WESP collecting electrode insertion part or extension part

Abstract

Methods and apparatus for cleaning pollution control equipment, such as particulate removal devices including wet electrostatic precipitators (WESPs). The WESP may include a housing, at least one air inlet in fluid communication with the housing, an air outlet spaced apart from and in fluid communication with the housing, one or more ionizing electrodes adapted to be connected to a high-voltage source within the housing, and one or more collecting electrodes within the housing. The housing may be in fluid communication with a flushing fluid source such as water. The effective length of the collecting electrodes increases with an extension that significantly increases the surface area of ​​the collecting electrodes while minimizing the corresponding height increase.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Application Serial No. 63 / 033,374, filed June 2, 2020, the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0003] Pollution control equipment, such as wet electrostatic precipitators (WESPs), uses electrostatic methods to remove dust, acid mist, and other particles from water-saturated air and other gases. For example, water-saturated air filled with particles and / or mist flows in the region between the electrode discharge and collection electrodes of the precipitator, where the particles and / or mist become charged by corona discharge emitted from the high-voltage discharge electrodes. As the water-saturated gas flows further within the precipitator, the charged particles and / or mist are electrostatically attracted to a grounded collection plate or electrode, where they are collected. The accumulated material is continuously flushed away by liquid rinsing membranes and periodic flushing to an exhaust pipe, etc.

[0004] Such systems are generally used to remove contaminants from gas streams emanating from various industrial sources, such as incinerators, coke ovens, glass furnaces, non-ferrous metallurgical plants, coal-fired power plants, forestry facilities, food drying plants, wood product manufacturing, and petrochemical plants.

[0005] Specifically, in wood product manufacturing, maintenance is problematic, particularly due to material buildup on current collectors and electrodes. Sticky particles, condensate, and the like tend to adhere to and accumulate inside the equipment, causing harmful downtime and unnecessary costs associated with removal. This is seen not only in the manufacture of wood products such as switchboards but also in biofuels and other markets. Manual intervention is often necessary to thoroughly clean the interior of the equipment to prevent the accumulation of contaminants, which is highly undesirable. Dirty WESP tubes and electrodes are therefore a persistent industry challenge that degrades the performance of all WESP styles and designs.

[0006] In almost all existing industrial WESP or dry ESP designs, the majority of particle collection occurs at the inlet of the dust collector. This becomes more pronounced as dust collector design efficiency increases. In many of these applications, 90%–98% removal efficiency is typical for single-stage WESPs. Using the standard Deutsch-Anderson equations for estimating WESP performance within this range, it can be shown that the first quarter of the WESP removes approximately 49%–64% of the particles, while the last quarter removes only 3%–9%. Other factors influence this distribution, but this is a reasonable estimate. Current industry standards use tube lengths ranging from 7 to 20 feet, with 12 to 14 feet being the most common. To provide a modular and shippable system, it is ideal to limit the tube length to a height of 10 feet, and therefore expect to achieve an equivalent tube height greater than 10 feet in a given space. Furthermore, the shorter the tube, the shorter the emitting electrode (typically a rod or tube with spikes or discs). Shorter electrodes are mechanically stiffer, producing less oscillation from the airflow and are easier to align. Proper alignment or centering of the electrodes is crucial for any electrostatic collector.

[0007] Therefore, it is desirable to increase the effectiveness of the collection surface (such as the collection electrode tubes in an electrostatic collector) without substantially increasing the height of the collection surface (or collector). The advantage of this is that it provides modular electrostatic collector units that are easy to ship without sacrificing particle collection efficiency. Summary of the Invention

[0008] The embodiments disclosed herein address the problems of the prior art, providing electrostatic collectors or dust collectors with improved electrode collector effectiveness, and a method for removing particles from a process stream using such electrostatic collectors. In some embodiments, a wet electrostatic precipitator is disclosed, comprising a housing, at least one inlet fluidly in communication with the housing, at least one outlet or exhaust port spaced apart from and fluidly in communication with the housing, one or more ionizing electrodes or current emitters in the housing adapted for connection to a high-voltage source, and one or more collecting electrodes in the housing, wherein the one or more ionizing electrodes are spaced apart from the one or more collecting electrodes to achieve corona discharge between them. In some embodiments, the one or more collecting electrodes may comprise a bundle or array of elongated tubes or grid cells (e.g., with a circular, square, rectangular, or hexagonal cross-section, or a plate shape) and one or more collecting electrode extensions or surface area enhancement members electrically in communication with at least one corresponding collecting electrode. In some embodiments, the collecting electrodes form an array of grid cells, and the number of collecting electrode extensions is equal to the number of grid cells in the array. In some embodiments, the number of collecting electrode extensions may be less than the number of grid cells in the array. In some embodiments, the grid cells have a hexagonal cross-section and form a honeycomb pattern of repeating hexagonal collecting areas or grid cells, and the collecting electrode extensions also have a hexagonal cross-section. In some embodiments, each ionizing electrode is supported from the bottom and extends vertically upward into a corresponding collecting electrode. In various embodiments, a lower high-voltage grid or support may be used to support one or more ionizing electrode rods. This lower high-voltage grid may be supported by an insulator mounted to the top wall or top plate of the WESP using one or more ionizing electrodes as supports, or by an insulator mounted in the side wall of the WESP below the collecting electrodes, or by an upper high-voltage grid, which in turn is supported by an insulator mounted in the top wall (top plate) or side wall of the WESP above the collecting electrodes.

