the power requirement must be met first. That is, the output current of the electrostatic filter device should meet the design requirements under the worst operating conditions (i.e., the operating voltage equals the first voltage value V1). To allow for a margin when connecting the first resistor in series at the output terminal of the first high-voltage power supply, it should also be ensured that V1′ is sufficiently large compared to V1. V1′ is the output voltage of the first high-voltage power supply when the first resistor is not connected in series at the output terminal, or when the first resistor is short-circuited, and the operating current is the first current value I. For example, V1′ ≥ 1.2 × V1, to ensure that a first resistor greater than or equal to 0.5MΩ can be connected in series, so that the operating voltage of the first high-voltage power supply at the first current value I is V1.

[0108] The formula for calculating the resistance R of the first resistor can be expressed as follows: In this calculation, without considering the voltage drop of the first high-voltage power supply itself (i.e., assuming the first high-voltage power supply is an ideal power supply and its output voltage does not decrease with the increase of operating current), V1′ = V0. V0 represents the initial operating voltage, that is, the operating voltage of the first high-voltage power supply when the electrostatic filter device initially operates. Therefore, V1′ in the above calculation formula can be replaced with V0, and the resistance value R of the first resistor can be calculated accordingly. It should be noted that if the first high-voltage power supply has a voltage drop when operating at I, the resistance value R of the first resistor can be appropriately reduced based on the result calculated based on V0.

[0109] The following example illustrates the range of values ​​for the first resistor.

[0110] The operating voltage of the first high-voltage power supply during the initial operation of the electrostatic filter (i.e., the initial operating voltage) can be denoted as the second voltage value. For example, if the first electrode plate is an insulating electrode plate, the second voltage value is greater than or equal to 3 kV / mm; if the first electrode plate is a high-resistance electrode plate, the second voltage value is between 2 kV / mm and 2.5 kV / mm. In some embodiments, the second voltage value can be considered as the initial operating voltage. The operating current of the electrostatic filter during initial operation is relatively small, typically 0–10 μA. Therefore, the second voltage value can also be considered as the minimum operating voltage of the first high-voltage power supply when the operating current is 0–10 μA.

[0111] When electrostatic filtration devices operate in indoor environments, specifically for filtering indoor air, the operating current should not be too high to account for ozone accumulation. Simultaneously, because indoor environments are relatively clean, leakage current is also relatively low. Considering these two factors, in practical operation, the initial current value can be set within the range of 20μA to 200μA.

[0112] When electrostatic filters operate in outdoor environments, i.e., filtering outdoor air, the load is heavy due to the direct processing of outdoor air, and leakage current is prone to increase. However, since ozone does not accumulate in fresh air environments, the operating current can be appropriately increased. Taking these two factors into consideration, in practical operation, the initial current value can be set in the range of 100μA to 500μA.

[0113] For example, the volt-ampere characteristic requirements of the first high-voltage power supply can be summarized in the following table.

[0114]

[0115] In the table above, 1.5kV / mm refers to the operating voltage (i.e., the first voltage value) under the worst operating conditions, and 1.5kV / mm refers to the operating current (i.e., the first current value) under the worst operating conditions.

[0116] Assume the initial operating voltage (V0) of the insulation scheme is 3D~4D (kV); the initial operating voltage of the high-resistance scheme is 2D~2.5D (kV); V1 is 1.5D (kV); the value range of D is 1mm~2mm for indoor products and 1mm~3mm for outdoor products; the value range of the first current value I is shown in the table above. According to the formula R = actual voltage difference / I, the resistance range of the first resistor connected in series with the first high-voltage power supply can be calculated, and the following calculation results can be obtained. In the table below, the actual voltage difference refers to the difference between the initial operating voltage V0 and the first voltage value V1.

[0117]

[0118]

[0119] Based on the actual volt-ampere characteristics of the first high-voltage power supply, V1′ must be less than V0. Therefore, the actual voltage operating conditions also need to be considered. Taking the requirement of V1′≥1.2×V1 as an example, assuming V1′=1.2×V1, that is, the actual voltage difference is 1.2×V1=0.3D(kV). Substituting the resistance value R=actual voltage difference / I into the calculation, the calculation results shown in the table below can be obtained. At this time, the data of the insulation scheme and the high-resistance scheme are the same, and the insulation scheme and the high-resistance scheme are no longer distinguished and are displayed together.

