Electrostatic filtering device

Abstract

The invention relates to an electrostatic filtering device. The electrostatic filtering device comprises a plurality of positive electrode plates and a plurality of negative electrode plates. At least one pair of adjacent first electrode plates exist in the plurality of positive electrode plates and the plurality of negative electrode plates, the first electrode plates are insulating electrode plates or high-resistance electrode plates, the plurality of positive electrode plates and the plurality of negative electrode plates are respectively connected by using different supporting parts, the initial working voltage of the electrostatic filtering device is greater than or equal to 2.0 kV / mm, and the initial working voltage of the electrostatic filtering device is greater than or equal to 2.0 kV / mm. The unit "kV / mm" refers to the working voltage per millimeter of the electrode spacing, and the electrostatic filtering device is configured to control the working voltage by controlling the working current, so that the working voltage is adaptively adjusted to be adaptive to the air withstand voltage value between the electrodes, and the working efficiency is dynamically optimized. Therefore, while the initial working efficiency is ensured, the dynamic optimization of the working efficiency in the long-term operation process can be realized, and meanwhile, the hidden danger of discharge sparking in the long-term operation process is avoided.

Description

Technical Field

[0001] The present disclosure relates to the technical field of electrostatic dust removal, and in particular to an electrostatic filtering device. Background Art

[0002] Electrostatic filters have been widely used and developed due to their advantages such as low wind resistance and repeated cleaning.

[0003] Electrostatic filters utilize alternating parallel arrangements of discharge and collection plates to create a strong electrostatic field, thereby achieving their filtering function. The plates are the core component 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 voltage limit, which varies with humidity and is also related to the flatness and surface finish of the electrostatic filter plates. The voltage limit for air is generally considered to be 3kV / mm. When the voltage between the electrodes exceeds this limit, the air will break down. Electrostatic filters typically use conductive materials for the electrode plates. However, due to environmental fluctuations, processing techniques, and dust absorption, the voltage that can be applied between the plates is typically only half of the air's voltage limit, meaning it can be less than 1.5kV / mm.

[0005] The filter composed of conductive material plates wrapped with insulating material (hereinafter referred to as the "strong electric field solution") is one of the current mainstream electrostatic filter solutions. Because its conductive electrodes are wrapped with insulating materials and are not exposed to the air, it can ensure that even when a voltage higher than the air withstand voltage is applied, no air breakdown will occur. A filter whose voltage applied to the air medium is higher than the air withstand voltage can be called a strong electric field electrostatic filter. Because the voltage applied to the air is positively correlated with the purification efficiency, the higher the voltage, the higher the purification efficiency, so the strong electric field electrostatic filter has higher purification efficiency and is smaller in size. Moreover, due to the wrapping of the insulating material, the working current of the strong electric field electrostatic filter is extremely low, and no ozone is produced, and it has very excellent performance characteristics. The long-term strong electric field solution is based on the strong electric field solution, and the conductive material inside the positive and negative electrodes is exposed, and the exposed parts are kept non-aligned to maintain the long-term operating efficiency of the filter.

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

[0007] Conventional filters are designed to operate reliably under worst-case operating conditions. However, if the initial operating voltage of an electrostatic filter is increased, the high resistance or insulation properties of the high-resistance / insulating material will be destroyed, and the air pressure resistance will decrease. If the filter is still driven at the initial high voltage, the current will increase significantly, leading to sparks and even fires.

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

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

[0010] Furthermore, the air withstand voltage between the electrodes of electrostatic filters (including those with high electric field and high surface resistivity) does not decrease monotonically. The air withstand voltage between the electrodes is strongly correlated with relative humidity. High relative humidity results in low air withstand voltage, which increases leakage current between the electrodes. Low relative humidity results in high air withstand voltage, which decreases leakage current between the electrodes. It is also impossible to simply track the impact of environmental changes on the air withstand voltage between the electrodes using timers or other methods.

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

[0012] A technical problem to be solved by the present disclosure is how to balance the initial high efficiency, long-term safe operation and dynamic maintenance of high purification efficiency of the electrostatic filter.

[0013] According to a first aspect of the present disclosure, an electrostatic filtering 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 alternately arranged at equal intervals, the positive electrode plates are connected to the positive pole of a high-voltage power supply, the negative electrode plates are connected to the negative pole of a high-voltage power supply, and at least one pair of adjacent first electrode plates exists among the plurality of positive electrode plates and the plurality of negative electrode plates, the first electrode plates are insulating electrode plates or high-resistance electrode plates, the insulating electrode plates are composed of insulating material wrapped around a conductive material, the conductive material inside the insulating electrode plates is connected to a high-voltage power supply, the surface resistivity of the high-resistance electrode plates is greater than or equal to 1E6Ω / sq, if the If the first electrode plate is an insulated electrode plate, there is exposed conductive material on the insulated electrode plate, and the exposed conductive material on two adjacent insulated electrode plates is not facing each other. The multiple positive electrode plates and the multiple negative electrode plates are connected using different supporting components, respectively. The initial working voltage of the electrostatic filtering device is greater than or equal to 2.0 kV / mm to improve the initial working efficiency, wherein the unit "kV / mm" refers to the working voltage per millimeter of electrode spacing. The electrostatic filtering device is configured to control the working voltage by controlling the working current, thereby adaptively adjusting the working voltage to match the air withstand voltage value between the electrodes to dynamically optimize the working efficiency.

[0014] Optionally, the electrostatic filtering device further includes: a first high-voltage power supply, the first high-voltage power supply includes a first resistor connected in series at the output end, the positive electrode plate in at least one pair of adjacent first electrode plates is connected to the positive pole 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 pole of the first high-voltage power supply. Based on the first resistor, the volt-ampere characteristic of the first high-voltage power supply is configured so that the working voltage gradually decreases from the initial working voltage to a first voltage value as the working current increases. The first voltage value is used to represent the working voltage that is adapted to the air withstand voltage value between electrodes when the pollution level is high and / or the ambient humidity is high.

[0015] Optionally, the operating voltage of the first high-voltage power supply when the electrostatic filtration device initially operates is a 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 operating current when the operating voltage is the first voltage value is a first current value, the first voltage value is 1.5kV / mm, if the electrostatic filtration device is used to filter indoor air, the first current value is between 20μA and 200μA, or if the electrostatic filtration device is used to filter outdoor air, the first current value is between 100μA and 500μA.

[0017] Optionally, the resistance of the first resistor is greater than or equal to 0.5 MΩ.

[0018] Optionally,

[0019] Among them, 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 end or the first resistor is short-circuited when the working current is a first current value, V1 is the first voltage value, I is the first current value, and the first current value is the current value of the working current when the working voltage is the first voltage value.

[0020] Optionally, the first electrode plate is an insulating electrode plate, the electrostatic filtering device is used to filter indoor air, and the resistance range of the first resistor is 1.5D~125D (MΩ); or the first electrode plate is a high-resistance electrode plate, the electrostatic filtering device is used to filter indoor air, and the resistance range of the first resistor is 1.5D~50D (MΩ); or the first electrode plate is an insulating electrode plate, the electrostatic filtering device is used to filter outdoor air, and the resistance range of the first resistor is 0.6D~25D (MΩ); or the first electrode plate is a high-resistance electrode plate, the electrostatic filtering device is used to filter outdoor air, and the resistance range of the first resistor is 0.6D~10D (MΩ), wherein D represents the plate spacing, and the unit of D is mm.

[0021] Optionally, the positive electrode of the first high-voltage power supply is connected in series with the first resistor.

[0022] Optionally, all positive electrode plates and all negative electrode plates are the first electrode plates, and 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 with the output end of the first high-voltage power supply, wherein 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 sum of the resistance of the fourth resistor is equal to the resistance of the first resistor.

