Particulate filters and methods for removing particles from particulate filters

Abstract

The particulate filter of the present invention includes a porous filter matrix comprising a first surface and a second surface. The porous filter matrix is ​​configured to filter gas flowing through it between the first surface and the second surface. A plurality of conductors are coupled to the porous filter matrix. The plurality of conductors are generally parallel to each other along the porous filter matrix. The particulate filter further includes a plurality of input nodes that communicate signalically with the plurality of conductors and are configured to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source.

Description

[0001] This application is a divisional application of the invention patent application filed on September 21, 2020, with application number 202080066000.5 (international application number: PCT / US2020 / 051886) and entitled "particulate filter and method for removing particulates from particulate filter". Technical Field

[0002] This disclosure relates generally to filters, and more specifically to filters having particulate mitigation systems. Background Technology

[0003] A particulate filter is a device that removes solid particles (such as dust, pollen, mold, and / or bacteria) from a gas (such as air). One type of particulate filter uses mechanical filtration to capture and separate particles from the gas as it flows through the filter. Summary of the Invention

[0004] In one example, a particulate filter includes a porous filter matrix comprising a first surface and a second surface. The porous filter matrix is ​​configured to filter gas flowing through it between the first surface and the second surface. A plurality of conductors are coupled to the porous filter matrix. The plurality of conductors are generally parallel to each other along the porous filter matrix. The particulate filter further includes a plurality of input nodes that communicate signalically with the plurality of conductors and are configured to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source.

[0005] In another example, a method for removing particles from a particulate filter includes receiving voltage signals from an input signal source at a plurality of input nodes of the particulate filter. The particulate filter includes a porous filter matrix and a plurality of conductors coupled to the porous filter matrix. The porous filter matrix is ​​configured to filter gas flowing between a first surface and a second surface of the porous filter matrix. The plurality of conductors are generally parallel to each other along the porous filter matrix. The plurality of input nodes are in signal communication with the plurality of conductors. The method further includes generating an electric field on at least one of the first surface or the second surface of the porous filter matrix using the voltage signals on the plurality of conductors. The method further includes removing particles from the at least one of the first surface or the second surface using the electric field.

[0006] In another example, a method of manufacturing a particulate filter includes attaching a porous filter matrix to a frame. The porous filter matrix includes a first surface and a second surface. The porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix between the first surface and the second surface. The method further includes: attaching a plurality of conductors to the porous filter matrix such that the plurality of conductors are generally parallel to each other along the porous filter matrix; and forming a plurality of input nodes that communicate signalically with the plurality of conductors and are configured to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source.

[0007] In another example, a filter system includes a particulate filter and an electromagnetic field generator. The particulate filter includes a porous filter matrix comprising a first surface and a second surface. The porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix between the first surface and the second surface. The particulate filter further includes a plurality of conductors coupled to the porous filter matrix. The conductors are generally parallel to each other along the porous filter matrix. The particulate filter further includes a plurality of input nodes that communicate signalically with the plurality of conductors and are configured to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source.

[0008] The electromagnetic field generator is located upstream of the particulate filter along the gas flow path. The electromagnetic field generator is operable to generate an electromagnetic field that is configured to charge the particles in the gas before it flows through the porous filter matrix.

[0009] According to another example, a filter system includes a particulate filter, a gas recirculation system, and a controller. The particulate filter includes a porous filter matrix comprising a first surface and a second surface. The porous filter matrix is ​​configured to filter gas flowing through it in a direction from the first surface toward the second surface. The particulate filter further includes a plurality of conductors coupled to the porous filter matrix. The plurality of conductors are generally parallel to each other along the porous filter matrix. The particulate filter further includes a plurality of input nodes that communicate signalically with the plurality of conductors and are configured to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source.

[0010] The gas recirculation system includes a conduit having an inlet and an outlet. The inlet of the conduit is configured to receive the gas exiting the particulate filter at the second surface into the conduit. The outlet of the conduit is configured to output the gas from the conduit at the first surface back to the particulate filter. The controller communicates with the input signal source. The controller is configured to (i) cause the input signal source to provide a first voltage signal when the gas first flows through the porous filter matrix, and (ii) after the gas has been recirculated by the gas recirculation system, cause the input signal source to provide a second voltage signal when the gas flows through the porous filter matrix a second time. The first voltage signal is different from the second voltage signal.

[0011] According to another example, a filter system includes a particulate filter and a gas mover. The particulate filter includes a porous filter matrix comprising a first surface and a second surface. The porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix between the first surface and the second surface. The particulate filter further includes a plurality of conductors coupled to the porous filter matrix. The conductors are generally parallel to each other along the porous filter matrix. The particulate filter further includes a plurality of input nodes that communicate signalically with the plurality of conductors and are configured to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source.

[0012] The gas mover is positioned upstream of the particulate filter along the gas flow path. The gas mover is operable to generate turbulence in the gas before it flows through the porous filter matrix.

[0013] The features, functions, and advantages already discussed can be implemented independently in various instances or combined in other instances, as can be seen in further details with reference to the following description and figures. Attached Figure Description

[0014] The appended claims set forth novel features that are considered characteristic of the illustrative examples. However, the illustrative examples, their preferred modes of use, further purposes, and descriptions will be best understood, when read in conjunction with the accompanying drawings, by referring to the following detailed description of the illustrative examples of this disclosure, in which:

[0015] Figure 1 A simplified block diagram of a particulate filter based on an example is depicted.

[0016] Figure 2A three-dimensional diagram of a particulate filter based on another example is depicted.

[0017] Figure 3 A three-dimensional diagram of a particulate filter based on another example is depicted.

[0018] Figure 4A A three-dimensional diagram of a particulate filter based on another example is depicted.

[0019] Figure 4B A three-dimensional diagram of a particulate filter based on another example is depicted.

[0020] Figure 5 A cross-sectional view of a particulate filter based on another example is depicted.

[0021] Figure 6 A three-dimensional diagram of a particulate filter including an actuator, based on an example, is depicted.

[0022] Figure 7A Cross-sectional views of a microparticle porous filter matrix and conductor based on an example are depicted.

[0023] Figure 7B A cross-sectional view of a particulate porous filter matrix and conductor according to another example is depicted.

[0024] Figure 7C A cross-sectional view of a particulate porous filter matrix and conductor according to another example is depicted.

[0025] Figure 7D A cross-sectional view of a particulate porous filter matrix and conductor according to another example is depicted.

[0026] Figure 8 A simplified block diagram of a filter system based on an example is depicted.

[0027] Figure 9A Depicting based on an instance Figure 8 The side view of the filter system shown.

[0028] Figure 9B Depicting based on an instance Figure 9A The electromagnetic field generator of the filter system shown.

[0029] Figure 10 A simplified block diagram of a filter system based on an example is depicted.

[0030] Figure 11 Depicting based on another instance Figure 10 The diagram shows a three-dimensional view of the filter system.

[0031] Figure 12 A simplified block diagram of a filter system based on an example is depicted.

[0032] Figure 13 Depicting based on an instance Figure 12 The image shows one implementation of the filter system.

[0033] Figure 14 A flowchart illustrating a process for removing particles from a particulate filter, based on an example, is provided.

[0034] Figure 15 Depicting and Figure 14 The flowchart shown illustrates a process used in conjunction with a particulate filter to remove particles.

[0035] Figure 16 Described with Figure 15 The flowchart shown illustrates a process used in conjunction with a particulate filter to remove particles.

[0036] Figure 17 Depicting and Figure 15 The flowchart shown illustrates a process used in conjunction with a particulate filter to remove particles.

[0037] Figure 18 Described with Figure 17 The flowchart shown illustrates a process used in conjunction with a particulate filter to remove particles.

[0038] Figure 19 Depicting and Figure 14 The flowchart shown illustrates a process used in conjunction with a particulate filter to remove particles.

[0039] Figure 20 Depicting and Figure 14 The flowchart shown illustrates a process used in conjunction with a particulate filter to remove particles.

[0040] Figure 21 Depicting and Figure 14 The flowchart shown illustrates a process used together to remove particles from a filter.

[0041] Figure 22 A flowchart depicts the process of manufacturing a particulate filter based on an example.

[0042] Specific implementation method

[0043] The disclosed examples will now be described more fully below with reference to the accompanying drawings, which show some, but not all, of the disclosed examples. In fact, several different examples may be described, and these examples should not be construed as limited to those set forth herein. Rather, the description of these examples makes this disclosure thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0044] The terms “approximately” or “substantially” used with respect to quantities or measurements described herein mean that the characteristic, parameter, or value does not need to be precisely achieved, but rather that deviations or variations (including, for example, tolerances, measurement errors, measurement accuracy limitations, and other factors known to those skilled in the art) may occur in a quantity that does not preclude the effect provided by the desired characteristic.

[0045] As used herein, the terms “greater than” and “less than” are intended to have their ordinary meanings. Therefore, if the first value is greater than the second value by any amount, then the first value is greater than the second value. Similarly, if the first value is less than the second value by any amount, then the first value is less than the second value.

[0046] As described above, when gas flows through a particulate filter, the particulate filter can capture and separate particles from the gas. For example, the particulate filter may include a porous filter matrix capable of capturing and retaining particles in the gas through impaction, interception, and / or diffusion mechanisms. During the lifetime of the particulate filter, particles may accumulate on the porous filter matrix and may impede the flow of gas through the particulate filter (i.e., particle accumulation may clog the particulate filter). Thus, the accumulated particles reduce the efficiency of the particulate filter.

[0047] One approach to addressing reduced particulate filter efficiency due to accumulated particles is to manually clean the porous filter substrate. This method can be labor-intensive, time-consuming, and / or inefficient. Another approach is to remove the existing porous filter substrate and replace it with a new one. This method can be expensive, labor-intensive, and / or time-consuming. Additionally, in some cases, replacing the porous filter substrate may involve storing multiple replacement substrates in the field, and therefore may involve challenging storage space and supply logistics considerations. For example, storing multiple replacement substrates for spacecraft applications may pose challenges to meeting space constraints and / or weight limitations associated with the effective operation of spacecraft.

[0048] In this example, a particulate filter is described that addresses one or more of the aforementioned challenges associated with particles accumulating on the filter over time. Specifically, in this example, the particulate filter may include a plurality of conductors coupled to a porous filter matrix and configured to generate an electric field on at least one of a first or second surface of the porous filter matrix in response to a voltage signal from an input signal source. When the electric field is generated, it can expel and remove particles accumulated on the porous filter matrix, and / or expel particles to inhibit particle accumulation on the porous filter matrix. In this way, the particulate filter can allow cleaning of the porous filter matrix without (or with reduced) manual intervention. This facilitates more efficient, frequent, and / or rapid cleaning of the porous filter matrix. Additionally, the particulate filter described herein addresses the challenges associated with replacing and / or storing replacement porous filter matrices.

[0049] Now for reference Figure 1 This illustration shows a particulate filter 100 for filtering one or more particles from a gas, according to one example. In this example, the particles may include dust (e.g., Earth dust and / or dust from the external environment), mold spores, bacteria, microorganisms, fabric lint, food residue, metal shavings, wood chips, and / or plastic debris. Furthermore, in this example, the gas may include air, nitrogen, hydrogen, oxygen, and / or carbon dioxide. The particulate filter 100 can be used in a variety of environments to filter gases and remove particulates. For example, the particulate filter 100 can be used to filter gases in ventilation systems, spacecraft, space habitats, and / or spacesuits.

[0050] like Figure 1 As shown, the particulate filter 100 includes a porous filter matrix 110 having a first surface 112 and a second surface 114. Typically, the porous filter matrix 110 is configured to filter gas by removing particulates from a gas flowing between the first surface 112 and the second surface 114. For example, the porous filter matrix 110 may be configured to capture and retain particulates in the gas through impaction, interception, and / or diffusion mechanisms. Capturing and retaining particulates can help improve gas quality and, in some cases, mitigate potential undesirable consequences associated with exposing people and / or equipment to particulates.

[0051] For example, the porous filter matrix 110 can be made of paper material (e.g. The porous filter matrix 110 can be formed from woven fabrics, nonwoven fabrics, fibrous materials, elastomers, flexible materials, non-flexible materials, and / or porous membranes. More generally, the porous filter matrix 110 may comprise one or more materials defining a plurality of pores between a first surface 112 and a second surface 114, and the pore size may affect the flow rate of gas through the porous filter matrix 110 and the extent to which the porous filter matrix 110 captures particles. For example, relatively large pores may help increase the flow rate of gas through the porous filter matrix 110, while relatively small pores may help capture particle types with relatively small particle sizes.

[0052] In one example, the pores of the porous filter matrix 110 may have an average pore size of about 0.5 micrometers to about 100 micrometers. In another example, the pores of the porous filter matrix 110 may have an average pore size of about 0.5 micrometers to about 5.0 micrometers. In yet another example, the pores of the porous filter matrix 110 may have an average pore size of about 1.0 micrometer to about 2.5 micrometers. However, in other examples, the pores of the porous filter matrix 110 may have an average pore size of less than 0.05 micrometers or greater than 3.0 micrometers. The average pore size of the porous filter matrix 110 may be determined by the particle size of the particles to be filtered, and one or more porous filter matrices 110 with different pore sizes can be used to filter different particle sizes.

[0053] In one example, the porous filter matrix 110 may have multiple accordion-like pleats, each pleat comprising multiple panels and multiple fold lines between the respective panels. This helps increase the surface area of ​​the porous filter matrix 110, thereby improving filtration efficiency relative to an unpleated porous filter matrix 110. However, in other examples, the porous filter matrix 110 may be unpleated. In some cases, an unpleated geometry may help reduce manufacturing costs and / or facilitate placing the porous filter matrix 110 in a relatively small space (e.g., by reducing the depth of the porous filter matrix 110 relative to a pleated porous filter matrix 110).

[0054] The physical properties of the porous filter matrix 110 can be selected based on one or more factors, such as (i) the type of gas to be filtered, (ii) the type of particles that the porous filter matrix 110 is configured to capture and retain as the gas passes through it, and / or (iii) the environment in which the particulate filter 100 is located. For example, the porosity (i.e., the percentage of open space in the volume of the porous filter matrix 110), geometry, and / or material type of the porous filter matrix 110 can be based on these factors to achieve at least a threshold performance efficiency of the particulate filter 100.

[0055] Furthermore, the particulate filter 100 can be deployed in an environment where gas flows through the porous filter matrix 110 as pressurized gas (e.g., at a pressure greater than ambient pressure) and / or unpressurized gas (e.g., at ambient pressure). The physical properties of the porous filter matrix 110 can be additionally or alternatively selected based on the expected pressure of the gas flowing through the porous filter matrix 110. For example, when the gas is pressurized, the porous filter matrix 110 can be configured to have a relatively small porosity, while when the gas is unpressurized, the porous filter matrix 110 can be configured to have a relatively large porosity (e.g., in a first environment where the gas flows at a first pressure, the first porous filter matrix 110 can have a first porosity, and in a second environment where the gas flows at a second pressure, the second porous filter matrix 110 can have a second porosity, wherein the first pressure is less than the second pressure and the first porosity is greater than the second porosity).

