Infinitely Variable Aftertreatment Systems and Manufacturing Process

Cross-Reference to Related Applications

This application is being filed as a PCT International Application in the name of Cummins Filtration IP, Inc., and claims the benefit of U.S. Patent Application Serial No. 11/523,462, filed September 19, 2006, entitled "INFINITELY VARIABLE AFTERTREATMENT SYSTEMS AND MANUFACTURING PROCESS."

Field A gas treatment system for use with an engine is described. In particular, constructions to facilitate the manufacture of aftertreatment systems for treating exhaust gas from an engine are described.

Background The use of an aftertreatment system to treat exhaust gases is known. Typically, an aftertreatment system is specially configured for use in a specific environment and configured to meet the specific space constraints dictated by that environment. As a result, an aftertreatment system is often custom-made, using parts that are specifically designed for that system. This customization leads to high engineering, design and manufacturing costs and long engineering, design and manufacturing times. In addition, making changes to the aftertreatment system after it is designed and manufacturing has started is difficult.

For example, Figure 1 illustrates a conventional aftertreatment system 200 in the form of a diesel oxidation catalyst aftertreatment system. The system 200 includes a catalyst subassembly 202 in which a substrate, containing a diesel oxidation catalyst, and a mounting mat material are wrapped with a metal body 206 to the required pressure to achieve the proper holding pressure on the substrate, and then the metal body 206 is welded. Support flanges are welded to the "canned" substrate, and the subassembly 202 is pushed into, and welded to, a pre-formed body 208. End flanges 210, 212 and inlet and outlet tubes (not shown) are then inserted and welded to the body 208. The body 208 is typically of a size and shape required for a particular application of the system.

Therefore, the configuration of the body 208 can vary greatly and a different configuration may be needed for each particular application.

Figure 2 illustrates another example of a conventional aftertreatment system 250 that includes a catalyst section 252, a filter section 254, an inlet section 256 and an outlet section 258. The sections are secured together using clamps 260. This type of construction allows for some modularization and standardization among the sections 252, 254, 256, 258, but leads to higher cost because of the additional parts (e.g. clamps, separate sections, etc.) and labor required.

Gas treatment systems, particularly aftertreatment systems, and a manufacturing process, that reduces engineering, design and manufacturing time, reduces cost, allows flexibility in making design changes, and allows use of standardized parts would be beneficial.

Summary Gas treatment systems for use with an engine and manufacturing process of the systems are described that allow for modular development of gas treatment systems using generally standardized parts and provide generally infinitely variable treatment systems to accommodate differing design requirements. The gas treatment systems can be systems that treat engine gases in a number of manners, including aftertreatment systems such as emissions treatment to treat exhaust gases or noise treatment to reduce noise associated with exhaust gases.

In the treatment system, a number of subsections are provided, including a treatment subsection containing a gas treatment device for treating the gas. The treatment performed by the gas treatment device can include, for example, emission treatment using a catalyst or a filter; noise treatment for reducing noise; combinations of emissions and noise treatment; and other treatments in which an action is performed on a gas within an engine environment to alter a property of the gas. The treatment subsection can include a single gas treatment device, or multiple gas treatment devices.

The treatment subsection is designed to be assembled, during manufacturing, with an inlet subsection, an outlet subsection, another treatment subsection, or other subsections in a manner to allow the positions of adjacent subsections relative to the

treatment subsection to be adjusted as required to fit the necessary design requirement. This permits an infinite number of length and/or clocking configurations for the treatment system to be manufactured. Once the appropriate adjustments have been made to satisfy the design requirements of the treatment system, the subsections can be fastened to maintain the positions of the subsections and the resulting configuration of the system. In one specific configuration, the connections between the subsections can be accomplished without the use of banded clamps if desired, for example by welding.

The treatment system can be used to treat gases in a number of applications, for example exhaust gases from vehicle and industrial engines such as diesel engines and gas combustion engines. Examples of suitable treatment devices, includes, but is not limited to, materials suitable for treating exhaust gases, such as catalysts, for example a diesel oxidation catalyst, or filters, for example a diesel particulate filter, and combinations thereof.