[0023] Optionally, each of the positive electrode plates is connected to the positive pole of the high-voltage power supply through a first dual-resistance conductive rod, the interior of the first dual-resistance conductive rod is made of low-resistance material, the exterior of the first dual-resistance conductive rod is made of high-resistance material, and the resistance of the high-resistance material portion of the exterior of the first dual-resistance conductive rod connected in series with the positive electrode plate is equivalent to the second resistance; and / or each of the negative electrode plates is connected to the positive pole of the high-voltage power supply through a second dual-resistance conductive rod, the interior of the second dual-resistance conductive rod is made of low-resistance material, the exterior of the second dual-resistance conductive rod is made of high-resistance material, and the resistance of the high-resistance material portion of the exterior of the second dual-resistance conductive rod connected in series with the negative electrode plate is equivalent to the third resistance.

[0024] Optionally, the first electrode plate is an insulating electrode plate, and each of the positive electrode plates further includes a first portion of high-resistance material, and the resistance of the first portion of high-resistance material is equivalent to the second resistance; and or each of the negative electrode plates further includes a second portion of high-resistance material, and the resistance of the second portion of high-resistance material is equivalent to the third resistance.

[0025] Optionally, an actual voltage value of the operating voltage and / or an actual resistance value of the resistor have a deviation of ±10% from the corresponding calculated value.

[0026] Optionally, the distance between the exposed conductive materials on two adjacent insulated electrode plates in a direction perpendicular to the plate spacing is greater than or equal to the plate spacing to achieve misalignment; or two adjacent insulated electrode plates are provided with exposed conductive materials on the plate surface on the same side, so that a layer of insulating material is separated between the exposed conductive materials on the two adjacent insulated electrode plates to achieve misalignment.

[0027] Optionally, the electrostatic filtering device further includes: an alarm module configured to output an alarm message in response to detecting that the operating current is greater than a first threshold.

[0028] The electrostatic filtration device disclosed in the present invention is an electrostatic filter that adopts an insulation solution or a high-resistance solution and can maintain long-term working efficiency. In addition, a necessary prerequisite is that the leakage current after contamination between the electrodes is controlled to a relatively low level through polarization support. On this basis, the present invention sets the initial working voltage to be greater than or equal to 2.0kV / mm to improve the initial working efficiency, and controls the working voltage through the working current, thereby adaptively adjusting the working voltage to match the air withstand voltage value between the electrodes, so as to avoid the hidden dangers of discharge and ignition caused by long-term operation of the equipment due to constant high voltage operation, while achieving dynamic optimization of equipment performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings, wherein like reference numerals generally represent like components in the exemplary embodiments of the present disclosure.

[0030] Figure 1 A structural schematic diagram of an electrostatic filtering device according to an embodiment of the present disclosure is shown.

[0031] Figure 2A A side cross-sectional view of an insulated electrode plate is shown.

[0032] Figure 2B A top cross-sectional view of an insulated electrode plate is shown.

[0033] Figure 2C A schematic diagram showing the connection between the insulated electrode plate and the power supply.

[0034] Figure 3 A schematic top cross-sectional view of two adjacent insulated electrode plates according to one embodiment of the present disclosure is shown.

[0035] Figure 4 A schematic top cross-sectional view of two adjacent insulated electrode plates according to another embodiment of the present disclosure is shown.

[0036] Figure 5A A schematic structural diagram of the surface of one of the insulating electrode plates is shown.

[0037] Figure 5B A schematic structural diagram of the surface of another electrode plate in the insulating electrode plate is shown.

[0038] Figure 6 A schematic top cross-sectional view of two adjacent insulated electrode plates according to another embodiment of the present disclosure is shown.

[0039] Figure 7 A schematic cross-sectional view of a dual-resistance conductive rod is shown.

[0040] Figure 8 A schematic structural diagram of an insulated electrode plate according to an embodiment of the present disclosure is shown.

[0041] Figure 9 A schematic structural diagram of an insulated electrode plate according to another embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0043] A complete electrostatic filter needs to include two parts: a charging device and a filtering device. The function of the charging device is to charge the fine particles in the air so that they are charged. The filtering device absorbs the charged particles through the electrostatic field to achieve the effect of air purification. The present disclosure only involves improvements to the filtering device, and does not involve improvements to the charging device. Therefore, the present disclosure does not describe the charging device, but focuses on describing the filtering device (i.e., the electrostatic filtering device). It should be known that the electrostatic filtering device described in the present disclosure can be used in conjunction with the charging device to form a complete electrostatic filter. In other words, the electrostatic filtering device described in the present disclosure can also include a charging device to form a complete electrostatic filter. In addition, some of the test cases mentioned in the text are by default the results of tests with the charging device. The terms "electrode" and "electrode plate" in the text can be used interchangeably.

[0044] Figure 1 A structural schematic diagram of an electrostatic filtering device according to an embodiment of the present disclosure is shown.

[0045] See also Figure 1 The electrostatic filtration device includes a plurality of positive electrode plates 20 and a plurality of negative electrode plates 10. The plurality of positive electrode plates 20 and the plurality of negative electrode plates 10 are alternately arranged at equal intervals. That is, the polarity of any two adjacent electrode plates is different, and the distance between any two adjacent electrode plates (this distance can be referred to as the plate spacing or electrode spacing) is equal. The positive electrode plates 20 are connected to the positive pole of the high-voltage power supply, and the negative electrode plates 10 are connected to the negative pole of the high-voltage power supply.

[0046] 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 plates are insulating electrode plates or high-resistance electrode plates. Exemplarily, all positive electrode plates 20 and all negative electrode plates 10 in the electrostatic filter device are first electrode plates.

[0047] When the first electrode plate is an insulated electrode plate, the electrostatic filtration device can also be referred to as a long-lasting, high-field electrostatic filter, or simply an insulation solution. The insulated electrode plate is composed of a conductive material wrapped in an insulating material. The insulating material may be, but is not limited to, PP (polypropylene), PET (polyethylene terephthalate), ABS (acrylonitrile butadiene styrene), PC (polycarbonate), and the like.

[0048] Figure 2A shows a side cross-sectional view of an insulated electrode plate; Figure 2B A top cross-sectional view of an insulated electrode plate is shown.

[0049] like Figure 2A 、 Figure 2B As shown, the insulated electrode plate is composed of two layers: an inner layer 110 made of a conductive material and an outer layer 120 made of an insulating material.

[0050] Figure 2C A schematic diagram showing the connection between the insulated electrode plate and the power supply.

[0051] 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.

[0052] If the first electrode plate is an insulating electrode plate, there is exposed conductive material in the effective ventilation area of ​​the insulating electrode plate (not shown in the figure), and the exposed conductive materials in the effective ventilation areas of two adjacent insulating electrode plates are not aligned.

[0053] The effective ventilation area, also known as the effective working area, refers to the area between two adjacent electrode plates through which unpurified gas can flow. The exposed conductive material is connected to the conductive layer inside the insulated electrode plate. By arranging the exposed conductive material in the effective working area, the conductive pollutants on the surface of the electrode plate can be connected to the power supply through the exposed conductive material, and then driven by the power supply, thereby being able to maintain the long-term operating efficiency of the electrostatic dust collector. At the same time, due to the high voltage applied by the conductive materials of the adjacent insulated electrode plates, they can only work normally when they are protected by insulation. Therefore, when there are exposed conductive materials on two adjacent insulated electrode plates, direct discharge and sparking can be avoided by setting the exposed conductive materials on the two adjacent insulated electrode plates to be not facing each other.

[0054] The misalignment of exposed conductive materials can be achieved in the following two ways.

[0055] The first approach is to arrange the exposed conductive material on two adjacent insulated electrode plates so that the distance between them in a direction perpendicular to the plate spacing is greater than or equal to the plate spacing, thereby achieving misalignment. That is, the exposed conductive material on two adjacent insulated electrode plates is misaligned in a direction perpendicular to the plate spacing (e.g., along the length of the plates).