[0056] The particulate filter 100 may also include a frame 116 coupled to and supporting the porous filter matrix 110. In one example, the frame 116 may define pores, and the porous filter matrix 110 may be coupled to the frame 116 such that the porous filter matrix 110 is positioned within the pores. This allows gas to flow through the frame 116 and the porous filter matrix 110. In an example, the frame 116 may be configured such that the pores defined by the frame 116 have a rectangular shape, a square shape, a circular shape, an elliptical shape, a triangular shape, a polygonal shape, and / or a non-polygonal shape.

[0057] In other instances, the particulate filter 100 may omit the frame 116. For example, in a self-supporting implementation of the porous filter matrix 110, the particulate filter 100 may omit the frame 116. For instance, the porous filter matrix 110 may be made of a material with rigidity that allows it to maintain a predetermined shape under expected operating conditions, thus making it self-supporting. In a self-supporting implementation of the porous filter matrix 110, the porous filter matrix 110 may have a pleated structure and / or an unpleated structure as described above.

[0058] For example, frame 116 may retain features through welding, adhesive bonding, non-adhesive bonding, snap-fit, friction coupling, and / or multiple hook-and-loop fasteners (e.g. The frame 116 is coupled to the porous filter matrix 110. In some implementations, the frame 116 can be configured to form a seal at the interface between the frame 116 and the porous filter matrix 110. This can help reduce (or may prevent) the flow of gas around the porous filter matrix 110 rather than through it. As an example, the frame 116 includes features for sealing. Figure 1 The gasket 118 at the interface between the frame 116 and the porous filter matrix 110.

[0059] In some instances, the frame 116 may have rigidity suitable for maintaining the shape of the porous filter matrix 110 and / or holding the structure of the porous filter matrix 110 in a fixed position relative to the environment in which the particulate filter 100 is deployed. This may be advantageous, for example, in implementations where the porous filter matrix 110 is made of a relatively flexible material. However, in other instances, the frame 116 may be omitted from the particulate filter 100, and the particulate filter 100 may be self-supporting.

[0060] During operation, particles may accumulate on the first surface 112 and / or the second surface 114 of the porous filter matrix 110. As mentioned above, the particles accumulated on the porous filter matrix 110 reduce the efficiency of the particulate filter 100, and therefore, it may be desirable to clean the porous filter matrix 110 to remove particles. In an example, the particulate filter 100 can remove particles from the porous filter matrix 110 by generating an electric field on the first surface 112 and / or the second surface of the porous filter matrix 110. Specifically, the electric field can be configured to use at least one force selected from electrostatic force, electrodynamic force, and dielectric force to expel and / or move particles away from the porous filter matrix 110.

[0061] like Figure 1 As shown, the particulate filter 100 further includes a plurality of conductors 120 coupled to a porous filter matrix 110 and a plurality of input nodes 122 in signal communication with the conductors 120. The input nodes 122 are configured to receive voltage signals from an input signal source 124. For example, the input node 122 may include at least one electrical connector selected from the group consisting of: conductive fasteners; mechanical clamps; torsion caps; crimp sleeve connectors; and pin connectors. The input node 122 may also include an electrically insulating material configured to insulate the conductors 120 from each other and mitigate short circuits between the conductors 120.

[0062] The type of input node 122 selected for particulate filter 100 can be based on the environment and / or background in which particulate filter 100 will be used. For example, the type of input node 122 can be selected based on at least one factor chosen from a group of factors consisting of: the mechanical strength of input node 122; the weight of input node 122; the size of input node 122; and the electrical insulation of input node 122. In some environments, it may be advantageous to select an input node 122 having: mechanical strength suitable for resisting separation of conductor 120 from input signal source 124; weight suitable for meeting weight constraints of the environment and / or background in which particulate filter 100 will be used (e.g., spacecraft and / or aircraft); size suitable for meeting size constraints of the environment and / or background in which particulate filter 100 will be used; and / or electrical insulation suitable for mitigating short circuits between conductors 120.

[0063] In some implementations, the input node 122 may be a separate structure. In alternative implementations, the input node 122 may be part of the frame 116. For example, in one implementation, the input node 122 may be integrally formed with the frame 116 using a 3D printing manufacturing process. Integrating the input node 122 with the frame 116, relative to a particulate filter 100 in which the input node 122 is separate from the frame 116, can help, for example, reduce the size and / or weight of the particulate filter 100.

[0064] As described in further detail below, the input signal source 124 can generate a voltage signal, the input node 122 can include electrodes for receiving and transmitting the voltage signal to the conductor 120, and the conductor 120 can use the voltage signal to radiate an electric field for manipulating particles on and / or near the porous filter matrix 110.

[0065] Typically, conductor 120 is configured to generate an electric field on at least one of the first surface 112 or the second surface 114 of the porous filter matrix 110 in response to receiving a voltage signal from input signal source 124 at input node 122. In some instances, conductor 120 may be coupled to both the first surface 112 and the second surface 114 of the porous filter matrix 110. In this arrangement, conductor 120 can provide an electric field in a manner that facilitates cleaning of both sides of the porous filter matrix 110, where particles may accumulate while filtering gases. However, in other instances, conductor 120 may be coupled only to the first surface 112 or only to the second surface 114. This can be useful in embodiments where a person can contact one surface of the first surface 112 or the second surface 114, omitting conductor 120.

[0066] In examples, conductor 120 can be coupled to the porous filter matrix 110 by braiding, screen printing, and / or embossing conductor 120 onto a first surface 112 and / or a second surface 114. For example, in one implementation, conductor 120 may comprise a plurality of conductive fibers (e.g., carbon nanotube fibers and / or graphite fibers) braided into the porous filter matrix 110. The conductive fibers may be made of a conductive material that (i) is elastic to fatigue, allowing the conductive fibers to repeatedly change shape without breaking, and (ii) has tensile strength resistant to tearing. This is advantageous in implementations where the porous filter matrix 110 is a braided material and / or a fibrous material. This may be additionally or optionally advantageous in implementations where the porous filter matrix 110 may undergo shape changes. In another implementation, for example, conductor 120 may comprise a conductive material (e.g., a metal and / or a conductive polymer) on at least one of the first surface 112 or the second surface 114 of the porous filter matrix 110. This is advantageous in implementations where the porous filter matrix 110 is a non-woven and / or non-fibrous material. This may also be advantageous, additionally or optionally, in implementations where the porous filter matrix 110 is unlikely to undergo shape changes.

[0067] Typically, conductors 120 are generally parallel to each other along the porous filter matrix 110. As described in further detail below, this can help generate an electric field that can expel and / or move particles away from the porous filter matrix 110. The term "generally parallel" means that conductors 120 are parallel, regardless of deviations or variations that may occur due to manufacturing tolerances, measurement errors, measurement accuracy limitations, and other factors that may arise due to the practical limitations of the manufacturing and / or measuring physics.

[0068] The position of conductors 120 on the porous filter matrix 110 and / or the spacing between conductors 120 can also affect the electric field generated by conductors 120 to expel and / or move particles away from the porous filter matrix 110. Thus, the position and / or spacing of conductors 120 on the porous filter matrix 110 can be based on the type and / or size of the particles to be expelled and / or moved by the electric field. The positioning and / or spacing of conductors 120 on the porous filter matrix 110 can additionally or alternatively be based on the geometry and / or porosity of the porous filter matrix 110. Figures 2 to 7D Various arrangements of conductors 120 on a porous filter matrix 110 according to some examples are depicted. In one example, conductors 120 may be spaced apart from about 1 mm to about 2 mm. In another example, conductors 120 may be spaced apart from about 0.3 mm to about 4.0 mm.

[0069] The input signal source 124 can be an alternating current (AC) voltage source and / or a direct current (DC) voltage source. As an example, the input signal source 124 may include a battery and / or an external power source (e.g., a power grid, battery and / or renewable energy generation system, such as a wind power system, a hydropower system, a solar power system and / or a fuel cell power system) located in the same place as the particulate filter 100.

[0070] Furthermore, in this example, the input signal source 124 can be configured to provide a single-phase AC signal and / or a multi-phase AC signal. The input signal source 124 can provide a single-phase AC signal and / or a DC signal to cause the conductor 120 to generate an electric field in the form of a standing wave on the first surface 112 and / or the second surface 114 of the porous filter matrix 110. Generating an electric field in the form of a standing wave can help remove and expel particles from the first surface 112 and / or the second surface 114 of the porous filter matrix 110 (e.g., by disrupting the adhesive or cohesive forces between the particles and the porous filter matrix 110, for example, due to electrostatic forces or van der Waals forces). Therefore, when a standing wave of the electric field is present, this can help remove particles that have already accumulated on the porous filter matrix 110 (i.e., clean the porous filter matrix 110) and / or inhibit the accumulation of other particles on the porous filter matrix 110.

[0071] The input signal source 124 may additionally or optionally provide a multiphase AC signal, such that the electric field generated by the conductor 120 forms a traveling wave along the first surface 112 and / or the second surface 114. Specifically, the conductor 120 may extend along the porous filter matrix 110 in a first direction, and the traveling wave may travel along the first surface 112 and / or the second surface 114 in a second direction transverse to the first direction. In this way, the traveling wave can expel particles from the porous filter matrix 110 and move particles along the porous filter matrix 110 (e.g., by disrupting the adhesion or cohesion between the particles and the porous filter matrix 110, for example, due to electrostatic forces or van der Waals forces).

[0072] like Figure 1 As shown, the particulate filter 100 may include a particulate collection container 126 surrounding the porous filter matrix 110. The particulate collection container 126 may be configured to collect particles removed from the porous filter matrix 110 by an electric field. For example, the particulate collection container 126 may be positioned along the path of the particles as a traveling wave of the electric field moves the particles in a second direction. In this way, the electric field generated by the conductor 120 can separate the particles from the porous filter matrix 110 and move the particles into the particulate collection container 126.

[0073] In some instances, the particulate collection container 126 may be removably coupled to the porous filter matrix 110 and / or frame 116 of the particulate filter 100. This facilitates rapid and efficient cleaning of the particulate filter 100 by separating the particulate collection container 126 for cleaning the particulates from the particulate collection container 126 and then reconnecting the particulate collection container 126 thereafter.

[0074] In other instances, the particulate collection container 126 may be fixedly coupled to the porous filter substrate 110 and / or the frame 116. In such instances, the particulate collection container 126 may still improve cleaning efficiency, at least because it can help concentrate particles in a central location that can be cleaned more easily and quickly than the porous filter substrate 110.

[0075] As described above, conductor 120, input node 122, and / or input signal source 124 are operable to generate an electric field, such that standing waves and / or traveling waves are formed on the first surface 112 and / or the second surface 114 of the porous filter matrix 110. Therefore, input signal source 124 can be configured to generate a voltage signal, such that the electric field forms a standing wave on at least one of the first surface 112 or the second surface 114. Alternatively or additionally, input signal source 124 can be configured to generate a voltage signal, such that the electric field forms a traveling wave that travels along at least one of the first surface 112 or the second surface 114 in a second direction transverse to the first direction of conductor 120.

[0076] exist Figure 1 In this document, the operation of the input signal source 124 can be controlled by a controller 128 that communicates with the input signal source 124. In this example, the controller 128 can be implemented using hardware, software, and / or firmware. For instance, the controller 128 may include one or more processors 130 and a non-transient computer-readable medium (e.g., volatile and / or non-volatile memory 132) storing machine language instructions or other executable instructions. When the instructions are executed by one or more processors 130, the instructions can cause components of the particulate filter 100 (e.g., the input signal source 124) to perform the various operations described herein. Therefore, the controller 128 can also receive data and store the data in memory.

[0077] Input signal source 124 can provide multiple voltage levels to the voltage signal, and controller 128 can be configured to select a voltage level from the multiple voltage levels for the voltage signal. In one example, input signal source 124 can provide a voltage signal with a voltage level between approximately 200 volts and approximately 10,000 volts based on a control signal from controller 128. In another example, input signal source 124 can provide a voltage signal with a voltage level between approximately 350 volts and approximately 1,200 volts based on a control signal from controller 128.

[0078] In an example, controller 128 may select the voltage level and / or waveform of a voltage signal from multiple voltage levels and / or multiple waveforms based on the type of particles, the size of the particles, the mass of the particles, and / or the atmospheric conditions of the environment in which the particle filter 100 is located (e.g., gravity, temperature, and / or humidity). For example, lunar dust (which can degrade spacesuits, degrade spacecraft systems, cause mechanical problems, obscure vision, negatively affect instrument readings, and / or affect health if inhaled) may be difficult to remove from conventional filters due to factors such as (1) lunar dust charged by solar wind and / or ultraviolet radiation due to lack of atmosphere, (2) lunar dust with irregular shapes and coarse particles that may adhere to the pores of the porous filter matrix, and / or (3) lunar dust with relatively small particle size. In one instance, to expel particles ranging in size from about 5 micrometers to about 400 micrometers in lunar conditions using conductor 120 with a thickness between about 0.5 micrometers and about 400 micrometers and a spacing between conductors between about 0.3 mm and about 4 mm, controller 128 enables input signal source 124 to provide voltage signals that are: (i) a voltage between about 500 volts and about 2000 volts, (ii) a frequency between about 5 hertz (Hz) and about 200 Hz, and (iii) as a single-phase or multi-phase signal. For Earth applications, these parameter values ​​can be increased by about 3 to about 5 times to account for the effects of gravity, humidity, and other atmospheric conditions.

[0079] As another example, in one implementation, the particulate filter 100 can be configured to use an electric field generated by conductor 120 to expel lunar dust and / or Martian dust with sizes between about 10 micrometers and about 75 micrometers. In this example implementation, conductor 120 can be a conductor with a thickness of about 180 micrometers to about 200 micrometers and can be spaced about 1 mm to about 2 mm apart. Additionally, in this example implementation, input signal source 124 can provide a voltage signal with a voltage level between about 350 volts and about 1200 volts based on a control signal from controller 128 to effectively expel lunar dust and / or Martian dust from the porous filter matrix 110.

[0080] The voltage level and / or waveform of the voltage signal may additionally or alternatively be based on the operating mode of the particle filter 100. For example, as described above, the input signal source 124 may operate in a first operating mode that causes the conductor 120 to generate an electric field in the form of a standing wave, and / or the input signal source 124 may operate in a second operating mode that causes the conductor 120 to generate an electric field in the form of a traveling wave. In an example, when the input signal source 124 operates in the first operating mode, the voltage signal may have a first voltage level and / or a first waveform, and when the input signal source operates in the second operating mode, the voltage signal may have a second voltage level and / or a second waveform. The first voltage level may be different from the second voltage level and / or the first waveform may be different from the second waveform.

[0081] In one implementation, controller 128 may initially provide a voltage signal to input signal source 124, causing an electric field to form a standing wave to separate particles from the porous filter matrix 110. When the electric field is applied in the form of a standing wave, particles may be suspended on a first surface 112 and / or a second surface 114 of the porous filter matrix 110. After the standing wave is formed, controller 128 may change the voltage signal of input signal source 124, causing the electric field to form a traveling wave that removes the suspended particles from the porous filter matrix 110 in a second direction (e.g., toward particle collection container 126).

[0082] Alternatively or concurrently, the controller 128 may cause the input signal source 124 to operate in a continuous mode and / or a pulsed mode. For example, when operating in continuous mode, the input signal source 124 may continuously provide a voltage signal, such that the electric field generated by the conductor 120 forms a barrier that prevents particles from reaching the porous filter matrix 110. Therefore, this helps to reduce the amount of particles accumulating on the porous filter matrix 110.