[0009] In some embodiments, the electrode extension significantly increases the surface area available for particle collection without significantly increasing the height of the collecting electrode. For example, the electrode extension may include surface area-enhancing components, such as a plurality of spaced-apart fins, which provide additional particle collection surface area without requiring a corresponding increase in the vertical height of the collecting electrode. In some embodiments, each collecting electrode extension or surface area enhancement member is positioned downstream of the corresponding collecting electrode in the direction of industrial gas flow. In other embodiments, each collecting electrode or surface area enhancement member is positioned within at least a portion of the internal volume of the collecting electrode, downstream of the ionization electrode location within the internal volume region of the corresponding collecting electrode in the direction of industrial gas flow. In this embodiment, the surface area enhancement member or multiple surface area enhancement members may be attached to one or more walls of the collecting electrode itself.

[0010] Therefore, certain aspects relate to an electrostatic precipitator comprising: a housing having an inlet for a gas process flow and an outlet spaced apart from the inlet for discharging treated gas; a particle collection surface including one or more collection electrodes positioned within the housing between the inlet and the outlet; one or more ionizing electrodes in the housing, each ionizing electrode associated with a corresponding collection electrode; and at least one collection surface extension or surface area enhancement member or plurality of members electrically connected to at least one collection electrode, the collection surface extension including, for example, a plurality of spaced-apart fins. In various embodiments, a lower high-voltage grid or support may be used to support one or more ionizing electrode masts. The lower high-voltage grid may be supported by an insulator mounted to the top wall or top plate of the WESP using one or more ionizing electrodes as a support, or by an insulator mounted in the side wall of the WESP below the collection electrodes, or by an upper high-voltage grid, which in turn is supported by an insulator mounted in the top wall (top plate) or side wall of the WESP above the collection electrodes.

[0011] In some embodiments, there are multiple collecting electrodes having hexagonal cross-sections and forming a honeycomb array of hexagonal grid cells. In some embodiments, there may be multiple collecting surface extensions, and each collecting surface extension may include a hexagonal periphery. In different embodiments, each collecting surface extension may be supported on and electrically connected to a corresponding collecting electrode. In some embodiments, each collecting surface extension may include an outer wall and an inner wall spaced apart from the outer wall, wherein a plurality of spaced-apart fins extend from the outer wall to the inner wall. In some embodiments, the inner wall may be discarded, and the fins extend from one region of the outer wall to another region of the outer wall. In some embodiments, each collecting electrode extension may be mechanically supported on a corresponding collecting electrode by providing one or more supports with aligned interconnections between the collecting electrode and the collecting electrode extension. Each such support may be a slotted cylindrical tube. In some embodiments, each grid cell has a grid cell surface area and a grid cell height, and each collecting surface extension has a collecting surface extension surface area and a collecting surface extension height. For each grid cell height, the collecting surface extension surface area may be at least four times larger than the grid cell surface area, corresponding to the collecting surface area height. In some embodiments, for each grid cell height, the collecting surface extension surface area may be at least eight times larger than the grid cell surface area, corresponding to the collecting surface area height. In some embodiments, for each grid cell height, the collecting surface extension surface area may be up to 20 times larger than the grid cell surface area, corresponding to the collecting surface area height. In some preferred embodiments, for each grid cell height, the collecting surface extension surface area is 8 to 12 times the grid cell surface area, corresponding to the collecting surface height.

[0012] In other embodiments, each or more surface reinforcement members are positioned inside the collecting electrode. For example, each ionizing electrode may be associated with a corresponding collecting electrode, each collecting electrode having an internal volume having a first region occupied by its corresponding ionizing electrode and at least a second region not occupied by the ionizing electrode, wherein at least a portion of the second region is occupied by one or more surface reinforcement members. The walls or walls of the collecting electrode may replace the outer walls of the collecting surface extension and support the surface reinforcement members or members (e.g., fins) in a manner similar to the outer walls of the collecting surface extension. Thus, the surface reinforcement members or members occupy the internal region of the collecting surface electrode, located downstream of the ionizing electrode in the industrial airflow direction, the ionizing electrode also being located within the internal region of the collecting electrode.

[0013] In terms of its method, this article discloses a method for removing particulate material from the process flow by introducing the process flow into the electrostatic precipitator described above and collecting the particulate material on the collecting electrode and the collecting extension.