[0056] Each electrode plate includes two surfaces, two side surfaces, a connection surface, and an opposite surface. The distance between the two adjacent surfaces of two adjacent electrode plates (i.e., the plate surfaces) is called the plate spacing. The connection surface refers to the surface where the connection part of the electrode plate and the high-voltage power supply is located, and the opposite surface refers to the surface parallel to the connection surface. For example, the electrode plate is Figure 1 The dimension in the x-axis direction can be called the electrode length. Figure 1 The dimension in the y-axis direction can be called the plate thickness. Figure 1 The dimension along the z-axis can be called the electrode plate width. The surface where the electrode plate connects to the high-voltage power supply (i.e., the connection surface) can be the surface composed of the electrode plate's width and thickness. The side surface refers to the surface composed of the electrode plate's length and thickness. The electrode plate surface refers to the surface composed of the electrode plate's length and width.

[0057] Figure 3 A schematic top cross-sectional view of two adjacent insulated electrode plates according to one embodiment of the present disclosure is shown.

[0058] See also Figure 3 , a row of exposed conductive materials 330 can be led out on different sides of two adjacent insulated electrode plates (for example, the sides located in the effective working area). The number of exposed conductive materials 330 led out can be set as needed, with a minimum number of 1. Figure 3 For example, the distance between the exposed conductive materials 330 of two adjacent insulated electrode plates is equal to the width of the plates. Figure 3 The width of the electrode plates is utilized to ensure that there is a sufficient staggered distance between the exposed conductive materials on two adjacent insulated electrode plates.

[0059] Figure 4 A schematic top cross-sectional view of two adjacent insulated electrode plates according to another embodiment of the present disclosure is shown.

[0060] See also Figure 4, at least one section of exposed conductive material can be respectively derived from the same side of two adjacent insulated electrode plates. For example, one or more sections of exposed conductive material can be derived from both sides of each of the two adjacent insulated electrode plates. And the exposed conductive materials derived from the same side of two adjacent insulated electrode plates can be staggered by a certain distance in the length direction of the electrode plate to meet the non-facing condition. That is to say, the distance between the exposed conductive materials derived from the same side of two adjacent insulated electrode plates in the length direction of the electrode plate is greater than or equal to the minimum plate spacing. For the exposed conductive materials derived from different sides of two adjacent insulated electrode plates, the width of the electrode plates can be used to naturally meet the non-facing condition.

[0061] It should be noted that Figure 3 、 Figure 4 It is only used to illustrate how to arrange the exposed conductive material on two adjacent electrode plates. Figure 3 、 Figure 4 It is not used to represent the actual arrangement of two adjacent electrode plates. The actual arrangement structure of the electrode plates can be found in Figure 1 shown.

[0062] The second method is that two adjacent insulated electrode plates may be provided with exposed conductive material on the plate surface on the same side, so that the exposed conductive materials on the two adjacent insulated electrode plates are separated by a layer of insulating material to achieve non-alignment.

[0063] Figure 5A A schematic structural diagram of the surface of one of the insulating electrode plates is shown.

[0064] Figure 5B A schematic structural diagram of the surface of another electrode plate in the insulating electrode plate is shown.

[0065] You can Figure 5A The plate surface shown is called the front surface and is Figure 5B The surface of the plate shown is called the reverse side.

[0066] See also Figure 5A 、 Figure 5B , the insulating electrode plate is provided with a groove 350 only on the surface of one of the plates. The groove 350 can be understood as removing the outer insulating material to form a groove, thereby exposing the conductive material inside the insulating electrode plate 1 at the groove 350. It should be understood that although the expression "groove" is used here, it does not mean that a groove must exist. For example, replacing part of the insulating material on the surface of the plate with exposed conductive material (or the high-resistance material described below) can also be regarded as a grooved structure. In this case, the entire surface of the electrode plate is flat and there is actually no groove.

[0067] Two adjacent insulated electrode plates can be used Figure 5A 、 Figure 5B The structure shown. Furthermore, after assembly, two adjacent insulated electrode plates have exposed conductive material on the same side of the plate surface. For example, each electrode plate includes two plate surfaces, and the plate surface on the left side of the electrode plate can be defined as the front side, and the plate surface on the right side of the electrode plate can be defined as the back side.

[0068] Assuming that the first insulated electrode plate and the second insulated electrode plate are two adjacent insulated electrode plates, if the first insulated electrode plate is provided with a groove 350 on the front side, then the second insulated electrode plate should also be provided with a groove 350 on the front side. Since the first insulated electrode plate and the second insulated electrode plate are provided with grooves on the plate surface on the same side, and the plate surface on the other side of the first insulated electrode plate and the second insulated electrode plate is made of insulating material (not provided with grooves), the exposed conductive material on the plate surface of the first insulated electrode plate and the second insulated electrode plate will be blocked by the insulating material on the other side of one of the insulated electrode plates. This can be regarded as another angle of misalignment, and can also avoid the risk of discharge and sparking caused by direct alignment.

[0069] Figure 6 A schematic top cross-sectional view of two adjacent insulated electrode plates according to another embodiment of the present disclosure is shown.

[0070] See also Figure 6 One insulating electrode plate can lead out a row of exposed conductive materials 330 on both sides. Another insulating electrode plate adjacent thereto can have a plurality of through holes 360 opened in the middle of the electrode plate, and the conductive materials inside can be exposed through the through holes 360.

[0071] When the first electrode plate is a high-resistance electrode plate, the electrostatic filtration device may also be referred to as a high-resistance electrostatic filter, or simply a high-resistance solution. The surface resistivity of the high-resistance electrode plate is greater than or equal to 1E6 Ω / sq. Here, 1E6 refers to 10 to the sixth power, and Ω / sq refers to ohms per square.

[0072] In some embodiments, the electrostatic filtering device may include a conductive electrode plate and a first electrode plate. The electrode surface of the conductive electrode plate is made of a conductive material.

[0073] In some embodiments, all electrode plates in the electrostatic filtration device are insulated electrode plates.

[0074] In some embodiments, all electrode plates in the electrostatic filtration device are high-resistance electrode plates.

[0075] In some embodiments, an electrostatic filtering device may also include insulating electrode plates and high-resistance electrode plates.

[0076] 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 originates from indoor sources and are used to filter indoor air. Outdoor products refer to electrostatic filtration devices whose input air originates, or partially originates, from the outdoors and are used to filter outdoor air.

[0077] Electrostatic filtration devices using either insulation or high-resistance designs operate in two different states: during initial operation and after long-term contamination. The operating voltage of an electrostatic filtration device is related to the electrode spacing. To accommodate designs with varying electrode spacings, the following description uses the operating voltage per millimeter of electrode spacing. In other words, the unit of operating voltage is kV / mm.

[0078] During initial operation, an electrostatic filter can be considered a clean filter. The air pressure between the electrodes is determined by the electrode material itself. Because the electrode surfaces are made of insulating or high-resistance materials, the air pressure between the electrodes is relatively high. This allows the electrostatic filter to initially operate at a higher voltage and a relatively low current.

[0079] Specifically, when the electrostatic filtration device uses an insulation solution, the initial operating voltage between the electrodes can be stabilized at, for example, 3kV / mm. This initial operating voltage is largely unaffected by the material and the environment; as long as the material withstands sufficient voltage, the initial operating voltage between the electrodes is essentially stable. When the electrostatic filtration device uses a high-resistance solution, 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.

[0080] After working for a period of time, the electrostatic filter device can be regarded as a dirty filter. At this time, the electrode becomes a conductor composed of the electrode material itself and the pollutants. Because the pollutants usually contain a certain proportion of carbon, the resistivity of the pollutants is relatively low. Especially when the relative humidity is high (for example, above 60%), the surface resistivity of the pollutants will be less than 1E6Ω / sq. Therefore, the resistivity of the pollutants usually dominates the electrode after contamination. At the same time, because the pollutants adsorbed by the electrode are a stack of many fine particles, the surface of the pollutants is rough and granular. Compared with the smooth electrode surface, this rough surface is more likely to produce discharge, which will further reduce the air withstand voltage value between the electrodes.