[0083] When operating in pulse mode, the input signal source 124 can provide a voltage signal in a pulsed manner, for example, a pulse with a duration of approximately 30 to approximately 60 seconds. This can help remove and expel particles that have previously accumulated on the porous filter matrix 110.

[0084] like Figure 1 As shown, the particulate filter 100 may further include a sensor 134 that can measure the amount of particles (e.g., dust) on the porous filter matrix 110. For example, the sensor 134 may include one or more capacitive sensors and / or one or more optical sensors. The sensor 134 may be located on, embedded in, or adjacent to the first surface 112 and / or the second surface 114 of the porous filter matrix 110.

[0085] The controller 128 can communicate with the sensor 134 and the input signal source 124. In one example, the controller 128 can be configured to automatically perform cleaning of the porous filter matrix 110 using sensor signals. For example, the controller 128 can (i) receive a sensor signal from the sensor 134 indicating the amount of particles (e.g., dust) on the porous filter matrix 110, (ii) determine, based on the amount of particles (e.g., dust) indicated by the sensor signal, that a particle quantity greater than a threshold has accumulated on the porous filter matrix 110, and (iii) in response to the determination that a particle quantity greater than the threshold has accumulated on the porous filter matrix 110, cause the input signal source 124 to provide voltage signals to a plurality of input nodes 122 to generate an electric field and remove particles from the porous filter matrix 110. Automatic cleaning of the porous filter matrix 110 can improve operational efficiency by cleaning the porous filter matrix 110 more effectively, quickly, and / or frequently while ensuring such cleaning.

[0086] The controller 128 may additionally or alternatively (i) receive a sensor signal from the sensor 134 indicating the amount of particles (e.g., dust) on the porous filter matrix 110, (ii) determine the value of an electrical parameter of a voltage signal based on the amount of particles (e.g., dust) indicated by the sensor signal, and (iii) cause the input signal source 124 to supply a voltage signal with that value to a plurality of input nodes 122. For example, the electrical parameter may be related to at least one of the voltage level or waveform (e.g., frequency, phase, and / or pulse width) of the voltage signal. In one example, the controller 128 may iteratively perform the following steps: receiving a sensor signal from the sensor 134; determining the electrical parameter; and causing the input signal source 124 to supply a voltage signal with that value. This can facilitate changing the voltage level and / or waveform (e.g., frequency, phase, and / or pulse width) in response to changes in the amount of particles on the porous filter matrix 110.

[0087] In one implementation where the electrical parameters include voltage values, the voltage value determined by the controller 128 can increase as the amount of particles measured by the sensor 134 increases (i.e., a relatively large voltage can be applied when the sensor 134 measures a relatively large number of particles on the porous filter matrix 110, and a relatively low voltage can be applied when the sensor 134 measures a relatively small number of particles on the porous filter matrix 110). For example, in one instance, the controller 128 can perform a comparison between the amount of particles measured by the sensor 134 and a threshold. In response to the controller 128 determining, based on the comparison, that the amount of particles measured by the sensor 134 is greater than the threshold, the controller 128 can cause the input signal source 124 to provide a voltage signal with a first voltage value to a plurality of input nodes 122. However, in response to the controller 128 determining, based on the comparison, that the amount of particles measured by the sensor 134 is less than the threshold, the controller 128 can cause the input signal source 124 to provide a voltage signal with a second voltage value to a plurality of input nodes 122. In this instance, the first voltage value can be greater than the second voltage value.

[0088] Additionally, for example, when the controller 128 activates the input signal source 124 before particles fall onto the porous filter matrix 110, a voltage signal with a relatively low voltage level can be provided by the input signal source 124 to expel and suppress particles from reaching the porous filter matrix 110. However, once particles have fallen onto the porous filter matrix 110, a voltage signal with a relatively high AC voltage level and / or DC voltage can be provided by the input signal source 124 to expel particles from the first surface 112 and / or the second surface 114 of the porous filter matrix 110.

[0089] In some instances, based on input data from sensor 134, controller 128 can use a lookup database (e.g., stored in memory 132) to determine electrical parameters (e.g., signal waveform type, frequency, voltage, phase, etc.) for use or adjustment to expel and / or remove particles falling or already fallen onto the porous filter matrix 110. The lookup database may include values ​​based on sensors or other sources that communicate with the controller.

[0090] Figure 2 Figure 7 illustrates some implementations of the particulate filter 100 according to the example. Figure 2 A particulate filter 200 comprising a porous filter matrix 210 is depicted. Figure 2In this porous filter substrate 210, there are multiple accordion-like folds 236, each fold including multiple panels 238 and multiple fold lines 240 between the respective panels of the multiple panels 238. As described above, providing accordion-like folds 236 to the porous filter substrate 210 for a specific height and width can help increase the surface area of ​​the porous filter substrate 210.

[0091] like Figure 2 As shown, the particulate filter 200 includes multiple conductors 220 extending across multiple panels 238 and multiple fold lines 240. This can facilitate the removal and expulsion of particulates from relatively large surface areas, and / or the removal and expulsion of relatively small particulates, when the conductors 120 are energized. Figure 2 In the middle, conductor 220 extends in a first direction 242 from a plurality of input nodes 222 that communicate with the input signal source 224. Although for ease of illustration, Figure 2 A conductor 220 is depicted extending over a portion of the porous filter matrix 210 (e.g., the upper half of the porous filter matrix 210), but in other instances, the conductor 220 may extend over other portions or the entire porous filter matrix 210.

[0092] In addition, such as Figure 2 As shown, the particulate filter 200 may include a frame 216 coupled to and supporting the porous filter matrix 210. Figure 2 In this example, frame 216 has a rectangular shape. However, in other instances, frame 216 can have different shapes. Frame 216 can also accommodate... Figure 2 The input signal source 224 is located in the frame 216. However, in other instances, the input signal source 224 may be located remotely outside the frame 216.

[0093] like Figure 2 As shown, the particulate filter 200 may further include a particulate collection container 226, which is located around the porous filter matrix 210 and configured to collect particles removed from the porous filter matrix 210 by an electric field, as described above. Figure 2 In this case, the particle collection container 226 can be connected to the frame 216.

[0094] As described above, in some cases, the input signal source 224 can generate a voltage signal, causing the electric field to form a traveling wave that travels along at least one of the first or second surfaces in a second direction 244 transverse to the first direction 242. For example... Figure 2As shown, the particle collection container 226 is positioned along the path of the particle as it is moved by the traveling wave in the second direction 244. The arrangement of the particle collection container 226 relative to the conductor 220 and this position of the traveling wave in the second direction 244 can help to efficiently collect particles in the particle collection container 226.

[0095] Figure 3 A particulate filter 300 comprising a porous filter matrix 310 is shown. Figure 3 In this porous filter substrate 310, multiple accordion-like folds 336 are provided. Each fold 336 includes multiple panels 338 and multiple fold lines 340 between the respective panels of the multiple panels 338. As described above, providing accordion-like folds 336 to the porous filter substrate 310 for a specific height and width can help increase the surface area of ​​the porous filter substrate 310. Figure 3 In this configuration, each conductor 320 extends along a corresponding fold line 340 of a plurality of fold lines 340. This can help remove and expel relatively large particles and / or reduce costs in implementations where a relatively small particle load may be expected.

[0096] In addition, such as Figure 3 As shown, the particulate filter 300 may include a frame 316 coupled to and supporting the porous filter matrix 310. The frame 316 may accommodate an input signal source 324 that is in signal communication with a plurality of input nodes 322, the plurality of input nodes 322 being in signal communication with conductor 320 and configured to receive voltage signals from the input signal source 324.

[0097] exist Figure 3 In this configuration, conductor 320 extends in a first direction 342. As described above, in some cases, input signal source 324 can generate a voltage signal, causing an electric field to form a traveling wave that travels along at least one of the first or second surfaces of the porous filter matrix 310 in a second direction 344 transverse to the first direction 342. Although in Figure 3 Although not shown, the particulate filter 300 may include a particulate collection container (e.g., particulate collection container 126, 226) around the porous filter matrix 310 (e.g., positioned along the path the particulate travels as it moves by traveling wave in the second direction 244) to facilitate the collection of particulates removed and / or expelled by the particulate filter 300.

[0098] exist Figures 2 to 3 In the particulate filters 200 and 300, a porous filter matrix 210 and 310 includes multiple accordion-like pleats 236 and 336. However, as mentioned above, in other embodiments, the accordion-like pleats 236 and 336 of the porous filter matrix 110 may be omitted. For example, Figures 4A to 4BParticulate filters 400A and 400B are depicted, both comprising a porous filter matrix 410 with pleats omitted. Figure 4A In this particulate filter 400A, a plurality of conductors 420 extend laterally across a porous filter matrix 410. In this arrangement, the conductors 420 can be formed in concentric circles, which, when energized, can contribute to alignment in a direction from the relatively larger circle to the relatively smaller circle (in Earth-like implementations, this direction is typically aligned with gravity). In the concentric circle arrangement, the conductors 420 can be substantially parallel to each other. Figure 4B In this particulate filter 400B, the conductor portion 420 extends longitudinally across the porous filter matrix 410. In this arrangement, the conductor 420 can be energized to remove and expel particles in the lateral direction (i.e., the direction transverse to the conductor 420).

[0099] In addition, such as Figures 4A to 4B As shown, particulate filters 400A and 400B include a frame 416 coupled to and supporting a porous filter matrix 410. In these examples, the frame 416 is coupled to a single end of the porous filter matrix 410 and helps to define an opening through which gas can flow at that end of the porous filter matrix 410. However, as mentioned above, the frame 416 may be omitted in other examples (e.g., in implementations where the porous filter matrix 410 is self-supporting).

[0100] Now for reference Figure 5 A cross-sectional view of a particulate filter 500 according to another example is shown. Figure 5 In this particulate filter 500, a porous filter matrix 510 and a frame 516 connected to and supporting the porous filter matrix 510 are also included. Figure 5 In this process, the porous filter matrix 510 includes a plurality of filter media 546A-546F disposed in a parallel plane between a first surface 512 and a second surface 514 of the porous filter matrix 510. The filter media 546A-546F may be formed of the same or similar materials as those described above with respect to the porous filter matrix 110. For example, the filter media 546A-546F may be made of paper material (e.g., paper). ), woven fabrics, nonwoven fabrics, fibrous materials, elastomers, flexible materials, non-flexible materials, and / or porous membranes. More generally, filter media 546A-546F may comprise one or more materials defining a plurality of pores between the first surface 512 and the second surface 514, and the pore size may affect the flow rate of gas through the porous filter matrix 510 and the extent to which the porous filter matrix 510 captures particles. Providing a plurality of filter media 546A-546F between the first surface 512 and the second surface 514 can help define a tortuous path for gas and particles to flow through the porous filter matrix 510, which can help improve filtration efficiency.

[0101] In some implementations, filter media 546A-546F may all be formed of a common type of material. This can be advantageous, for example, in implementations where the porous filter matrix 510 is configured to capture a specific type of particle and / or multiple types of particles with very similar particle sizes. In other implementations, at least one of the filter media 546A-546F may be formed of a material different from the material forming at least one of the filter media 546A-546F. This can be advantageous, for example, in implementations where the porous filter matrix 510 is configured to capture multiple different types of particles with multiple different particle sizes.

[0102] like Figure 5 As shown, the particulate filter 500 further includes a plurality of conductors 520, which are coupled to the porous filter matrix 510 in a manner similar to that described above with respect to conductors 120 coupled to the porous filter matrix 110 (e.g., by braiding, screen printing, and / or embossing the conductors 520 onto the porous filter matrix 510). Specifically, the plurality of conductors 520 are connected to the filter media 546A-546F of the porous filter matrix 510. For example, in Figure 5 In this process, multiple conductors 520 are connected to filter media 546A among multiple filter media 546, and filter media 546A defines a first surface 512 of porous filter matrix 510. Furthermore, in Figure 5 In this process, multiple conductors can be connected to the filter medium 546F that defines the second surface 514 of the porous filter matrix 510 and / or the filter medium 546C located between the first surface 512 and the second surface 514 of the porous filter matrix 510.

[0103] Despite Figure 5The conductor 520 is connected to filter media 546A, 546C, and 546F, but in other instances, conductor 520 may be connected to different filter media among filter media 546A-546F. For example, conductor 520 may be connected to any combination or arrangement of filter media 546A-546F based on one or more factors, such as the type of particles that filter media 546A-546F are configured to capture, the amount of filter media 546A-546F, and / or the relative positions of filter media 546A-546F within the porous filter matrix 510. Additionally, although in Figure 5 The porous filter matrix 510 includes six filter media 546A-546F, but in other embodiments, the porous filter matrix 510 may include fewer or more filter media 546A-546F. For example, the porous filter matrix 510 may include fewer filter media 546A-546F to provide relatively greater airflow, or the porous filter matrix 510 may include more filter media 546A-546F to increase the filtration capacity of the porous filter matrix 510 (i.e., to capture a larger number of particles).

[0104] Now for reference Figure 6 The image shows a particulate filter 600 according to another example. Figure 6 In this particulate filter 600, a porous filter matrix 310 is included, the porous filter matrix 310 having a plurality of accordion-like pleats 636, the pleats 636 including a plurality of panels 638 and a plurality of fold lines 640 between the respective panels of the plurality of panels 638. Figure 6 In this context, each conductor 620 extends along a corresponding fold line 640 of a plurality of fold lines 640, as described above regarding... Figure 3 As stated above.

[0105] The particulate filter 600 may also include a frame 616 coupled to and supporting the porous filter matrix 610. The frame 616 may accommodate an input signal source 624 that is in signal communication with a plurality of input nodes 622, the plurality of input nodes 622 being in signal communication with conductor 620 and configured to receive voltage signals from the input signal source 624.

[0106] exist Figure 6 In this particulate filter 600, the particulate filter 600 further includes an actuator 648 (e.g., an electromechanical actuator, a pneumatic actuator, and / or a hydraulic actuator) coupled to accordion-like pleats 636 and configured to adjust the shape of the porous filter matrix 610 from a first shape to a second shape. For example, the actuator 648 is operable to move one or more of the accordion-like pleats 636 relative to at least one other (and / or the frame 616). For example, in Figure 6In the middle, actuator 648 has moved the accordion-like folds 636 to open and expose the region 650 between a pair of adjacent accordion-like folds 636 (i.e., the porous filter matrix 610 in the middle). Figure 6 (The middle part is the second shape). When the accordion-like folds 636 are opened in this manner, the conductor 620 can generate an electric field to expel and / or remove particles. Using the actuator 648 to open the accordion-like folds 636 can help improve cleaning efficiency.

[0107] In some implementations, actuator 648 can repeatedly open and close each pair of adjacent accordion-like folds 636 and apply an electric field to perform a cleaning cycle. In some instances, actuator 648 can also be coupled with... Figure 1 The controller 128 shown communicates with the actuator 648 and is operable to control the operation of the actuator 648. For example, the controller 128 can be configured to operate the actuator 648 to open the accordion-like fold 636, and when the accordion-like fold 636 is opened, the controller 128 can cause the input signal source 624 to provide a voltage signal to the conductor 620, as described above.

[0108] As described above, conductor 120 can be bonded to the first surface 112 and / or the second surface 114 of the porous filter matrix 110 by braiding, screen printing, and / or embossing. As an example, Figures 7A to 7D Cross-sectional views of multiple conductors 720A to 720D connected to the corresponding porous filter substrates 710A to 710D are depicted according to the example.