[0120]

[0121] By summarizing the resistance range calculation results in the two tables above for the first resistor (i.e., taking the union of the two value ranges for the same product), we can obtain exemplary value ranges for the resistance of the first resistor in different application scenarios.

[0122] For example, if the first electrode plate is an insulated electrode plate and the electrostatic filter is used to filter indoor air, that is, the electrostatic filter adopts an insulated scheme and is an indoor product, then the resistance value of the first resistor can be the union of 7.5D to 125D calculated based on V0 and 1.5D to 15D calculated based on V1′(1.2×V1), that is, 1.5D to 125D (unit MΩ).

[0123] For example, if the first electrode plate is a high-resistance electrode plate and the electrostatic filter is used to filter indoor air, that is, the electrostatic filter adopts a high-resistance scheme and is an indoor product, then the resistance value of the first resistor can be the union of 2.5D to 50D calculated based on V0 and 1.5D to 15D calculated based on V1′(1.2×V1), that is, 1.5D to 50D (unit MΩ).

[0124] For example, if the first electrode plate is an insulated electrode plate and the electrostatic filter is used to filter outdoor air, that is, the electrostatic filter adopts an insulated solution and is an outdoor product, then the resistance value of the first resistor can be the union of 3D to 25D calculated based on V0 and 0.6D to 3D calculated based on V1′(1.2×V1), that is, 0.6D to 25D (unit MΩ).

[0125] For example, if the first electrode plate is a high-resistance electrode plate and the electrostatic filter is used to filter outdoor air, that is, the electrostatic filter adopts a high-resistance scheme and is an outdoor product, then the resistance value of the first resistor can be the union of 1D to 10D calculated based on V0 and 0.6D to 3D calculated based on V1′(1.2×V1), that is, 0.6D to 10D (unit MΩ).

[0126] It should be understood that in practical applications, the actual voltage value of the working voltage and / or the actual resistance value (including the various resistors mentioned above) may have a certain deviation from the corresponding calculated value, for example, a deviation of ±10%.

[0127] The following example illustrates the effect of the series resistor (i.e., the first resistor) on the current-voltage characteristics and performance of the electrostatic filtration device.

[0128] The original volt-ampere characteristics of the first high-voltage power supply used are shown in the table below.

[0129] 6.0 10 5.8 20 5.6 50 5.4 80 5.2 125 4.6 200 4.2 280

[0130] 1) Insulation room

[0131] Assuming D = 1.5mm, the electrostatic filter uses an insulated design and is an indoor product, and the operating current (i.e., the first current value) at V1 = 2.25kV is set to 50μA. It can be seen that if the volt-ampere characteristics of the first high-voltage power supply are not configured before use, the operating current at V1 = 2.25kV will be too high, failing to meet design requirements. In other words, if the output voltage (i.e., the operating voltage) is too high when the operating current reaches 50μA (i.e., in a harsh operating environment), it will break down the air withstand voltage between the electrodes, leading to discharge and sparking, and in severe cases, even causing a fire.

[0132] Substituting V1′=5.6kV, V1=2.25kV, and I=50μA into the above resistance calculation formula, we can obtain the required resistance value of 67MΩ. After connecting a 66MΩ first resistor in series at the output terminal of the first high-voltage power supply, the volt-ampere characteristic of the first high-voltage power supply is tested, and the results are shown in the table below.

[0133] 6.0 10 5.34 5.8 20 4.48 5.6 50 2.3 5.4 80 0.12

[0134] After connecting a resistor in series at the output terminal of the first high-voltage power supply, the output voltage of the series resistor is equivalent to the working voltage. The output voltage of the series resistor refers to the voltage applied between two adjacent electrodes after subtracting the voltage shared by the series resistor from the output voltage.

[0135] As can be seen from the table above, after adding a suitable resistor at the power output terminal according to the calculation, the operating voltage (i.e., the output voltage with series resistor) when the output current is 50μA is 2.3KV, which is close to the design value of 2.25KV, with an error of less than 5%.