[0081] When the surface resistivity of the electrodes in an electrostatic filter device gradually decreases due to contamination and rough particles appear on the electrode surface, the pressure that the air between the electrodes can withstand decreases. At this time, if the electrostatic filter device is still powered by the same voltage, air breakdown discharge will occur.

[0082] This disclosure uses D to represent the plate spacing, measured in millimeters. The following table lists the initial ignition voltages for a contaminated electrostatic filter device with D = 1.5 mm and at different humidity conditions. It should be noted that the following table is only an example, and the initial ignition voltages will vary under different contamination conditions.

[0083] Ignition voltage (kV) 30% humidity 4 60% humidity 3.3 80% humidity 3.0

[0084] Therefore, the power supply for the electrostatic filter device needs to be able to automatically adjust the operating voltage according to the actual working state of the electrostatic filter device to avoid the risk of ignition caused by the operating voltage exceeding the air pressure resistance value between the electrodes.

[0085] At the same time, the resistivity of contaminants on the electrode surface is not constant. It varies with ambient humidity. When humidity is high, contaminant resistivity is low, and the air pressure between the electrodes decreases. In this case, the power supply voltage must be lowered, and the efficiency of the electrostatic filter device will also decrease accordingly. When humidity is low, contaminant resistivity is high, and the air pressure between the electrodes increases. In this case, the voltage must be increased to ensure the electrostatic filter device operates at its highest performance.

[0086] The inventors of this disclosure conducted extensive testing to determine the withstand voltage performance of an insulated filter (i.e., an electrostatic filter) and a high-resistance filter under different operating conditions. The test results are shown in the table below.

[0087]

[0088] Based on the test results shown in the table above, we can roughly understand that for electrostatic filtration devices with insulating or high-resistance electrode surfaces, the power supply must meet two conditions: first, the initial operating voltage of the electrostatic filtration device should be sufficiently high, such as at least greater than or equal to 2.0kV / mm, to improve initial operating efficiency; second, during operation, the operating voltage needs to be adaptively adjusted according to environmental changes (such as pollution level and / or humidity) to improve operating efficiency while not exceeding the air pressure withstand value between the electrodes.

[0089] The first condition can be met by setting the initial operating voltage of the electrostatic filtration device. For example, the initial operating voltage can be set to greater than or equal to 2.0kV / mm to improve the initial operating efficiency. Among them, for the insulation solution, the initial operating voltage can be set relatively high, for example, it can be greater than or equal to 3kV / mm; for the high-resistance solution, the initial operating voltage can be set relatively low, for example, it can be between 2kV / mm and 2.5kV / mm. Based on engineering practice, the actual operating voltage of the insulation solution should be ≤12kV.

[0090] To meet the second condition, the present disclosure proposes to control the working voltage by controlling the working current, so as to adaptively adjust the working voltage to match the air withstand voltage value between the electrodes to dynamically optimize the working efficiency. The working voltage is adapted to the air withstand voltage value between the electrodes, which means that the working voltage is as large as possible to improve the working efficiency while not exceeding the current air withstand voltage value between the electrodes to avoid the risk of discharge and ignition. Exemplarily, the working voltage is adapted to the air withstand voltage value between the electrodes, which may mean that the working voltage is less than the air withstand voltage value between the electrodes and the difference between the working voltage and the air withstand voltage value between the electrodes is not greater than a preset threshold. For example, the working voltage may be close to or equal to the air withstand voltage value between the electrodes.

[0091] On the one hand, the operating current changes due to environmental influences. For example, in the initial operating state, the operating current is relatively small (usually between 0 and 10 μA). During the operation of the electrostatic filtration device, as the degree of pollution and / or humidity increases, the operating current also increases. On the other hand, changes in the operating current will in turn affect the operating voltage. For example, as the operating current increases, the operating voltage will decrease. Therefore, the volt-ampere characteristics of the high-voltage power supply that supplies power to the electrostatic filtration device (more specifically, the first electrode plate in the electrostatic filtration device) can be configured so that the volt-ampere characteristics of the configured high-voltage power supply (i.e., the relationship between the configured operating current and the operating voltage) are adapted to the environmental changes during the operation of the electrostatic filtration device. This allows the operating voltage to be adaptively adjusted as the operating current changes during the operation of the electrostatic filtration device, adapting to the dynamically changing air withstand voltage between the electrodes, thereby optimizing work efficiency while ensuring safety.

[0092] Furthermore, the operating state of an electrostatic filter is determined not only by the withstand voltage between the electrodes but also by the operating current. For electrostatic filters with surface contamination, a high operating current translates to higher operating voltage and filtration efficiency. For example, for an electrostatic filter using a high-resistance design, the relationship between operating current and efficiency at different voltages in its initial clean state can be summarized as follows: the higher the voltage, the greater the operating current, and the higher the filtration efficiency.

[0093]

[0094]

[0095] The table above shows the operating current and filtration efficiency of a high-resistance solution with a D of 1.5mm at different operating voltages. As can be seen, below 2.5kV / mm, increasing the operating voltage increases the operating current and significantly improves filtration efficiency. When the operating voltage exceeds 2.5kV / mm, increasing the operating voltage significantly increases the current, but the improvement in filtration efficiency is very limited.

[0096] As can be seen from the table above, the normal operating current of an electrostatic filter is approximately several microamperes to tens of microamperes. This, of course, 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 controlled lower to ensure greater safety. In outdoor applications, due to the high level of pollution, the operating current of the electrostatic filter can be relaxed (i.e., increased). For example, when the electrostatic filter is used indoors, the operating current is preferably less than or equal to 20μA; when the electrostatic filter is used indoors, the operating current is preferably less than or equal to 200μA.

[0097] Another factor that affects the operating current is the leakage current between the positive and negative electrodes during long-term filter operation. This can vary significantly depending on the environment. Indoor electrostatic filters operating long-term typically exhibit low leakage currents, typically in the tens of microamperes. Outdoor filters can experience leakage currents of hundreds of microamperes or even milliamperes.

[0098] The present disclosure aims to control the working voltage by the working current according to the changes in the working current of the electrostatic filter which are affected by the environment, so as to achieve the purpose of "adaptively adjusting the working voltage according to environmental changes, thereby adaptively adjusting the working voltage to match the current air withstand voltage value between the electrodes, so as to dynamically optimize the working efficiency."

[0099] As can be seen from the table above, the typical operating current is only in the hundreds of microamperes, so excessive leakage current between electrodes cannot be allowed. This is because if the leakage current between electrodes is too large, it will be impossible to distinguish whether the power supply output current is the operating current or the leakage current, and thus it will be impossible to accurately control the operating voltage based on the operating current.

[0100] Therefore, leakage current between electrodes must be controlled. Specific control measures include two aspects: first, by using separate positive and negative pole supports to prevent short circuits through the support structure; second, by using pre-coarse effect to prevent the ingress of foreign matter such as lint and large particles.

[0101] The positive and negative electrode support method refers to the use of different support components to connect the positive electrode plates and negative electrode plates in the electrostatic filter. In other words, the support components connecting each positive electrode plate are different from the support components connecting each negative electrode plate. Figure 1 , Figure 1 The blue lines 210 in FIG. 2 represent support members for connecting electrode plates of one polarity (eg, all positive electrode plates 20 ). Figure 1 The red line 220 in FIG. 1 represents a support component for connecting electrode plates of another polarity (such as all negative electrode plates 10). This polarity-divided support method is called a polarization support method. Figure 1As shown, a plurality of groove-shaped support structure fixing positions 320 can be provided on the electrode plate to fix the polarity of the electrode plate to be connected to the support component with different polarity. Figure 1 As shown, multiple groove-shaped support structure avoidance locations 310 can also be provided on the electrode plate to avoid supporting components with different polarity than the electrode plate to be connected. The groove depth of the support structure avoidance location 310 is greater than the support structure fixing location 320. Exposed conductive material 330 can be provided near the support structure fixing location 320.

