APPARATUS AND SYSTEM FOR TRAPPING DEBRIS AND ARRESTING SPARKS

Abstract

Described herein are various embodiments of an apparatus and system for trapping debris and arresting sparks that overcomes at least some shortcomings of the prior art approaches. According to one embodiment, an apparatus is disclosed for mitigating failure of an exhaust after-treatment component in an internal combustion engine system capable of generating an exhaust gas stream. The apparatus includes a housing that includes an exhaust inlet, exhaust outlet, and exhaust flow channel positioned between the exhaust inlet and outlet. Also, the apparatus includes a tubular-shaped mesh screen positioned substantially entirely within the exhaust flow channel. The mesh screen includes a closed end positioned proximate the exhaust inlet of the housing and an opposing open end positioned proximate the exhaust outlet of the housing. The mesh screen is configured to capture failed exhaust after-treatment component particles within the exhaust gas stream.

Description

FIELD

This disclosure relates to exhaust gas after-treatment systems for internal combustion engines, and more particularly to an apparatus and system for trapping debris and arresting sparks in an exhaust gas after-treatment system for a diesel-powered internal combustion engine.

BACKGROUND

Exhaust emissions regulations for internal combustion engines have become more stringent over recent years. For example, the regulated emissions of NO_x and particulates from diesel-powered internal combustion engines are low enough that, in many cases, the emissions levels cannot be met with improved combustion technologies. Therefore, the use of exhaust after-treatment systems on engines to reduce harmful exhaust emissions is increasing. Typical exhaust after-treatment systems include any of various components configured to reduce the level of harmful exhaust emissions present in the exhaust gas. For example, some exhaust after-treatment systems for diesel-powered internal combustion engines include various components, such as a diesel oxidation catalyst (DOC), a particulate matter filter or diesel particulate filter (DPF), and a selective catalytic reduction (SCR) catalyst. In some exhaust after-treatment systems, exhaust gas first passes through the diesel oxidation catalyst, then passes through the diesel particulate filter, and subsequently passes through the SCR catalyst.

Each of the DOC, DPF, and SCR catalyst components is configured to perform a particular exhaust emissions treatment operation on the exhaust gas passing through or over the components. The DOC, DPF, and SCR catalyst each include a catalyst bed or substrate that facilitates the corresponding exhaust emissions treatment operation. Generally, the catalyst bed of the DOC reduces the amount of carbon monoxide and hydrocarbons present in the exhaust gas via oxidation techniques. The substrate of the DPF filters harmful diesel particulate matter and soot present in the exhaust gas. Finally, the catalyst bed of the SCR catalyst reduces the amount of nitrogen oxides (NO_x) present in the exhaust gas.

Unfortunately, the substrates of the DOC, DPF, and SCR catalyst are prone to failure due to any of various conditions, such as age, vibrations, high temperature events, etc. Substrate failure is often catastrophic resulting in portions of the substrates breaking off and entering the exhaust gas. Although typical on-board diagnostic systems alert an operator of the failure of the components, conventional systems are not equipped to capture the broken pieces of the failed substrates before they enter the atmosphere. The emission of failed substrate pieces into the atmosphere is undesirable due to the potentially harmful effects the substrate pieces may have on the environment. Generally, conventional diesel-powered engine systems do not include failure mode mitigation devices to capture pieces of failed after-treatment components due to the added size and significantly increased exhaust restriction associated with such devices.

In addition to the above-mentioned exhaust emission reduction requirements, current regulations require the use of spark arrestors in engine systems for certain industrial applications. For example, the U.S. Department of Agriculture (USDA) requires that engine systems have spark arrestors when used in protected environmental areas, such as forests. Compliant spark arrestors should capture engine sparks larger than a regulated size before the sparks are emitted into the atmosphere. Generally, sparks include combustible materials or flaming debris that may cause fires if emitted into the atmosphere.

Conventional spark arrestors include stator-type spark arrestors and screen-type spark arrestors. Stator-type spark arrestors capture sparks by creating vane-induced centrifugal forces to separate the sparks from the exhaust gas. Screen-type spark arrestors capture sparks using a fine mesh screen that traps the sparks on the screen. Stator-type spark arrestors typically are larger, bulkier, and more complex than screen-type spark arrestors due to the significant increase in exhaust resistance that would be induced by smaller stator-type spark arrestors. Further, stator-type spark arrestors are inadequate to capture large sparks or failed substrate pieces for many engine systems. Although smaller than stator-type spark arrestors and inducing less exhaust resistance than stator-type spark arrestors, screen-type spark arrestors are prone to rapid soot build-up. Accordingly, conventional screen-type spark arrestors have been relegated to use with non-soot-producing gasoline-powered engine systems.

