An intrinsically safe electrostatic precipitator

Abstract

The present invention discloses an intrinsically safe electrostatic precipitator. Its high-potential plates are all connected to a high-potential power supply through a first resistor network, and its low-potential plates are all connected to a low-potential power supply through a second resistor network; the high-potential plates are completely coated with an insulating film material; the low-potential plates are partially coated by means of opening holes or slots in the insulating coating layer. This application supplies power by setting a resistor network at the busbar end, provides relatively independent power supply for each stage of the dust collection electric field, and controls the flow of the inter-electrode current, thereby avoiding the occurrence of dangerous phenomena such as oscillating sparking caused by the capacitive busbar effect generated when local breakdown / damage occurs; due to strictly controlling the current collection of the plate capacitance effect and eliminating the influence of local voltage mutation between the plates, the precipitator eliminates the potential risks of local sparking, melting, carbonization and even fire, and at the same time has intrinsic safety and stable dust collection efficiency and dust holding capacity.

Description

Technical Field

[0001] The present invention relates to the field of dust collectors, and particularly to an intrinsically safe electrostatic dust collector. Background Art

[0002] Particle collection devices made using the Coulomb force deflection effect of charged particles in an electric field have a history of nearly a hundred years. A typical method is to use parallel conductive metal plates arranged in a high-low potential cross-parallel pattern to form an equally spaced dust collection plate array structure with a certain width. After charged particles enter the space between the parallel plates with the airflow, they are deflected under the action of the Coulomb force, collide with the plates, and are adsorbed and captured on the plate surface under the action of electrostatic force and van der Waals force, achieving the purpose of removing particles from the gas. When the number of captured particles reaches a certain level, the captured particles are removed by means of vibration or water washing desorption and then put back into use. Electrostatic collection has the characteristics of low wind resistance and renewable reuse, and is widely used in industrial soot purification, dust purification, civil ventilation and purification devices and other fields.

[0003] The charge carried by particles is proportional to the particle size, and the Coulomb force received is proportional to the charge carried. For fine particles such as PM2.5, when the charge carried is certain, to perform electrostatic collection, a higher electric field strength between the plates, a longer electric field length, or a smaller plate spacing is required. For parallel plates with metal conductors as the plates and air as the medium, it is inevitable that inter-electrode spark discharge is likely to occur, and the generated spark noise, electromagnetic interference, and ozone are sufficient to affect the use environment, limiting the application scenarios. The increase in the airflow passage length between the plates will cause the dust collector to become bulky.

[0004] At the beginning of this century, a structure with coated electrodes was applied. An insulating polymer material was used to coat the parallel electrodes to form a combined structure of a high-potential electrode - insulating medium - air channel - insulating medium - low-potential electrode. Inside the air channel, an electric field is formed through the polarization, corona, and electret effects of the insulating polymer material of the electrode to capture the charged particles passing through. The advantages of this method are as follows:

[0005] 1. Under the action of the insulating medium, the plate spacing can be reduced, and the insulating medium increases the voltage at which sparking occurs.

[0006] 2. The increase in the supply voltage further increases the electric field strength between the plates. Coupled with the reduced plate spacing, the length of the airflow channel can be shortened, enabling the volume of products with the same purification efficiency to be reduced, which brings convenience to the application design.

[0007] 3. The increase in electric field strength is beneficial to the capture of fine particulate matter. Currently, the products applied in the market use polypropylene (PP) as the coating material and a high-resistance carbon film material as the electrode, with a multi-stage high-low potential cross combination. After using conductor materials to converge the high-potential electrode plate and the low-potential electrode plate respectively, they are connected to a high-voltage power supply to form the structure of an electrostatic particulate matter collector.

[0008] However, during the application of this type of electrostatic collector structure, the following problems have been found:

[0009] 1. It is prone to rapid failure, a sudden drop in efficiency, and a low dust capacity.

[0010] 2. There is a fatal problem of arcing between electrodes and between external structures, local melting and carbonization, which poses a fire hazard.

[0011] 3. The high-voltage power supply is prone to heating and even burnout.

[0012] The above problems do not exist in traditional conductive electrode plate structure products, but have a relatively high occurrence probability in insulated coating products. The reasons for the above problems have been found through the test analysis of products obtained in the market.