[0102] The separate positive and negative pole supports prevent short circuits in the power supply through the support structure. With this separate positive and negative pole support 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 deposition are unavoidable and must be avoided as much as possible. By strengthening the pre-coarse filter, direct short circuits between electrodes can be greatly reduced. Furthermore, the short-circuit current caused by direct short circuits between electrodes caused by lint is generally not large. Therefore, leakage current between electrodes can be reduced to a sufficiently low level by controlling the leakage current or by regularly cleaning the filter. This allows the operating voltage of the electrostatic filter to be controlled relatively accurately using the operating current.

[0103] In summary, the electrostatic filtration device disclosed in the present invention is an electrostatic filter that adopts an insulation scheme or a high-resistance scheme and can maintain long-term working efficiency; and, a necessary prerequisite for the present invention to control the working voltage by the working current so that the working voltage can be adaptively adjusted according to environmental changes is to control the leakage current between the electrodes at a relatively low level through polarization support.

[0104] The following measured data demonstrates the gradual contamination process of a new electrostatic filter. Data is provided for both the insulation and high-resistance designs, operating indoors and outdoors. The electrostatic filter dimensions are 600 x 300 x 50 mm, with a D of 1.5 mm. The measured data is as follows.

[0105]

[0106]

[0107] The above data shows that the initial operating conditions of the insulation solution and the high-resistance solution differ significantly. Initially, the insulation solution's inter-electrode air withstand voltage is greater than that of the high-resistance solution. Therefore, the insulation solution can operate at higher voltages. Alternatively, the high-resistance solution can be considered an insulation solution for lightly contaminated conditions.

[0108] After long-term operation, the overall operating conditions of the two solutions are similar. As contaminants accumulate, the insulation or high-resistance properties of the electrode surface gradually deteriorate, and the product enters an operating state dominated by contaminants on the electrode surface.

[0109] As the number of pollutants increases, the air pressure between the electrodes decreases, and the leakage current between the electrodes increases. Because the power supply cannot distinguish whether the current flowing through the device is operating current or leakage current, the power supply design does not distinguish between the two types of current. Instead, it considers only the combined output current, which is the sum of all currents. That is, the operating current referred to in this disclosure may refer to the combined output current, which includes both the air leakage current between the electrodes and the leakage current between the electrodes through the support structure.

[0110] The following is a further exemplary description of the details involved in the present disclosure.

[0111] In some embodiments, the electrostatic filtration device further includes a first high-voltage power supply. The first high-voltage power supply is configured to supply power to at least one pair of adjacent first electrode plates. Specifically, the positive electrode plate in at least one pair of adjacent first electrode plates is connected to the positive electrode 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 electrode of the first high-voltage power supply.

[0112] It should be known that in the case where a conductive electrode plate whose electrode surface material is a conductive material and a first electrode plate whose electrode surface material is an insulating material or a high-resistance material coexist in the electrostatic filtration device, the high-voltage power supply for supplying power to the conductive electrode plate and the high-voltage power supply for supplying power to the first electrode plate may be different high-voltage power supplies. The present disclosure is intended to configure the volt-ampere characteristics of the first high-voltage power supply for supplying power to the first electrode plate. In addition, the operating voltage mentioned in the present disclosure refers to the voltage between two adjacent first electrode plates. The operating current mentioned in the present disclosure refers to the total output current of the high-voltage power supply for supplying power to the first electrode plate (including the air leakage current between the first electrode plates and the leakage current between the first electrode plates through the support structure).

[0113] The first high-voltage power supply includes a first resistor connected in series at the output end. Based on the first resistor, the volt-ampere characteristic of the first high-voltage power supply is configured so that the operating voltage gradually decreases from the initial operating voltage to a first voltage value as the operating current increases. The first voltage value is used to characterize the operating voltage that is adapted to the air withstand voltage between electrodes when the pollution level is high and / or the ambient humidity is high. The first voltage value can be regarded as the operating voltage of the electrostatic filtering device in an extremely harsh environment (such as high pollution, high humidity). The first voltage value can be close to but not exceed the air withstand voltage between electrodes of the electrostatic filtering device in an extremely harsh environment. Exemplarily, the first voltage value is 1.5kV / mm.

[0114] On the one hand, the first resistor can be used to adjust the volt-ampere characteristic 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 under extremely harsh conditions, that is, the operating current when the operating voltage is the first voltage value. On the other hand, the first high-voltage power supply typically contains energy storage elements such as capacitors and inductors, so the instantaneous current output by the first high-voltage power supply will be very high. By connecting the first resistor in series with the output end of the first high-voltage power supply, high-intensity discharge caused by a power short circuit can also be prevented.

[0115] Exemplarily, the resistance of the first resistor is greater than or equal to 0.5 MΩ.

[0116] When selecting the first high-voltage power supply, the power requirements must be met first. That is, when the electrostatic filtering device is in the worst working conditions (i.e., the working voltage is equal to the first voltage value V1), the output current can meet the design requirements. In order to leave a margin for connecting the first resistor in series at the output end of the first high-voltage power supply, when selecting the first high-voltage power supply, it should also be ensured that V1v is sufficiently large compared to V1. V1′ is the output voltage of the first high-voltage power supply when the working current is the first current value I when the first resistor is not connected in series at the output end or the first resistor is short-circuited. For example, V1′≥1.2×V1, to ensure that the first resistor greater than or equal to 0.5MΩ can be connected in series, so that the working voltage of the first high-voltage power supply at the first current value I is V1.

[0117] The calculation formula of the resistance value R of the first resistor can be expressed as: Without considering the voltage drop of the first high-voltage power supply itself, that is, assuming that the first high-voltage power supply is an ideal power supply and its output voltage does not decrease with increasing operating current, V1′ = V0. V0 represents the initial operating voltage, i.e., the operating voltage of the first high-voltage power supply during initial operation of the electrostatic filtration device. 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 understood 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.

[0118] The following is an exemplary description of the resistance range of the first resistor.

[0119] The value of the operating voltage (i.e., the initial operating voltage) of the first high-voltage power supply when the electrostatic filtration device initially operates can be recorded 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 3kV / mm; if the first electrode plate is a high-resistance electrode plate, the second voltage value is between 2kV / mm and 2.5kV / mm. In some embodiments, the second voltage value can be regarded as the initial operating voltage. The operating current of the electrostatic filtration device during initial operation is relatively small, typically 0 to 10μA. Therefore, the second voltage value can also be regarded as the minimum value of the operating voltage of the first high-voltage power supply when the operating current is 0 to 10μA.

[0120] When operating in an indoor environment, i.e., filtering indoor air, the electrostatic filter's operating current should be kept to a minimum due to concerns about ozone accumulation. Furthermore, because indoor environments are relatively clean, leakage current is also relatively low. Taking these two factors into consideration, in practice, the first current value can be set within a range of 20μA to 200μA.

[0121] When operating in an outdoor environment, i.e., filtering outdoor air, electrostatic filtration devices directly process outdoor air, imposing a heavy load and easily increasing leakage current. However, since ozone does not accumulate in fresh air, the operating current can be appropriately increased. Taking these two considerations into account, in practice, the first current value can be set within the range of 100μA to 500μA.

[0122] Exemplarily, the volt-ampere characteristic requirements of the first high-voltage power supply can be summarized as the following table.

[0123]

[0124] In the above table, 1.5kV / mm refers to the operating voltage under the worst working conditions (ie, the first voltage value), and 1.5kV / mm refers to the operating current under the worst working conditions (ie, the first current value).