[0014] Therefore, certain aspects relate to a method for removing particles from a process stream, the method comprising: providing a particle removal apparatus, the particle removal apparatus comprising: a housing having at least one ionizing electrode charged by a high-voltage source, at least one collecting electrode, at least one inlet for the process stream, at least one outlet spaced apart from the inlet, and at least one collecting surface extension or surface area enhancement member electrically connected to the at least one collecting electrode; generating a corona discharge between the at least one ionizing electrode and the at least one collecting electrode; introducing the process stream into the inlet, whereby the process stream contacts the at least one collecting electrode; depositing particles in the process stream onto the collecting electrode and the collecting surface extension or surface area enhancement member; and removing the deposited particles from the collecting electrode and the collecting electrode extension or surface area enhancement member.

[0015] To better understand the embodiments disclosed herein, reference is made to the accompanying drawings and description that form part of this disclosure. Attached Figure Description

[0016] The embodiments disclosed herein can take various forms, including various component arrangements and various process operations. The accompanying drawings are for illustrative purposes only and should not be construed as limiting. This disclosure includes the following drawings.

[0017] Figure 1 This is a perspective view of a wet electrostatic precipitator according to a specific embodiment;

[0018] Figure 2 It is a partial cross-sectional perspective view of a portion of a collection electrode that forms a bundle or array of collection grid cells according to a particular embodiment and includes a collection electrode extension or surface area enhancement member.

[0019] Figure 3 This is a top perspective view of the collecting electrode extension or surface area enhancement member according to a specific embodiment;

[0020] Figure 4 This is a bottom perspective view of the collecting electrode extension or surface area enhancement member according to a specific embodiment;

[0021] Figure 5 This is a perspective view of the collecting electrode extension, showing an embodiment of its attachment to a collecting electrode or a surface area enhancement member;

[0022] Figure 6 This is an internal perspective view of the upper region of a particle removal apparatus according to a specific embodiment;

[0023] Figure 7 This is an internal perspective view of the lower region of a particle removal apparatus according to a specific embodiment;

[0024] Figure 8This is another internal perspective view of the lower region of a particle removal apparatus according to a particular embodiment;

[0025] Figure 9A This is a front view of an electrode stabilizer according to a specific embodiment; and

[0026] Figure 9B This is a perspective view of an electrode stabilizer according to a specific embodiment. Detailed Implementation

[0027] A more complete understanding of the components, processes, and apparatus disclosed herein can be obtained by referring to the accompanying drawings. The drawings are merely illustrative representations for convenience and ease of illustrating this disclosure and are therefore not intended to indicate the relative size and dimensions of the apparatus or its components, and / or to define or limit the scope of protection of the exemplary embodiments.

[0028] Although specific terms are used in the following description for clarity, these terms are intended to refer only to the specific structures chosen for the embodiments illustrated in the accompanying drawings and are not intended to limit or restrict the scope of this disclosure. In the drawings and the following description, it should be understood that the same numerical designations refer to components having the same function.

[0029] Unless the context clearly specifies otherwise, the singular forms “a,” “an,” and “the” include plural indicators.

[0030] As used in the specification, various devices and components may be described as “including” other components. As used herein, the terms “comprising,” “including,” “having,” “possibly,” “containing,” and variations thereof are intended to be open-ended transitional phrases, terms, or words that do not exclude the possibility of additional components.

[0031] All ranges disclosed herein include the endpoints and can be combined independently (e.g., the range “2 inches to 10 inches” includes the endpoints 2 inches and 10 inches, as well as all intermediate values).

[0032] As used herein, approximate language can be used to modify any quantitative expression that can be altered without causing a change in its underlying function. Therefore, in some cases, a value modified by one or more terms such as “about” and “substantially” may not be limited to the specified exact value. The modifier “about” should also be considered as disclosing a range defined by the absolute values ​​of its two endpoints. For example, the expression “about 2 to about 4” also discloses a range of “2 to 4”.

[0033] It should be noted that many of the terms used herein are relative terms. For example, the terms “upper” and “lower” are relative to each other, i.e., the upper component is located at a higher height than the lower component and should not be construed as requiring a particular orientation or position of the structure. As a further example, the terms “inner,” “outer,” “inward,” and “outward” are relative to a center and should not be construed as requiring a specific orientation or position of the structure.

[0034] The terms "top" and "bottom" are relative to an absolute reference point, namely the Earth's surface. In other words, the top position is always located at a higher altitude than the bottom position, relative to the Earth's surface.

[0035] The terms "horizontal" and "vertical" are used to indicate directions relative to an absolute reference point, i.e., the ground plane. However, these terms should not be interpreted as requiring structures to be absolutely parallel or absolutely perpendicular to each other.