[0013] The fully encapsulated structure of the electrode, especially when using polypropylene (PP) as the coating material, is equivalent to directly introducing a highly insulating covering layer on the electrode surface. Polypropylene belongs to non-polar polymer materials, has excellent insulation performance, a low dielectric constant, and the characteristics of electrostatic charge storage. When the combination of electrode - PP - air gap - PP - electrode is applied with high and low potentials, in the initial state, the internal electric field distribution in the air gap will be formed in the order of high - low potential. Charged particulate matter will deflect respectively according to the different charged polarities and be collected on the PP surface. However, when the insulating particulate matter reaches a certain thickness, especially when the charges carried by the particulate matter distributed on the insulating layer cannot be released and potential accumulation occurs, the new insulating layer will cause the polarity reversal of the surface charges, and then polarization phenomenon will occur, rapidly weakening the internal electric field strength and leading to a rapid decline in the particulate matter capture efficiency. In the products visible in the current market, the phenomenon of local failure is very common, manifested as a very obvious chromaticity difference on the dust collection surface of the filter after using for a period of time. The dark part indicates a high dust collection amount and significant efficiency, while the light part is basically in a failure state.

[0014] In parallel electrode plate electrostatic precipitators for industrial applications, how to contain the occurrence of surface polarization and avoid rapid failure has been a subject of continuous research and practice. One of the measures is to effectively release the charges carried by the trapped particulate matter and maintain the electric field strength in the air flow channel. However, products on the market that use PP insulation materials to coat the electrodes do exactly the opposite. They directly introduce insulating layers that prevent charge release on both electrodes, leading to a phenomenon of easy surface polarization and subsequent failure. The local voltage mutation caused by this polarization change may further cause the change of the charge sign of the electret polarization in the PP material with electret characteristics, resulting in voltage superposition and then insulation breakdown. Although this breakdown does not cause arc discharge, it is sufficient to cause changes in the molecular structure (chain breakage, oxidation) of the material at the breakdown point, and the insulation strength of the discharge channel decreases.

[0015] Further application tests and theoretical analyses have found the reasons for the fire hazard and safety of such structures:

[0016] In the multi-layer composite structure of "electrode - PP - air gap - PP - electrode", once local breakdown occurs (caused by electrical weaknesses such as breakage, defects, etc.), a continuous vicious cycle of intermittent discharge may occur. The area of the discharge ignition melts, carbonizes, and expands, even leading to combustion. Some engineering applications and test processes have directly resulted in combustion.

[0017] Due to the difficulty of achieving flame retardant modification of PP materials that take into account film-forming and welding characteristics, this phenomenon has a great potential safety hazard in applications.

[0018] The analysis of this process is as follows:

[0019] 1. Local defects (electrostatic breakdown channels, air holes, cracks, material impurities, electrical weakness areas such as punctures and cuts, etc.) cause the ionization of the air at the defect points, which in turn triggers local discharge and ignition between the electrodes or between the discharge point and the conductive structural components.

[0020] 2. The charges accumulated by the remaining electrodes due to the capacitance effect are discharged at the ignition point through the current collecting electrode, and the current intensity is sufficient to generate arc discharge.

[0021] 3. The high temperature of the arc discharge causes partial melting / carbonization of the material at the ignition point.

[0022] 4. In the case of using high-impedance electrodes and a high internal resistance voltage multiplier rectifier power supply, the ignition discharge causes the voltage to drop rapidly, and the arc discharge cannot continue, so the ignition stops.

[0023] 5. Since the current at the ignition point mainly comes from the charges accumulated by the capacitance effect, there is no continuous increase in current for the power supply, and the short-circuit protection of the power supply generally does not respond.

[0024] 6. The power supply continues to supply power to the dust collector, and the voltage continues to rise.

[0025] 7. When the voltage rises to a certain value, an arc discharge is re-generated at the breakdown ignition point.

[0026] 8. The process from 2 to 7 continues to occur, entering a vicious cycle.

[0027] 9. The continuous occurrence of the above phenomena will, in the mild case, cause the carbonized area to gradually expand, and in the severe case, it may lead to combustion.