[0125] Assume that the initial operating voltage (V0) of the insulation solution is 3D-4D (kV); the initial operating voltage of the high-resistance solution 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; and the value range of the first current value I is as shown in the table above. Calculating the resistance range of the first resistor connected in series with the first high-voltage power supply according to the principle of resistance R = actual voltage difference / I yields the following results. In the table below, the actual voltage difference refers to the difference between the initial operating voltage V0 and the first voltage value V1.

[0126]

[0127] 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 must also be considered. For example, assuming V1' ≥ 1.2 × V1, and assuming V1' = 1.2 × V1, the actual voltage difference is 1.2 × V1 = 0.3D (kV). Substituting the resistance value R = actual voltage difference / I for calculation, we obtain the results shown in the table below. In this case, the data for the insulation and high-resistance solutions are identical, so the two solutions are no longer distinguished and are presented together.

[0128]

[0129]

[0130] By summarizing the resistance range calculation results in the above two tables of the first resistor (i.e., taking the union of the two value ranges of the same product), exemplary value ranges of the resistance value of the first resistor in different application scenarios can be obtained.

[0131] For example, if the first electrode plate is an insulated electrode plate and the electrostatic filter device is used to filter indoor air, that is, the electrostatic filter device adopts an insulation scheme and is an indoor product, then the resistance range of the first resistor can be the union of 7.5D~125D calculated based on V0 and 1.5D~15D calculated based on V1′(1.2×V1), that is, 1.5D~125D (unit: MΩ).

[0132] For another example, if the first electrode plate is a high-resistance electrode plate and the electrostatic filter device is used to filter indoor air, that is, the electrostatic filter device adopts a high-resistance solution and is an indoor product, then the resistance range of the first resistor can be the union of 2.5D~50D calculated based on V0 and 1.5D~15D calculated based on V1′(1.2×V1), that is, 1.5D~50D (unit: MΩ).

[0133] For another example, if the first electrode plate is an insulated electrode plate and the electrostatic filter device is used to filter outdoor air, that is, the electrostatic filter device adopts an insulation scheme and is an outdoor product, then the resistance range of the first resistor can be the union of 3D~25D calculated based on V0 and 0.6D~3D calculated based on V1′(1.2×V1), that is, 0.6D~25D (unit: MΩ).

[0134] For another example, if the first electrode plate is a high-resistance electrode plate and the electrostatic filter device is used to filter outdoor air, that is, the electrostatic filter device adopts a high-resistance solution and is an outdoor product, then the resistance range of the first resistor can be the union of 1D~10D calculated based on V0 and 0.6D~3D calculated based on V1′(1.2×V1), that is, 0.6D~10D (unit: MΩ).

[0135] It should be understood that in practical applications, the actual voltage value of the operating voltage and / or the actual resistance value of the resistor (including the various resistors mentioned above) may have a certain deviation from the corresponding calculated value, for example, a deviation of ±10%.

[0136] The following examples illustrate the influence of the series resistor (ie, the first resistor) on the volt-ampere characteristics and performance of the electrostatic filtering device.

[0137] The original volt-ampere characteristics of the first high-voltage power supply used are shown in the following table.

[0138] Output voltage (kV) Output current (μA) 6.0 10 5.8 20 5.6 50 5.4 80 5.2 125 4.6 200 4.2 280

[0139] 1) Insulation indoor

[0140] Assuming D = 1.5mm, the electrostatic filter device uses an insulation solution and is an indoor product, and the operating current (i.e., the first current value) is set to 50μA when V1 = 2.25kV. It can be seen that if the volt-ampere characteristic of the first high-voltage power supply is not configured and used directly, the operating current at V1 = 2.25kV is too high and does not meet the design requirements. In other words, when the operating current reaches 50μA (i.e., the operating environment is harsh), the output voltage (i.e., the operating voltage) is too high, which can break down the air pressure between the electrodes, causing discharge and sparking, and in severe cases, even causing a fire.

[0141] Substituting V1′ = 5.6 kV, V1 = 2.25 kV, and I = 50 μA into the above resistance calculation formula, we obtain the required series resistor value of 67 MΩ. After connecting a 66 MΩ first resistor in series with the output of the first high-voltage power supply, we tested the volt-ampere characteristics of the first high-voltage power supply. The results are shown in the table below.

[0142] Output voltage (kV) Output current (μA) Series resistance output voltage (kV) 6.0 10 5.34 5.8 20 4.48 5.6 50 2.3 5.4 80 0.12

[0143] After a resistor is connected in series to the output terminal of the first high-voltage power supply, the output voltage of the series resistor is equivalent to the operating voltage. The output voltage of the series resistor refers to the voltage between two adjacent electrodes after subtracting the voltage shared by the series resistor from the output voltage.

[0144] As can be seen from the table above, after adding the appropriate resistance at the power supply output end as calculated, the operating voltage (i.e. the output voltage of the 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%.

[0145] Below, we used a first high-voltage power supply with the aforementioned original volt-ampere characteristics, with different resistor configurations connected in series at its output, to drive a filter while drawing in 500 cigarettes. The power supply configurations included: output without a resistor, output with a 66MΩ resistor connected in series as recommended, and output with a 200MΩ resistor connected in series.

[0146]

[0147] 2) Insulation outdoor

[0148] Assuming D = 1.5mm, the electrostatic filter device uses an insulation solution and is an outdoor product, and the operating current (i.e., the first current value) is set to 200μA when V1 = 2.25kV. It can be seen that if the volt-ampere characteristic of the first high-voltage power supply is not configured and used directly, the operating current at V1 = 2.25kV is too high and does not meet the design requirements. In other words, when the operating current reaches 50μA (i.e., in a harsh operating environment), the output voltage (i.e., the operating voltage) is too high, which can break down the air pressure between the electrodes, causing discharge and sparking, and in severe cases, even causing a fire.

[0149] Substituting V1′ = 4.6 kV, V1 = 2.25 kV, and I = 200 μA into the above resistance calculation formula, we obtain the required series resistor value of 11.75 MΩ. After connecting a 12 MΩ resistor in series with the output of the first high-voltage power supply, the volt-ampere characteristics of the first high-voltage power supply were tested, and the results are shown in the table below.

[0150]

[0151] As can be seen from the table above, after adding the appropriate resistance at the power supply output as calculated, the operating voltage (i.e., the output voltage of the series resistor) is 2.2kV when the output current is 200μA, which is close to the design value of 2.25kV, with an error of less than 5%.

[0152] Using the above power supply, we connected resistors of varying configurations in series to the output to drive a filter that had been operating outdoors for three months and observed its performance. The power supply configurations included: no resistor connected in series to the output, a 12MΩ resistor connected in series to the output as recommended, and a 40MΩ resistor connected in series to the output.

[0153]

[0154] Based on actual test data from both insulated indoor and outdoor systems, we can see that initial purification efficiency is excellent using different power supply configurations. However, after the filter has operated for a period of time, power supplies without a series resistor can experience sparking. Filters with excessively high series resistance can experience a significant drop in efficiency under high humidity conditions. Only a power supply that meets the designed parameters can meet safety requirements while dynamically maintaining high efficiency.

[0155] The following is an exemplary description of how to connect the first resistor in series to the output terminal of the first high-voltage power supply.

[0156] The first resistor refers to a resistor connected in series with 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, resistors can be connected in series with either the power supply side or the load side (i.e., the electrode plate side), or with both the power supply side and the load side, as long as the equivalent resistance of all series resistors on the power supply side is equal (with some deviation allowed) to the pre-designed resistance value of the first resistor.