[0136] The following describes how a high-voltage power supply with the aforementioned original voltage-current characteristics was used to drive a filter that inhales 500 cigarettes, with resistors of different configurations connected in series at its output terminal, and the working status was observed. The power supply configurations are: a power supply without a resistor connected in series at the output, a power supply with a 66MΩ resistor connected in series at the output according to the recommended configuration, and a power supply with a 200MΩ resistor connected in series at the output.

[0137]

[0138]

[0139] 2) Outdoor insulation

[0140] Assuming D = 1.5mm, the electrostatic filter uses an insulation scheme and is an outdoor product, and the operating current (i.e., the first current value) at V1 = 2.25kV is set to 200μA. It can be seen that if the volt-ampere characteristics of the first high-voltage power supply are not configured and it is used directly, the operating current at V1 = 2.25kV will be too high, failing to meet design requirements. Alternatively, if the output voltage (i.e., the operating voltage) is too high when the operating current reaches 50μA (i.e., in harsh operating environments), it will break down the air withstand voltage between the electrodes, leading to discharge and arcing, and in severe cases, even causing a fire.

[0141] Substituting V1′=4.6kV, V1=2.25kV, and I=200μA into the above resistance calculation formula, we can obtain the required resistance value of 11.75MΩ. After connecting a 12MΩ resistor in series at the output terminal of the first high-voltage power supply, the volt-ampere characteristic of the first high-voltage power supply is tested, and the results are shown in the table below.

[0142] 6.0 10 5.9 5.8 20 5.6 5.6 50 5.0 5.4 80 4.4 5.2 125 3.7 4.6 200 2.2 4.2 280 0.9

[0143] As can be seen from the table above, after adding a suitable resistor at the power output terminal according to the calculation, the operating voltage (i.e., the output voltage with series resistor) when the output current is 200μA is 2.2kV, which is close to the design value of 2.25kV, with an error of less than 5%.

[0144] Using the above power supplies, we drove a filter that had been running outdoors for three months with resistors of different configurations in series at the output, and observed its working status. The power supply configurations were: power supply without a resistor in series at the output, power supply with a 12MΩ resistor in series at the output according to the recommended configuration, and power supply with a 40MΩ resistor in series at the output.

[0145]

[0146]

[0147] Actual test data from both the indoor and outdoor insulated versions of the product show that initial purification efficiency is good regardless of the power supply configuration. However, after the filter has been running for a period of time, the power supply without series resistance will exhibit discharge and arcing; the filter with excessively high series resistance will experience a significant drop in efficiency under high humidity conditions. Only a power supply that meets the design parameters can satisfy safety characteristics while dynamically maintaining good efficiency.

[0148] The following is an example of how to connect a first resistor in series at the output terminal of the first high-voltage power supply.

[0149] The first resistor refers to the resistor that is equivalent to being connected in series at the output terminal of the first high-voltage power supply in order to configure the volt-ampere characteristics of the first high-voltage power supply. It should be understood that in practical applications, a resistor can be connected in series on the power supply side, on the load side (i.e., the electrode plate side), or simultaneously on both sides, as long as the equivalent resistance of all series resistors on the power supply side is equal to (with allowable deviation) the pre-designed value of the first resistor.

[0150] In some embodiments, all positive electrode plates and all negative electrode plates are first electrode plates. Each positive electrode plate is connected in series with a second resistor; and / or each negative electrode plate is connected in series with a third resistor; and / or the output terminal of the first high-voltage power supply is connected in series with a fourth resistor. The sum of the parallel value of the second resistors connected in series with all positive electrode plates, the parallel value of the third resistors connected in series with all negative electrode plates, and the resistance of the fourth resistor is equal to the resistance of the first resistor. Wherein, when no second resistor is connected in series with each positive electrode plate, the parallel value of the second resistors connected in series with all positive electrode plates is 0. Correspondingly, when no second resistor is connected in series with each negative electrode plate, the parallel value of the third resistors connected in series with all negative electrode plates is 0. The fourth resistor can be connected in series with either the high-voltage output terminal (i.e., the positive terminal) or the low-voltage output terminal (i.e., the negative terminal) of the first high-voltage power supply. Optionally, a resistor can be connected in series with both the high-voltage and low-voltage output terminals of the first high-voltage power supply simultaneously, and the sum of the resistances of these two resistors is the fourth resistor.