[0028] The oscillating arc discharge ignition phenomenon will greatly increase the burden on the power supply, which is equivalent to continuously charging the capacitor with a large current, resulting in an overloaded power supply load, overheating and even burnout; in some tests, it was also found that voltage mutation pulses are generated during the discharge process, breaking down the voltage multiplier rectifier diode or capacitor, causing the supply voltage to drop. The damage to the power supply will lead to the overall failure of the dust collection device.

[0029] Improving the current protection characteristics of the high-voltage power supply for power supply cannot curb the occurrence of this phenomenon, but only prolongs the cycle of intermittent discharge. Although the development of this phenomenon can be identified and suppressed through the protective design of the power supply, this will greatly increase the design and manufacturing costs of the power supply, reduce the reliability of the power supply, and cannot solve the overall failure problem. Therefore, it must be solved from the characteristics of the dust collector itself.

[0030] To control the occurrence of surface polarization phenomenon, at least one of the high and low potential electrode pairs needs to be kept at the initial potential for the air gap during use. Considering factors such as electric field strength, insulation, safety, and manufacturing process, keeping the low-potential (ground potential) electrode plate in a stable state for the air gap can weaken the generation of polarization phenomenon. However, the lack of dielectric coverage on the low-potential electrode plate will reduce the capacitance value between the plates, which is not conducive to controlling the generation of polarization phenomenon. The method adopted is to use an insulating dielectric material to partially cover the electrode plate, and then balance the requirements of potential maintenance and capacitance value optimization.

[0031] Using an insulating material with a larger dielectric constant can increase the capacitance value between the plates, thereby enhancing the anti-polarization ability. At the same time, the insulating dielectric material should be flame-retardant, and its flame-retardant properties should not affect the basic physical properties such as insulation strength, dielectric constant, and material strength. Using a polar polymer material with polar groups and electret properties, when the polarization phenomenon occurs, the direction of the electret symbol is not easy to change, and the voltage superposition effect is also correspondingly avoided.

[0032] Controlling the parallel effect of the capacitances formed by each electrode pair to avoid the intermittent arc discharge caused by the current concentration effect is the key problem to be solved. By adopting a relatively isolated and independently powered method, the charges accumulated by each electrode pair due to the capacitance effect cannot directly flow into the discharge ignition area, thus avoiding the occurrence of arc discharge and the resulting fire hazard, and at the same time preventing the overall failure of the dust collector and the damage of the power supply due to breakdown or overloading.

[0033] For an electrostatic dust collector, an important factor determining the dust collection efficiency is to continuously ensure a stable electric field strength in the dust collection gap space.

[0034] The information disclosed in this background art section is only intended to deepen the understanding of the overall background art of the present invention, and should not be regarded as an admission or any form of implication that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0035] The purpose of the present invention is to provide an intrinsically safe electrostatic dust collector to solve the technical problems existing in the prior art.

[0036] To achieve the above purpose, the present invention adopts the following technical solutions:

[0037] The present invention provides an intrinsically safe electrostatic dust collector, which includes a plurality of groups of high-potential plates and low-potential plates arranged in a cross-layered and stacked manner in sequence; the high-potential plates are all connected to a high-potential power supply through a first resistor network, and the low-potential plates are all connected to a low-potential power supply through a second resistor network to provide relatively independent power supply for each dust collection electric field; the high-potential plates are completely coated with an insulating film material; the low-potential plates are partially coated by opening holes or slots in the insulating coating layer, that is, the electrode material in the low-potential plates is partially exposed in the dust collection gap.

[0038] As a further technical solution, the first resistor network includes a plurality of groups of series-connected first resistors and second resistors corresponding one-to-one to the high-potential plates, and the two ends of the series-connected first resistors and second resistors are respectively connected to the high-potential power supply and the high-potential plates; the series connection points of each group of first resistors and second resistors are sequentially connected through a third resistor;

[0039] The second resistor network includes a plurality of groups of series-connected fourth resistors and fifth resistors corresponding one-to-one to the low-potential plates, and the two ends of the series-connected fourth resistors and fifth resistors are respectively connected to the low-potential power supply and the low-potential plates; the series connection points of each group of fourth resistors and fifth resistors are sequentially connected through a sixth resistor.

[0040] As a further technical solution, the sheet resistance of the resistors in the first resistor network is 10 6 ~10 9Ω; The sheet resistance of the resistors in the second resistor network is 10 3 ~10 6 Ω.