[0036] The embodiments disclosed herein include an apparatus for removing particulate matter from a process stream containing particulate matter, and may include a mist-generating component that mixes the incoming gas stream with droplets; one or more ionizing electrodes that charge the particulate matter and the droplets; one or more collection surfaces (such as one or more collection electrodes or surface area enhancement components) that attract the charged particulate matter and the mixed droplets and are capable of removing the charged particulate matter and the mixed droplets from the gas stream; and a washing fluid source. In some embodiments, one or more collection surfaces comprise one or more elongated tubes or grid cells. In some embodiments, the cross-section of the tubes or grid cells is hexagonal. In other embodiments, the cross-section of the tubes or grid cells is circular, rectangular, or other polygonal. Preferably, the cross-section of the tubes or grid cells is hexagonal, they are repeating, and they are bundled to form a honeycomb array. In some embodiments, each grid cell 30A has a diameter of 16 inches and a length of 10 feet. Preferably, each grid cell 30A has the same size. A honeycomb arrangement is effective in minimizing wasted space; the hexagonal structure uses minimal material to create a grid of cells within a given volume. The cells used in the electrostatic precipitator can be constructed from any convenient building material suitable for its function, including carbon steel, stainless steel, corrosion-resistant and heat-resistant alloys, lead, and glass fiber reinforced plastics. In some embodiments, the cells are at ground potential during operation of the grid cells. The one or more ionizing electrodes may also provide a collection surface.

[0037] In some embodiments, the WESP unit 100 is an upward flow design, which eliminates the need for demisting at the outlet, allows liquid and solid contaminants to be collected by gravity before they reach (and potentially contaminate) the collection electrodes, and achieves a simplified layout if discharged directly to the stack. However, other designs, including downward flow designs, can be used.

[0038] See now Figure 1 and 2 An exemplary WESP unit 100 is shown, which is an upward flow design with a vertical orientation. The advantage of an upward flow design is that any water droplets present are carried upward by the airflow and eventually collected on a collection surface. Therefore, the upward flow design functions as a demister, preventing any droplets from being entrained in the airflow leaving the device.

[0039] In some embodiments, unit 100 has a lower inlet 12 and an upper outlet or vent 14 spaced apart from the lower inlet 12. The lower inlet 12 may be in fluid communication with a suitable conduit or the like to guide industrial gas to be processed by unit 100 in a generally upward flow toward a collection surface, which in the illustrated embodiment includes a plurality of grid cells 30A. Figure 2 The array 30 of grid cells 30A is preferably hexagonal in cross-section. The array 30 of grid cells 30A is disposed in the cell 100 in the region between the inlet 12 and the outlet 14. The array 30 of grid cells 30A can be supported in the cell 100 by any suitable means, such as supporting the outer periphery of the array 30 from the sides and / or bottom using angle irons or similar supports. In some embodiments, the array 30 can be formed by joining individual plates or walls in a desired shape, such as by welding. Figure 1 As can be seen in the embodiments, adjacent grid cells 30A share a common wall.

[0040] In some embodiments, the volume of each grid cell 30A, defined by one or more of its outer walls, is empty (i.e., without structural material), except for the mast 50. In some embodiments, the volume of one or more grid cells 30A in the farthest downstream region in the direction of industrial gas flow (e.g., the region near the free end of the grid cell 30A closest to the outlet 14 of cell 100) is occupied by one or more surface-reinforcing members. In some embodiments, this portion of the volume is the volume of the grid cell 30A not occupied by the mast 50. In some embodiments, each mast 50 may be pre-aligned before being assembled into cell 100. When positioned within each grid cell 30A, the mast 50 maintains the array 30 of grid cells 30A at a desired voltage. In some embodiments, the potential difference between the mast 50 and the collection surface is sufficient to induce current flow via corona discharge, which charges particles entrained in the process flow.

[0041] In some embodiments, water may be periodically introduced into the cells and applied to the array 30 of grid cells 30A to remove specific substances collected on the collection surfaces. Gas distribution devices (such as perforated plates 7) may be provided to help distribute the process gas evenly through these grid cells 30A, having a similar residence time in each grid cell 30A.

[0042] In some embodiments, the effective length of one or more collection surfaces (such as grid cells 30A in the array 30 of grid cells 30A) can be increased by providing one or more large-area grounding trap collection surface extensions or surface reinforcement members 90, for example in... Figure 1-4 As can be seen, the extensions 90, with their compact design, increase the effective surface area of ​​the collection surface without a corresponding significant increase in the vertical height of the grid cell 30A. The increased area at the outlet of the WESP is in the area where the minimum amount of particles needs to be removed, so the smaller gaps between these collection plates (e.g., 0.125 to 2.0 inches) are not more prone to clogging compared to the normal gaps at the inlet of the collection tube, where particle removal is much higher. In some embodiments, the majority of the additive surface area provided by one or more extensions 90 is in the horizontal direction rather than in the vertical direction; that is, the vertical component of the surface extension member is minimized relative to its horizontal component in cell 100. For a given height of each extension 90, the surface area of ​​each extension 90 is substantially greater than the corresponding surface area of ​​the grid cell 30A at the same height.