SUMMARY

The subject matter of the present application has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available debris traps and spark arrestors. Accordingly, the subject matter of the present application has been developed to provide an apparatus and system for trapping debris and arresting sparks that overcomes at least some shortcomings of the prior art approaches.

According to one embodiment, an apparatus is disclosed for mitigating failure of an exhaust after-treatment component in an internal combustion engine system capable of generating an exhaust gas stream. The apparatus includes a housing that includes an exhaust inlet, exhaust outlet, and exhaust flow channel positioned between the exhaust inlet and outlet. Also, the apparatus includes a tubular-shaped mesh screen positioned substantially entirely within the exhaust flow channel. The mesh screen includes a closed end positioned proximate the exhaust inlet of the housing and an opposing open end positioned proximate the exhaust outlet of the housing. The mesh screen is configured to capture failed exhaust after-treatment component particles within the exhaust gas stream.

In certain implementations of the apparatus, the mesh screen defines an interior space having an increasing cross-sectional area in a closed-to-open end direction. In some implementations, the cross-sectional area of the interior space proximate the open end is approximately equal to a cross-sectional area of the exhaust outlet of the housing. The cross-sectional area of the exhaust outlet of the housing can be approximately equal to a maximum cross-sectional area of the exhaust flow channel.

According to some implementations, the open end of the mesh screen is secured directly to an interior surface of the housing. The exhaust inlet of the housing can be removably coupleable to an exhaust outlet of an upstream exhaust after-treatment device. Similarly, the exhaust outlet of the housing can be configured to engage an exhaust inlet of a downstream exhaust after-treatment device. Additionally, the housing of the apparatus can have a length between approximately 8 inches and approximately 10 inches. In certain implementations, the mesh screen comprises sidewalls that diverge from the closed end to the open end at an angle of at least about 5°.

According to another embodiment, an exhaust gas after-treatment system for a diesel-powered internal combustion engine includes a diesel particulate filter and an arrestor positioned downstream of the diesel particulate filter. The diesel particulate filter is in exhaust receiving communication with the diesel-powered internal combustion engine. Moreover, the diesel particulate filter includes a filter substrate for capturing particulate matter in the exhaust. The arrestor is in exhaust receiving communication with the diesel particulate filter. Additionally, the arrestor includes a mesh screen through which flows all exhaust received by the arrestor. The mesh screen comprises a plurality of openings sized to capture sparks above a threshold size. The sparks are generated by the diesel-powered internal combustion engine. The plurality of openings is also sized to capture failed component debris above the threshold size where the failed component debris can be pieces of a failed after-treatment component upstream of the arrestor.

In some implementations, the exhaust gas after-treatment system further includes a diesel oxidation catalyst upstream of the diesel particulate filter and a selective catalytic reduction catalyst positioned downstream of the diesel particulate filter and upstream of the arrestor. The failed after-treatment component comprises at least one of the diesel particulate filter, diesel oxidation catalyst, and selective catalytic reduction catalyst. The arrestor can be configured to induce less than about a 0.5 in-Hg increase in exhaust gas backpressure within the exhaust gas after-treatment system.

According to certain implementations, the arrestor includes an exhaust inlet and an exhaust outlet. The mesh screen can include a closed end and an open end opposite the closed end. The closed end can be closer to the exhaust inlet of the arrestor than the open end. Alternatively, in other implementations, the open end can be closer to the exhaust inlet of the arrestor than the closed end.

The exhaust gas after-treatment system can further include a component housing and an exhaust gas after-treatment component positioned within the housing. The arrestor can be positioned within the component housing downstream of the exhaust gas after-treatment component. The arrestor also can be external and removably securable to the component housing.

According to yet another embodiment, an internal combustion engine system includes a diesel-powered internal combustion engine capable of generating an exhaust gas stream. The system also includes an exhaust gas after-treatment system in exhaust gas receiving communication with the diesel-powered internal combustion engine. The after-treatment system includes a diesel particulate filter with a filter substrate for capturing particulate matter in the exhaust gas stream. The system may further include an arrestor positioned downstream of the diesel particulate filter in exhaust receiving communication with the diesel particulate filter. The arrestor includes a generally tubular-shaped mesh screen through which all exhaust received by the arrestor flows. The mesh screen includes a plurality of openings sized to capture sparks above a threshold size and failed component debris above the threshold size.

In certain implementations of the internal combustion engine system, the diesel-powered internal combustion engine generates at least 50 horsepower. In other implementations, the diesel-powered internal combustion engine generates at least 500 horsepower. In some implementations, the diesel-powered internal combustion engine and exhaust gas after-treatment system satisfy at least one of U.S. Tier 4 and Europe Stage IIb exhaust emissions standards.

Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the subject matter of the present disclosure should be or are in any single embodiment. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment.

Furthermore, the described features, advantages, and characteristics of the subject matter of the present disclosure may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the subject matter may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages will become more fully apparent from the following description and appended claims, or may be learned by the practice of the subject matter as set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the advantages of the subject matter may be more readily understood, a more particular description of the subject matter briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the subject matter and are not therefore to be considered to be limiting of its scope, the subject matter will be described and explained with additional specificity and detail through the use of the drawings, in which:

FIG. 1 is a schematic block diagram of an internal combustion engine having an exhaust gas after-treatment system and an arrestor according to one representative embodiment;

FIG. 2 is an exploded perspective view of an exhaust gas after-treatment system according to one embodiment;

FIG. 3 is a cross-sectional side view of an arrestor according to one embodiment; and

FIG. 4 is a cross-sectional side view of an arrestor according to another embodiment.

DETAILED DESCRIPTION

Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. Similarly, the use of the term “implementation” means an implementation having a particular feature, structure, or characteristic described in connection with one or more embodiments of the present disclosure, however, absent an express correlation to indicate otherwise, an implementation may be associated with one or more embodiments.

Furthermore, the described features, structures, or characteristics of the subject matter described herein may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of controls, structures, devices, algorithms, programming, software modules, user selections, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments of the subject matter. One skilled in the relevant art will recognize, however, that the subject matter may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the disclosed subject matter.

FIG. 1 depicts one embodiment of an internal combustion engine system 100. The main components of the engine system 100 include an internal combustion engine 110 and an exhaust gas after-treatment system 120 coupled to the engine. The internal combustion engine 110 can be a compression ignited internal combustion engine, such as a diesel-powered engine. In some embodiments, the diesel engine 110 outputs at least about 50 horsepower. In certain other embodiments, the diesel engine 110 outputs at least about 500 horsepower. According to some embodiments, the internal combustion engine system 100 satisfies advanced emissions standards, such as at least one of U.S. Tier 4 emissions standards, Europe Stage IIb emissions standards, and beyond.

Within the internal combustion engine 110, the air from the atmosphere is combined with fuel to power the engine. Combustion of the fuel and air produces exhaust gas. At least a portion of the exhaust gas generated by the internal combustion engine 110 is operatively vented to the exhaust gas after-treatment system 120. In certain implementations, the engine system 100 includes an exhaust gas recirculation (EGR) line (not shown) configured to allow a portion of the exhaust gas generated by the engine to recirculate back into the engine for altering the combustion properties of the engine 110.

Generally, the exhaust gas after-treatment system 120 is configured to remove various chemical compound and particulate emissions present in the exhaust gas received from the engine 110. The exhaust gas after-treatment system 120 includes a diesel oxidation catalyst (DOC) 130, a diesel particulate filter (DPF) 140, and an SCR system 150. In an exhaust flow direction, indicated by directional arrows between the exhaust gas after-treatment system components, exhaust may flow from the engine 110, through the DOC 130, through the DPF 140, and through the SCR system 150. In other words, in the illustrated embodiment, the DPF 140 is positioned downstream of the DOC 130, and the SCR system 150 is positioned downstream of the DPF 140. In other embodiments, the components of the exhaust gas after-treatment system 120 can be positioned in any of various arrangements, and the system can include other components, such as an AMOX catalyst (not shown) downstream of the SCR system 150, or fewer components. Generally, exhaust gas treated in the exhaust gas after-treatment system 120 and released into the atmosphere consequently contains significantly fewer pollutants, such as diesel particulate matter, NO_x, hydrocarbons, such as carbon monoxide and carbon dioxide, than untreated exhaust gas.

The DOC 130 can be any of various flow-through oxidation catalysts. Generally, the DOC 130 includes a substrate with an active catalyst layer configured to oxidize at least some particulate matter (e.g., the soluble organic fraction of soot) in the exhaust and reduce unburned hydrocarbons and CO in the exhaust to less environmentally harmful compounds. For example, in some implementations, the DOC 130 may sufficiently reduce the hydrocarbon and CO concentrations in the exhaust to meet the requisite emissions standards.

The DPF 140 can be any of various particulate filters known in the art configured to reduce particulate matter concentrations, e.g., soot and ash, in the exhaust gas to meet requisite emission standards. The DPF 140 includes a filter substrate that captures soot and other particular matter generated by the engine 110. The engine system 100 periodically regenerates the DPF 140 to remove particulate matter that has accumulated on the DPF over time. Basically, the DPF 140 is regenerated by increasing the temperature of the exhaust gas above a threshold temperature corresponding with combustion of the particulate matter.