[0041] As a further technical solution, the electrode material of the high-potential electrode plate uses a material with a sheet resistance < 100 Ω or a sheet resistance of 10 6 ~10 10 Ω; The electrode coating material of the high-potential electrode plate uses a polymer material with a breakdown voltage > 30 KV / mm, a dielectric constant of 2 - 3.5, a flame retardant level of at least V2 as specified in the UL94 standard, and a thickness ≤ 0.5 mm.

[0042] As a further technical solution, the electrode coating material of the high-potential electrode plate includes polytetrafluoroethylene, polyvinylidene fluoride, flame retardant modified polypropylene, and polycarbonate.

[0043] As a further technical solution, the electrode material of the high-potential electrode plate using a material with a sheet resistance < 100 Ω specifically refers to the self-healing capacitor conductive film material used in the capacitor industry, and is manufactured by means of zinc-aluminum alloy vacuum coating.

[0044] As a further technical solution, the electrode material of the low-potential electrode plate uses a material with a sheet resistance < 100 Ω or a sheet resistance of 10 3 ~10 7 Ω; The electrode coating material of the low-potential electrode plate uses a polymer material with a flame retardant level of at least V2 as specified in the UL94 standard and a thickness ≤ 0.5 mm.

[0045] As a further technical solution, the electrode coating material of the low-potential electrode plate includes polytetrafluoroethylene, polyvinylidene fluoride, flame retardant modified polypropylene, and polycarbonate.

[0046] As a further technical solution, the electrode material of the low-potential electrode plate using a material with a sheet resistance < 100 Ω specifically refers to the self-healing capacitor conductive film material used in the capacitor industry.

[0047] As a further technical solution, both the first resistor network and the second resistor network are integrally formed, with one end connected to the electrode lead-out terminal and the other end connected to the power supply.

[0048] Adopting the above technical solutions, the present invention has the following beneficial effects:

[0049] This application is powered by setting up a resistor network at the busbar end, providing relatively independent power supply for each stage of the dust collection electric field, and controlling the flow of the inter-electrode current, thereby avoiding the occurrence of dangerous phenomena such as oscillatory sparking caused by the capacitive busbar effect resulting from local breakdown / damage; the high-potential electrode is completely coated, the low-potential electrode is partially coated, and an asymmetric electric field is formed with the high-potential electrode by opening holes or grooves on the surface of the coating layer, stabilizing the surface potential, and avoiding the problem of voltage superposition breakdown of the dielectric material and rapid decline of the dust collection efficiency caused by the instantaneous polarity reversal of the coating material with electret characteristics due to the surface polarization effect, maintaining the electric field intensity continuously stable; due to strictly controlling the current collection of the plate capacitance effect and eliminating the influence of local voltage mutation between the plates, the dust collector eliminates the potential risks of local sparking, melting, carbonization and even causing a fire, and at the same time has intrinsic safety and stable dust collection efficiency and dust capacity, and is suitable for application in civil and industrial air purification devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0051] Figure 1 Schematic diagram of the connection structure of the high-potential plate and the low-potential plate and the resistor network provided by the embodiment of the present invention;

[0052] Figure 2 Schematic diagram of the structure of the low-potential plate provided by the embodiment of the present invention;

[0053] Figure 3 Schematic diagram of the structure of the high-potential plate provided by the embodiment of the present invention;

[0054] Figure 4 Schematic diagram of the connection array of the high-potential plate and the low-potential plate and the resistor network provided by the embodiment of the present invention;

[0055] Figure 5 Radar chart of the comparative test of the intrinsically safe electrostatic precipitator provided by the embodiment of the present invention;

[0056] Figure 6 Schematic diagram of the manufacturing method of the intrinsically safe electrostatic precipitator provided by the embodiment of the present invention.