[0043] Figure 2 An embodiment of an extension 90 associated with a grid cell 30A of array 30 is shown. In the illustrated embodiment, the extension 90 has a hexagonal periphery that matches the top hexagonal periphery of the grid cell 30A and is electrically connected to the grid cell 30A. In some embodiments, the extension 90 is supported on the grid cell 30A. In some embodiments, each extension is located at or near the downstream end of the array 30 of grid cells 30A, for example, downstream of the area on the collection surface of the grid cell 30A in the industrial gas flow direction from inlet 12 to outlet 14 of cell 100. In other embodiments, the extension or surface area enhancement member 90 is located within the internal volume of the grid cell 30A, in the downstream region of the grid cell 30A (in the direction of industrial gas flow), for example, downstream of the mast 50 in the grid cell 30A.

[0044] like Figure 3 and Figure 4As shown, each extension 90 may include a plurality of connected outer walls, which may be one or more external slotted plates 101 defining the outer perimeter of the extension 90. This or these external slotted plates 101 may be arranged in a configuration that matches the cross-sectional configuration of the grid cell 30A. In the illustrated embodiment, the configuration of the array 30 is a honeycomb structure formed by hexagonal cells, and thus provides six external slotted plates 101 for the extension 90. Alternatively, fewer than six plates (including a single plate) may be formed in a suitable configuration instead of using multiple plates to form the perimeter of the extension 90. In some embodiments, the extension 90 also includes a plurality of surface area-enhancing components, such as fins 110, each fin 110 extending radially inward from the external slotted plates or the plurality of external slotted plates toward the central region 115 of the extension 90. In the illustrated embodiment, each fin 110 has one or more end tabs 111 that facilitate attachment of the fin 110 to the outer slotted plate 101 via slots 102 penetrating the plate (preferably two vertically spaced and aligned slots 102). Other methods of attaching each fin to the plate can be used, in which case the plate may not require slotting and the fins may not require end tabs. Thus, unlike the volume of the grid cells 30A that are not occupied except for the mast 50 located therein, the volume of the extension is occupied by surface area-increasing components such as the fins 110.

[0045] In embodiments where the surface area enhancement member or multiple members 90 are positioned within the internal volume of the grid cell 30A, the walls of the grid cell 30A itself or multiple walls may be used to support the surface area enhancement member or fins 110, such as in the same manner as the external slotted plate 101.

[0046] In some embodiments, the central region 115 of the extension 90 is defined by one or more inner walls, which may be internal slotted plates 121 that define the finless region 115. The finless region 115 may be advantageously positioned at the center of the extension 90 to facilitate downward drainage in the WESP, which helps remove debris from the collection surface of the grid cell 30A associated with the extension. In other embodiments, the region 115 may be discarded, wherein the fins 110 extend through the diameter of the extension 90.

[0047] In some embodiments, each fin 110 has one or more end tabs 112 that facilitate attachment of the fin 110 to the inner slotted plate 121 via slots 113 (preferably two vertically spaced and aligned slots 113) in the penetrating plate 121. Other methods of attaching each fin 110 to the inner slotted plate 121 may be used, in which case the inner slotted plate may not need to be slotted and the fins may not require end tabs. The fins 110 thus extend radially from the outer slotted plate 101 to the inner slotted plate 121 as shown, providing surface area for particle collection. In some embodiments, the length of each fin 110 (e.g., from the outer slotted plate 101 to the inner slotted plate 121) is more than one time the height of the fin 110, preferably two times or more the height of each fin 110. In some embodiments, the surface area of ​​the extension 90 is greater than eight times the surface area of ​​the equivalent grid cell 30A height. The advantage of extension 90 is that it reduces the migration distance of the particles until they contact the collection surface, for example, to less than 1 / 8 of the distance that the particles must travel to contact the surface in the grid cell 30A.

[0048] In some embodiments, the fins 110 are equally spaced. In some embodiments, the spacing between the fins 110 is such that there is no gap greater than about 2 inches. In some embodiments, the spacing between the fins 110 is 0.125 inches to 1.0 inch. In some embodiments, the fins 110, when assembled in the extension 90, define a substantially flat or planar top surface, such as... Figure 3 As shown. For example, the generally flat or open top surface provides a walking surface for maintenance personnel to maintain the upper pressure ventilation chamber. Figure 4As shown, in some embodiments, each fin 110 has a curved bottom edge. The curved bottom edge has a first generally straight region 117A, followed by a sloping generally parabolic region 117B that terminates at the inner slotted plate 111. The curved bottom is designed such that the bottom and top of the extension of the electrode post mounted in the unit 30 maintain a constant distance. This distance should not be closer than the gap between the current emitter on the mast 50 and the wall of the unit 30, and should not be greater than 125% of that gap, preferably less than 110% of that gap. Maintaining the gap within this range will prevent short-circuiting of the electric field, while maintaining the electric field strength at the bottom of the extension similar to the electric field strength present in the unit 30 below. Maintaining the electric field strength at the entrance of the extension gives particles the greatest chance of being collected in the smaller gap of the collecting electrode extension. Those skilled in the art will understand that each fin 110 may have a different shape without departing from the spirit and scope of the embodiments disclosed herein; a key objective of the extension 90 is to provide additional surface area for particle collection, specifically without significantly increasing the height of the collecting surface. The extensions 90 do not significantly impede airflow, for example, they cause a pressure drop of less than 0.1 inch (H2O), and provide at least about 30% to about 80%, preferably at least about 40%, of the equivalent grid cell 30A surface area.

