EXHAUST SYSTEM INCLUDING IONIZATION ASSEMBLY

Abstract

An exhaust system includes an electrically conductive shell defining an exhaust pathway. The shell includes a tapered portion that tapers inward toward a longitudinal axis of the shell to define a narrowing region of the exhaust pathway. The exhaust system further includes an ionization assembly and an electrical subsystem that applies an electrical potential difference between the shell and at least a portion of the ionization assembly located within the exhaust pathway. The ionization assembly includes a support arm located within the exhaust pathway that extends into the narrowing region of the exhaust pathway. The ionization assembly further includes a plurality of electrically conductive discs mounted on and supported by the support arm. The ionization assembly is electrically insulated from the shell by an electrically insulating support structure.

Description

BACKGROUND

Products of combustion in the form of exhaust gases may be directed through an exhaust system where the exhaust gases may be treated before being discharged to the environment or other suitable location. A variety of exhaust system configurations, and chemical and/or physical processing techniques may be used to remove and sequester products of combustion from the exhaust gases before discharging the remaining components.

SUMMARY

According to an aspect of the present disclosure, an exhaust system ionizes exhaust gases to remove products of combustion from an exhaust stream. The exhaust system includes an electrically conductive shell defining an exhaust pathway. The shell has a tapered portion that tapers inward to define a narrowing region of the exhaust pathway. The exhaust system further includes an ionization assembly and an electrical subsystem that applies an electrical potential difference between the shell and at least a portion of the ionization assembly located within the exhaust pathway.

The ionization assembly includes a support arm located within the exhaust pathway that extends into and along the narrowing region of the exhaust pathway. The ionization assembly further includes a plurality of electrically conductive discs mounted on and supported by the support arm. At least some of the discs are located within the narrowing region of the exhaust pathway, and are spaced apart from each other along a longitudinal axis of the exhaust pathway. The discs decrease in size relative to each other along the longitudinal axis with tapering of the shell. Components of the ionization assembly, such as the support arm and the discs are electrically insulated from the shell by an electrically insulating support structure.

A voltage source of the electrical subsystem includes a high electrical potential terminal in electrical communication with the shell, and a low electrical potential terminal in electrical communication with the discs to apply an electrical potential difference between the shell and the discs. Particles within exhaust gases traveling along the exhaust pathway are ionized and become negatively charged by the low electrical potential applied to the discs. These negatively charged particles are attracted by the high electrical potential of the shell. A filter element located along an inner surface of the tapered portion of the shell that surrounds the narrowing region of the exhaust pathway captures larger ionized particles, such as particulate matter or other products of combustion contained in the exhaust gases.

This Summary describes aspects of the present disclosure in a simplified form. This Summary is not intended to identify key features or essential features of claimed subject matter, nor is this Summary intended to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 depicts an internal view of an example exhaust system.

FIG. 2 depicts an example external view of the exhaust system of FIG. 1.

FIG. 3 depicts another example external view of the exhaust system of FIG. 1 with optional components omitted.

FIG. 4 depicts an exploded view of the example exhaust system.

FIG. 5 depicts the example insulating support structure of FIG. 1 in further detail.

FIG. 6 depicts an example of an overlapping region between shell components of the exhaust system of FIG. 1.

FIGS. 7 and 8 depict additional aspects of the example ionization assembly of FIG. 1 as exploded view and assembled views, respectively.

FIGS. 9 and 10 depict a non-limiting example of an electrically conductive disc in further detail.

DETAILED DESCRIPTION

FIG. 1 depicts an internal view of an example exhaust system 100 that ionizes exhaust gases to remove products of combustion and incomplete combustion from an exhaust stream. Exhaust system 100 includes an electrically conductive shell 110 defining an exhaust pathway 112. Shell 110 forms a generally tubular structure to convey exhaust gases along exhaust pathway 112. In this example, shell 110 may have a circular shape when viewed in section along a longitudinal axis 114 of shell 110. In other examples, shell 110 may have a non-circular shape when viewed in section, such as a non-circular oval shape, polygonal shape, or other suitable shape. Example section views of shell 110 are depicted in FIGS. 4-6.