[0057] In the figure: 1 - first resistor network, 11 - first resistor, 12 - second resistor, 13 - third resistor, 2 - second resistor network, 21 - fourth resistor, 22 - fifth resistor, 23 - sixth resistor, 3 - high - potential electrode plate, 4 - low - potential electrode plate, 5 - electrode coating material of the low - potential electrode plate, 51 - hole - type opening, 52 - groove - type opening, 6 - electrode material of the low - potential electrode plate, 7 - electrode coating material of the high - potential electrode plate, 8 - electrode material of the high - potential electrode plate, 9 - support structure, 91 - partition plate. Detailed implementation manners

[0058] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0059] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0060] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] The following will describe in detail the specific implementation manners of the present invention with reference to the accompanying drawings. It should be understood that the specific implementation manners described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0062] Combined with Figures 1 to 4 As shown, this embodiment provides an intrinsically safe electrostatic precipitator. The precipitator includes a plurality of groups of high - potential electrode plates 3 and low - potential electrode plates 4 arranged in a cross - laminated and distributed manner in sequence; the high - potential electrode plates 3 are all connected to a high - potential power supply through a first resistor network 1, and the low - potential electrode plates 4 are all connected to a low - potential power supply through a second resistor network 2; wherein,

[0063] The first resistor network 1 includes several groups of series-connected first resistors 11 and second resistors 12 that correspond one by one to the high-potential plates 3. The two ends of the series-connected first resistors 11 and second resistors 12 are respectively connected to the high-potential power supply and the high-potential plates 3; the series connection points of each group of first resistors 11 and second resistors 12 are sequentially connected through third resistors 13;

[0064] The second resistor network 2 includes several groups of series-connected fourth resistors 21 and fifth resistors 22 that correspond one by one to the low-potential plates 4. The two ends of the series-connected fourth resistors 21 and fifth resistors 22 are respectively connected to the low-potential power supply and the low-potential plates 4; the series connection points of each group of fourth resistors 21 and fifth resistors 22 are sequentially connected through sixth resistors 23.

[0065] This application supplies power by setting a resistor network at the current collecting end, provides relatively independent power supply for each stage of the dust collecting electric field, and controls the flow of the inter-electrode current, thereby avoiding the occurrence of dangerous phenomena such as oscillating sparking caused by the capacitive current collecting effect generated when local breakdown / damage occurs.

[0066] In this embodiment, as a further technical solution, the high-potential plates 3 are completely coated with an insulating film material; the low-potential plates 4 are partially coated by opening holes (hole-shaped openings 51) or slots (slot-shaped openings 52) in the insulating coating layer, that is, the electrode material in the low-potential plates 4 is partially exposed in the dust collecting gap.

[0067] This application adopts a completely coated high-potential electrode, a partially coated low-potential electrode, and forms an asymmetric electric field with the high-potential electrode by opening holes or slots on the surface of the coating layer, stabilizes the surface potential, and avoids the problem of voltage superposition breakdown of the dielectric material and rapid decline of the dust collecting efficiency caused by the instantaneous polarity reversal of the coating material with electret characteristics due to the surface polarization effect, and maintains the electric field intensity continuously stable.

[0068] In this embodiment, as a further technical solution, the sheet resistance of the resistors in the first resistor network is 10 6 ~10 9 Ω; the sheet resistance of the resistors in the second resistor network is 10 3 ~10 6 Ω.

[0069] The first resistor 11, the second resistor 12, the fourth resistor 21, and the fifth resistor 22 can limit the maximum short-circuit current of the electrode plate. The third resistor 13 and the sixth resistor 23 can balance the voltages between the electrode plates, improving the connection reliability. When local damage or even short circuit occurs, the resistor network restricts the charge collection in other areas to the potential arcing area, preventing the formation of arc high-temperature discharge, thereby inhibiting the generation of a vicious cycle, making the potential arcing area relatively isolated, and keeping the whole safe. The resistors and capacitors form a filtering structure, which can reduce electromagnetic interference. The first resistor 11, the second resistor 12, the fourth resistor 21, and the fifth resistor 22 can also prevent the voltage mutation caused by arcing from damaging the power supply.

[0070] In this embodiment, as a further technical solution, the electrode material 8 of the high-potential electrode plate uses a material with a sheet resistance < 100 Ω or a sheet resistance of 10 6 ~10 10 Ω; the electrode coating material 7 of the high-potential electrode plate uses a polymer material with a breakdown voltage > 30 KV / mm, a dielectric constant of 2 - 3.5, a flame retardant level of at least V2 standard specified by UL94 standard, and a thickness ≤ 0.5 mm; such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride, flame retardant modified polypropylene (PP), and polycarbonate (PC) and other corona-resistant and aging-resistant materials.