[0109] exist Figure 7A In this process, conductor 720A comprises a plurality of conductive fibers woven into porous filter matrix 710A. Specifically, conductor 720A is woven into porous filter matrix 710A such that conductor 720A extends into (and / or through) a first surface 712A and a second surface 714A of porous filter matrix 710A. In this way, conductor 720A can generate an electric field at the first surface 712A and the second surface 714A of porous filter matrix 710A. This helps to expel and / or remove particles from the first surface 712A and the second surface 714A of porous filter matrix 710A.

[0110] exist Figure 7B In this context, conductor 720B further comprises multiple conductive fibers woven into the porous filter matrix 710B. However, in Figure 7BIn this design, conductor 720B extends to (and / or through) the first surface 712B, but does not extend to the second surface 714B of the porous filter matrix 710B. Thus, conductor 720B can generate an electric field at the first surface 712B, but not at the second surface 714B of the porous filter matrix 710B. This helps to expel and / or remove particles from the first surface 712B.

[0111] exist Figures 7A to 7B In this embodiment, conductors 720A and 720B comprise conductive fibers woven into the porous filter substrates 710A and 710B. However, as described above, the conductors may additionally or optionally comprise conductive material printed on at least one of the first or second surfaces of the porous filter substrate. Figure 7C In this embodiment, conductor 720C comprises a conductive material printed on a first surface 712C of the porous filter matrix 710C but not on a second surface 714C of the porous filter matrix 710C. Thus, conductor 720C can generate an electric field at the first surface 712C, but not at the second surface 714C of the porous filter matrix 710C. This facilitates the expulsion and / or removal of particles from the first surface 712C.

[0112] exist Figure 7D In this process, conductor 720D comprises conductive material printed on a first surface 712D and a second surface 714D. Thus, conductor 720D can generate an electric field at the first surface 712D and the second surface 714D of the porous filter matrix 710D. This helps to expel and / or remove particles from the first surface 712D and the second surface 714D of the porous filter matrix 710D.

[0113] Now for reference Figure 8 A simplified block diagram of a filter system 852 according to an example is shown. Figure 8 As shown, the filter system 852 includes a particulate filter 800 and an electromagnetic field generator 854. The particulate filter 800 may be similar to or equivalent to the one described above. Figures 1 to 6 Particulate filters 100, 200, 300, 400, 500, and 600 are shown and described. For example, particulate filter 800 may include a porous filter matrix 810, which includes a first surface 812 and a second surface 814. As described above, the porous filter matrix 810 is configured to filter gas flowing through the porous filter matrix 810 between the first surface 812 and the second surface 814.

[0114] The particulate filter 800 may further include a plurality of conductors 820 coupled to a porous filter matrix 810. The conductors 820 may be generally parallel to each other along the porous filter matrix 810. Additionally, the particulate filter 800 may include a plurality of input nodes 822 that are in signal communication with the plurality of conductors 820 and are configured to receive voltage signals from an input signal source 824. The plurality of conductors 820 are configured to generate an electric field on at least one of a first surface 812 or a second surface 814 of the porous filter matrix 810 in response to the plurality of input nodes 822 receiving voltage signals from the input signal source 824. As described above, when an electric field is generated, the electric field can expel and remove particles accumulated on the porous filter matrix 810, and / or expel particles to inhibit particle accumulation on the porous filter matrix 810.

[0115] In an example, conductor 820 may be coupled to at least one surface selected from a first surface 812 and a second surface 814 of the porous filter matrix 810. For example, as described above, conductor 820 may be coupled to at least one surface selected from a first surface 812 and a second surface 814 of the porous filter matrix 810. Figures 7A to 7D The first surface 812 and / or the second surface 814 of the porous filter matrix 810 are connected by weaving, screen printing, and / or embossing. Therefore, in one implementation, the conductor 820 may include a plurality of conductive fibers woven into the porous filter matrix 810.

[0116] The particulate filter 800 may also include the above and / or Figure 1 Any other features of the particulate filters 100, 200, 300, 400, 500, and 600 shown in Figure 7. For example, in some implementations, the particulate filter 800 may include a frame 816 to help provide structural rigidity to the periphery of the particulate filter 800, or in other implementations where the porous filter matrix 810 is self-supporting, the particulate filter 800 may omit the frame 816. Additionally, for example, the particulate filter 800 may include a gasket 818 for sealing the interface between the frame 816 and the porous filter matrix 810, as described above.

[0117] In some instances, the particulate filter 800 may further include an input signal source 824, as described above. Therefore, as described above, the input signal source 824 can operate in a first operating mode that generates an electric field in the form of a standing wave in the conductor 820, and / or the input signal source 824 can operate in a second operating mode that generates an electric field in the form of a traveling wave in the conductor 820. Thus, in the first operating mode, the input signal source 824 can generate a voltage signal that causes the electric field to form a standing wave on at least one of the first surface 812 or the second surface 814 of the porous filter matrix 810. However, in the second operating mode, the input signal source 824 can generate a voltage signal that causes the electric field to form a traveling wave. More specifically, as described above, the conductor 820 may extend along the porous filter matrix 810 in a first direction, and the input signal source 824 may generate a voltage signal that causes the electric field to form a traveling wave that travels along at least one of the first surface 812 or the second surface 814 in a second direction transverse to the first direction.

[0118] exist Figure 8 In this document, the operation of the input signal source 824 can be controlled by a controller 828 that communicates with the input signal source 824. In some examples, the controller 828 can be implemented using hardware, software, and / or firmware. For instance, the controller 828 may include one or more processors 830 and a non-transient computer-readable medium (e.g., volatile and / or non-volatile memory 832) storing machine language instructions or other executable instructions. When the instructions are executed by one or more processors 830, the instructions can cause components of the particulate filter 800 (e.g., the input signal source 824) to perform the various operations described herein. Therefore, the controller 828 can also receive data and store the data in memory.

[0119] In some instances, the particulate filter 800 may additionally or alternatively include a particulate collection container 826 located around the periphery of the porous filter matrix 810 and configured to collect particles removed from the porous filter matrix 810 by an electric field, as described above. In some implementations, the particulate collection container 826 may be positioned along the path of the particles as a traveling wave of the electric field moves the particles in a second direction. Thus, the electric field generated by the conductor 820 can separate the particles from the porous filter matrix 810 and move them into the particulate collection container 826. As described above, the particulate collection container 826 can help improve cleaning efficiency, at least because it can help concentrate the particles in a central location, which can be cleaned more easily and quickly than the porous filter matrix 810.

[0120] Furthermore, in some instances, the particulate filter 800 may include an actuator 848 operable to adjust the shape of the porous filter matrix 810, as described above. Figure 6As described. For example, actuator 848 is operable to cause accordion-like folds in the porous filter matrix 810 (e.g., Figure 6 One or more of the accordion-like folds 636 move relative to at least another of the accordion-like folds (and / or frame 816). As described above, when the accordion-like folds are opened in this manner, conductor 820 can generate an electric field to expel and / or remove particles. Using actuator 848 to open the accordion-like folds can help improve cleaning efficiency.

[0121] In some instances, the particulate filter 800 may include a sensor 834 that can measure the amount of particles (e.g., dust) on the porous filter matrix 810 as described above. Additionally, as described above, the sensor 834 may communicate with a controller 828, and the controller 828 may use the sensor signals received from the sensor 834 as a basis for: (i) triggering the generation of an electric field on the conductor 820; and / or (ii) determining electrical parameters of the voltage signal used to generate the electric field on the conductor 820.

[0122] exist Figure 8 In this configuration, the electromagnetic field generator 854 is operable to generate an electromagnetic field 856, which is configured to charge particles in the gas before the gas flows through the porous filter matrix 810. For example, in Figure 8 In this configuration, the electromagnetic field generator 854 is operable to generate an electromagnetic field 856 in a space 858 upstream of the particulate filter 800 along the gas flow path (e.g., the electromagnetic field generator 854 may be positioned upstream of the particulate filter 800 along the gas flow path). Charging the particles in the gas before the gas flows through the porous filter matrix 810 can help to more effectively use the electric field generated by the conductor 820 of the particulate filter 800 to expel and remove particles accumulated on the porous filter matrix 810, and / or expel particles to inhibit particle accumulation on the porous filter matrix 810.

[0123] In one example, the electromagnetic field generator 854 may include an EMF power supply 860 and an electromagnetic radiation element 862. The EMF power supply 860 may supply power to the electromagnetic radiation element 862, and the electromagnetic radiation element 862 may use the power to radiate an electromagnetic field 856 in the space 858 upstream of the particulate filter 800. As an example, the electromagnetic radiation element 862 may include at least one element selected from an antenna, coil, and mesh structure formed of a conductive material.

[0124] In some implementations, the electromagnetic field generator 854 may include an EMF controller 864. In such an implementation, the EMF controller 864 may be operable to control the EMF power supply 860 and / or the electromagnetic radiation element 862 to set and / or adjust the frequency, intensity, and / or spatial radiation mode of the electromagnetic field 856. In one example, the electromagnetic field generator 854 may generate an electromagnetic field with a frequency between approximately 1 Hz and approximately 300 Hz.

[0125] Figure 9A Depicting according to Figure 8 A side view of filter system 952, illustrating an example implementation of filter system 852. (See attached image.) Figure 9A As shown, the filter system 952 includes a particulate filter 900 and an electromagnetic field generator 954, which are substantially similar to or equivalent to the particulate filter 800 and electromagnetic field generator 854 described above. Figure 9A As shown, an electromagnetic field generator 954 is positioned upstream of the particulate filter 900 along the gas flow path 966. In this arrangement, the electromagnetic field generator 954 is operable to generate an electromagnetic field that charges the particles in the gas before the gas flows through the particulate filter 900.

[0126] Figure 9B The electromagnetic radiation element of an electromagnetic field generator 954, based on an example, is depicted. For example... Figure 9B As shown, the electromagnetic field generator 954 includes a mesh structure 962 offset from the first surface 912 of the particulate filter 900 by a gap 968 between the electromagnetic field generator 954 and the particulate filter 900. The mesh structure 962 includes a plurality of conductive strands 970 defining a plurality of orifices 972. The size of the orifices 972 is larger than the size of the particles in the gas. In this arrangement, an EMF power source (e.g., EMF power source 860) can supply power to the mesh structure 962 to cause the conductive strands 970 to radiate an electromagnetic field that can charge the particles in the gas, while the orifices 972 allow the particles in the gas to flow through the mesh structure 962 for filtration and / or collection by the particulate filter 900.

[0127] As described above, the mesh structure 962 can be separated from the particulate filter 900 by a gap 968. The gap 968 between the mesh structure 962 and the particulate filter 900 can help reduce interference between the electric field generated by the conductors (e.g., conductors 120, 820) of the particulate filter 900 and the electromagnetic field generated by the electromagnetic field generator 954.

[0128] Now for reference Figure 10 A simplified block diagram of a filter system 1052 according to an example is shown. Figure 10As shown, the filter system 1052 includes a particulate filter 1000 and a gas mover 1074. The particulate filter 1000 may be similar to or equivalent to the above reference. Figures 1 to 6 and Figures 8 to 9A Particulate filters 100, 200, 300, 400, 500, 600, and 800 are shown and described. For example, particulate filter 1000 may include a porous filter matrix 1010, which includes a first surface 1012 and a second surface 1014. As described above, the porous filter matrix 1010 is configured to filter gas flowing through the porous filter matrix 1010 between the first surface 1012 and the second surface 1014.

[0129] The particulate filter 1000 may further include a plurality of conductors 1020 coupled to a porous filter matrix 1010. The conductors 1020 may be generally parallel to each other along the porous filter matrix 1010. Additionally, the particulate filter 1000 may include a plurality of input nodes 1022 that are in signal communication with the plurality of conductors 1020 and configured to receive voltage signals from an input signal source 1024. The plurality of conductors 1020 are configured to generate an electric field on at least one of a first surface 1012 or a second surface 1014 of the porous filter matrix 1010 in response to the plurality of input nodes 1022 receiving voltage signals from the input signal source 1024. As described above, when an electric field is generated, the electric field can expel and remove particles accumulated on the porous filter matrix 1010, and / or expel particles to inhibit particle accumulation on the porous filter matrix 1010.

[0130] In this example, conductor 1020 may be coupled to at least one surface selected from a first surface 1012 and a second surface 1014 of the porous filter matrix 1010. For example, as described above, conductor 1020 may be coupled to at least one surface selected from a first surface 1012 and a second surface 1014 of the porous filter matrix 1010. Figures 7A to 7D The first surface 1012 and / or the second surface 1014 of the porous filter matrix 1010 are attached by weaving, screen printing and / or embossing.

[0131] The particulate filter 1000 may also include the above and / or Figures 1 to 9A Any other features of the particulate filters 100, 200, 300, 400, 500, 600, 800, and 900 shown. For example, in some implementations, the particulate filter 1000 may include a frame 1016 to help provide structural rigidity to the periphery of the particulate filter 1000, or in other implementations where the porous filter matrix 1010 is self-supporting, the particulate filter 1000 may omit the frame 1016. Additionally, for example, the particulate filter 1000 may include a gasket 1018 for sealing the interface between the frame 1016 and the porous filter matrix 1010, as described above.

[0132] In some instances, the particulate filter 1000 may further include an input signal source 1024, as described above. Therefore, as described above, the input signal source 1024 can operate in a first operating mode that generates an electric field in the form of a standing wave in the conductor 1020, and / or the input signal source 1024 can operate in a second operating mode that generates an electric field in the form of a traveling wave in the conductor 1020. Thus, in the first operating mode, the input signal source 1024 can generate a voltage signal that causes the electric field to form a standing wave on at least one of the first surface 1012 or the second surface 1014 of the porous filter matrix 1010. However, in the second operating mode, the input signal source 1024 can generate a voltage signal that causes the electric field to form a traveling wave. More specifically, as described above, the conductor 1020 may extend along the porous filter matrix 1010 in a first direction, and the input signal source 1024 may generate a voltage signal that causes the electric field to form a traveling wave that travels along at least one of the first surface 1012 or the second surface 1014 in a second direction transverse to the first direction.

[0133] exist Figure 10 In this document, the operation of the input signal source 1024 can be controlled by a controller 1028 that communicates with the input signal source 1024. In this example, the controller 1028 can be implemented using hardware, software, and / or firmware. For instance, the controller 1028 may include one or more processors 1030 and a non-transient computer-readable medium (e.g., volatile and / or non-volatile memory 1032) storing machine language instructions or other executable instructions. When the instructions are executed by one or more processors 1030, the instructions can cause components of the particulate filter 1000 (e.g., the input signal source 1024) to perform the various operations described herein. Therefore, the controller 1028 can also receive data and store the data in memory.

[0134] In some instances, the particulate filter 1000 may additionally or alternatively include a particulate collection container 1026 located around the periphery of the porous filter matrix 1010 and configured to collect particles removed from the porous filter matrix 1010 by an electric field, as described above. In some implementations, the particulate collection container 1026 may be positioned along the path of the particles as a traveling wave of the electric field moves the particles in a second direction. Thus, the electric field generated by the conductor 1020 can separate the particles from the porous filter matrix 1010 and move them into the particulate collection container 1026. As described above, the particulate collection container 1026 can help improve cleaning efficiency, at least because it can help concentrate the particles in a central location, which can be cleaned more easily and quickly than the porous filter matrix 1010.