The SCR system 160 includes a reductant delivery system and an SCR catalyst downstream of the reductant delivery system. The reductant delivery system is operable to inject or dose a reductant into the exhaust gas prior to the gas entering the SCR catalyst. The injected reductant (or broken-down byproducts of the reductant, such as when urea is reduced to form ammonia) reacts with NO_x in the presence of the SCR catalyst to reduce NO_x in the exhaust gas to less harmful emissions, such as N₂ and H₂O. The SCR catalyst can be any of various catalysts known in the art. For example, in some implementations, the SCR catalyst is a vanadium-based catalyst, and in other implementations, the SCR catalyst is a zeolite-based catalyst, such as a Cu-Zeolite or a Fe-Zeolite catalyst Like the filter substrate of the DPF 140, the SCR catalyst can be subject to high temperatures, such as during a regeneration event on the DPF.

Each of the catalyst or filter substrates of the DOC 130, DPF 140, and SCR system 150 are subject to failure due to any of various conditions. For example, high exhaust temperature events (e.g., DPF regeneration events), high vibration environments, and relative age of the subjects can each lead to failure of the substrates. Failure of the substrates can be minor (e.g., crack formation) and major (e.g., disintegration of the substrate). Minor failures of the substrates can be detectable and correctible before substantially negatively impacting the environment. Major failures, however, often are not correctible before pieces of the substrate are emitted into the environment. Conventional diesel-powered engine systems employing exhaust after-treatment components do not have failed substrate debris traps, particularly when the failed substrate is associated with a DPF or downstream SCR catalyst. Accordingly, for diesel-powered engine systems, failed substrate debris would be emitted into the environment before mitigating actions could be implemented.

In addition to the possibility of substrate emissions due to a major failure of a substrate of an exhaust after-treatment component, internal combustion engines are susceptible to spark emissions. Because of the hazardous and combustible nature of spark emissions, the USDA requires the implementation of spark arrestors in certain engine systems when used within protected areas. One common application includes the use of engine systems in certain vehicles and/or non-vehicular equipment operated in forested areas. Conventionally, to satisfy the USDA regulations regarding spark arrestors, gasoline-powered engine systems use screen-type spark arrestors and diesel-powered engine systems use stator-type spark arrestors. Screen-type spark arrestors are more conducive to gasoline-powered engine systems due to the smaller size and reduced restriction properties of screen-type spark arrestors. Stator-type spark arrestors are conventionally used with diesel-powered engine systems because the high soot and particular matter output of previous diesel engines would rapidly clog screen-type arrestors.

Although contrary to conventional techniques, the diesel engine system 100 of the present disclosure includes a screen-type arrestor 160 or particle trap downstream of the DOC 130, DPF 140, and SCR system 150 to provide the dual functionality of a failed substrate debris trap and spark accumulator (see FIG. 1). Generally, the arrestor 160 receives 100% of the exhaust gas flowing through the DOC 130, DPF 140, and SCR system 150. The arrestor 160 mitigates the major failure of exhaust after-treatment system components by capturing pieces or disintegrated portions of failed components on a mesh-like screen before they are emitted into the environment. Similarly, the mesh-like screen of the arrestor 160 is configured to captures sparks emitted from the diesel engine 110 before they are emitted into the environment in compliance with USDA requirements. In some implementations, the arrestor 160 is in-line with and separately connectible to the components of the exhaust after-treatment system 120. For example, in one implementation, the DOC 130, DPF 140, and SCR catalyst of the SCR system 150 are housed within a single housing having a housing outlet. In this implementation, the arrestor 160 can be removably coupled to the housing outlet. In other implementations, the arrestor 160 is integrated into the housing of an after-treatment component, such as an outlet section of the SCR system 150. For example, the arrestor 160 can be positioned within an after-treatment component housing just upstream of the housing outlet.

As shown in FIG. 2, a diesel engine system 200 includes an exhaust gas after-treatment system 220 having an arrestor 230 according to one embodiment. The after-treatment system 220 includes an after-treatment component housing or can 210 within which is housed one or more emissions-reducing components. In one embodiment, the housing 210 houses at least one of a DOC, DPF, and SCR catalyst. In the illustrated embodiment, the housing 210 houses at least a DPF. The housing 210 includes an exhaust inlet 212 and an exhaust outlet 214. Exhaust gas generated by an engine flows into the housing through the inlet 212, the component(s) within the housing 210 reduce emissions within the exhaust gas, and the exhaust gas flows out of the housing through the outlet 214. The housings of the present disclosure can be made from any of various materials, such as metal or metal alloys.