[0071] In this embodiment, as a further technical solution, the electrode material of the high-potential electrode plate with a sheet resistance < 100 Ω specifically refers to the self-healing capacitor conductive film material used in the capacitor industry, and is manufactured by the method of zinc-aluminum alloy vacuum coating. Under the condition of arc discharge, the impedance of the breakdown point is significantly reduced, and the current density flowing through it increases sharply, causing the metallized coating to generate high heat, and the metal conductor around the breakdown point quickly evaporates and disperses, forming a blank area of the metal coating. The breakdown point automatically restores insulation, insulating this area from the power supply electrode, and the discharge area self-heals and will not generate discharge again. The time from discharge to self-healing < 10 μS, and the area < 10 mm 2 , far from causing the melting and carbonization of the coating material, and the loss of dust collection efficiency and dust holding capacity caused by the failure area can be ignored.

[0072] In this embodiment, as a further technical solution, the electrode material 6 of the low-potential electrode plate uses a material with a sheet resistance < 100 Ω or a sheet resistance of 10 3 ~10 7 Ω; the electrode coating material 5 of the low-potential electrode plate uses a polymer material with a flame retardant level of at least V2 standard specified by UL94 standard and a thickness ≤ 0.5 mm; such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride, flame retardant modified polypropylene (PP), and polycarbonate (PC) and other corona-resistant and aging-resistant materials.

[0073] In this embodiment, as a further technical solution, the electrode material of the low-potential electrode plate is a material with a sheet resistance < 100 Ω, specifically the self-healing capacitor conductive film material used in the capacitor industry.

[0074] Partial coating of the low-potential electrode plate can balance the contradiction between the internal electric field strength and polarization control, and improve the collection efficiency and dust-holding capacity of particulate matter. The electrode pair with a certain length, air-gap height, and air-flow channel width fabricated in the above manner is cross-bonded and stacked to a certain height in the form of high-high - low-low - high-high according to the high-potential-to-high-potential and low-potential-to-low-potential methods. The high- and low-potential electrodes are respectively led out at both ends, connected to the resistor array, and connected to the high-voltage power supply to form the electrostatic dust collection device of the present invention.

[0075] Through the above design method, for the dust collection structure powered by the resistor array, no matter what kind of electrode plate resistance value structure is adopted, beneficial effects of improved safety can be obtained:

[0076] By adopting the high-resistance electrode plate method, the discharge current is comprehensively controlled, and arc discharge is not sufficient to form.

[0077] By adopting the low-resistance electrode plate method, through the use of the self-healing thin-film electrode, the discharge area is isolated and healed, and continuous oscillating discharge will not occur.

[0078] Preferably, both the electrode material and the coating material in this application are transparent materials.

[0079] In this embodiment, as a further technical solution, both the first resistor network and the second resistor network are integrally formed, with one end connected to the electrode plate lead-out end and the other end connected to the power supply.

[0080] The applicant verifies the performance and characteristics of the intrinsically safe electrostatic precipitator of this application through the following several embodiments:

[0081] Example 1 (High-impedance film electrode):

[0082] As shown in Figure 6 , using flame-retardant modified polycarbonate with a thickness of 0.1 - 0.2 mm as the coating material, a support structure 9 with an intermediate partition is fabricated by an injection molding device. The height of the partition 91 is 3 mm, and it is cut into strips with an air-channel width of 50 mm and a length of 400 mm. One side of the support structure is not perforated, and the other side is surface-perforated with a hole diameter of 0.2 mm and a hole pitch of 2 mm. The perforated area is centered and evenly distributed, with a coverage area of 70%.

[0083] Coat the non-perforated surface of the support structure with a resistor sheet resistance value of 10 7 ~10 8The transparent antistatic coating serves as the high-potential electrode 3; on the porous surface of the support structure, a transparent conductive coating with a resistance value of 10 5 ~10 6 Ω serves as the low-potential electrode 4. The coating is 3 - 10 mm away from the edge of the material. One end of the electrode connection end reaches the end, and the other end is 5 - 25 mm away from the end face point.

[0084] The non-porous surface of one support structure is bonded to the non-porous surface of another support structure with the electrodes facing the same direction, and then the porous surface of the support structure is bonded to the porous surface of another support structure. Stacking is carried out continuously in this way, with 40 layers stacked and a height of approximately 120 mm.