[0135] Furthermore, in some instances, the particulate filter 1000 may include an actuator 1048 operable to adjust the shape of the porous filter matrix 1010, as described above. Figure 6 As described. For example, actuator 1048 is operable to cause accordion-like folds in the porous filter matrix 1010 (e.g., Figure 6 One or more of the accordion-like folds 636 move relative to at least another of the accordion-like folds (and / or frame 1016). As described above, when the accordion-like folds are opened in this manner, conductor 1020 can generate an electric field to expel and / or remove particles. Using actuator 1048 to open the accordion-like folds can help improve cleaning efficiency.

[0136] In some instances, the particulate filter 1000 may include a sensor 1034 that can measure the amount of particles (e.g., dust) on the porous filter matrix 1010 as described above. Additionally, as described above, the sensor 1034 may communicate with a controller 1028, and the controller 1028 may use the sensor signals received from the sensor 1034 as a basis for: (i) triggering the generation of an electric field on the conductor 1020; and / or (ii) determining electrical parameters of the voltage signal used to generate the electric field on the conductor 1020.

[0137] exist Figure 10 In this configuration, the gas mover 1074 is operable to generate turbulence in the gas before it flows through the porous filter matrix 1010. For example, in Figure 10 In this configuration, the gas mover 1074 is operable to generate turbulence in the space 1058 upstream of the particulate filter 1000 along the gas flow path (e.g., the gas mover 1074 may be positioned upstream of the particulate filter 1000 along the gas flow path). Generating turbulence in the gas before it flows through the porous filter matrix 1010 can help to more effectively capture particles in the porous filter matrix 1010 and / or more effectively use the electric field generated by the conductor 1020 to expel and inhibit particle accumulation on the porous filter matrix 1010.

[0138] In one example, the gas mover 1074 may include a fan positioned to blow gas (e.g., air) toward a space 1058 upstream of the particulate filter 1000 along a gas flow path. The gas blown at space 1058 may interact with the gas flowing along the flow path to generate turbulence in the gas flowing toward the particulate filter 1000 along the flow path. In another example, the gas actuator 1974 may additionally or optionally include a compressor. This may be advantageous, for example, in an implementation of the particulate filter 1000 for an air-conditioned environment.

[0139] Figure 11 Depicting according to Figure 10 The image shows a side view of filter system 1152, an example implementation of filter system 1052. Figure 11 As shown, the filter system 1152 includes a particulate filter 1100 and a gas mover 1174, which are substantially similar to or equivalent to the particulate filter 1000 and gas mover 1174 described above. Figure 11 As shown, the gas mover 1174 is positioned upstream of the particulate filter 1100 along the gas flow path 1166. In this arrangement, the gas mover 1174 is operable to direct the gas flow into the gas flow path 1166, thereby creating turbulence in the gas before it flows through the particulate filter 1100.

[0140] exist Figure 11 In this embodiment, the gas actuator 1174 is connected to the frame 1116 of the particulate filter 1100. This helps to maintain the gas actuator 1174 and the particulate filter 1100 in a fixed position and orientation relative to each other. However, in other instances, the gas actuator 1174 may be coupled to a structure separate from the particulate filter 1100. This is advantageous in implementations where the porous filter matrix 1110 of the particulate filter 1100 is self-supporting and the frame 1116 is omitted.

[0141] In addition, Figure 11 In this configuration, the gas mover 1174 is arranged relative to the particulate filter 1100 such that the gas mover 1174 can guide the gas flow in a direction transverse to the flow path 1166 of the gas flowing through the particulate filter 1100. This helps to generate turbulence in the gas flowing along the flow path 1166. In particular, in Figure 11 In this embodiment, the gas mover 1174 is arranged to guide the gas flow in a direction perpendicular to the flow path 1166. However, in other embodiments, the gas mover 1174 may be arranged differently relative to the particulate filter 1100 and / or the flow path 1166.

[0142] Now for reference Figures 12 to 13 The diagram illustrates a filter system 1252 based on an example. Specifically, Figure 12 A simplified block diagram of a filter system 1252 based on an example is depicted, and Figure 13 An implementation of a filter system 1252 based on an instance is described.

[0143] like Figures 12 to 13 As shown, the filter system 1252 includes a particulate filter 1200 and a gas recirculation system 1276. The particulate filter 1200 may be similar to or equivalent to the above reference. Figures 1 to 6 and Figures 8 to 11Particulate filters 100, 200, 300, 400, 500, 600, 800, and 1000 are shown and described. For example, particulate filter 1200 may include a porous filter matrix 1210, which includes a first surface 1212 and a second surface 1214. As described above, the porous filter matrix 1210 is configured to filter gas flowing through the porous filter matrix 1210 between the first surface 1212 and the second surface 1214.

[0144] The particulate filter 1200 may further include a plurality of conductors 1220 coupled to the porous filter matrix 1210. The conductors 1220 may be generally parallel to each other along the porous filter matrix 1210. Additionally, the particulate filter 1200 may include a plurality of input nodes 1222 that communicate signalically with the plurality of conductors 1220 and are configured to receive voltage signals from an input signal source 1224. The plurality of conductors 1220 are configured to generate an electric field on at least one of a first surface 1212 or a second surface 1214 of the porous filter matrix 1210 in response to the plurality of input nodes 1222 receiving voltage signals from the input signal source 1224. As described above, when the electric field is generated, it can expel and remove particles accumulated on the porous filter matrix 1210, and / or expel particles to inhibit particle accumulation on the porous filter matrix 1210.

[0145] In an example, conductor 1220 may be coupled to at least one surface selected from a first surface 1212 and a second surface 1214 of the porous filter matrix 1210. For example, as described above, conductor 1220 may be coupled to at least one surface selected from a first surface 1212 and a second surface 1214 of the porous filter matrix 1210. Figures 7A to 7D The weaving, screen printing and / or embossing shown are attached to the first surface 1212 and / or the second surface 1214 of the porous filter matrix 1210.

[0146] The particulate filter 1200 may also include the above and / or Figures 1 to 11 Any other features of the particulate filters 100, 200, 300, 400, 500, 600, 800, 900, 1000, and 1100 shown. For example, in some implementations, particulate filter 1200 may include a frame 1216 to help provide structural rigidity to the periphery of particulate filter 1200, or in other implementations where the porous filter matrix 1210 is self-supporting, particulate filter 1200 may omit the frame 1216. Additionally, for example, particulate filter 1200 may include a gasket 1218 for sealing the interface between frame 1216 and porous filter matrix 1210, as described above.

[0147] In some instances, the particulate filter 1200 may further include an input signal source 1224, as described above. Therefore, as described above, the input signal source 1224 can operate in a first operating mode that generates an electric field in the form of a standing wave in the conductor 1220, and / or the input signal source 1224 can operate in a second operating mode that generates an electric field in the form of a traveling wave in the conductor 1220. Thus, in the first operating mode, the input signal source 1224 can generate a voltage signal that causes the electric field to form a standing wave on at least one of the first surface 1212 or the second surface 1214 of the porous filter matrix 1210. However, in the second operating mode, the input signal source 1224 can generate a voltage signal that causes the electric field to form a traveling wave. More specifically, as described above, the conductor 1220 may extend along the porous filter matrix 1210 in a first direction, and the input signal source 1224 may generate a voltage signal that causes the electric field to form a traveling wave that travels along at least one of the first surface 1212 or the second surface 1214 in a second direction transverse to the first direction.

[0148] exist Figures 12 to 13 In this document, the operation of the input signal source 1224 can be controlled by a controller 1228 that communicates with the input signal source 1224. In this example, the controller 1228 can be implemented using hardware, software, and / or firmware. For instance, the controller 1228 may include one or more processors 1230 and a non-transient computer-readable medium (e.g., volatile and / or non-volatile memory 1232) storing machine language instructions or other executable instructions. When the instructions are executed by one or more processors 1230, the instructions can cause components of the particle filter 1200 (e.g., the input signal source 1224) to perform the various operations described herein. Therefore, the controller 1228 can also receive data and store the data in memory.

[0149] In some instances, the particulate filter 1200 may additionally or alternatively include a particulate collection container 1226 located around the periphery of the porous filter matrix 1210 and configured to collect particles removed from the porous filter matrix 1210 by an electric field, as described above. In some implementations, the particulate collection container 1226 may be positioned along the path of the particles as a traveling wave of the electric field moves the particles in a second direction. Thus, the electric field generated by the conductor 1220 can separate the particles from the porous filter matrix 1210 and move them into the particulate collection container 1226. As described above, the particulate collection container 1226 can help improve cleaning efficiency, at least because it can help concentrate the particles in a central location, which can be cleaned more easily and quickly than the porous filter matrix 1210.

[0150] Furthermore, in some instances, the particulate filter 1200 may include an actuator 1248 operable to adjust the shape of the porous filter matrix 1210, as described above. Figure 6 As described. For example, actuator 1248 is operable to cause accordion-like folds in the porous filter matrix 1210 (e.g., Figure 6 One or more of the accordion-like folds 636 move relative to at least one other of the accordion-like folds (and / or frame 1216). As described above, when the accordion-like folds are opened in this manner, conductor 1220 can generate an electric field to expel and / or remove particles. Using actuator 1248 to open the accordion-like folds can help improve cleaning efficiency.

[0151] In some instances, the particulate filter 1200 may include a sensor 1234, which can measure the amount of particles (e.g., dust) on the porous filter matrix 1210 as described above. Additionally, as described above, the sensor 1234 may communicate with a controller 1228, and the controller 1228 may use the sensor signal received from the sensor 1234 as a basis for: (i) triggering the generation of an electric field on the conductor 1220; and / or (ii) determining electrical parameters of the voltage signal used to generate the electric field on the conductor 1220.

[0152] exist Figures 12 to 13 In this system, the gas recirculation system 1276 includes a conduit 1278 having an inlet 1280 and an outlet 1282. The inlet 1280 of the conduit 1278 is configured to receive gas exiting the particulate filter 1200 at a second surface 1214 into the conduit 1278. The outlet 1282 of the conduit 1278 is configured to output gas from the conduit 1278 to the particulate filter 1200 at a first surface 1212. Thus, the conduit 1278 provides a conduit for recirculating gas from the second surface 1214 back to the first surface 1212, allowing the gas to pass through the porous filter matrix 1210 multiple times. This helps remove a relatively large number of particles from the gas compared to a filter system that allows gas to pass through the porous filter matrix 1210 only once.

[0153] In this example, as the gas is repeatedly circulated through the porous filter matrix 1210, the filter system 1252 can controllably adjust the electric field generated on the first surface 1212 and / or the second surface 1214 of the conductor 1220. For example, the controller 1228 can: (i) cause the input signal source 1224 to provide a first voltage signal when the gas first flows through the porous filter matrix 1210; and (ii) cause the input signal source 1224 to provide a second voltage signal when the gas flows through the porous filter matrix 1210 for the second time after the gas has been recirculated by the gas recirculation system 1276. The first voltage signal is different from the second voltage signal. Because different types of particles can be affected differently by different types of electric fields, adjusting the electric field when recirculating the gas through the porous filter matrix 1210 can more effectively remove more different types of particles from the given volume of gas compared to when a given volume of gas passes through the porous filter matrix 1210 once.

[0154] As described above, the first voltage signal is different from the second voltage signal. In some instances, the first voltage signal has a first voltage level and a first waveform, the second voltage signal has a second voltage level and a second waveform, and the first voltage level is different from the second voltage level. In some instances, the first voltage signal has a first voltage level and a first waveform, the second voltage signal has a second voltage level and a second waveform, and the first waveform is different from the second waveform. In another instance, when the gas recirculation system 1276 recirculates gas N times through the porous filter matrix 1210, the controller 1228 can cause the input signal source 1224 to provide M voltage signals that are different from each other in at least one aspect of voltage level or waveform, where N and M are integer values ​​greater than 1.

[0155] In some instances, the gas recirculation system 1276 may additionally include one or more baffles to assist in controlling the flow path of the gas in the gas recirculation system 1276. For example, as Figure 13 As shown, the gas recirculation system 1276 may include a first baffle 1284 downstream of inlet 1280 and a second baffle 1286 upstream of outlet 1282. The first baffle 1284 can be positioned at a first location ( Figure 13 (as shown by the dashed line) and the second position ( Figure 13(shown by the solid line in the middle) Actuation. When the first baffle 1284 is in the first position, the first baffle 1284 is configured to guide gas from the second surface 1214 to the inlet 1280 of the conduit 1278 of the gas recirculation system 1276. When the first baffle 1284 is in the second position, the first baffle 1284 is configured to allow gas to flow away from the inlet 1280 of the conduit 1278 of the gas recirculation system 1276. In this arrangement, the first baffle 1284 can be actuated to the first position to recirculate gas through the particulate filter 1200, and the first baffle 1284 can be actuated to the second position to discharge gas from the particulate filter 1200 and out of the filter system 1252 after recirculation and filtration are complete.

[0156] The second baffle 1286 can also be in the first position ( Figure 13 (as shown by the dashed line) and the second position ( Figure 13 (shown by the solid line in the middle) Actuation. When the second baffle 1286 is in the first position, the second baffle 1286 is configured to guide gas from the outlet 1282 of the conduit 1278 toward the first surface 1212 of the porous filter matrix 1210. When the second baffle 1286 is in the second position, the second baffle 1286 is configured to allow gas flow through the outlet 1282 of the conduit 1278 to reach the first surface 1212 of the porous filter matrix 1210. In this arrangement, the second baffle 1286 can be actuated to the second position to provide initial gas entry into the filter system 1252 and toward the particulate filter 1200, and the second baffle 1286 can be actuated to the first position to aid gas recirculation through the particulate filter 1200.

[0157] In some instances, controller 1228 may communicate with first baffle 1284 and second baffle 1286. In one implementation, controller 1228 may actuate second baffle 1286 to a second position to allow an initial volume of gas to flow into gas recirculation system 1276 and onto the first surface 1212 of porous filter matrix 1210. To recirculate the initial volume of gas, controller 1228 may actuate first baffle 1284 and second baffle 1286 to corresponding first positions. After the initial volume of gas has passed through porous filter matrix 1210 multiple times, controller 1228 may actuate first baffle 1284 from the first position to the second position to discharge gas from filter system 1252. For example, in an implementation where gas passes through porous filter matrix 1210 twice, after the gas has flowed through porous filter matrix 1210 a second time, controller 1228 may actuate first baffle 1284 from the first position to the second position. The controller 1228 can also actuate the second baffle 1286 to a second position to allow subsequent volumes of gas to flow into the filter system 1252, and the process can be repeated.

[0158] In some instances, the gas recirculation system 1276 may also include a recirculation fan 1288, configured to increase gas flow from inlet 1280 to outlet 1282. In this way, the gas recirculation system 1276 can help improve gas flow, which, compared to implementations omitting the recirculation fan 1288, can contribute to faster and / or more efficient gas recirculation and filtration. Figure 13 In this configuration, the recirculation fan 1288 is located within duct 1278 between inlet 1280 and outlet 1282. This can advantageously reduce or mitigate the obstruction of gas flow by the recirculation fan 1288 when gas is discharged from filter system 1252 (e.g., when the first baffle 1284 is in the second position). However, in other embodiments, the recirculation fan 1288 may be located in a different position (e.g., outside duct 1278).