The arrestor 230 includes a housing 231 extending from an inlet end 232 to an outlet end 234. In certain implementations, the housing 231 is a generally cylindrically-shaped hollow canister. The inlet end 232 of the housing 231 defines an inlet and the outlet end 234 of the housing defines an outlet of the arrestor 230. The housing 231 houses a mesh screen 236 extending from a closed inlet end 250 proximate the inlet end 232 of the housing 231 to an open outlet end (not shown) proximate (e.g., adjacent, adjoining, and/or coextensive with) the outlet end 234 of the housing. The mesh screen 236 is arranged (e.g., wrapped about itself) to form a 3-dimensional shape that defines an interior space. Exhaust gas entering the housing 231 via the inlet at the inlet end 232 passes through the mesh screen 236 into the interior space before exiting the housing via the outlet at the outlet end 234. Because the closed inlet end 250 of the mesh screen 236 is closed or plugged and the open outlet end is generally coextensive with the outlet end 234 of the housing 231, all exhaust gas entering the housing 231 of the arrester 230 passes through the mesh screen 236.

The mesh screen 236 can be arranged in any of various arrangements. Preferably, the mesh screen 236 is generally elongate and tubular-shaped to define a hollow interior channel. The mesh screen can have any of various shapes such that the hollow interior channel has any of various cross-sectional shapes and still be generally tubular. In other words, the mesh screen 236 can be non-cylindrical and still be tubular. To conserve space while improving performance, the closed inlet end 250 of the screen 236 can be collapsed and crimped to form a generally “X-shaped” or “+-shaped” plug 252. As the screen 236 extends from the closed inlet end 250 toward the open outlet end, the screen gradually unfolds or expands into a generally circular-shaped opening at the open outlet end. Although the closed inlet end 250 of the illustrated embodiment is generally “X-shaped” or “+-shaped,” in other embodiments, the closed inlet end of the mesh screen 236 can have other shapes, such as circular, rounded, pointed, polygonal, linear, etc.

The mesh screen 236 includes a plurality of openings having a specific size, shape, and number. The size and shape of the openings are selected to allow particles below a threshold size to pass through and prevent passage of particles above the threshold size. The threshold size can be any of various selectable sizes based on any of various factors. However, in certain implementations, the threshold size is based on governmentally regulated thresholds. For example, in one implementation, each opening of the mesh sheet has a maximum dimension of about 0.023 inches. Generally, the number of openings is maximized under the constraints of the material from which the mesh screen 236 is made. Preferably, the mesh screen 236 is made from a metallic wire mesh screen, such as a stainless steel wire mesh screen. In these implementations, the number of particles is based on the size and strength of the wires forming the screen. In other implementations, the mesh screen 236 is made from a closely perforated material. The mesh screen 236 is also configured to reduce exhaust backpressure inducement. For example, in certain implementations, the increase in exhaust gas backpressure (e.g., restriction) induced by the arrestor is less than about 0.5 in-Hg.

The arrestor 230 is removably coupled to the exhaust outlet 214 of the housing 210. The inlet end 232 of the arrestor housing 231 includes a stepped portion that is sized to receive the exhaust outlet 214 of the housing 210. More specifically, the inner diameter of the inlet end 232 is approximately the same as the outer diameter of the exhaust outlet 214, while the inner diameter of the inlet end 232 is approximately the same as the inner diameter of the exhaust outlet 214. In this manner, the exhaust outlet 214 is nestably received within the inlet end 232 of the arrestor housing 231 with the inner surfaces of the exhaust outlet 214 and arrestor inlet end 232 being substantially flush. The inlet end 232 can include notches (see, e.g., notches 380 of FIG. 3) to facilitate tightening of the inlet end about the exhaust outlet 214. In the illustrated embodiment, the inlet end 232 is tightened about the exhaust outlet 214 via a clamp 238 wrapped around the inlet end.

Another exhaust after-treatment component 220 and housing 221 can be coupled to the outlet end 234 of the arrestor 230 if desired. For example, in certain implementations, the component 220 can be a muffler device with a housing having an exhaust inlet 222. Similar to the inlet end 232 of the arrestor 230, the exhaust inlet 222 of the housing 221 matingly receives the outlet end 234 of the arrestor. The exhaust inlet 222 of the component 220 is tightened to the outlet end 234 via a clamp 224 similar to clamp 238.