[0151] For example, suppose an electrostatic filter device includes 50 positive electrode plates, each of which is connected in series with a 200MΩ resistor. Then, the 50 200MΩ resistors connected in series with these 50 positive electrode plates are equivalent to 50 200MΩ resistors connected in parallel on the power supply side, which is equivalent to 4MΩ.

[0152] In principle, the first resistor can be connected in series with either the positive or negative terminal of the first high-voltage power supply, or simultaneously with both the positive (anode) and negative (cathode) terminals. However, the absolute potential of the electrostatic filter differs depending on the position of the first resistor. For example, the electrostatic filter uses a negative high-voltage power supply with the anode grounded. The initial operating voltage is -6kV, and the long-term operating voltage is -3kV. Assuming a long-term operating current of 50μA, a 60MΩ resistor is connected in series at the power output to achieve a 3kV voltage drop. If the first resistor is connected in series at the negative high-voltage cathode terminal, then during long-term operation, the anode potential of the filter will be 0V, and the cathode potential will be -3kV. If the first resistor is connected in series at the anode ground terminal, then during long-term operation, the anode potential of the filter will be -3kV, and the cathode potential will be -6kV.

[0153] In some special cases where it is necessary to raise the potential of the electrostatic filter, the first resistor can be connected in series with the anode of the first high-voltage power supply to achieve this function.

[0154] A typical application involves a negative high-voltage ion charging device preceding the electrostatic filter, assuming its operating voltage is -8kV. According to safety regulations regarding electrical clearances, the negative high-voltage ion discharge device and the subsequent electrostatic filter must be at least 8mm apart. In practical applications, not only must arcing be prevented, but the coupling current between the preceding and following stages must also be considered; therefore, an even larger clearance is required.

[0155] If designed as described above, the filter's potential will rise during long-term operation, allowing for a reduction in the gap between it and the upstream ion charging device. This is highly beneficial for products with limited space requirements.

[0156] Meanwhile, the initial operating voltage of the insulation scheme can be appropriately increased. If the initial operating voltage of the electrostatic filter is set to -8kV, the long-term operating voltage remains -3kV, and the long-term operating current is 50μA. By connecting a 100MΩ resistor in series at the anode terminal, the anode potential of the filter will be -5kV and the cathode potential will be -8kV during long-term operation. The voltage difference between the filter and the front-end charging device will be reduced to 3kV. This can moderately reduce the distance between the charging device and the electrostatic filter. Alternatively, while maintaining the same distance, it can reduce the spatial coupling between the charging device and the electrostatic filter, improving equipment performance. Therefore, in situations where a potential increase in the electrostatic filter is required, a first resistor is connected in series at the positive terminal of the first high-voltage power supply.

[0157] In summary, the electrostatic filtration device of this invention has a high initial operating voltage and good initial filter performance. Furthermore, it uses technology to suppress leakage current between electrodes, reducing the leakage current caused by direct circuit connection between the positive and negative electrodes to a low level. At the same time, by configuring the volt-ampere characteristics of the high-voltage power supply by connecting a resistor in series, the device can maintain a working state close to the maximum voltage that air can withstand even in harsh environments after long-term operation. This avoids the hidden danger of discharge and arcing caused by long-term operation of the device due to constant high voltage, and greatly improves the performance of the device.

[0158] The electrostatic filtration device of this utility model has been described in detail above with reference to the accompanying drawings.