Shell 110 includes a tapered portion 128 that tapers inward toward longitudinal axis 114 in a first direction 116 along longitudinal axis 114. Tapered portion 128 defines a narrowing region 118 of exhaust pathway 112 that narrows in the first direction 116 along longitudinal axis 114. In this example, first direction 116 corresponds to a flow direction of exhaust gases along exhaust pathway 112 in which longitudinal axis 114 of shell 110 is oriented parallel to the X-coordinate axis.

Exhaust system 100 includes an ionization assembly 140. Ionization assembly 140 includes a support arm 142 located within exhaust pathway 112. Support arm 142 extends into and along at least a portion of narrowing region 118 of exhaust pathway 112. Support arm 142 may be supported relative to shell 110 and electrically insulated from shell 110 by an electrically insulating support structure 144. Support structure 144 serves as an electrical insulator that electrically insulates discs 146 and/or support arm 142 from shell 110. In this example, support arm 142 projects from support structure 144 in the first direction 116 along longitudinal axis 114 and is collinear with the longitudinal axis. In other examples, support arm 142 may be parallel to and offset from the longitudinal axis. Also in other examples, support arm 142 may extend in an opposite or counter direction from the direct depicted in FIG. 1 in which the support arm projects upstream from an electrically insulating support structure.

FIG. 1 depicts support structure 144 being located within the exhaust pathway. Support structure 144 may be secured to the shell at one or more points via one or more mounting surfaces of the support structure. In this example, support structure 144 has three mounting surfaces for securing the support structure to shell 110 at three points radially spaced apart from each other about longitudinal axis 114. Two of these points are depicted in FIG. 1 at 180 and 182. Support structure 144 is depicted in further detail with reference to FIGS. 4, 5, 7, and 8.

Ionization assembly 140 includes a plurality of electrically conductive discs 146 mounted on and supported by support arm 142. In this example, ionization assembly 140 includes six discs, indicated individually by reference numerals 150-160. In other examples, an ionization assembly may include a single electrically conductive disc or 2, 3, 4, 5, 7, 8, 9, 10 or more electrically conductive discs. At least some or all of discs 146 may be located within narrowing region 118 of exhaust pathway 112. In other embodiments, narrowing region 118 may instead be a non-narrowing region, and expanding region, cylindrical, etc.

Discs 146 are spaced apart from each other along longitudinal axis 114 and along the support arm 142. In at least some examples, some or all of discs 146 may have different sizes and/or shapes relative to some or all of the other discs. In this example, discs 146 have a circular shape when viewed along longitudinal axis 114, and decrease in size (e.g., in diameter or width as measured in a plane that is orthogonal to longitudinal axis 114) relative to each other in first direction 116 along longitudinal axis 114 and along support arm 142. For example, disc 150 is larger than disc 152, disc 152 is larger than disc 154, disc 154 is larger than disc 156, disc 156 is larger than disc 158, and disc 158 is larger than 160. In other examples, at least some or all of discs 146 may have the same size and/or shape relative to each other. Also in other examples, at least some or all of discs 146 may have a non-circular shape when viewed along longitudinal axis 114, including a non-circular oval shape, polygonal shape, or other suitable shape.

Exhaust system 100 includes an electrical subsystem 170. Electrical subsystem 170 includes a voltage source 172 having a high (e.g., positive charge relative to a ground reference) electrical potential terminal 174 in electrical communication with shell 110, and a low (e.g., negative charge relative to a ground reference) electrical potential terminal 176 in electrical communication with discs 146. In this example, a high electrical potential is applied to shell 110 by voltage source 172 via a first electrical pathway 178 that is in communication with high electrical potential terminal 174, and a low electrical potential is applied by voltage source 172 via a second electrical pathway 179 to discs 146 via low electrical potential terminal 176 to create an electrical potential difference between shell 110 and discs 146. In some examples, support arm 142 may take the form of an electrically conductive support arm that is also in electrical communication with low electrical potential terminal 176 (e.g., via electrical pathway 179) and with each of discs 146, so that a low electrical potential is applied to both support arm 142 and discs 146. As an example, support arm 142, as an electrically conductive support arm, may form part of electrical pathway 179 that electrically couples discs 146 to low electrical potential terminal 176.