The removable connection between the component housings 210, 221 and the arrestor 230 promote the serviceability of the arrestor 230. For example, when the arrestor 230 becomes full of captured particles, the arrestor 230 can be easily serviced by loosening the clamps 224, 238 and removing the arrestor 230. Following service of the arrestor 230 (e.g., removing the capture particles from the screen 236), the arrestor 230 can be reinstalled on the system 200 by matingly engaging the exhaust outlet 214 of the housing 210 and inlet end 232 of the arrestor, matingly engaging the exhaust inlet 222 of the housing 221 and the outlet end 234 of the arrestor, and tightening the clamps 224, 238. Alternatively, the serviced arrestor 230 can be installed on a different system. In this manner, the arrestor 230 is easily serviceable and reusable on the same or a different system.

According to another embodiment shown in FIG. 3, an arrestor 330 similar to arrestor 230 includes a housing 331 extending from an inlet end 332 to an outlet end 334. In certain implementations, the housing 331 is a tube or can with an exterior surface 371 exposed to the environment and an interior surface 372 opposite the exterior surface. The housing 331 defines an interior exhaust flow channel 344 through which exhaust flows from an inlet 333 defined by the inlet end 332 to an outlet 335 defined by the outlet end 334. The housing 331 has a length equal to the distance between the inlet end 332 and the outlet end 334. In certain implementations, the length of the housing is between about eight inches and about ten inches. Also, in some implementations, the approximate diameter of the interior exhaust flow channel 344 is between about four inches and about five inches. In one specific implementation, the housing 331 has a length of about eight inches and an inside diameter of about four inches (i.e. a length-to-diameter ratio of about 0.5). In another specific implementation, the housing 331 has a length of about ten inches and an inside diameter of about five inches (i.e. a length-to-diameter ratio of about 0.5).

Like the arrestor 230, the arrestor 330 includes a mesh screen 336 extending from a closed end 340 to an open end 342. The mesh screen 336 is shaped to define an interior space 345. The closed or plugged end 340 is collapsed and forms a generally “X-shaped” or “+-shaped” plug 346 similar to the closed end 250 of the mesh screen 236 of arrestor 230. The plug 346 can be formed by crimping the closed end 340 of the screen 336 using any of various crimping techniques. The open end 342 defines a generally circular-shaped opening. Accordingly, the cross-sectional shape of the interior space 345 along a plane perpendicular to the exhaust flow direction 360 gradually transitions from a generally “X-shape” or “+−shape” to a generally circular shape. Similarly, the cross-sectional area of the interior space 345 along a plane perpendicular to the exhaust flow direction 360 gradually increases from a minimum area proximate the plug 346 to a maximum area proximate the open end 342. As shown, the maximum cross-sectional area of the interior space 345 along a plane perpendicular to the exhaust flow direction 360 is about equal to a maximum cross-sectional area of the interior channel 344 (excluding the portion of the interior channel 344 defined by the coupling step 370 at the inlet portion 332).

The radially outermost portions or sidewalls 352 of the mesh screen 336 are angled radially outwardly in an exhaust flow direction indicated by directional arrows 360, 364. In other words, the radially outermost sidewall 352 of the mesh screen 336 diverges in the exhaust flow direction 360, 364. In some implementations, the radially outermost sidewall 352 diverges at an angle θ between about 5° and about 60°. In one particular implementation, the angle θ is about 30°. The mesh type and configuration of the screen 336 can be similar to the screen 236.

The mesh screen 336 has a length defined as the distance between the closed end 340 and the open end 342. In the illustrated embodiment, the length of the mesh screen 336 is less than a length of the housing 331 defined between the inlet end 332 and the outlet end 334. Accordingly, in the illustrated embodiment, the mesh screen 336 is entirely contained within the housing 331. The mesh screen 336 is coupled to the housing 331 via engagement between a tab portion 354 of the open end 342 of the mesh screen 336 and the interior surface 372 of the housing. More specifically, the tab portion 354 is adhered or welded to the interior surface 372 of the housing 331. In this manner, the mesh screen is secured directly to an interior surface 372 of the housing or can 331. In other embodiments, the mesh screen 336 is secured to the housing 331 by using other attachment or coupling techniques. Notwithstanding the method of securing the open end 342 to the housing 331, the mesh screen 336 is cantilevered such that the closed end 340 is a free or non-fixed end.

In operation, as shown in FIG. 3, exhaust gas 360 containing undesirable particles 375 (e.g., failed substrate debris and/or engine sparks) enter the housing 331 of the arrestor 330 via the inlet 333. After passing through the inlet 333, the exhaust gas 360 enters a space 348 defined between the mesh screen 236 and the wall of the housing 331. From the space 348, the exhaust gas 360 passes through the plurality of openings 350 in the mesh screen 336 into the interior space 345 as indicated by directional arrows 362. From the interior space 345, the exhaust gas exits the arrestor 330 through the outlet 335 as indicated by directional arrows 364. As the exhaust gas 362 passes through the mesh screen 336, undesirable particles 375 above a threshold size are captured on the radially outward facing surface 353 of the mesh screen. Particles smaller than the threshold size are allowed to pass through the openings of the mesh screen 336 along with the exhaust gas 362.