[0159] As described above, controller 1228 can cause input signal source 1224 to provide multiple voltage signals with different electrical characteristics to generate multiple electric fields that can interact differently with different types of particles in the gas. In some instances, controller 1228 can additionally or alternatively adjust the shape of porous filter matrix 1210 as the gas is repeatedly recirculated through the porous filter matrix. For example, as described above, filter system 1252 may include actuator 1248, which in some implementations can adjust the shape of porous filter matrix 1210 from a first shape to a second shape. Controller 1228 can communicate with actuator 1248, and controller 1228 can be configured to: (i) cause actuator 1248 to arrange porous filter matrix 1210 into a first shape when the gas first flows through porous filter matrix 1210; and (ii) cause actuator 1248 to arrange porous filter matrix 1210 into a second shape when the gas flows through porous filter matrix a second time after the gas has been recirculated by gas recirculation system 1276. This helps to expose the gas to different portions of the porous filter matrix 1210 during different passes of the gas through the porous filter matrix 1210, which helps to improve filtration efficiency.

[0160] In one implementation, the porous filter matrix 1210 has a plurality of accordion-like folds, the plurality of accordion-like folds comprising a plurality of panels and a plurality of fold lines between the respective panels of the plurality of panels (e.g., Figure 6As shown, the accordion-like folds 636 include a panel 638 and fold lines 640. In this implementation, actuator 1248 can move at least one panel of the plurality of panels relative to at least another panel of the plurality of panels to adjust the shape of the porous filter matrix 1210 from a first shape to a second shape. In an implementation where the gas is further recirculated, controller 1228 can further cause actuator 1248 to further adjust the shape of the porous filter matrix 1210. For example, controller 1228 can further cause actuator 1248 to move at least one additional panel relative to at least another panel to further adjust the shape of the porous filter matrix 1210.

[0161] Now for reference Figure 14 The diagram illustrates a flowchart of a process 1400 for removing particles from a filter, based on an example. Figure 14 As shown, at block 1412, process 1400 includes receiving voltage signals from an input signal source at multiple input nodes of a particulate filter. The particulate filter includes a porous filter matrix and multiple conductors coupled to the porous filter matrix. The porous filter matrix is ​​configured to filter gas flowing between a first surface and a second surface of the porous filter matrix. The multiple conductors are generally parallel to each other along the porous filter matrix. The multiple input nodes are in signal communication with the multiple conductors.

[0162] At block 1414, process 1400 includes generating an electric field on at least one of a first or second surface of a porous filter matrix using voltage signals on a plurality of conductors. At block 1416, process 1400 includes removing particles from at least one of the first or second surfaces using the electric field.

[0163] Figures 15 to 21 Further aspects of process 1400 according to another example are described. In one example, multiple conductors extend along a porous filter matrix in a first direction. For example... Figure 15 As shown, generating an electric field at block 1414 using voltage signals on multiple conductors may include forming a traveling wave at block 1418 that travels along at least one of the first or second surfaces in a second direction transverse to the first direction.

[0164] like Figure 16 As shown, removing particles from at least one of the first or second surfaces using an electric field at box 1416 may include moving the particles toward the particle collection container in a second direction using an electric field at box 1420, and containing the particles in the particle collection container at box 1422.

[0165] like Figure 17As shown, generating an electric field at block 1414 using voltage signals on multiple conductors may include: (i) forming a standing wave at block 1424 at a first time using the electric field to separate particles from at least one of the first or second surfaces, and (ii) forming a traveling wave at block 1426 at a second time after forming the standing wave at block 1424 to move the particles in a second direction.

[0166] like Figure 18 As shown, receiving voltage signals from an input signal source at multiple input nodes at block 1412 may include: receiving a first voltage signal at a first time at block 1428; and receiving a second voltage signal at a second time at block 1430. The electrical parameters of the first voltage signal may have values ​​different from the electrical parameters of the second voltage signal.

[0167] like Figure 19 As shown, process 1400 may also include measuring the amount of particles on the porous filter matrix by a sensor at frame 1432. Figure 19 In this process, process 1400 may further include using a controller at block 1434 and determining whether to remove particles from the porous filter matrix based on the amount of particles measured by a sensor. In response to determining to remove particles from the porous filter matrix at block 1434, process 1400 may include providing voltage signals from an input signal source to a plurality of input nodes at block 1436.

[0168] like Figure 20 As shown, process 1400 may also include measuring the amount of particles on the porous filter matrix by a sensor at frame 1438. Additionally, in Figure 20 In this process, process 1400 may include, at block 1440, a controller receiving a sensor signal from a sensor indicating the amount of particles on the porous filter matrix. Process 1400 may also include, at block 1442, determining a value for an electrical parameter for a voltage signal based on the amount of particles indicated by the sensor signal. Process 1400 may further include, at block 1444, an input signal source providing a voltage signal with the electrical parameter set to that value to a plurality of input nodes.

[0169] like Figure 21 As shown, process 1400 may further include: filtering gas flowing through the porous filter matrix between a first surface and a second surface of the porous filter matrix at block 1446, and using an actuator at block 1448 to adjust the shape of the porous filter matrix from a first shape to a second shape. Figure 21 In this configuration, filtering the gas flowing through the porous filter matrix at frame 1446 may also include filtering the gas flowing through the porous filter matrix at frame 1450 when the porous filter matrix is ​​in its first shape. Furthermore, in Figure 21In this context, removing particles from at least one of the first or second surfaces using an electric field at frame 1416 may include removing particles from at least one of the first or second surfaces at frame 1452 when the porous filter matrix is ​​in a second shape.

[0170] Now for reference Figure 22 The diagram illustrates a flowchart of a filter manufacturing process 2200 based on an example. Figure 22 As shown, process 2200 includes attaching a porous filter matrix to a frame at frame 2212. The porous filter matrix includes a first surface and a second surface. The porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix between the first surface and the second surface.

[0171] At block 2214, process 2200 includes coupling a plurality of conductors to a porous filter matrix such that the conductors are generally parallel to each other along the porous filter matrix. At block 2216, process 2200 includes forming a plurality of input nodes that communicate signalically with the plurality of conductors and are configured to receive voltage signals from an input signal source. The plurality of conductors are configured to generate an electric field on at least one of the first or second surfaces of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source.

[0172] Figures 14 to 22 One or more boxes shown may represent a module, segment, or portion of program code, which includes one or more instructions executable by a processor for implementing a specific logical function or step in a process. The program code can be stored on any type of computer-readable medium or data storage, such as storage devices including disks or hard disk drives. Furthermore, the program code may be encoded in a machine-readable format on a computer-readable storage medium or on other non-transitory media or articles of art. Computer-readable media may include non-transitory computer-readable media or storage, such as computer-readable media that store data for short periods, like register memory, processor cache, and random access memory (RAM). Computer-readable media may also include non-transitory media, such as secondary or persistent long-term storage, such as read-only memory (ROM), optical disks or magnetic disks, and optical disc read-only memory (CD-ROM). Computer-readable media may also be any other volatile or non-volatile storage system. For example, a computer-readable medium can be considered a tangible computer-readable storage medium.

[0173] In some cases, components of the apparatus and / or system described herein may be configured to perform functions such that the components are actually configured and structured (in hardware and / or software) to achieve this performance. An example configuration may include one or more processors that execute instructions to cause the system to perform functions. Similarly, components of the apparatus and / or system may be configured to be arranged or adapted to perform these functions, for example, when operating in a particular manner.

[0174] Furthermore, this disclosure includes examples pursuant to the following provisions:

[0175] Clause 1. A particulate filter comprising: a porous filter matrix including a first surface and a second surface, wherein the porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix between the first surface and the second surface; a plurality of conductors coupled to the porous filter matrix, wherein the plurality of conductors are substantially parallel to each other along the porous filter matrix; and a plurality of input nodes in signal communication with the plurality of conductors and configured to receive voltage signals from the input signal source, wherein the plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source.

[0176] Clause 2. The particulate filter as described in Clause 1, wherein the plurality of conductors are coupled to the first surface of the porous filter matrix and the second surface of the porous filter matrix.

[0177] Clause 3. A particulate filter as described in Clause 1 or 2, wherein the plurality of conductors comprises a plurality of conductive fibers woven into the porous filter matrix.

[0178] Clause 4. The particulate filter as described in Clause 1 or 2, wherein the plurality of conductors comprises a conductive material printed on at least one of the first surface of the porous filter matrix or the second surface of the porous filter matrix.

[0179] Clause 5. The particulate filter of any one of Clauses 1 to 4, wherein the plurality of conductors extend along the porous filter matrix in a first direction, and wherein the particulate filter further includes the input signal source configured to generate the voltage signal such that the electric field forms a traveling wave that travels along at least one of the first surface or the second surface in a second direction transverse to the first direction.

[0180] Clause 6. The particulate filter as described in any one of Clauses 1 to 5 further includes the input signal source configured to generate the voltage signal such that the electric field forms a standing wave on at least one of the first surface or the second surface.

[0181] Clause 7. The particulate filter of any one of Clauses 1 to 6, further comprising: a sensor configured to measure the amount of particulates on the porous filter matrix; and a controller communicating with the sensor and the input signal source, wherein the controller is configured to: receive from the sensor a sensor signal indicating the amount of particulates on the porous filter matrix; determine a value of an electrical parameter for the voltage signal based on the amount of particulates indicated by the sensor signal; and cause the input signal source to provide the voltage signal to the plurality of input nodes with the electrical parameter being the value.

[0182] Clause 8. The particulate filter of any one of Clauses 1 to 7 further includes a particulate collection container surrounding the porous filter matrix and configured to collect particulates removed from the porous filter matrix by the electric field.

[0183] Clause 9. The particulate filter of any one of Clauses 1 to 8, wherein the porous filter matrix has a plurality of accordion-like folds, the plurality of accordion-like folds comprising a plurality of panels and a plurality of fold lines between respective panels in the plurality of panels, and wherein each conductor extends along a respective fold line of the plurality of fold lines.

[0184] Clause 10. The particulate filter of any one of Clauses 1 to 9, wherein the porous filter matrix has a plurality of accordion-like folds, the plurality of accordion-like folds comprising a plurality of panels and a plurality of fold lines between corresponding panels in the plurality of panels, and wherein the plurality of conductors extend across the plurality of panels and the plurality of fold lines.

[0185] Clause 11. The particulate filter of any one of Clauses 1 to 10, further comprising a frame coupled to and supporting the porous filter matrix, wherein the porous filter matrix comprises a plurality of filter media arranged in a parallel plane between the first surface and the second surface, and wherein the plurality of conductors are coupled to a filter media defining the first surface of the porous filter matrix among the plurality of filter media.

[0186] Clause 12. A method for removing particulates from a particulate filter, comprising: receiving voltage signals from an input signal source at a plurality of input nodes of the particulate filter, wherein the particulate filter includes a porous filter matrix and a plurality of conductors coupled to the porous filter matrix, wherein the porous filter matrix is ​​configured to filter gas flowing between a first surface and a second surface of the porous filter matrix, wherein the plurality of conductors are substantially parallel to each other along the porous filter matrix, wherein the plurality of input nodes are in signal communication with the plurality of conductors; generating an electric field on at least one of the first surface or the second surface of the porous filter matrix using the voltage signals on the plurality of conductors; and removing particulates from the at least one of the first surface or the second surface using the electric field.

[0187] Clause 13. The method of Clause 12, wherein the plurality of conductors extend along the porous filter matrix in a first direction, and wherein generating the electric field using the voltage signal on the plurality of conductors comprises forming a traveling wave that travels along at least one of the first surface or the second surface in a second direction transverse to the first direction.

[0188] Clause 14. The method as described in Clause 12 or 13, wherein removing the particles from at least one of the first surface or the second surface using the electric field comprises: moving the particles toward the particle collection container in the second direction using the electric field; and containing the particles in the particle collection container.

[0189] Clause 15. The method of any one of Clauses 12 to 14, wherein generating the electric field using the voltage signals on the plurality of conductors comprises: forming a standing wave by means of the electric field at a first time to separate the particle from at least one of the first surface or the second surface; and, after forming the standing wave, forming a traveling wave at a second time to move the particle in the second direction.

[0190] Clause 16. The method of Clause 15, wherein receiving the voltage signal from the input signal source at the plurality of input nodes comprises: receiving a first voltage signal at a first time; and receiving a second voltage signal at a second time, wherein the electrical parameters of the first voltage signal have values ​​different from the values ​​of the electrical parameters of the second voltage signal.

[0191] Clause 17. The method of any one of Clauses 12 to 16 further comprises: measuring the amount of particles on the porous filter matrix by a sensor; using a controller and determining, based on the amount of particles measured by the sensor, to remove the particles from the porous filter matrix; and, in response to the determination to remove the particles from the porous filter matrix, providing the voltage signal from the input signal source to the plurality of input nodes.

[0192] The method of any one of Clauses 12 to 17, further comprising: measuring the amount of particles on the porous filter matrix by a sensor; receiving from the sensor a sensor signal indicating the amount of particles on the porous filter matrix by a controller; determining a value of an electrical parameter for the voltage signal based on the amount of particles indicated by the sensor signal; and providing the voltage signal with the value of the electrical parameter to the plurality of input nodes by the input signal source.

[0193] Clause 19. The method of any one of Clauses 12 to 18, further comprising: filtering gas flowing through the porous filter matrix between a first surface of the porous filter matrix and a second surface of the porous filter matrix; and adjusting the shape of the porous filter matrix from a first shape to a second shape using an actuator, wherein filtering the gas flowing through the porous filter matrix includes filtering the gas flowing through the porous filter matrix when the porous filter matrix is ​​in the first shape, and wherein removing the particles from at least one of the first surface or the second surface using the electric field includes removing the particles from at least one of the first surface or the second surface when the porous filter matrix is ​​in the second shape.

[0194] Clause 20. A method of manufacturing a filter, comprising: attaching a porous filter matrix to a frame, wherein the porous filter matrix includes a first surface and a second surface, wherein the porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix between the first surface and the second surface; attaching a plurality of conductors to the porous filter matrix such that the plurality of conductors are substantially parallel to each other along the porous filter matrix; and forming a plurality of input nodes that are in signal communication with the plurality of conductors and are configured to receive voltage signals from the input signal source, wherein the plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source.

[0195] Clause 21. A filter system comprising: a particulate filter including: a porous filter matrix including a first surface and a second surface, wherein the porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix between the first surface and the second surface; a plurality of conductors coupled to the porous filter matrix, wherein the plurality of conductors are generally parallel to each other along the porous filter matrix; and a plurality of input nodes signal-communicating with the plurality of conductors and configured to receive voltage signals from the input signal source, wherein the plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source; and an electromagnetic field generator positioned upstream of the particulate filter along a gas flow path, wherein the electromagnetic field generator is operable to generate an electromagnetic field configured to charge particles in the gas before the gas flows through the porous filter matrix.

[0196] Clause 22. The filter system as described in Clause 21, wherein the electromagnetic field generator includes a mesh structure offset from the first surface by a gap between the electromagnetic field generator and the particulate filter.

[0197] Clause 23. The filter system as described in Clause 22, wherein the mesh structure comprises a plurality of conductive strands defining a plurality of pores, and wherein the size of the plurality of pores is larger than the size of the particles in the gas.