Voltage source 172 is depicted schematically in FIG. 1, and may take other suitable forms and may be positioned at other suitable locations relative to shell 110. Voltage source 172 may be implemented as an electric battery, an electric motor, or other suitable device or system that provides an electrical potential difference that may be applied between shell 110 and discs 146. In some examples, one or both of electrical pathways 178, 179 may include one or more intermediate switches that enable one or both of the electrical pathways 178, 179 to be opened to disconnect voltage source 172 from exhaust system components, and thereby remove the electrical potential difference from between shell 110 and discs 146.

During operation of exhaust system 100, exhaust gases traveling along exhaust pathway 112 in the first direction 116 enter shell 110 via inlet portion 120. Particles within the exhaust gases are ionized and become negatively charged by the low electrical potential applied to discs 146. These negatively charged particles are attracted by the high electrical potential of shell 110. Narrowing region 118 may further compress exhaust gases traveling along exhaust path 112 within the vicinity of discs 146 to further improve ionization of exhaust gases at surfaces of the discs and/or support arm 142, which in turn increases the removal of exhaust components from the exhaust gases.

In at least some examples, exhaust system 100 may include a filter element 190 located along an inner surface of tapered portion 128 of the shell 110 that surrounds narrowing region 118 of exhaust pathway 112. Filter element 190 captures ionized particles that are attracted to the high electrical potential of the shell, such as particulate matter or other combustion products contained within the exhaust gases. Remaining exhaust gases are discharged from shell 110 via outlet portion 134.

Non-limiting use-environments for exhaust system 100 include within vehicle exhaust systems, building exhaust systems, building HVAC systems, building emergency/fire exhaust systems, and exhaust systems for electrical power generation to name a few examples. As a prophetic example, exhaust system 100 may eliminate approximately 80% of products of combustion from the exhaust gases without adding undue flow obstruction or backpressure to the exhaust pathway. Another potential benefit of the ionization of exhaust gases provided by exhaust system 100 includes the reduction of odors contained in the exhaust gases, for example, by the production of ozone via the ionization process.

In this example, filter element 190 covers interior surfaces of the tapered portion of the shell and tapers with the tapered portion of the shell. For example, filter element 190 tapers inward toward longitudinal axis 114 in the first direction 116 along longitudinal axis 114, and forms a generally conical structure. Filter element 190 may have a circular shape when viewed in section along longitudinal axis 114. In other examples, filter element 190 may have a non-circular shape when viewed in section (e.g., to conform with a shell having a non-circular shape), such as a non-circular oval shape, polygonal shape, or other suitable shape. Another view of filter element 190 is depicted in FIG. 4. FIG. 1 further depicts an example in which a downstream end of filter element 190 extends beyond tapered portion 128 and projects into exhaust pathway 112, as indicated at 192. In other examples, filter element 190 may conform to interior walls of tapered portion 128 without extending beyond tapered portion 128 or without projecting into exhaust pathway 112. Filter element 190 may take the form of a paper filter or other suitable filter type that is disposable or alternatively reusable. In some examples, filter element 190 may be omitted. If the filter element is omitted, ionized exhaust gas components that are attracted to the shell may adhere to interior surfaces of the shell and thereby removed from the exhaust gases that exit the exhaust system.

FIG. 2 depicts an example of an external view of exhaust system 100 of FIG. 1. Shell 110 from FIG. 1 may be formed by one or more shell components. In this example, a shell is formed by an inlet shell component 210 and an outlet shell component 212 that join each other at an interface 214 to collectively define exhaust pathway 112. An internal view of interface 214 is depicted in FIG. 1 as including an overlapping region 136 depicted in FIG. 1, in which outlet shell component 212 surrounds and overlaps with inlet shell component 210 within overlapping region 136. In other examples, shell 110 may be formed by a single shell component, or by three or more shell components.

In this example, inlet shell component 210 includes an inlet portion 120, an inlet-side tapered portion 122 that tapers outward away from longitudinal axis 114 in the first direction 116 (shown in FIG. 1), and a first intermediate portion 124. Also in this example, outlet shell component 212 includes a second intermediate portion 126 that interfaces with first intermediate portion 124 at interface 214. Outlet shell component 212 further includes previously described tapered portion 128, and an outlet portion 134. Outlet shell component 212 may optionally include an additional outlet-side tapered portion 132 that further tapers inward toward longitudinal axis 114 in the first direction 116, and an additional intermediate portion 130 located between tapered portion 128 and outlet-side tapered portion 132. In other examples, intermediate portion 130 and outlet-side tapered portion 132 may be omitted, such that tapered portion 128 joins outlet portion 134, as depicted in FIG. 3, for example.