[0085] As Figure 1 and Figure 4 shown, connect the high-potential terminal of the power supply to one end of the high-potential busbar electrode resistance array, and connect the tooth center line of the busbar electrode to the high-potential plate.

[0086] As Figure 1 and Figure 4 shown, connect the low-potential terminal of the power supply to one end of the low-potential busbar electrode resistance array, and connect the tooth center line of the busbar electrode to the low-potential plate.

[0087] Reference example:

[0088] This reference example uses the same manufacturing process as in Example 1. The coating material is a PP material with the same wall thickness, the electrodes are completely coated, and the busbar electrodes use metal conductors.

[0089] Example 2 (self-healing film electrode):

[0090] This example uses the same coating material as in Example 1 in terms of performance and structural dimensions. Slots are formed on one side of the low-potential surface to form a coating ratio of approximately 60%.

[0091] The electrode plate uses a self-healing capacitor film material with a sheet resistance of 90 Ω and a film thickness of 5.8 μm. The electrode is centered and bonded on the coating material, with a width of 80 - 90% of the width of the coating material. The arrangement of the electrode connection ends is the same as in Example 1.

[0092] The stacking and bonding and the assembly method of the busbar electrodes are the same as in Example 1.

[0093] Example 3 (high-resistance high-potential film, low-resistance self-healing film, low-potential film):

[0094] This example uses the same coating material as in Example 1 in terms of performance and structural dimensions. The low-potential electrode uses a self-healing film with slots formed on one side to form a coating ratio of approximately 40%. The remaining manufacturing processes are the same as in Example 1.

[0095] The above Examples 1, reference example, Example 2, and Example 3 are tested as follows:

[0096] Weak electric point discharge test:

[0097] 1. Taking the sum of the thickness of the high-potential electrode coating material, the length of the air gap, and the product of the coverage rate and thickness of the low-potential electrode coating material as the total thickness of the dielectric between the electrode plates, apply the inter-electrode voltage at the electric field intensity of 3V, 5V, and 7V per micrometer respectively, and at the same time observe the change of the input current. When the weak electric point breaks down and discharges, it will be reflected in the instantaneous change of the current.

[0098] The test results are shown in the following table:

[0099]

[0100] 2. Oscillatory discharge suppression test:

[0101] Power supply: 30KV adjustable high-voltage DC power supply, maximum supply current 1mA.

[0102] Use a metal needle with a diameter of 0.2mm to pierce a group of adjacent high- and low-potential coating layers and electrode plates to form an artificial weak electric point. Load the examples at 15KV and 25KV respectively for a duration of 60S, observe the weak electric point discharge situation in the dark, and record the current change.

[0103] The test results are shown in the following table:

[0104]

[0105] 3. Performance test:

[0106] Adopt the GB / T34012 standard, use natural dust in the atmospheric environment as the particulate matter pollution source, with a face wind speed of 1.2m / S, use a TSI8530 particulate matter gravimetric analyzer to test the particulate matter content at the inlet and outlet respectively, and calculate the removal efficiency.

[0107] The test period is 21 days, and it is tested and recorded once a day.

[0108] The test results are shown in the following table:

[0109]

[0110]

[0111] The analysis of the above test results shows that the method of the present invention adopted can effectively suppress the occurrence of oscillatory sparking, improve the safety of the product, and at the same time control the local failure problem caused by surface polarization, improving the overall efficiency and dust capacity of the dust collector.

[0112] The applicant separately conducted comparative tests on the material anti-aging performance, anti-surface polarization failure, anti-Faraday cage failure, dust accumulation capacity, ultrafine particle capture, power supply safety, prevention of discharge and sparking, control of ozone generation, and plate flame retardancy safety of the intrinsically safe electrostatic precipitator of the present invention and the precipitator with completely coated electrodes and metal electrodes; the test results are shown in the following table:

[0113] Serial number Test item Complete coating of electrode Metal electrode The present invention 1 Anti-aging performance of material 42 75 90 2 Anti-surface polarization failure 20 85 75 3 Anti-Faraday cage failure 30 95 80 4 Dust accumulation capacity 35 45 90 5 Ultra-fine particle capture 65 30 85 6 Power supply safety 55 30 95 7 Prevent discharge and sparking 65 20 99 8 Control ozone generation 80 20 95 9 Plate flame retardant safety 40 100 90