[0198] Clause 24. The filter system of any one of Clauses 21 to 23, wherein the plurality of conductors are coupled to at least one surface selected from the first surface of the porous filter matrix and the second surface of the porous filter matrix.

[0199] Clause 25. The filter system of any one of Clauses 21 to 24, wherein the plurality of conductors comprises a plurality of conductive fibers woven into the porous filter matrix.

[0200] Clause 26. The filter system of any one of Clauses 21 to 25, wherein the plurality of conductors extend along the porous filter matrix in a first direction, and wherein the particulate filter further includes the input signal source configured to generate the voltage signal such that the electric field forms a traveling wave that travels along at least one of the first surface or the second surface in a second direction transverse to the first direction.

[0201] Clause 27. The filter system of any one of Clauses 21 to 26 further includes the input signal source configured to generate the voltage signal such that the electric field forms a standing wave on at least one of the first surface or the second surface.

[0202] Clause 28. The filter system of any one of Clauses 21 to 27 further includes a particulate collection container located at the periphery of the porous filter matrix and configured to collect particulates removed from the porous filter matrix by the electric field.

[0203] Clause 29. A filter system comprising: a particulate filter including: a porous filter matrix including a first surface and a second surface, wherein the porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix in a direction from the first surface toward the second surface; a plurality of conductors coupled to the porous filter matrix, wherein the plurality of conductors are substantially parallel to each other along the porous filter matrix; and a plurality of input nodes signal-communicating with the plurality of conductors and configured to receive voltage signals from the input signal source, wherein the plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source; and gas. A recirculation system includes a conduit having an inlet and an outlet, wherein the inlet of the conduit is configured to receive gas exiting the particulate filter at a second surface into the conduit, and wherein the outlet of the conduit is configured to output the gas from the conduit at the first surface to the particulate filter; and a controller communicating with an input signal source, wherein the controller is configured to: cause the input signal source to provide a first voltage signal when the gas first flows through the porous filter matrix; and after the gas is recirculated by the gas recirculation system, cause the input signal source to provide a second voltage signal when the gas flows through the porous filter matrix a second time, wherein the first voltage signal is different from the second voltage signal.

[0204] Clause 30. The filter system as described in Clause 29, wherein the first voltage signal has a first voltage level and a first waveform, wherein the second voltage signal has a second voltage level and a second waveform, and wherein the first voltage level is different from the second voltage level.

[0205] Clause 31. The filter system as described in Clause 29 or 30, wherein the first voltage signal has a first voltage level and a first waveform, wherein the second voltage signal has a second voltage level and a second waveform, and wherein the first waveform is different from the second waveform.

[0206] Clause 32. The filter system of any one of Clauses 29 to 31 further includes an actuator configured to adjust the shape of the porous filter matrix from a first shape to a second shape, wherein the controller communicates with the actuator, and wherein the controller is configured to: cause the actuator to arrange the porous filter matrix in the first shape when the gas first flows through the porous filter matrix; and after the gas is recirculated by the gas recirculation system, cause the actuator to arrange the porous filter matrix in the second shape when the gas flows through the porous filter matrix a second time.

[0207] Clause 33. The filter system as described in Clause 32, wherein the porous filter matrix has a plurality of accordion-like folds, the plurality of accordion-like folds comprising a plurality of panels and a plurality of fold lines between corresponding panels of the plurality of panels, and wherein the actuator is configured to move at least one of the plurality of panels relative to at least another panel of the plurality of panels in order to adjust the shape of the porous filter matrix from a first shape to a second shape.

[0208] Clause 34. The filter system of any one of Clauses 29 to 33, wherein the gas recirculation system further includes a baffle actuable between a first position and a second position, wherein when the baffle is in the first position, the baffle is configured to direct the gas toward the inlet of the conduit of the gas recirculation system, and wherein when the baffle is in the second position, the baffle is configured to allow the gas to flow away from the inlet of the conduit of the gas recirculation system.

[0209] Clause 35. The filter system as described in Clause 34, wherein the controller communicates with the baffle, and wherein the controller is configured to actuate the baffle from the first position to the second position after the gas flows through the porous filter matrix for the second time.

[0210] Clause 36. The filter system of any one of Clauses 29 to 35, wherein the gas recirculation system includes a recirculation fan configured to increase the flow of the gas from the inlet to the outlet.

[0211] Clause 37. The filter system of any one of Clauses 29 to 36 further includes a particulate collection container surrounding the porous filter matrix and configured to collect particulates removed from the porous filter matrix by the electric field.

[0212] Clause 38. A filter system comprising: a particulate filter including: a porous filter matrix including a first surface and a second surface, wherein the porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix between the first surface and the second surface; a plurality of conductors coupled to the porous filter matrix, wherein the plurality of conductors are generally parallel to each other along the porous filter matrix; and a plurality of input nodes signal-communicating with the plurality of conductors and configured to receive voltage signals from the input signal source, wherein the plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source; and a gas mover positioned upstream of the particulate filter along a gas flow path, wherein the gas mover is operable to generate turbulence in the gas before the gas flows through the porous filter matrix.

[0213] Clause 39. The filter system as described in Clause 38, wherein the plurality of conductors are coupled to at least one surface selected from the first surface of the porous filter matrix and the second surface of the porous filter matrix.

[0214] Clause 40. A filter system as described in Clause 38 or 39, wherein the gas mover includes a fan.

[0215] Clause 41. A filter system comprising: a particulate filter including: a porous filter matrix including a first surface and a second surface, wherein the porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix in a direction from the first surface toward the second surface; and a plurality of conductors coupled to the porous filter matrix, wherein the plurality of conductors are substantially parallel to each other along the porous filter matrix, wherein the plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to a voltage signal from an input signal source; and a gas recirculation system including a conduit having an inlet and an outlet, wherein the inlet of the conduit is configured to receive the gas exiting the particulate filter at the second surface into the gas recirculation system. The pipeline, wherein the outlet of the pipeline is configured to output the gas from the pipeline at the first surface to the particulate filter; and a controller communicating with the input signal source, wherein the controller is configured to: cause the input signal source to provide a first voltage signal to the plurality of conductors when the gas first flows through the porous filter matrix, and after the gas is recirculated from the inlet to the outlet by the gas recirculation system, cause the input signal source to provide a second voltage signal to the plurality of conductors when the gas flows through the porous filter matrix for the second time, wherein the first voltage signal is different from the second voltage signal, such that the electric field is adjusted between the first and second flows of the gas through the porous filter matrix.

[0216] Clause 42. The filter system as described in Clause 41, wherein the first voltage signal has a first voltage level and a first waveform, wherein the second voltage signal has a second voltage level and a second waveform, and wherein the first voltage level is different from the second voltage level.

[0217] Clause 43. The filter system as described in Clause 41 or 42, wherein the first voltage signal has a first voltage level and a first waveform, wherein the second voltage signal has a second voltage level and a second waveform, and wherein the first waveform is different from the second waveform.

[0218] Clause 44. The filter system of any one of Clauses 41 to 43 further includes an actuator configured to adjust the shape of the porous filter matrix from a first shape to a second shape, wherein the controller communicates with the actuator, and wherein the controller is configured to: cause the actuator to arrange the porous filter matrix in the first shape when the gas first flows through the porous filter matrix, and to arrange the porous filter matrix in the second shape when the gas flows through the porous filter matrix a second time after the gas has been recirculated by the gas recirculation system.

[0219] Clause 45. The filter system of any one of Clauses 41 to 44, wherein the porous filter matrix has a plurality of accordion-like folds, the plurality of accordion-like folds comprising a plurality of panels and a plurality of fold lines between respective panels of the plurality of panels, and wherein the actuator is configured to move at least one of the plurality of panels relative to at least another panel of the plurality of panels to adjust the shape of the porous filter matrix from a first shape to a second shape.

[0220] Clause 46. The filter system of any one of Clauses 41 to 45, wherein the gas recirculation system further includes a baffle actuable between a first position and a second position, wherein when the baffle is in the first position, the baffle is configured to direct the inlet of the conduit toward the gas recirculation system, wherein when the baffle is in the second position, the baffle is configured to allow the gas to flow away from the inlet of the conduit of the gas recirculation system, wherein the controller communicates with the baffle, and wherein the controller is configured to actuate the baffle from the first position to the second position after the gas has flowed through the porous filter matrix for the second time.

[0221] Clause 47. The filter system of any one of Clauses 41 to 46, wherein the gas recirculation system further includes a first baffle downstream of the inlet and a second baffle upstream of the outlet, wherein the controller communicates with the first baffle and the second baffle, and wherein the controller is configured to actuate the first baffle and the second baffle to control the flow path of the gas in the gas recirculation system.

[0222] Clause 48. The filter system of Clause 47, wherein the first baffle is actuated between a first position and a second position, wherein when the first baffle is in the first position, the first baffle is configured to guide the gas from the second surface toward the inlet of the conduit of the gas recirculation system, wherein when the first baffle is in the second position, the first baffle is configured to allow the gas to flow away from the inlet of the conduit of the gas recirculation system, wherein the second baffle is actuated between the first position and the second position, wherein when the second baffle is in the first position, the second baffle is configured to guide the gas from the outlet of the conduit toward the first surface of the porous filter matrix, and wherein when the second baffle is in the second position, the second baffle is configured to allow the gas to flow through the outlet of the conduit to the first surface of the porous filter matrix.

[0223] Clause 49. The filter system of any one of Clauses 41 to 48, wherein the gas recirculation system includes a recirculation fan configured to increase the flow of the gas from the inlet to the outlet.

[0224] Clause 50. The filter system as described in Clause 49, wherein the recirculation fan is positioned in the duct between the inlet and the outlet.

[0225] Clause 51. The filter system of any one of Clauses 41 to 50 further includes a particulate collection container surrounding the porous filter matrix and configured to collect particulates removed from the porous filter matrix by the electric field.

[0226] Clause 52. A filter system comprising: a particulate filter including: a porous filter matrix including a first surface and a second surface, wherein the porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix in a direction from the first surface toward the second surface; and a plurality of conductors coupled to the porous filter matrix, wherein the plurality of conductors are substantially parallel to each other along the porous filter matrix, wherein the plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to a voltage signal from an input signal source; and a gas recirculation system including a conduit having an inlet and an outlet, wherein the inlet of the conduit is configured to pass through the second surface. The gas exiting the particulate filter at the surface is received into the conduit, wherein the outlet of the conduit is configured to output the gas from the conduit at the first surface to the particulate filter; an actuator configured to adjust the shape of the porous filter matrix from a first shape to a second shape; and a controller communicating with the actuator, wherein the controller is configured to: cause the actuator to arrange the porous filter matrix into the first shape when the gas first flows through the porous filter matrix, and after the gas is recirculated from the inlet to the outlet by the gas recirculation system, cause the actuator to arrange the porous filter matrix into the second shape when the gas flows through the porous filter matrix for the second time.

[0227] Clause 53. The filter system as described in Clause 52, wherein the porous filter matrix has a plurality of accordion-like folds, the plurality of accordion-like folds comprising a plurality of panels and a plurality of fold lines between corresponding panels of the plurality of panels, and wherein the actuator is configured to move at least one of the plurality of panels relative to at least another panel of the plurality of panels to adjust the shape of the porous filter matrix from a first shape to a second shape.

[0228] Clause 54. The filter system as described in Clause 52 or 53, wherein the gas recirculation system further includes a baffle actuated between a first position and a second position, wherein when the baffle is in the first position, the baffle is configured to direct the gas toward the inlet of the conduit of the gas recirculation system, wherein when the baffle is in the second position, the baffle is configured to allow the gas to flow away from the inlet of the conduit of the gas recirculation system, wherein the controller communicates with the baffle, and wherein the controller is configured to actuate the baffle from the first position to the second position after the gas has flowed a second time through the porous filter matrix.

[0229] Clause 55. The filter system of any one of Clauses 52 to 54, wherein the gas recirculation system further includes a first baffle downstream of the inlet and a second baffle upstream of the outlet, wherein the controller communicates with the first baffle and the second baffle, and wherein the controller is configured to actuate the first baffle and the second baffle to control the flow path of the gas in the gas recirculation system.

[0230] Clause 56. The filter system of Clause 55, wherein the first baffle is actuated between a first position and a second position, wherein when the first baffle is in the first position, the first baffle is configured to guide the gas from the second surface toward the inlet of the conduit of the gas recirculation system, wherein when the first baffle is in the second position, the first baffle is configured to allow the gas to flow away from the inlet of the conduit of the gas recirculation system, wherein the second baffle is actuated between the first position and the second position, wherein when the second baffle is in the first position, the second baffle is configured to guide the gas from the outlet of the conduit toward the first surface of the porous filter matrix, and wherein when the second baffle is in the second position, the second baffle is configured to allow the gas to flow through the outlet of the conduit to the first surface of the porous filter matrix.

[0231] Clause 57. The filter system of any one of Clauses 52 to 56, wherein the gas recirculation system includes a recirculation fan configured to increase the flow of the gas from the inlet to the outlet.

[0232] Clause 58. The filter system of any one of Clauses 52 to 57, wherein the recirculation fan is positioned in the duct between the inlet and the outlet.

[0233] Clause 59. The filter system of any one of Clauses 52 to 58 further includes a particulate collection container around the porous filter matrix and configured to collect particulates removed from the porous filter matrix by the electric field.

[0234] Clause 60. A method for removing particulates from a particulate filter, comprising: receiving a first voltage signal from an input signal source at a plurality of input nodes of the particulate filter, wherein the particulate filter includes a porous filter matrix and a plurality of conductors coupled to the porous filter matrix, wherein the porous filter matrix is ​​configured to filter gas flowing from a first surface of the porous filter matrix to a second surface of the porous filter matrix, wherein the plurality of conductors are substantially parallel to each other along the porous filter matrix, wherein the plurality of input nodes are in signal communication with the plurality of conductors; generating an electric field on at least one of the first surface or the second surface of the porous filter matrix using the first voltage signal on the plurality of conductors when the gas first flows through the porous filter matrix; and recirculating the gas from the second surface of the porous filter matrix back to the porous filter matrix using a gas recirculation system after the gas first flows through the porous filter matrix. The first surface, wherein the gas recirculation system includes a conduit having an inlet and an outlet, wherein the inlet of the conduit is configured to receive gas exiting the particulate filter at the second surface into the conduit, wherein the outlet of the conduit is configured to output the gas from the conduit at the first surface to the particulate filter; after the gas is recirculated using the gas recirculation system, a second voltage signal is received from the input signal source at the plurality of input nodes of the particulate filter; and when the gas flows through the porous filter matrix for the second time, the second voltage signal on the plurality of conductors is used to generate the electric field on at least one of the first surface or the second surface of the porous filter matrix, wherein the first voltage signal is different from the second voltage signal, such that the electric field is modulated between the first time the gas flows through the porous filter matrix and the second time the gas flows through the porous filter matrix.

[0235] Descriptions of various advantageous arrangements have been presented for illustrative and descriptive purposes and are not intended to be exhaustive or limited to examples of the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. Furthermore, different advantageous examples may describe different advantages compared to other advantageous examples. The selection and description of one or more examples are intended to explain the principles, practical applications, and to enable others skilled in the art to understand the disclosure of various examples with various modifications suitable for the intended particular purpose.