FIG. 4 depicts an exploded view of exhaust system 100 of FIG. 1. Within FIG. 4, first intermediate portion 124 of inlet shell component 210 may include a plurality of keyways 412 (or slots) located along a terminal end of the inlet shell component that accommodate a corresponding plurality of shafts 410 (or other suitable key structures) that project from an interior surface of second intermediate portion 126 of outlet shell component 212. FIG. 6 depicts additional aspects of keyways 412 and shafts 410 in further detail. Shafts 410 may be inserted into keyways 412 and inlet shell component 210 may be rotated relative to outlet shell component 212 to lock or otherwise secure shell component 210 to outlet shell component 212. Opening 420 in inlet shell component 210 is aligned with opening 422 in outlet shell component 212 when shafts 410 are fully inserted and rotated into keyways 412. A fastener 424 (e.g., a bolt, screw, pin, or other suitable fastener) may be inserted into openings 420 and 422 to inhibit rotation of inlet shell component 210 relative to outlet shell component 212, thereby precluding shafts 410 from exiting keyways 412.

FIG. 4 further depicts insulating support structure 144 including three arms 460, 462, and 464 that are secured to inlet shell component 210. FIGS. 5, 7, and 8 depict additional views of insulating support structure 144. Inlet shell component 210 further includes an opening 416 through which a fastener 418 (e.g., e.g., a bolt, screw, pin, or other suitable fastener) may be inserted and engaged with an opening 414 in a terminal end of arm 462 to secure insulating support structure 144 to the shell. Arm 464 may be secured to inlet shell component 210 in a similar manner as arm 462. Arm 460 includes an opening 436 that aligns with opening 438 in inlet shell component 210. A deformable fastener 440 may be inserted through opening 438 to engage with opening 436 of arm 460. A compression cap 442 engages with deformable fastener 440 to provide a clamping force that secures one or more wires, cables, or other suitable electrical pathways that pass through opening 450. As shown in further detail in FIGS. 5, 7 and 8, opening 450 passes through cap 442, deformable fastener 440, inlet shell component 210 (via opening 438), and arm 460 (via opening 436), and connects to opening 428 located in a hub of insulating support structure 144. Electrical pathway 179 (shown in FIG. 1) may pass through opening 450 to be connected with electrically conductive components of the ionization assembly, such as discs 146 and support arm 142.

Support arm 142 may be secured to insulating support structure 144 at opening 428 via an intermediate fastener 426. Opening 428 passes through the hub of insulating support structure 144, enabling a fastener 432 located on an upstream side of support structure 144 to engage with intermediate fastener 426 through opening 428. A cover 434 may be inserted into opening 428 over fastener 432 on the upstream side of insulating support structure 144 to provide a more aerodynamic upstream surface.

FIG. 5 depicts insulating support structure 144 and surrounding first intermediate shell portion 124 in further detail as viewed along longitudinal axis 114. Insulating support structure 144 is shown in further detail including hub 510, which joins arms 460, 462, and 464 that radially project from the hub. Arms 460, 462, and 464 are depicted as each including a number of fin structures. Arms 462 and 464 are secured to first intermediate shell portion 124 by fasteners 418 inserted into openings 414 formed at a terminal end of arms 462 and 464. Inlet portion 120 is depicted in FIG. 5 for illustrative purposes, and is located upstream of insulating support structure 144. Opening 450 is depicted passing through cap 442, deformable fastener 440, arm 460, and joins with opening 428 formed in hub 510. Arm 460 is secured to first intermediate shell portion 124 by deformable fastener 440, as depicted in further detail in FIGS. 7 and 8.