The described treatment systems and manufacturing process addresses the need to have one design that can be adapted to meet many design configurations, by permitting adjustment of the relative positions of the subsections relative to one another. The treatment subsection forms the standard subsection of the treatment system. In one embodiment, the treatment subsection is configured for telescoping connection to one or more adjacent subsections. Telescoping connections permit relative length adjustment between the treatment subsection and adjacent subsections, as well as relative rotational adjustment between the treatment subsection and adjacent subsections, during manufacturing. In another embodiment, the standard treatment subsection can be provided with flared joint geometry to permit fastening to flared joint geometry on one or more adjacent subsections. The process of manufacturing a treatment system includes obtaining a treatment subsection having a housing with an end that is configured to be assembled with an end of an adjacent subsection of the gas treatment system, a gas flow path through the housing, and a gas treatment device secured within the housing in the gas flow path for treating gas in the flow path. The treatment subsection is then assembled with the adjacent subsection in a manner that permits adjustment in the combined length of the treatment subsection and the adjacent subsection. In one embodiment, assembling

comprises telescoping at least one of the ends of the treatment subsection with an adjacent subsection.

Brief Description Of The Drawings Figure 1 illustrates a conventional exhaust gas aftertreatment system.

Figure 2 illustrates another conventional exhaust gas aftertreatment system. Figure 3 is a longitudinal sectional view of a gas treatment system according to one embodiment.

Figure 4 is an exploded perspective view of the subsections of another embodiment of a gas treatment system.

Figure 5 is a longitudinal sectional view taken along line 5-5 in Figure 6 of the subsections of Figure 4 assembled.

Figure 6 is an end view of the system in Figure 5.

Figure 7 is a view similar to Figure 5 with the length and clocking angle of the system adjusted.

Figure 8 is a longitudinal sectional view of another embodiment. Figure 9 is an end view of the system in Figure 8.

Figures 1OA and 1OB illustrate different embodiments of the treatment subsection including a flange. Figure 11 is a longitudinal sectional view of another embodiment of a gas treatment system.

Detailed Description

Figures 3-11 illustrate gas treatment systems that permit modular development of a number of gas treatment systems using generally standardized parts. The gas treatment systems are constructed from a number of subsections, including, but not limited to, a treatment subsection containing a gas treatment device for treating gas, an inlet subsection and an outlet subsection.

For sake of convenience, the inventive concepts will be described herein with respect to an exhaust gas aftertreatment system. However, it is to be realized that the inventive concepts can be used in other types of gas treatment systems as well.

The subsections are designed to be connected to one another to form the aftertreatment system. In particular, the subsections are designed to allow the positions of the treatment subsection relative to adjacent subsections, for example the inlet and outlet subsections or another treatment subsection, to be adjusted as required. This permits an infinite number of length and/or clocking configurations for the aftertreatment system to be manufactured.

The treatment subsection forms the standard subsection of the aftertreatment system. In one embodiment, the treatment subsection is designed for telescoping connection with one or both of the inlet and outlet subsections, or other adjacent subsections. Telescoping connections permit relative length adjustment between the treatment subsection and adjacent subsections, as well as relative rotational adjustment between the treatment subsection and adjacent subsections. In another embodiment, the standard treatment subsection can be provided with flared joint geometry to permit connection to flared joint geometry on one or more adjacent subsections. The aftertreatment systems can be used to treat exhaust gases in a number of applications, for example on vehicle and industrial engines such as diesel engines and gas combustion engines. The exhaust gases can be treated in a number of manners, including, but not limited to, emissions treatment to treat the exhaust gases; noise treatment to reduce noise associated with the exhaust gases; combinations of emissions and noise treatment; and other treatments in which an action is performed on the exhaust gases to alter a property of the gas. The treatment subsection can include a single gas treatment device, or multiple gas treatment devices. Example of suitable emissions treatment includes, but is not limited to, a catalyst, such as a diesel oxidation catalyst, or a filter, such as a diesel particulate filter. To facilitate the description, the exhaust gas will be hereinafter described as being diesel engine exhaust from a diesel engine and the exhaust gas treatment device in the treatment subsection will be described as a diesel oxidation catalyst. However, it is to be realized that the inventive concepts described herein can be used on other aftertreatment systems to treat other exhaust gases from other types of engines and that the exhaust gas treatment device can be other types of materials or devices that are used to treat exhaust gases.

With reference now to Figure 3, an aftertreatment system 10 is illustrated. The system includes a treatment subsection 12, an inlet subsection 14, and an outlet subsection 16. The inlet and outlet subsections 14, 16 are designed to connect with the treatment subsection 12 in telescoping fashion which allows adjustment in the length of the system 10 during assembly, as indicated by the arrows in Figure 3. Once the desired length is achieved, the subsections are then fastened together to fix their positions, for example by welding the subsections 12, 14, 16 to one another.