[0157] 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 end 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 to all positive electrode plates, the parallel value of the third resistors connected in series to all negative electrode plates, and the resistance of the fourth resistor is equal to the resistance of the first resistor. Wherein, when each positive electrode plate is not connected in series with the second resistor, the parallel value of the second resistors connected in series to all positive electrode plates is 0. Correspondingly, when each negative electrode plate is not connected in series with the second resistor, the parallel value of the third resistors connected in series to all negative electrode plates is 0. The fourth resistor can be connected in series with either the high-voltage output end (i.e., the positive electrode) of the first high-voltage power supply or the low-voltage output end (i.e., the negative electrode) of the first high-voltage power supply. Optionally, a resistor can be connected in series with both the high-voltage output end and the low-voltage output end of the first high-voltage power supply at the same time, and the sum of the resistances of these two resistors is the fourth resistor.

[0158] For example, assuming that the electrostatic filtration 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 the resistance value of 50 200MΩ resistors connected in parallel on the power supply side, which is equivalent to 4MΩ.

[0159] It is not easy to implement engineering to connect a resistor in series with each electrode plate. Some feasible implementation methods are given below.

[0160] See also Figure 1 The electrode plates are typically connected to a high-voltage power source on one side via a conductive rod 40 for power supply. Conventional conductive rods are typically made of low-resistance materials, such as metal wire or rod. Unlike conventional conductive rods, the present invention utilizes a conductive rod with dual resistance values ​​when viewed from a cross-section, enabling a resistor to be connected in series with each electrode plate. Figure 7 A schematic cross-sectional view of a dual-resistance conductive rod is shown.

[0161] See also Figure 7The inner red region 420 is a low-resistance material with a resistivity below 1 kΩ·cm. The outer blue region 410 is a high-resistance semiconductor material. By controlling the resistivity and wall thickness of the dual-resistance conductive rods used to power the electrode plates, the resistance of each electrode series resistor can be controlled.

[0162] In some embodiments, each positive electrode plate is connected to the positive electrode of the high-voltage power supply through a first dual-resistance conductive rod, the interior of the first dual-resistance conductive rod is a low-resistance material, and the exterior of the first dual-resistance conductive rod is a high-resistance material. The resistance of the high-resistance material portion of the exterior of the first dual-resistance conductive rod that is connected in series with the positive electrode plate is equivalent to the second resistance.

[0163] In some embodiments, each negative electrode plate is connected to the positive pole of the high-voltage power supply through a second dual-resistance conductive rod, the interior of the second dual-resistance conductive rod is a low-resistance material, the exterior of the second dual-resistance conductive rod is a high-resistance material, and the resistance of the high-resistance material portion of the exterior of the second dual-resistance conductive rod connected in series with the negative electrode plate is equivalent to a third resistor.

[0164] For insulated electrode plates, a series resistance can be achieved between each electrode, from the power supply side to the conductive material connected to the power supply, by adding a portion of high-resistance semiconductor material inside the insulated electrode plate. For example, each positive electrode plate also includes a first portion of high-resistance material inside, and the resistance of the first portion of high-resistance material is equivalent to the second resistance. For another example, each negative electrode plate also includes a second portion of high-resistance material inside, and the resistance of the second portion of high-resistance material is equivalent to the third resistance. For high-resistance electrode plates, a similar approach to that for insulated electrode plates can also be adopted.

[0165] Figure 8 A schematic structural diagram of an insulated electrode plate according to an embodiment of the present disclosure is shown.

[0166] See also Figure 8 At least one section of exposed conductive material 330 can be led out from the side of the insulating electrode plate. For example, one or more sections of exposed conductive material 330 can be led out from both sides of each insulating electrode plate. In addition, a high resistance material 340 ( Figure 8 (shown in green in the middle), high-resistance material 340 extends from the interior of the insulated electrode plate to the surface of the connection surface to connect to the high-voltage power supply. The resistivity of high-resistance material 340 is greater than the conductive material within the insulated electrode plate, but lower than the insulating material. High-resistance material 340 embedded in the connection surface of the insulated electrode plate can be considered the series resistance between the insulated electrode plate and the conductive material connected to the power supply.

[0167] Figure 9 A schematic structural diagram of an insulated electrode plate according to another embodiment of the present disclosure is shown.

[0168] See also Figure 9At least one section of exposed high-resistance material 340 ( Figure 9 (as shown in the green part in the middle). For example, one or more sections of exposed high-resistance material 340 can be derived from both sides of each insulating electrode plate. On the one hand, the high-resistance material 340 can be regarded as a resistor connected in series in the insulating electrode plate for configuring the volt-ampere characteristics of the high-voltage power supply (i.e., the first high-voltage power supply). On the other hand, the high-resistance material 340 is connected to the conductive material inside the insulating electrode plate, so the high-resistance material 340 is also equivalent to the "exposed conductive material" mentioned above, and plays a similar effect to the "exposed conductive material" mentioned above. That is, the conductive pollutants on the surface of the electrode plate can be connected to the power supply through the high-resistance material 340 and the conductive material inside the insulating electrode plate, and then be driven by the power supply, so that the long-term operating efficiency of the electrostatic precipitator can be well maintained.

[0169] In principle, the first resistor can be connected in series with either the positive or negative pole of the first high-voltage power supply, or with both the positive (i.e., anode) and negative (i.e., cathode) poles. However, the absolute potential of the electrostatic filter device varies depending on the position of the first resistor. For example, the electrostatic filter device uses a negative high-voltage power supply, with the anode of the power supply grounded. The initial operating voltage is -6kV, and the long-term operating voltage is -3kV. Assuming the long-term operating current is 50μA, a 60MΩ resistor is connected in series with the power supply output to achieve a 3kV voltage drop. If the first resistor is connected in series with the negative high-voltage cathode terminal, then during long-term operation, the filter's anode potential is 0V, and the cathode potential is -3kV. If the first resistor is connected in series with the grounded anode terminal, then during long-term operation, the filter's anode potential is -3kV, and the cathode potential is -6kV.

[0170] In some special occasions, when the potential of the electrostatic filtering device needs to be raised, the first resistor is connected in series with the anode of the first high-voltage power supply to achieve this function.

[0171] A typical application involves a negative high-voltage ion charging device placed before an electrostatic filter, assuming its operating voltage is -8kV. Safety regulations require electrical clearances of at least 8mm between the negative high-voltage ion charging device and the subsequent electrostatic filter. In practical applications, considerations must be given not only to preventing sparks but also to the effects of coupling currents between the upstream and downstream stages, necessitating even greater clearances.

[0172] If the above design is followed, the potential of the filter will rise during long-term operation, and the gap between the filter and the front-stage ion charging device can be reduced. This is very beneficial for products with limited equipment space.

[0173] At the same time, the initial operating voltage of the insulation scheme can be appropriately increased. If the initial operating voltage of the electrostatic filter device 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 with the anode terminal, during long-term operation, the filter's anode potential is -5kV, and the cathode potential is -8kV. The voltage difference with the front-end charging device is reduced to 3kV. This can moderately reduce the distance between the charging device and the electrostatic filter device. Alternatively, while maintaining the same distance, the spatial coupling between the charging device and the electrostatic filter device can be reduced, improving device performance. Therefore, in situations where the potential of the electrostatic filter device needs to be increased, a first resistor is connected in series with the positive terminal of the first high-voltage power supply.

[0174] In summary, the electrostatic filtration device disclosed in the present invention has a high initial operating voltage and good initial filter performance; and the technology of suppressing leakage current between electrodes is used to reduce the leakage current caused by the direct connection between the positive and negative electrodes through the circuit to a lower level; at the same time, through dynamic power supply technology, the operating voltage of the device is adaptively adjusted according to the changes in the operating current of the device affected by the environment, so that the device can always maintain an operating state close to the maximum voltage that the air can withstand, while avoiding the hidden dangers of discharge and sparking during long-term operation of the equipment due to constant high voltage operation, and greatly improving the performance of the equipment.