FIG. 6 depicts overlapping region 136 of interface 214 between shell components 210 and 212 in further detail, as viewed along longitudinal axis 114. First intermediate portion 124 of inlet shell component 210 is depicted within second intermediate portion 126 of outlet shell component 212. Shafts 410 are engaged with keyways 412 in FIG. 6. Fastener 424 passes through opening 422 in first intermediate portion 126 and engages with second intermediate portion 124 via opening 420 to inhibit portions 124 and 126 of the shell from rotating and/or disengaging from each other.

FIG. 7 depicts additional aspects of ionization assembly 140 in an exploded view. Within FIG. 7, an internal view of insulating support structure is provided, which reveals internal threads within opening 436 that engage with external threads 718 of a lower portion of deformable fastener 440. Deformable fastener 440 further includes an upper portion that includes external threads 720 that engage internal threads 722 of compression cap 442. When compression cap 442 is threaded onto deformable fastener 440 via threads 720 and 722, internal wall surfaces that define an interior region 726 of compression cap 442 contact deformable elements 724 causing the deformable elements to deform inward, thereby providing a clamping force on an object (e.g., a wire, cable, or other electrical pathway) that passes through deformable fastener 440 via opening 450.

Opening 450 joins opening 428 that passes through hub 510. Fastener 432 having external threads may be inserted into opening 428 on the upstream side of support structure 144 where it engages internal threads of intermediate fastener 426 to retain intermediate fastener within opening 428 on the downstream side of the support structure. Cap 434 may be inserted behind fastener 432 to cover opening 428. When fastener 432 is threaded onto intermediate fastener 426, the fasteners may collectively provide a clamping force upon a narrowed region 714 of opening 428 of the support structure. Intermediate fastener 426 further includes internal threads 711 that accommodate external threads of support arm 142. In at least some examples, intermediate fastener 426 includes an opening 716 that aligns with opening 450 when threads 712 are engaged with threads of fastener 432. Opening 716 may accommodate one or more wires, cables, electrical connectors, or other suitable electrical pathways that pass through opening 450 from outside of the ionization assembly.

FIG. 8 depicts components of ionization assembly 140 in an assembled configuration. In FIG. 8, a wire 812 passing through opening 450 is connected to a low electrical potential of a voltage source. Wire 812 terminates at a conductive element 810 (e.g., an electrical connector) that is sized and shaped for insertion into opening 716 of intermediate fastener 426. In some examples, fastener 432 may extend to or beyond opening 716 and may contact conductive element 810 when threaded into threads 712 of intermediate fastener 426 to retain or otherwise clamp conductive element 810 within opening 716. Additionally or alternatively, deformable elements 724 may clamp onto wire 812 to retain conductive element 810 within opening 716 when cap 442 is threaded onto deformable fastener 440. Intermediate fastener 426 and fastener 432 may be electrically conductive to establish an electrical pathway between conductive element 810 and support arm 142 upon which the electrically conductive discs are mounted and supported.

FIGS. 9 and 10 depict an example of an electrically conductive disc 900. Disc 900 is a non-limiting example of any of the previously described electrically conductive discs 146 of FIGS. 1 and 4. FIGS. 9 and 10 provide an example orientation of disc 900 relative to the same coordinate system of FIGS. 1 and 4. For example, FIG. 9 depicts a face 910 of disc 900 presented orthogonal to the view provided by FIG. 9, which is parallel with the X-coordinate axis and longitudinal axis 114 of FIG. 1. FIG. 10 depicts disc 900 in the same orientation as discs 146 of FIG. 1.

In this example, disc 900 has a circular shape bounded by outer edge 912. Disc 900 has an opening 916 located at a centroid of its circular shaped face 910 to accommodate a support arm, such as previously described support arm 142. In some examples, a diameter of opening 916 may vary among or between each disc of an ionization assembly that contains a plurality of electrically conductive discs. In this example, a support arm for supporting the plurality of discs may vary in size (e.g., diameter) and/or shape along its length to define a particular location along its length where each disc resides. For example, referring also to FIG. 1, a size (e.g., a diameter) of support arm 142 decreases in a step-wise manner between each disc as the support arm extends away from insulating support structure 144 and along longitudinal axis 114 in the first direction 116. In this example, each of the plurality of discs 146 has an opening at its centroid for accommodating support 142, in which the size (e.g., diameter) of each opening decreases as the size of the disc decreases.