The treatment subsection 12 includes a housing 20 that has a first end portion 22 defining an inlet of the subsection 12, and a second end portion 24 defining an outlet of the subsection 12. The housing 20 is preferably made of a material that is suitable for withstanding the temperatures and pressures of exhaust gas treatment, for example steel. An exhaust gas flow path, illustrated by arrows, is defined through the housing 20 from the first end portion 22 to the second end portion 24 to allow exhaust gases to flow into, through and out of the housing 20. As shown in Figure 3, the first end portion 22 and the second end portion 24 both extend generally parallel to the exhaust gas flow path and parallel to a central axis A-A of the housing 20.

An exhaust gas treatment device 26, for example a substrate, such as a ceramic brick, containing a catalyst such as a diesel oxidation catalyst, is disposed within the housing and fills substantially the entire flow path. The device 26 is inserted into the housing 20, for example manually, and isolator rings 28 are inserted on either side of the substrate 26. Retainer rings 30 are then inserted on the outsides of the rings 28, and the rings 30 are then welded to the housing 20 to secure the substrate 26, rings 28 and rings 30 in the housing 20.

The inlet subsection 14 includes a housing 32 that is preferably made of a material that is suitable for withstanding the temperatures and pressures of exhaust gas treatment, for example the same material as the housing 20. The housing 32 includes an open, telescoping end section 34 that telescopes with the first end portion 22. The end section 34 is illustrated as being telescoped over the first end portion 22. However, the system could be designed so that the end portion 22 telescopes over the end section 34. The opposite end of the housing 32 is closed by a wall 36, with an inlet opening

38 formed through the wall 36 to enable exhaust gases to enter the system 10. The axis

of the inlet opening 38 is illustrated as being coaxial to the axis A-A in Figure 3, but may also be in any position and orientation with respect to the axis A-A as illustrated in later embodiments. In use, the inlet opening 38 will be suitably connected to an engine 40, for example a diesel engine, shown diagrammatically in Figure 3, to receive exhaust gas from the engine.

The outlet subsection 16 includes a housing 42 that is preferably made of a material that is suitable for withstanding the temperatures and pressures of exhaust gas treatment, for example the same material as the housings 20 and 32. The housing 42 includes an open, telescoping end section 44 that telescopes with the second end portion 24. The end section 44 is illustrated as being telescoped over the second end portion 24. However, the system could be designed so that the end portion 24 telescopes over the end section 44.

The opposite end of the housing 42 is closed by a wall 46, with an outlet opening 48 formed through the wall 46 to enable exhaust gases to exit the system 10. The axis of the outlet opening 48 is illustrated as being coaxial to the axis A-A in Figure 3, but may also be in any position and orientation with respect to the axis A-A as illustrated in later embodiments. In use, the outlet opening 48 will be suitably connected to exhaust outlet tubing, a secondary treatment device, or an exhaust stack.

As discussed above, the end portions 22, 24 of the treatment subsection 12 are telescoped with the end sections 34, 44 of the inlet and outlet subsections 14, 16. Any shape of the end portions 22, 24 and end sections 34, 44 that permit this telescoping relation can be used. For example, with reference to Figures 4, 6 and 9, the end portion 24 (as well as the end portion 22) and the end section 44 (as well as the end section 34) can be generally circular. However, other shapes that permit telescoping connection, such as oval, square, rectangular, triangular and the like, can be used.

Returning to Figure 3, once the inlet and outlet subsections 14, 16 are telescoped with the treatment subsection 12, the length of the system 10 can be adjusted to the desired length by adjusting the relative positions of the subsections, for example by retaining the subsection 12 and moving one or more of the subsections 14, 16 relative to the subsection 12. In addition, the positions of the subsections 14, 16 relative to the subsection 12 can be adjusted to permit the system 10 to fit within the desired space.

Once the desired positioning of the subsections 12, 14, 16 is achieved, the subsections 14, 16 are then securely fastened to the subsection 12, for example by welding, to fix the configuration of the system 10.

With reference to Figures 4-7, an alternative embodiment of an aftertreatment system 50 is illustrated. In the system 50, the treatment subsection 12 is the same construction as in the system 10. However, in the system 50, an inlet subsection 52 is provided with a side inlet 54 and an outlet subsection 56 is provided with a side outlet 58. The ends of the subsections 52, 56 are closed by walls 60, 62, respectively.