[0049] In some embodiments, the ionizing electrode mast 50 may extend through the extension 90. In this embodiment, the mast would need to be covered in an insulating material (such as ceramic) through which the mast passes to prevent electrical short circuits. This is not a preferred embodiment because conductive materials (most notably water) can deposit on the exterior of the insulating material and provide an electrical path between the ionizing electrode mast 50 and the extension 90 that could cause an electrical short circuit.

[0050] Other ways of increasing the effective surface area of ​​the collecting surfaces without significantly increasing their height are considered, such as by similarly attaching fins or other components to the ends of one or more grid cells 30A (or to the interior of one or more grid cells (30A) with different constructions (e.g., concentric circles or hexagons)).

[0051] Figure 5An embodiment of supporting extensions 90 on a grid cell 30A is shown. In the illustrated embodiment, each extension 90 is mechanically attached to the grid cell 30A via aligned interconnections, which facilitates its removability from the grid cell 30A for cleaning or maintenance, e.g., without damaging the extension 90 or the grid cell 30A, and thereby allows for reuse or replacement of the extension 90 when maintenance and / or cleaning are completed. These interconnections may be provided by a cylindrical post 85 having three bottom slots 87 (one shown), each slot 87 receiving the free end of the top wall 300 of the grid cell 30A at the Y-shaped intersection of the cell array. In the embodiment of the grid cell 30A, the slots 87 are spaced 120° apart. Similarly, the cylindrical post 85 has three top slots 88, each top slot 88 receiving a fin 110 extending radially beyond the outer slotted plate 101, e.g., at a bend or connection between two outer slotted plates 101 (e.g., Figure 4 (e.g., fins 110A in the grid). During assembly, the cylindrical posts 85 thus support the extensions 90 on the grid cells 30A. In some embodiments, the cylindrical posts 85 may be positioned at all six corners of each extension 90 to fully support each corresponding grid cell 30A. Other methods of supporting the extensions 90 on the grid cells 30A may be used, and these other methods are within the scope of the embodiments disclosed herein. Preferably, the supports are configured to facilitate easy removal and replacement of the extensions 90, such as for cleaning the collection electrodes.

[0052] In some embodiments, the extension 90 may be mounted and electrically connected to the bottom of the collecting electrode. This arrangement may be preferred if the process flow through the WESP is downward. This is not a preferred embodiment in applications with high particle loading because all collected particles need to be washed through the extension, and the small gaps in the extension may potentially clog and require manual cleaning.

[0053] Turn now Figure 6 , 7 In some embodiments, a high-pressure frame 40 is provided upstream or downstream (in the direction of industrial gas flow from inlet 12 to outlet 14). Figure 6 ) and upstream or downstream (in the direction of the treated gas flow from inlet 12 to outlet 14) high-pressure frame 41 ( Figure 7 and 8The upper high-voltage frame 40 is suspended from the top wall or top plate 46 of unit 100 by suitable supports including one or more support rods (three shown as 45A, 45B, and 45C). In some embodiments, the upper high-voltage frame 40 may include four connected support members 40A, 40B, 40C, and 40D forming a rectangular upper high-voltage frame 40 as shown. The top wall 46 of unit 100 may be electrically insulated from the support rods 45A, 45B, and 45C by corresponding insulators (not shown), which may be housed in corresponding insulator compartments. In various embodiments, the lower high-voltage frame 41 may be supported from the top wall 46, such as via an insulator mounted on the top wall, or may be supported from an insulator mounted on a side wall.

[0054] In some embodiments, the lower high-voltage frame 41 is supported from the high-voltage frame 40 by one or more (preferably four) support electrodes 37. By arranging the lower high-voltage frame 41 in this way, the collection surface extension 90 can be easily accommodated in the unit 100.