The arrestors 230, 330 described above are configured as a stand-alone component positionable in-line with other components of an exhaust after-treatment system. In other words, the arrestors 230, 330 are physically independent from the other components of the system. However, in some embodiments, an arrestor of the present disclosure for capturing failed substrate particles and sparks can be integrated into an existing component of an after-treatment system. For example, as shown in FIG. 4, an arrestor 430 according to one embodiment forms part of an existing component 420 of an after-treatment system. The existing component 420 can be an exhaust outlet section of a housing 410 within which a conventional exhaust emissions-reducing component (e.g., DOC, DPF, SCR catalyst) is positioned. The exhaust outlet section 420 includes a housing 422 extending between an exhaust inlet end 432 and exhaust outlet end 434. Exhaust gas 460 from the housing 410 flows into the outlet section 430 through the inlet end 432 and out of the outlet section through the outlet end 434.

The arrestor 430 includes a mesh screen 436 similar to the mesh screens 236, 336. However, the mesh screen 436 is shaped and arranged in a manner different than the mesh screens 236, 336. For example, the mesh screen 436 includes an open inlet end 440 and a closed outlet end 445. The mesh screen 436 may have a generally circular cross-sectional shape along a plane perpendicular to the exhaust flow direction 460 that gradually decreases in area in the exhaust flow direction. In other embodiments, the mesh screen 436 can have other cross-sectional shapes as desired with decreasing cross-sectional areas in the exhaust flow direction. The open inlet end 440 is coextensive with the exhaust inlet end 432 of the housing 422 such that all exhaust gas passing through the exhaust inlet end 432 of the housing 422 passes through the open inlet end 440 of the mesh screen 436. In certain implementations, the open inlet end 440 is secured (e.g., welded) to an interior surface of the housing 422 proximate the exhaust inlet end 432.

In operation, exhaust gas 460 containing undesirable particles 470 enters the outlet section 420 via the inlet end 432. After passing through the inlet end 432, the exhaust gas 460 passes through the open inlet end 440 of the arrestor 430 and enters a space 444 defined within the mesh screen 436. From the space 444, the exhaust gas 460 passes through a plurality of openings 450 in the mesh screen 436 and exits the arrestor 430 as indicated by directional arrows 462. After exiting the arrestor 430, the exhaust gas exits the outlet section 420 by passing through the outlet end 434 as indicated by directional arrows 464. As the exhaust gas 462 passes through the mesh screen 436, undesirable particles 470 above a threshold size are captured on the radially inward facing surface 452 of the mesh screen. Particles smaller than the threshold size are allowed to pass through the openings of the mesh screen 436 along with the exhaust gas 462.

The mesh screen 336 of the arrestor 330 is oriented in a closed-to-open end orientation relative to the exhaust flow direction 360. In contrast, the mesh screen 436 of the arrestor 430 is oriented in an open-to-closed end orientation relative to the exhaust flow direction 460. Although not shown, in some embodiments, the mesh screen 336 is oriented in an open-to-closed end orientation relative to the exhaust flow direction 360 and the mesh screen 436 is oriented in a closed-to-open end orientation relative to the exhaust flow direction 460. Further, in embodiments of the mesh screen 436 in the closed-to-open end orientation, the closed end 445 of the mesh screen can be positioned outside of the outlet section 420 (e.g., upstream of the inlet end 432 of the outlet section within the component housing 210). Additionally, although the mesh screen 436 has a generally circular-shaped cross-section along its length, the mesh screen 436 can be shaped in a manner similar to the mesh screens 236, 336 of the arrestors 230, 330, respectively.

The present subject matter may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. An apparatus for mitigating failure of an exhaust gas after-treatment component in an internal combustion engine system capable of generating an exhaust gas stream, comprising:

a housing comprising an exhaust inlet, an exhaust outlet, and an exhaust flow channel positioned between the exhaust inlet and outlet; and

a tubular-shaped mesh screen positioned substantially entirely within the exhaust flow channel, the mesh screen comprising a closed end positioned proximate the exhaust inlet of the housing and an opposing open end positioned proximate the exhaust outlet of the housing, wherein the mesh screen is configured to capture failed exhaust gas after-treatment component particles within the exhaust gas stream.