Claims

1. A filter system, comprising: Particulate filters, comprising: A porous filter matrix includes a first surface and a second surface, wherein the porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix between the first surface and the second surface, the porous filter matrix having a porous structure defining a plurality of pores between the first surface and the second surface, and configured to capture particles in the gas flowing through the pores. A plurality of conductors connected to the porous filter matrix, wherein the plurality of conductors are substantially parallel to each other along the porous filter matrix; and A plurality of input nodes, which communicate with the plurality of conductors and are configured to receive voltage signals from an input signal source, wherein the plurality of conductors are configured to generate an electric field on at least one of the first or second surfaces of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source; and An electromagnetic field generator is positioned upstream of the particulate filter along the gas flow path. The electromagnetic field generator is operable to generate an electromagnetic field configured to charge particles in the gas before the gas flows through the porous filter matrix.

2. The filter system according to claim 1, wherein, The electromagnetic field generator includes a mesh structure offset from the first surface to form a gap between the electromagnetic field generator and the particulate filter.

3. The filter system according to claim 1, wherein, The plurality of conductors are connected to at least one surface selected from the first surface and the second surface of the porous filter matrix.

4. The filter system according to claim 1, wherein, The plurality of conductors extend along the porous filter matrix in a first direction, and The particulate filter further includes the input signal source configured to generate the voltage signal, such that the electric field forms a traveling wave that travels along at least one of the first surface or the second surface in a second direction transverse to the first direction.

5. The filter system of claim 1, further comprising the input signal source configured to generate the voltage signal such that the electric field forms a standing wave on at least one of the first surface or the second surface.

6. The filter system of claim 1, further comprising a particulate collection container located at the periphery of the porous filter matrix and configured to collect particulates removed from the porous filter matrix by the electric field.

7. The filter system according to claim 2, wherein, The mesh structure includes a plurality of conductive strands defining a plurality of holes, wherein the size of the plurality of holes is larger than the size of the particles in the gas.

8. A filter system comprising: Particulate filters, comprising: A porous filter matrix includes a first surface and a second surface, wherein the porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix in a direction from the first surface toward the second surface, the porous filter matrix having a porous structure defining a plurality of pores between the first surface and the second surface, and configured to capture particles in the gas flowing through the pores; A plurality of conductors are connected to the porous filter matrix, wherein the plurality of conductors are substantially parallel to each other along the porous filter matrix; Multiple input nodes are configured to communicate with the multiple conductors and receive voltage signals from an input signal source, wherein the multiple conductors are configured to generate an electric field on at least one of the first or second surfaces of the porous filter matrix in response to the multiple input nodes receiving the voltage signals from the input signal source. A gas recirculation system includes a conduit having an inlet and an outlet, wherein the inlet of the conduit is configured to receive gas exiting the particulate filter at a second surface into the conduit, and wherein the outlet of the conduit is configured to output the gas from the conduit at the first surface back to the particulate filter; and A controller that communicates with the input signal source, wherein the controller is configured to: The input signal source provides a first voltage signal when the gas first flows through the porous filter matrix; and After the gas is recirculated by the gas recirculation system, the input signal source provides a second voltage signal when the gas flows through the porous filter matrix for the second time. The first voltage signal is different from the second voltage signal, wherein the first voltage signal has a first voltage level and a first waveform. Wherein, the second voltage signal has a second voltage level and a second waveform, and, Wherein, the first voltage level is different from the second voltage level, and / or The first voltage signal has a first voltage level and a first waveform. The second voltage signal has a second voltage level and a second waveform, and The first waveform is different from the second waveform.

9. The filter system of claim 8, further comprising an actuator configured to adjust the shape of the porous filter matrix from a first shape to a second shape. in, The controller communicates with the actuator, and The controller is configured to: The actuator arranges the porous filter matrix into the first shape when the gas first flows through it; and After the gas is recirculated by the gas recirculation system, the actuator arranges the porous filter matrix into the second shape as the gas flows through the porous filter matrix for the second time.

10. The filter system according to claim 9, wherein, The porous filter substrate has multiple accordion-like folds, each fold comprising multiple panels and multiple fold lines between corresponding panels. The actuator is configured to move at least one of the plurality of panels relative to at least another panel in order to adjust the shape of the porous filter matrix from the first shape to the second shape.

11. The filter system according to claim 8, wherein, The gas recirculation system further includes a baffle that can be actuated between a first position and a second position. Wherein, when the baffle is in the first position, the baffle is configured to guide the gas toward the inlet of the pipe of the gas recirculation system, and When the baffle is in the second position, the baffle is configured to allow the gas to flow away from the inlet of the pipe of the gas recirculation system.

12. The filter system according to claim 8, wherein, The gas recirculation system includes a recirculation fan configured to increase the flow of gas from the inlet to the outlet.

13. The filter system of claim 8, further comprising a particulate collection container surrounding the porous filter matrix and configured to collect particulates removed from the porous filter matrix by the electric field.

14. The filter system of claim 11, wherein, The controller communicates with the baffle, and The controller is configured to actuate the baffle from the first position to the second position after the gas flows through the porous filter matrix for the second time.

15. A filter system comprising: Particulate filters, comprising: A porous filter matrix includes a first surface and a second surface, wherein the porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix between the first surface and the second surface, the porous filter matrix having a porous structure defining a plurality of pores between the first surface and the second surface, and configured to capture particles in the gas flowing through the pores; A plurality of conductors connected to the porous filter matrix, wherein the plurality of conductors are substantially parallel to each other along the porous filter matrix; and A plurality of input nodes, which communicate with the plurality of conductors and are configured to receive voltage signals from an input signal source, wherein the plurality of conductors are configured to generate an electric field on at least one of the first or second surfaces of the porous filter matrix in response to the plurality of input nodes receiving the voltage signals from the input signal source; and A gas mover is positioned upstream of the particulate filter along the flow path of the gas. The gas mover is operable to generate turbulence in the gas before it flows through the porous filter matrix.

16. The filter system of claim 15, wherein, The plurality of conductors are coupled to at least one surface selected from the first surface and the second surface of the porous filter matrix.

17. A filter system comprising: Particulate filters, comprising: A porous filter matrix includes a first surface and a second surface, wherein the porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix in a direction from the first surface toward the second surface, the porous filter matrix having a porous structure defining a plurality of pores between the first surface and the second surface, and configured to capture particles in the flowing gas within the pores; and A plurality of conductors coupled to the porous filter matrix, wherein the plurality of conductors are substantially parallel to each other along the porous filter matrix, wherein the plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to a voltage signal from an input signal source; and A gas recirculation system includes a conduit having an inlet and an outlet, wherein the inlet of the conduit is configured to receive gas exiting the particulate filter at a second surface into the conduit, and wherein the outlet of the conduit is configured to output the gas from the conduit at the first surface back to the particulate filter; and A controller that communicates with the input signal source, wherein the controller is configured to: The input signal source provides a first voltage signal to the plurality of conductors when the gas first flows through the porous filter matrix, and After the gas is recirculated from the inlet to the outlet by the gas recirculation system, the input signal source provides a second voltage signal to the plurality of conductors when the gas flows through the porous filter matrix for the second time. The first voltage signal is different from the second voltage signal, which adjusts the electric field between the first time the gas flows through the porous filter matrix and the second time the gas flows through the porous filter matrix.

18. The filter system of claim 17, wherein, The first voltage signal has a first voltage level and a first waveform. The second voltage signal has a second voltage level and a second waveform, and Wherein, the first voltage level is different from the second voltage level, and / or The first voltage signal has a first voltage level and a first waveform. The second voltage signal has a second voltage level and a second waveform, and The first waveform is different from the second waveform.

19. The filter system of claim 17, further comprising an actuator configured to adjust the shape of the porous filter matrix from a first shape to a second shape. in, The controller communicates with the actuator, and The controller is configured to: The actuator arranges the porous filter matrix into the first shape when the gas first flows through it, and After the gas is recirculated by the gas recirculation system, the actuator arranges the porous filter matrix into the second shape as the gas flows through the porous filter matrix for the second time.

20. The filter system of claim 19, wherein, The porous filter substrate has multiple accordion-like folds, each fold comprising multiple panels and multiple fold lines between corresponding panels. The actuator is configured to move at least one of the plurality of panels relative to at least another panel of the plurality of panels to adjust the shape of the porous filter matrix from the first shape to the second shape.

21. The filter system of claim 17, wherein, The gas recirculation system further includes a baffle that is actuable between a first position and a second position. When the baffle is in the first position, the baffle is configured to guide the gas toward the inlet of the pipe of the gas recirculation system. When the baffle is in the second position, the baffle is configured to allow the gas to flow away from the inlet of the pipe of the gas recirculation system. The controller communicates with the baffle, and The controller is configured to actuate the baffle from the first position to the second position after the gas flows through the porous filter matrix for the second time.

22. The filter system of claim 17, wherein, The gas recirculation system further includes a first baffle downstream of the inlet and a second baffle upstream of the outlet. The controller communicates with the first baffle and the second baffle, and The controller is configured to actuate the first baffle and the second baffle to control the flow path of the gas in the gas recirculation system.

23. The filter system of claim 22, wherein, The first baffle is actuable between a first position and a second position. When the first baffle is in the first position, the first baffle is configured to guide the gas from the second surface toward the inlet of the pipe of the gas recirculation system. When the first baffle is in the second position, the first baffle is configured to allow the gas to flow away from the inlet of the pipe of the gas recirculation system. The second baffle is actuable between the first position and the second position. When the second baffle is in the first position, the second baffle is configured to guide the gas from the outlet of the pipe toward the first surface of the porous filter matrix, and Wherein, the second baffle is in the second position, and the second baffle is configured to allow the gas to flow through the outlet of the pipe to reach the first surface of the porous filter matrix.

24. The filter system of claim 17, wherein, The gas recirculation system includes a recirculation fan configured to increase the flow of gas from the inlet to the outlet.

25. The filter system of claim 24, wherein, The recirculation fan is positioned in the duct between the inlet and the outlet.

26. The filter system of claim 17, further comprising a particulate collection container surrounding the porous filter matrix and configured to collect particulates removed from the porous filter matrix by the electric field.

27. A filter system comprising: Particulate filters, comprising: A porous filter matrix includes a first surface and a second surface, wherein the porous filter matrix is ​​configured to filter gas flowing through the porous filter matrix in a direction from the first surface toward the second surface, the porous filter matrix having a porous structure defining a plurality of pores between the first surface and the second surface, and configured to capture particles in the flowing gas within the pores, and A plurality of conductors coupled to the porous filter matrix, wherein the plurality of conductors are substantially parallel to each other along the porous filter matrix, wherein the plurality of conductors are configured to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix in response to a voltage signal from an input signal source; and A gas recirculation system includes a conduit having an inlet and an outlet, wherein the inlet of the conduit is configured to receive gas exiting the particulate filter at a second surface into the conduit, and wherein the outlet of the conduit is configured to output the gas from the conduit at a first surface to the particulate filter; An actuator configured to adjust the shape of the porous filter matrix from a first shape to a second shape; and A controller that communicates with the actuator, wherein the controller is configured to: The actuator arranges the porous filter matrix into the first shape when the gas first flows through it, and After the gas is recirculated from the inlet to the outlet by the gas recirculation system, the actuator arranges the porous filter matrix into the second shape as the gas flows through the porous filter matrix for the second time.

28. The filter system of claim 27, wherein, The porous filter substrate has multiple accordion-like folds, each fold comprising multiple panels and multiple fold lines between corresponding panels. The actuator is configured to move at least one of the plurality of panels relative to at least another panel of the plurality of panels to adjust the shape of the porous filter matrix from the first shape to the second shape.

29. The filter system of claim 27, wherein, The gas recirculation system further includes a baffle that is actuable between a first position and a second position. When the baffle is in the first position, the baffle is configured to guide the gas toward the inlet of the pipe of the gas recirculation system. When the baffle is in the second position, the baffle is configured to allow the gas to flow away from the inlet of the pipe of the gas recirculation system. The controller communicates with the baffle, and The controller is configured to actuate the baffle from the first position to the second position after the gas flows through the porous filter matrix for the second time.

30. The filter system of claim 27, wherein, The gas recirculation system further includes a first baffle downstream of the inlet and a second baffle upstream of the outlet. The controller communicates with the first baffle and the second baffle, and The controller is configured to actuate the first baffle and the second baffle to control the flow path of the gas in the gas recirculation system.

31. The filter system according to claim 30, wherein, The first baffle can be actuated between a first position and a second position. When the first baffle is in the first position, the first baffle is configured to guide the gas from the second surface toward the inlet of the pipe of the gas recirculation system. When the first baffle is in the second position, the first baffle is configured to allow the gas to flow away from the inlet of the pipe of the gas recirculation system. The second baffle is actuable between the first position and the second position. Wherein, when the second baffle is in the first position, the second baffle is configured to guide the gas from the outlet of the pipe toward the first surface of the porous filter matrix, and Wherein, the second baffle is in the second position, and the second baffle is configured to allow the gas to flow through the outlet of the pipe to reach the first surface of the porous filter matrix.

32. The filter system of claim 27, wherein, The gas recirculation system includes a recirculation fan configured to increase the flow of gas from the inlet to the outlet.

33. The filter system according to claim 32, wherein, The recirculation fan is positioned in the duct between the inlet and the outlet.

34. The filter system of claim 27, further comprising a particulate collection container surrounding the porous filter matrix and configured to collect particulates removed from the porous filter matrix by the electric field.

35. A method for removing particulate matter from a particulate filter, comprising: A first voltage signal is received from an input signal source at multiple input nodes of a particulate filter, wherein the particulate filter includes a porous filter matrix and multiple conductors coupled to the porous filter matrix, wherein the porous filter matrix is ​​configured to filter gas flowing from a first surface of the porous filter matrix to a second surface of the porous filter matrix, the porous filter matrix having a porous structure defining multiple pores between the first surface and the second surface, and configured to capture particles in the gas flowing through the pores, wherein the multiple conductors are generally parallel to each other along the porous filter matrix, and wherein the multiple input nodes are in signal communication with the multiple conductors; When the gas flows through the porous filter matrix for the first time, the first voltage signal on the plurality of conductors is used to generate an electric field on at least one of the first surface or the second surface of the porous filter matrix. After the gas flows through the porous filter matrix for the first time, a gas recirculation system is used to recirculate the gas from the second surface of the porous filter matrix to the first surface of the porous filter matrix. The gas recirculation system includes a pipe having an inlet and an outlet. The inlet of the pipe is configured to receive the gas exiting the particulate filter at the second surface into the pipe, and the outlet of the pipe is configured to output the gas from the pipe at the first surface to the particulate filter. After the gas is recirculated using the gas recirculation system, a second voltage signal is received from the input signal source at the plurality of input nodes of the particulate filter; and When the gas flows through the porous filter matrix for the second time, the second voltage signal on the plurality of conductors generates the electric field on at least one of the first surface or the second surface of the porous filter matrix. The first voltage signal is different from the second voltage signal, which adjusts the electric field between the first and second times the gas flows through the porous filter matrix. The first voltage signal has a first voltage level and a first waveform. Wherein, the second voltage signal has a second voltage level and a second waveform, and, Wherein, the first voltage level is different from the second voltage level, and / or The first voltage signal has a first voltage level and a first waveform. The second voltage signal has a second voltage level and a second waveform, and The first waveform is different from the second waveform.

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