[0114] The radar chart of the above comparative tests is as Figure 5 shown. It can be seen from the test comparison that the present invention has the advantages of safety / high efficiency.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An intrinsically safe electrostatic precipitator, the precipitator comprising a plurality of groups of high-potential plates and low-potential plates arranged in a cross-laminated and distributed manner in sequence; characterized in that, The high-potential plates are all connected to the high-potential power supply through the first resistor network, and the low-potential plates are all connected to the low-potential power supply through the second resistor network to provide relatively independent power supply for each stage of the dust collection electric field; the high-potential plates are completely coated with an insulating film material; the low-potential plates are partially coated by opening holes or slots in the insulating coating layer, that is, the electrode material in the low-potential plates is partially exposed in the dust collection gap. The first resistor network includes several groups of series-connected first resistors and second resistors corresponding one-to-one to the high-potential plates. The two ends of the series-connected first resistor and second resistor are respectively connected to the high-potential power supply and the high-potential plate; the series connection points of each group of first resistors and second resistors are sequentially connected through the third resistor. The second resistor network includes several groups of series-connected fourth resistors and fifth resistors corresponding one-to-one to the low-potential plates. The two ends of the series-connected fourth resistor and fifth resistor are respectively connected to the low-potential power supply and the low-potential plate; the series connection points of each group of fourth resistors and fifth resistors are sequentially connected through the sixth resistor. It also includes a support structure with an intermediate partition, one side of the support structure is not perforated, and the other side surface is perforated; a transparent antistatic coating with a sheet resistance value of 10 7 ~10 8 is applied on the non-perforated surface of the support structure as the high-potential electrode plate, and a transparent conductive coating with a sheet resistance value of 10 5 ~10 6 Ω is applied on the perforated surface of the support structure as the low-potential electrode plate; The non-porous surface of one support structure is bonded to the non-porous surface of another support structure, and the porous surface of one support structure is bonded to the porous surface of another support structure, and they are continuously stacked in this way.

2. The intrinsically safe electrostatic precipitator according to claim 1, wherein The sheet resistance of the resistors in the first resistor network is 10 6 ~10 9 Ω; the sheet resistance of the resistors in the second resistor network is 10 3 ~10 6 Ω.

3. The intrinsically safe electrostatic precipitator according to claim 1, characterized in that, The electrode material of the high-potential electrode plate uses a material with a sheet resistance < 100 Ω or a sheet resistance of 10 6 ~10 10 Ω; the electrode coating material of the high-potential electrode plate uses a polymer material with a breakdown voltage > 30 KV / mm, a dielectric constant of 2 to 3.5, a flame retardant level of at least V2 standard specified by UL94 standard, and a thickness ≤ 0.5 mm; The electrode material of the low-potential electrode plate uses a material with a sheet resistance < 100 Ω or a sheet resistance of 10 3 ~10 7 Ω; the electrode coating material of the low-potential electrode plate uses a polymer material with a flame retardant level of at least V2 specified by the UL94 standard and a thickness ≤ 0.5 mm.

4. The intrinsically safe electrostatic precipitator according to claim 3, characterized in that, The electrode coating material of the high-potential plate includes polytetrafluoroethylene, polyvinylidene fluoride, flame-retardant modified polypropylene, and polycarbonate.

5. The intrinsically safe electrostatic precipitator according to claim 3, characterized in that, The electrode material of the high-potential plate uses a material with a sheet resistance of less than 100Ω, specifically the self-healing capacitor conductive film material used in the capacitor industry, and is manufactured by the method of zinc-aluminum alloy vacuum coating.

6. The intrinsically safe electrostatic precipitator according to claim 3, characterized in that, The electrode coating material of the low-potential plate includes polytetrafluoroethylene, polyvinylidene fluoride, flame-retardant modified polypropylene, and polycarbonate.

7. The intrinsically safe electrostatic precipitator according to claim 3, wherein The electrode material of the low-potential plate uses a material with a sheet resistance of less than 100Ω, specifically the self-healing capacitor conductive film material used in the capacitor industry.

8. The intrinsically safe electrostatic precipitator according to claim 1, wherein Both the first resistor network and the second resistor network are integrally formed, with one end connected to the plate lead-out end and the other end connected to the power supply.

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