Also in this example, disc 900 tapers toward outer edge 912 as indicated by tapered region 914 to provide a sharp outer edge or corner that may improve ionization of exhaust gas components flowing over or past the disc. FIG. 10 depicts an example taper angle 1000 for tapered region 914. In FIG. 10, taper angle 1000 is measured relative to face 910 of the disc. As a non-limiting example, taper angle 1000 may be 28 degrees. As another example, taper angle 1000 may be between 25 degrees and 30 degrees. As yet another example, taper angle 1000 may be greater than zero degrees and less than 30 degrees. As yet another example, taper angle 1000 may be an angle greater than 28 degrees. A taper angle may be the same for either side of a disc to provide a symmetric configuration, such as depicted in FIG. 10. In other examples, a taper angle on one side of a disc may differ from a taper angle on an opposite side of the disc.

The various components described as being electrically conductive may be formed from any suitable material that provides substantial electrical conductivity, including materials that are or include electrically conductive metals such as copper, steel, aluminum, and iron, to name a few non-limiting examples. Components described as being electrically insulating, such as support structure 144 of ionization assembly 140, may be formed from any suitable material that does not provide substantial electrical conductivity. Where the electrically insulating material is located within the exhaust pathway that may contain exhaust gases of relatively high temperatures or is otherwise used in high temperature environments (such as support structure 144 located within the exhaust pathway) suitable electrically insulating materials may include ceramic, heat-tolerant polymers, or other heat tolerant electrical insulators.

The drawings accompanying this disclosure include schematic representations of example geometries and configurations. These drawings are not necessarily to scale. A non-limiting example of physical measurements for components of exhaust system 100 is provided below. These physical measurements in combination with each other describe a non-limiting example of the relative sizes and shapes of exhaust system components. These relative sizes and shapes may vary (e.g., by 10%, by 20%, or more) from the specific physical measurements described herein while still providing suitable or adequate removal of exhaust gas components.

In a non-limiting example, each of discs 146 have a thickness of 1 cm and are spaced 20 cm apart from each other on support structure 142. Disc 150 has a diameter of 75.7 cm and an opening at its centroid of 9 cm. Disc 152 has a diameter of 66.2 cm and an opening at its centroid of 8 cm. Disc 154 has a diameter of 56.7 cm and an opening at its centroid of 7 cm. Disc 156 has a diameter of 47.2 cm and an opening at its centroid of 6 cm. Disc 158 has a diameter of 37.7 cm and an opening at its centroid of 5 cm. Disc 150 has a diameter of 28.2 cm and an opening at its centroid of 4 cm. Outlet shell component 212 has a total length, as measured along longitudinal axis 114 of 270 cm. Tapered portion 128 has a length of approximately 182.3 cm, and tapers from a diameter of 111.6 cm to 42 cm with walls having a taper angle of 11 degrees relative to longitudinal axis 114. Inlet shell component 210 has a total length of 155 cm as measured along longitudinal axis 114 and varies in diameter from 68.4 cm to 110 cm. Support structure 144 has a thickness of 40 cm as measured along the longitudinal axis 114, with arms 460, 462, and 464 radially projecting from hub 510 at approximately 120 degrees relative to each other. Filter element 190 has a total length of 178.3 cm as measured along the longitudinal axis, and tapers from a diameter of 109-110 cm to 41 cm with walls having a taper angle of 11 degrees relative to longitudinal axis 114.

The various examples disclosed herein include features that may be used individually or in any combination. Claimed subject matter is not limited to the combination of features disclosed by an individual example, since features that are present in two or more of the disclosed examples may be used together in other combinations. Accordingly, it should be understood that the disclosed examples are illustrative and not restrictive. Variations to the disclosed examples that fall within the metes and bounds of the claims or equivalence of such metes and bounds are intended to be embraced by the claims.

Claims

1. An exhaust system, comprising: an electrically conductive shell defining an exhaust pathway, the shell having a tapered portion that tapers inward toward a longitudinal axis of the shell to define a narrowing region of the exhaust pathway that narrows in a first direction along the longitudinal axis;an ionization assembly, including: a support arm located within the exhaust pathway and extending into the narrowing region of the exhaust pathway,a plurality of electrically conductive discs supported by the support arm, with at least some of the discs located within the narrowing region of the exhaust pathway, the discs spaced apart from each other along the longitudinal axis, the discs decreasing in size relative to each other, as measured in a plane orthogonal to the longitudinal axis, in the first direction along the longitudinal axis; andan electrical subsystem, including: a voltage source having a high electrical potential terminal in electrical communication with the shell, and a low electrical potential terminal in electrical communication with the discs.