[0055] Support electrode 37 can support multiple rigid electrode support beams 49 ( Figure 7 This, in turn, supports the ionizing electrodes or masts 50. In some embodiments, the rigid electrode support beams 49 are spaced apart and positioned in a parallel horizontal array, each supporting multiple masts 50 respectively. Each of the multiple masts 50 may typically be elongated and rod-shaped, extending upward into a corresponding grid cell 30A, and preferably positioned at the center of and coaxial with each grid cell 30A. In this embodiment, the mast 50 is supported from the bottom by multiple rigid electrode support beams 49, with its free end downstream of its support end (in the direction of industrial gas flow from inlet to outlet). Preferably, the masts 50 are relatively short (e.g., less than 12 feet long, e.g., 10-12 feet long) to minimize deflection. To further minimize deflection, the walls of the masts 50 may be thicker than conventional, for example, 0.083 inches thick. Furthermore, cross bracing may be used to prevent swaying of the support structure (e.g., insulating rods or struts connecting the upper high-voltage frame 40 and / or the lower high-voltage frame 41 to the walls of the WESP). In some embodiments, the volume of each grid cell 30A, defined by its one or more outer walls, is empty, except for the mast 50. For example... Figure 7 and 8 As shown, in some embodiments, each mast 50 is attached to a rigid electrode support beam 49 using a single bolt or other fastener 99, and each mast 50 may be pre-aligned before being assembled into the unit 100. In some embodiments, suitable position adjusters may be provided on the masts 50 or the support beam 49 to properly position them in the unit 100.

[0056] In some embodiments, such as Figure 9A and 9BAs shown, the top of mast 50 may extend past the top of the collecting electrode or grid unit 30A. In this embodiment, two or more masts 50 (preferably at least three) can then be connected at a height sufficiently above the collecting electrode to prevent electrical short circuits, thereby stabilizing the masts 50. This height should be at least 110% and preferably greater than 125% of the distance between the mast 50 and the collecting electrode. In some embodiments, this height is about ten inches. In some embodiments, the stabilizer assembly includes a plurality of straps or plates 400 (three shown) that are attached to the upper end of the mast 50, for example, by means of coil pins that lock the mast 50 in place. Figure 9B Holes 402 may be formed in each plate 400 to receive coiled pins. In one embodiment, each plate 400 is a 14-gauge metal plate with a height of approximately 3 inches. A top plate 410 may be attached to the plate 400 to prevent the rod 50 from moving vertically.

[0057] In some embodiments, during operation of the dust collector 100, a process flow carrying particles is introduced into the inlet 12 of the unit and directed upwards to the outlet 14. Corona discharge is achieved between the ionizing electrode or column 50 and the array 30 of collecting electrodes such as grid cells 30A, which causes charged particles in the airflow to deposit on the collecting surface. The accumulated particulate deposits can then be removed, for example, by washing with a water spray.

[0058] While various aspects and embodiments have been disclosed herein, other aspects, embodiments, modifications, and changes will be apparent to those skilled in the art upon reading and understanding the foregoing detailed description. The aspects and embodiments disclosed herein are for illustrative purposes and are not intended to be limiting. This disclosure is intended to be construed as including all such aspects, embodiments, modifications, and changes, provided they fall within the scope of the appended claims or their equivalents.

Claims

1. An electrostatic precipitator (100), comprising: The housing has an inlet (12) for a gas process flow and an outlet (14) spaced apart from the inlet (12) for discharging the processed gas; a particle collection surface including one or more collection electrodes (30A) positioned within the housing and between the inlet (12) and the outlet (14); one or more ionization electrodes (50) in the housing, each ionization electrode (50) associated with a corresponding collection electrode (30A); and at least one collection surface extension (90) electrically connected to the collection electrode (30A), characterized in that the collection surface extension (90) includes a plurality of spaced-apart fins (110) to substantially increase the surface area available for particle collection without substantially increasing the height of the collection electrode.

2. The electrostatic precipitator (100) according to claim 1, wherein, The electrostatic precipitator is a wet electrostatic precipitator.

3. The electrostatic precipitator (100) according to claim 2, wherein, There are multiple collecting electrodes (30A) having hexagonal cross-sections and forming a honeycomb array of hexagonal grid cells.

4. The electrostatic precipitator (100) according to claim 3, wherein, There are multiple collection surface extensions (90), each collection surface extension (90) including a hexagonal periphery and supported on a corresponding collection electrode (30A).

5. The electrostatic precipitator (100) according to claim 4, wherein, Each collecting surface extension (90) includes an outer wall (101) and an inner wall (121) spaced apart from the outer wall (101), wherein the plurality of spaced-apart fins (110) extend from the outer wall (101) to the inner wall (121).

6. The electrostatic precipitator (100) according to claim 4, wherein, Each collecting surface extension (90) is mechanically supported on a corresponding collecting electrode (30A) by one or more supports (85) that provide aligned interconnection between the collecting electrode (30A) and the collecting surface extension (90).

7. The electrostatic precipitator (100) according to claim 6, wherein, Each support (85) is a slotted cylindrical tube.

8. The electrostatic precipitator (100) according to any one of the preceding claims, wherein, The collecting surface extension (90) is positioned downstream of the corresponding collecting electrode (30A) in the direction of industrial gas flow, or downstream of the ionization electrode position in the internal volume region of the corresponding collecting electrode in the direction of industrial gas flow, within at least a portion of the internal volume of the collecting electrode.