[0159] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. An electrostatic filtration device, characterized in that, include: Multiple positive electrode plates and multiple negative electrode plates are arranged alternately at equal intervals. The positive electrode plates are connected to the positive terminal of a high-voltage power supply, and the negative electrode plates are connected to the negative terminal of the high-voltage power supply. Among the plurality of positive electrode plates and the plurality of negative electrode plates, at least one pair of adjacent first electrode plates exists. The first electrode plate is an insulating electrode plate or a high-resistivity electrode plate. The insulating electrode plate is composed of an insulating material encasing a conductive material. The conductive material inside the insulating electrode plate is connected to a high-voltage power supply. The surface resistivity of the high-resistivity electrode plate is greater than or equal to 1E6Ω / sq. If the first electrode plate is an insulating electrode plate, then the insulating electrode plate has exposed conductive material, and the exposed conductive material on two adjacent insulating electrode plates is not aligned. The plurality of positive electrode plates and the plurality of negative electrode plates are connected using different support components. The initial operating voltage of the electrostatic filtration device is greater than or equal to 2.0 kV / mm to improve initial operating efficiency. Here, "kV / mm" refers to the operating voltage per millimeter of electrode spacing. The electrostatic filtration device further includes a first high-voltage power supply, which includes a first resistor connected in series at the output terminal. The positive electrode plate of at least one pair of adjacent first electrode plates is connected to the positive terminal of the first high-voltage power supply, and the negative electrode plate of at least one pair of adjacent first electrode plates is connected to the negative terminal of the first high-voltage power supply. The operating voltage when the operating current is a first current value is a first voltage value. The first voltage value is used to characterize the operating voltage that is compatible with the inter-electrode air pressure resistance value when the pollution level is high and / or the ambient humidity is high.

2. The electrostatic filtration device according to claim 1, characterized in that, The first voltage value is 1.5 kV / mm. If the electrostatic filter is used to filter indoor air, the first current value is between 20μA and 200μA; or if the electrostatic filter is used to filter outdoor air, the first current value is between 100μA and 500μA.

3. The electrostatic filtration device according to claim 1, characterized in that, The first high-voltage power supply operates at the second voltage value during the initial operation of the electrostatic filtration device. If the first electrode plate is the insulating electrode plate, the second voltage value is greater than or equal to 3kV / mm; or if the first electrode plate is the high-resistivity electrode plate, the second voltage value is between 2kV / mm and 2.5kV / mm.

4. The electrostatic filtration device according to claim 1, characterized in that, The resistance of the first resistor is greater than or equal to 0.5MΩ.

5. The electrostatic filtration device according to claim 1, characterized in that, Where R is the resistance value of the first resistor, and V1 ′ V1 is the first voltage value, and I is the first current value, when the first high-voltage power supply is not connected in series with the first resistor at the output terminal or the first resistor is short-circuited.

6. The electrostatic filtration device according to claim 1, characterized in that, The first electrode plate is an insulated electrode plate, the electrostatic filter device is used to filter indoor air, and the resistance value of the first resistor ranges from 1.5D to 125D (MΩ); or The first electrode plate is a high-resistance electrode plate, the electrostatic filter device is used to filter indoor air, and the resistance value of the first resistor is in the range of 1.5D to 50D (MΩ). or The first electrode plate is an insulated electrode plate, the electrostatic filter device is used to filter outdoor air, and the resistance value of the first resistor is in the range of 0.6D to 25D (MΩ). or The first electrode plate is a high-resistance electrode plate, and the electrostatic filter device is used to filter outdoor air. The resistance value of the first resistor ranges from 0.6D to 10D (MΩ). Where D represents the electrode spacing, and the unit of D is mm.

7. The electrostatic filtration device according to claim 1, characterized in that, The positive terminal of the first high-voltage power supply is connected in series with the first resistor.

8. The electrostatic filtration device according to claim 1, characterized in that, All positive electrode plates and all negative electrode plates are the first electrode plates. Each of the positive electrode plates is connected in series with a second resistor; and / or Each of the negative electrode plates is connected in series with a third resistor; and / or A fourth resistor is connected in series at the output terminal of the first high-voltage power supply. The sum of the parallel value of the second resistors connected in series to all the positive electrode plates, the parallel value of the third resistors connected in series to all the negative electrode plates, and the resistance value of the fourth resistor is equal to the resistance value of the first resistor.

9. The electrostatic filtration device according to claim 1, characterized in that, The exposed conductive material on two adjacent insulating electrode plates is at a distance greater than or equal to the electrode plate spacing in the direction perpendicular to the electrode plate spacing, so as to achieve misalignment; or Two adjacent insulating electrode plates have exposed conductive material on the same side of the electrode plate surface, so that the exposed conductive material on the two adjacent insulating electrode plates is separated by an insulating material layer to achieve non-alignment.

10. The electrostatic filtration device according to any one of claims 1 to 9, characterized in that, The actual voltage value of the operating voltage and / or the actual resistance value of the resistor have a deviation of ±10% from the corresponding calculated value.

Images