2. The apparatus of claim 1, wherein the mesh screen defines an interior space having an increasing cross-sectional area in a closed-to-open end direction.

3. The apparatus of claim 1, wherein the cross-sectional area of the interior space proximate the open end is approximately equal to a cross-sectional area of the exhaust outlet of the housing.

4. The apparatus of claim 1, wherein the cross-sectional area of the exhaust outlet of the housing is approximately equal to a maximum cross-sectional area of the exhaust flow channel.

5. The apparatus of claim 1, wherein the open end of the mesh screen is secured directly to an interior surface of the housing.

6. The apparatus of claim 1, wherein the exhaust inlet of the housing is removably coupleable to an exhaust outlet of an upstream exhaust after-treatment device.

7. The apparatus of claim 1, wherein the exhaust outlet of the housing is configured to engage an exhaust inlet of a downstream exhaust after-treatment device.

8. The apparatus of claim 1, wherein the housing has a length between approximately 8 inches and approximately 10 inches.

9. The apparatus of claim 1, wherein the mesh screen comprises sidewalls that diverge from the closed end to the open end at an angle of at least about 5°.

10. An exhaust gas after-treatment system for a diesel-powered internal combustion engine, comprising:

a diesel particulate filter in exhaust receiving communication with the diesel-powered internal combustion engine, the diesel particulate filter comprising a filter substrate for capturing particulate matter in the exhaust; and

an arrestor positioned downstream of the diesel particulate filter in exhaust receiving communication with the diesel particulate filter, the arrestor comprising a mesh screen through which flows all exhaust received by the arrestor, wherein the mesh screen comprises a plurality of openings sized to capture sparks above a threshold size, the sparks being generated by the diesel-powered internal combustion engine, and capture failed component debris above the threshold size, the failed component debris comprising pieces of a failed after-treatment component upstream of the arrestor.

11. The exhaust gas after-treatment system of claim 10, further comprising a diesel oxidation catalyst upstream of the diesel particulate filter and a selective catalytic reduction catalyst positioned downstream of the diesel particulate filter and upstream of the arrestor, wherein the failed after-treatment component comprises at least one of the diesel particulate filter, diesel oxidation catalyst, and selective catalytic reduction catalyst.

12. The exhaust gas after-treatment system of claim 10, wherein the arrestor is configured to induce less than about a 0.5 in-Hg increase in exhaust gas backpressure within the exhaust gas after-treatment system.

13. The exhaust gas after-treatment system of claim 10, wherein the arrestor comprises an exhaust inlet and an exhaust outlet, and wherein the mesh screen comprises a closed end and an open end opposite the closed end, the closed end being closer to the exhaust inlet of the arrestor than the open end.

14. The exhaust gas after-treatment system of claim 10, wherein the arrestor comprises an exhaust inlet and an exhaust outlet, and wherein the mesh screen comprises a closed end and an open end opposite the closed end, the open end being closer to the exhaust inlet of the arrestor than the closed end.

15. The exhaust gas after-treatment system of claim 10, further comprising a component housing and an exhaust gas after-treatment component positioned within the housing, wherein the arrestor is positioned within the component housing downstream of the exhaust gas after-treatment component.

16. The exhaust gas after-treatment system of claim 10, further comprising a component housing and an exhaust gas after-treatment component positioned within the housing, wherein the arrestor is external and removably securable to the component housing.

17. An internal combustion engine system, comprising:

a diesel-powered internal combustion engine capable of generating an exhaust gas stream;

an exhaust gas after-treatment system in exhaust gas receiving communication with the diesel-powered internal combustion engine, the exhaust gas after-treatment system comprising a diesel particulate filter comprising a filter substrate for capturing particulate matter in the exhaust gas stream; and

an arrestor positioned downstream of the diesel particulate filter in exhaust receiving communication with the diesel particulate filter, the arrestor comprising a generally tubular-shaped mesh screen through which all exhaust received by the arrestor flows, wherein the mesh screen comprises a plurality of openings sized to capture sparks above a threshold size, the sparks being generated by the diesel-powered internal combustion engine, and capture failed component debris above the threshold size, the failed component debris comprising pieces of a failed after-treatment component upstream of the arrestor.

18. The exhaust gas after-treatment system of claim 17, wherein the diesel-powered internal combustion engine generates at least 50 horsepower.

19. The exhaust gas after-treatment system of claim 18, wherein the diesel-powered internal combustion engine generates at least 500 horsepower.

20. The exhaust gas after-treatment system of claim 17, wherein the diesel-powered internal combustion engine and exhaust gas after-treatment system satisfy at least one of U.S. Tier 4 and Europe Stage IIb exhaust emissions standards.