In the system 50, the inlet subsection 52 and the outlet subsection 56 are telescoped with the treatment subsection 12, as with the system 10, to permit adjustment of the length of the system, as shown by the arrows in Figures 4, 5 and 7. Figure 5 illustrates the subsections with one length, and Figure 7 illustrates the subsections adjusted to a shorter length. In addition, the inlet subsection 52 and the outlet subsection 56 are rotatable relative to the treatment subsection 12 about the axis A-A, as indicated by the arrows in Figures 4 and 6, to allow adjustment of the positions of the side inlet 54 and the side outlet 58 (i.e. changing the clocking angle α of the inlet 54 and the outlet 58). The clocking angle between the inlet and outlet is defined as the angle between the axis of the inlet 54 and the axis of the outlet 58.

The system 50 permits an infinite number of lengths as well as clocking configurations of the system 50. The end portions 22, 24 of the subsection 12 and the end sections 34, 44 of the subsections 52, 56 must be configured to permit such relative rotation as well as the telescoping. For example, the end portion 24 (as well as the end portion 22) and the end section 44 (as well as the end section 34) can be generally circular as shown in Figures 4 and 6. Figures 8 and 9 illustrate another embodiment of an aftertreatment system 70 where the inlet subsection 52 is the same construction as in the system 50 of Figures 4-7. In the system 70, a treatment subsection 72 is generally similar to the subsection 12 in the system 10. However, the subsection 12 is modified by the provision of a flange or flare 74 at the end portion 24. As illustrated in Figure 1OA, the flange 74 can be formed by bending the terminal end of the end portion 24 of the subsection 12 outward.

Alternatively, as illustrated in Figure 1OB, the flange 74 can be a separate flange that

attaches, for example by welding, to the housing of subsection 72. Figures 8, 1OA and 1OB illustrates the flange 74 as extending generally radially outward, perpendicular to the flow path and to the axis A-A. However, other angles for the flange could be used.

Another treatment subsection 76 is connected to the subsection 72. The treatment subsection 76 includes a housing 78 having flanges 80, 82 at each end thereof. The flange 80 is abutted against the flange 74 sandwiching a gasket between them, and connected thereto by a clamp 84, such as a banded clamp. The flange 82 can be used to connect the subsection 76 to a downstream component 79, such as an outlet subsection. A similar flange could be provided at the other end of the treatment subsection 72 for use in connecting the other end of the treatment subsection to the inlet subsection or another subsection.

The treatment subsection 76 is also illustrated as including an exhaust gas treatment device 86 disposed therein for further treating the exhaust gas. The treatment device 86 can be the same type of device as the device 26, or it can be a different type of device. For example, the device 86 can be a filter for filtering particulate matter from the exhaust gas, or a catalyst, such as a reduction catalyst for removing nitrogen oxides from the exhaust gas.

Even though the system 70 of Figure 8 uses a slightly modified treatment subsection 72, the subsection 72 is formed from the subsection 12. Therefore, the single subsection 12 configuration can be used to form a number of different aftertreatment systems.

Also in Figures 8 and 9, the subsection 79 includes an end outlet 94 that is offset from the axis A-A. As shown in Figure 9, the inlet clocking angle α, measured between the axis of the inlet and a horizontal axis is larger than the outlet clocking angle α ₀ measured between the axis of the outlet and the horizontal axis. However, other relationships between the inlet clocking angle and outlet clocking angle can be used.

Figure 11 illustrates an embodiment of an aftertreatment system 100 that is similar to the system 50 shown in Figures 4-7. In the system 100, intermediate telescoping sections 102, 104 are provided between the treatment subsection and the inlet subsection. The intermediate telescoping sections 102, 104 permit adjustment of the length between the treatment subsection and the inlet subsection. Similar telescoping

subsections could be provided between the treatment subsection and the outlet subsection or other subsections as well.

As should be evident from the above description, a single treatment subsection design, and a relatively small number of inlet and outlet subsection designs, can be used to form a large number of different aftertreatment systems. As a result, the time and cost of engineering, design and manufacturing an aftertreatment system can be reduced since there is a reduction in the need to custom-make parts, design changes can be easily made, and standardized parts can be used.

The invention may be embodied in other forms without departing from the spirit or novel characteristics thereof. The embodiments disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.