2. The exhaust system of claim 1, further comprising: a filter element covering interior surfaces of the tapered portion of the shell and tapering with the tapered portion of the shell.

3. The exhaust system of claim 1, wherein the ionization assembly further includes an electrically insulating support structure located within the exhaust pathway, and secured to the shell at one or more points; and wherein the support arm is supported relative to the shell by the electrically insulating support structure.

4. The exhaust system of claim 3, wherein the electrically insulating support structure is secured to shell at least at three points radially spaced apart from each other about longitudinal axis.

5. The exhaust system of claim 3, wherein the support arm projects from the insulating support structure in the first direction along the longitudinal axis of the exhaust pathway.

6. The exhaust system of claim 5, wherein the support arm is collinear with the longitudinal axis of the exhaust pathway.

7. The exhaust system of claim 6, wherein the support arm passes through each of the plurality of electrically conductive discs at a centroid of a face of each of the discs that is orthogonal to the longitudinal axis.

8. The exhaust system of claim 1, wherein the plurality of electrically conductive discs includes five or more electrically conductive discs.

9. The exhaust system of claim 1, wherein the plurality of electrically conductive discs includes at least six electrically conductive discs.

10. The exhaust system of claim 1, wherein the plurality of electrically conductive discs includes exactly six electrically conductive discs.

11. The exhaust system of claim 1, wherein each of the plurality of electrically conductive discs have a circular shaped face that is orthogonal to the longitudinal axis.

12. The exhaust system of claim 1, wherein each of the plurality of electrically conductive discs have sharp tapered edges.

13. The exhaust system of claim 1, wherein the electrical subsystem further includes one or more intermediate switches that enable one or both of the high electrical potential terminal and/or the low electrical potential terminal to be electrically disconnected from the shell and/or the discs.

14. An ionization assembly for an exhaust system, the ionization assembly comprising: an electrically insulating support structure having one or more mounting surfaces for securing the support structure to an electrically conductive shell defining an exhaust pathway of the exhaust system;a support arm secured to the support structure; anda plurality of electrically conductive discs mounted on the support arm, the discs spaced apart from each other and decreasing in size relative to each other along the support arm.

15. The ionization assembly of claim 14, wherein the plurality of electrically conductive discs includes five or more circular electrically conductive discs.

16. The ionization assembly of claim 15, wherein the support arm passes through each of the plurality of electrically conductive discs at a centroid of a face of each of the discs that is orthogonal to the support arm.

17. The ionization assembly of claim 16, wherein each of the plurality of electrically conductive discs have sharp tapered edges.

18. The ionization assembly of claim 14, wherein the electrically insulating support structure includes three arms radially spaced about a hub in which the one or more mounting surfaces include a mounting surface located at a terminal end of each arm.

19. An exhaust system, comprising: an electrically conductive shell defining an exhaust pathway, the shell having a tapered portion that tapers inward toward a longitudinal axis of the shell to define a narrowing region of the exhaust pathway that narrows in a first direction along the longitudinal axis;an ionization assembly, including: an electrically insulating support structure located within the exhaust pathway, and secured to the shell at one or more points,a support arm located within the exhaust pathway and extending into the narrowing region of the exhaust pathway, the support arm is supported relative to the shell by the electrically insulating support structure.a plurality of electrically conductive discs mounted on and supported by the support arm, with at least some of the discs located within the narrowing region of the exhaust pathway, the discs spaced apart from each other along the longitudinal axis, the discs decreasing in size relative to each other, as measured in a plane orthogonal to the longitudinal axis, in the first direction along the longitudinal axis; anda filter element covering interior surfaces of the tapered portion of the shell and tapering with the tapered portion of the shell.

20. The exhaust system of claim 19, further comprising: an electrical subsystem, including: a voltage source having a high electrical potential terminal in electrical communication with the shell, and a low electrical potential terminal in electrical communication with the discs.