9. The electrostatic precipitator (100) according to claim 1 further comprises: Upper high-pressure support grid (40) is positioned downstream of the particle collection surface in the housing in the direction of gas process flow from the inlet (12) to the outlet (14); And a lower high-pressure support grid (41) located upstream of the particle collection surface in the housing in the direction of gas process flow from the inlet (12) to the outlet (14), the lower high-pressure support grid (41) supporting one or more ionization electrodes (50).

10. The electrostatic precipitator (100) according to claim 9 further includes at least one collecting surface extension (90) electrically connected to the collecting electrode (30A), the collecting surface extension (90) including a plurality of spaced-apart fins (110).

11. The electrostatic precipitator (100) according to claim 9 or 10, wherein, The housing has a top plate (46), and the electrostatic precipitator (100) further includes an electrical insulator supported from the top plate (46), wherein the lower high-voltage support grid (41) is connected to and supported by the electrical insulator.

12. The electrostatic precipitator (100) according to claim 9 or 10, wherein, The lower high-pressure support grid (41) is connected to and supported by the upper high-pressure support grid.

13. The electrostatic precipitator (100) according to claim 9 or 10, wherein, The housing has sidewalls, and wherein the lower high-voltage support grid (41) is supported by an electrical insulator mounted below the at least one collecting electrode (30A) in an insulating compartment on the sidewalls.

14. The electrostatic precipitator (100) according to any one of claims 1, 9, and 10, wherein, Each collecting electrode (30A) has an internal volume, a first region of which is occupied by its corresponding ionizing electrode (50), and at least a second region of which is not occupied by the ionizing electrode (50), wherein at least a portion of the second region is occupied by one or more collecting surface extensions (90).

15. The electrostatic precipitator (100) according to claim 14, wherein, Each portion of the second region occupied by the collecting surface extension (90) is located downstream of the corresponding ionizing electrode (50) that occupies the internal volume of the collecting electrode (30A) in the direction of the process airflow during operation of the electrostatic precipitator (100).

16. An electrostatic precipitator (100), comprising: A housing having an inlet (12) for a gas process flow and an outlet (14) spaced apart from the inlet (12) for discharging the treated gas; a particle collection surface including one or more collection electrodes (30A) positioned within the housing and between the inlet (12) and the outlet (14); and one or more ionization electrodes (50) within the housing, each ionization electrode (50) being associated with a corresponding collection electrode (30A). Associated with 0A); and at least one collecting surface extension (90) electrically connected to a collecting electrode (30A), characterized in that: each collecting electrode (30A) includes a grid cell having a grid cell surface area and a grid cell height, each collecting surface extension (90) having a collecting surface extension surface area and a collecting extension surface height, and wherein, for each grid cell height, the collecting surface extension surface area is at least four times larger than the grid cell surface area, and is equal to the collecting extension surface height.

17. The electrostatic precipitator (100) according to claim 16, wherein, The electrostatic precipitator is a wet electrostatic precipitator.

18. The electrostatic precipitator (100) according to claim 17, wherein, There are multiple collecting electrodes (30A) having hexagonal cross-sections and forming a honeycomb array of hexagonal grid cells.

19. The electrostatic precipitator (100) according to claim 18, wherein, There are multiple collection surface extensions (90), each collection surface extension (90) including a hexagonal periphery and electrically connected to a corresponding collection electrode (30A).

20. The electrostatic precipitator (100) according to claim 19, wherein, Each collecting surface extension (90) includes an outer wall (101) and an inner wall (121) spaced apart from the outer wall (101), wherein the plurality of spaced-apart fins (110) extend from the outer wall (101) to the inner wall (121).

21. A method for removing particles from a process stream using an electrostatic precipitator according to at least one of claims 1 to 8, 10, or 20, comprising: A corona discharge is generated between the at least one ionizing electrode (50) and the at least one collecting electrode (30A); The process flow is introduced into the inlet (12), whereby the process flow contacts the at least one collecting electrode (30A); The particles in the process flow are deposited on the collecting electrode (30A) and the collecting surface extension (90); as well as The deposited particle shell is removed from the collecting electrode (30A) and the collecting surface extension (90).

22. The method according to claim 21, wherein, There are multiple collecting electrodes (30A) having hexagonal cross-sections and forming a honeycomb array of hexagonal grid cells.

23. The method according to claim 22, wherein, There are multiple collection surface extensions (90), each collection surface extension (90) including a hexagonal periphery and supported on a corresponding collection electrode (30A).

24. The method according to claim 23, wherein, Each collecting surface extension (90) includes an outer wall (101) and an inner wall (121) spaced apart from the outer wall (101), wherein the plurality of spaced-apart fins (110) extend from the outer wall (101) to the inner wall (121).

25. The method according to claim 23, wherein, Each collecting surface extension (90) is mechanically supported on a corresponding collecting electrode (30A) by one or more supports (85) that provide aligned interconnection between the collecting electrode (30A) and the collecting surface extension (90).

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