[0175] In the present disclosure, the long-term operating current of the electrostatic filtration device is pre-designed, and this long-term operating current represents the worst-case operating current (i.e., the first current value). Therefore, during operation, the electrostatic filtration device will operate at a current less than or equal to the set long-term operating current. Due to the discrete nature of components, such as power supplies and resistors, there may be variations in the operating current during actual operation. However, when an abnormality occurs, such as a change in the electrode gap due to aging of filter components, or a direct short circuit between the positive and negative electrodes due to severe contamination, the operating current may increase significantly. To address this, the present disclosure proposes that the electrostatic filtration device may also be equipped with an alarm module. The alarm module can detect the operating current of the high-voltage power supply (such as the first high-voltage power supply mentioned above) to determine the operating status of the device. If the operating current is abnormally high, such as exceeding a first threshold, an alarm may be triggered. For example, the first threshold may be 1.5 times the long-term operating current. Accordingly, the alarm module is configured to output an alarm message in response to detecting that the operating current exceeds the first threshold. The output of the alarm message may include, but is not limited to, an electrical signal, a light alert, or an audible warning. The electrical signal may be, but is not limited to, a level signal (e.g., a high or low level) or an on / off signal. The electrical signal may also transmit information via a communication protocol. For example, if the electrical signal output by the warning module is a level signal, the level signal may be subsequently converted into a warning message (e.g., displayed on-site by an indicator light), and / or a superior may be notified via a cable.

[0176] The electrostatic filtering device of the present disclosure has been described above in detail with reference to the accompanying drawings.

[0177] While various embodiments of the present disclosure have been described above, the above descriptions are illustrative, non-exhaustive, and not intended to be limiting of 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 selected to best explain the principles of the embodiments, their practical applications, or improvements to existing technologies, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. An electrostatic filtration device, 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 alternately arranged at equal intervals, the positive electrode plates are connected to the positive pole of the high-voltage power supply, and the negative electrode plates are connected to the negative pole of the high-voltage power supply, There is at least one pair of adjacent first electrode plates among the multiple positive electrode plates and the multiple negative electrode plates, and the first electrode plates are insulating electrode plates or high-resistance electrode plates. The insulating electrode plates are composed of insulating material wrapped with conductive material, and the conductive material inside the insulating electrode plates is connected to a high-voltage power supply. The surface resistivity of the high-resistance electrode plates is greater than or equal to 1E6Ω / sq. If the first electrode plate is an insulated electrode plate, there is exposed conductive material on the insulated electrode plate, and the exposed conductive materials on two adjacent insulated electrode plates are not facing each other. The plurality of positive electrode plates and the plurality of negative electrode plates are connected using different supporting members, respectively. The initial working voltage of the electrostatic filtration device is greater than or equal to 2.0 kV / mm to improve the initial working efficiency, wherein the unit "kV / mm" refers to the working voltage per millimeter of electrode spacing. The electrostatic filtering device is configured to control the operating voltage by controlling the operating current, thereby adaptively adjusting the operating voltage to match the air pressure resistance value between the electrodes, so as to dynamically optimize the working efficiency.

2. The electrostatic filtration device according to claim 1, further comprising: a first high-voltage power supply, wherein the first high-voltage power supply comprises a first resistor connected in series to an output end; The positive electrode plate in at least one pair of adjacent first electrode plates is connected to the positive electrode of the first high-voltage power supply. The negative electrode plate in at least one pair of adjacent first electrode plates is connected to the negative electrode of the first high-voltage power supply. Based on the first resistor, the volt-ampere characteristic of the first high-voltage power supply is configured so that the operating voltage gradually decreases from the initial operating voltage to a first voltage value as the operating current increases, and the first voltage value is used to represent the operating voltage that is adapted to the air withstand voltage between electrodes when the pollution level is high and / or the ambient humidity is high.

3. The electrostatic filtration device according to claim 2, wherein: The operating voltage of the first high-voltage power supply when the electrostatic filtering device is initially operating is a second voltage value. If the first electrode plate is the insulating electrode plate, the second voltage value is greater than or equal to 3 kV / mm, or if the first electrode plate is the high-resistance electrode plate, the second voltage value is between 2 kV / mm and 2.5 kV / mm.

4. The electrostatic filtration device according to claim 2, wherein: When the operating voltage is the first voltage value, the operating current is the first current value. The first voltage value is 1.5kV / mm, If the electrostatic filtering device is used to filter indoor air, the first current value is between 20 μA and 200 μA; or if the electrostatic filtering device is used to filter outdoor air, the first current value is between 100 μA and 500 μA.

5. The electrostatic filtration device according to claim 2, wherein: The resistance of the first resistor is greater than or equal to 0.5 MΩ.

6. The electrostatic filtration device according to claim 2, wherein: Wherein, R is the resistance value of the first resistor, V1 ′ It is the output voltage of the first high-voltage power supply when the first resistor is not connected in series at the output end or the first resistor is short-circuited and the working current is the first current value. V1 is the first voltage value, I is the first current value, and the first current value is the current value of the working current when the working voltage is the first voltage value.

7. The electrostatic filtration device according to claim 2, wherein: The first electrode plate is an insulated electrode plate, the electrostatic filtering 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 filtering device is used to filter indoor air, and the resistance value of the first resistor ranges from 1.5D to 50D (MΩ); or The first electrode plate is an insulated electrode plate, the electrostatic filtering device is used to filter outdoor air, and the resistance value of the first resistor ranges from 0.6D to 25D (MΩ); or The first electrode plate is a high-resistance electrode plate. The electrostatic filter device is used to filter outdoor air. The resistance value of the first resistor ranges from 0.6D to 10D (MΩ). Wherein, D represents the plate spacing, and the unit of D is mm.

8. The electrostatic filtration device according to claim 2, wherein: The positive electrode of the first high-voltage power supply is connected in series with the first resistor.

9. The electrostatic filtration device according to claim 2, wherein: 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 to the output end 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 of the fourth resistor is equal to the resistance of the first resistor.

10. The electrostatic filtration device according to claim 9, wherein: Each of the positive electrode plates is connected to the positive electrode of the high-voltage power supply via a first dual-resistance conductive rod, the interior of the first dual-resistance conductive rod is made of a low-resistance material, the exterior of the first dual-resistance conductive rod is made of a high-resistance material, and the resistance of the high-resistance material portion of the exterior of the first dual-resistance conductive rod connected in series with the positive electrode plate is equivalent to the second resistance; and / or Each of the negative electrode plates is connected to the positive pole of the high-voltage power supply through a second dual-resistance conductive rod, the interior of the second dual-resistance conductive rod is made of low-resistance material, and the exterior of the second dual-resistance conductive rod is made of high-resistance material. The resistance of the high-resistance material portion of the exterior of the second dual-resistance conductive rod that is connected in series with the negative electrode plate is equivalent to the third resistor.

11. The electrostatic filtration device according to claim 9, wherein: The first electrode plate is an insulating electrode plate, Each of the positive electrode plates further includes a first portion of high-resistance material, the resistance of the first portion of high-resistance material being equivalent to the second resistance; and or Each of the negative electrode plates further includes a second portion of high-resistance material therein, and the resistance of the second portion of high-resistance material is equivalent to the third resistor.

12. The electrostatic filtration device according to any one of claims 2 to 11, wherein: 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.

13. The electrostatic filtration device according to claim 1, wherein: The distance between the exposed conductive materials on two adjacent insulated electrode plates in a direction perpendicular to the distance between the electrode plates is greater than or equal to the distance between the electrode plates, so as to achieve non-alignment; or Two adjacent insulated electrode plates are provided with exposed conductive material on the plate surface on the same side, so that the exposed conductive materials on the two adjacent insulated electrode plates are separated by a layer of insulating material to achieve non-alignment.

14. The electrostatic filtration device according to claim 1, further comprising: The warning module is configured to output warning information in response to detecting that the operating current is greater than a first threshold.

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