GB2574397A

GB2574397A - Engine exhaust aftertreatment canister assembly

Info

Publication number: GB2574397A
Application number: GB1809078.7A
Authority: GB
Inventors: Turoczy Arpad; Ahmed Niaz Naseer; Harrison Augustine
Original assignee: Perkins Engines Co Ltd
Current assignee: Perkins Engines Co Ltd
Priority date: 2018-06-04
Filing date: 2018-06-04
Publication date: 2019-12-11
Also published as: GB201809078D0

Abstract

An engine exhaust aftertreatment canister assembly 10 comprises a canister body 12 having a first end and a second end. First and second end cans 18, 20 are provided at the respective ends of the canister body, each of the first and second end cans comprising an end plate 22, a wall 24 extending from a periphery of the end plate, and an opening 32 which forms an inlet or outlet of the assembly. First and second pressure ports 26, 26' arc spaced apart in fluid communication with a flowpath F extending through the canister body 12 between the openings 32, with the first pressure port 26 being arranged generally centrally in the end plate of the first end can 18. The flowpath may extend through one or more permeable bodies 100 or other aftertreatment devices which are arranged in-between the two pressure ports 26, 26’. The first pressure port is provided generally centrally on the end plate of the first end cap, enabling the first end cap to be mounted in alternative angular orientations relative to the second end cap. The conduits can drain freely towards the respective pressure ports along substantially all of the length of the conduits.

Description

ENGINE EXHAUST AFTERTREATMENT CANISTER ASSEMBLY

Technical Field [1] The present disclosure relates to engine exhaust aftertreatment systems, and in particular to an end can assembly for an engine exhaust aftertreatment canister.

Background [2] Engine exhaust aftertreatment systems are used to reduce emissions in the exhaust stream of an internal combustion engine. Aftertreatment systems may consist of one or more aftertreatment devices, such as particulate filters and catalytic converters.

Aftertreatment devices are typically provided in a housing or canister through which the exhaust stream passes. End caps are mounted on each end of the canister. Each end cap has a pipe which acts as an inlet or outlet depending on which end of the canister the end cap is mounted to.

[3] In some aftertreatment systems it is desirable to measure the difference in pressure between the inlet and the outlet. For instance, in aftertreatment systems including a particulate filter this pressure difference may yield information on soot loading in the particulate filter. A differential pressure sensor may be used for this measurement. Such sensors have two inputs and measure a pressure difference between the inputs. The inputs may be connected to a pressure port formed near the periphery of each end cap. US patent 20 8,950,173 describes one such aftertreatment system.

[4] The configuration of the end caps, such as the location of the inlet/outlet pipe, is typically customised for a specific engine configuration. However, the use of customised end cap configurations does not permit reduction of manufacturing costs.

Summary of the Disclosure [5] In one aspect of the present disclosure, an engine exhaust aftertreatment canister assembly is provided. The assembly comprises a canister body configured to receive at least one aftertreatment device therein, the canister body having a first end and a second end. A first end can is provided at the first end of the canister body, and a second end can is provided at the second end of the canister body. The assembly further comprises

-2first and second pressure ports. Each of the first and second end cans comprises an end plate, a wall extending from a periphery of the end plate, and an opening provided in the end can to form an inlet or outlet of the assembly. The assembly defines a flowpath extending through the canister body between the openings of the first and second end cans 5 to pass through an aftertreatment device, such as one or more permeable bodies, arranged in the canister body. The first and second pressure ports are spaced apart in fluid communication with the flowpath, with the first pressure port being arranged generally centrally in the end plate of the first end can.

[6] Other features and aspects of this disclosure will be apparent from the 10 following description and the accompanying drawings.

Brief Description of the Drawings [7] FIG. 1 shows an exploded side view of an engine exhaust aftertreatment canister assembly in which embodiments of the present disclosure may be provided;

[8] FIG. 2 is an end view of the assembly according of FIG. 1; and [9] FIG. 3 is a perspective view of the assembly of FIG. 1 showing a modification.

Detailed Description [10] Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts.

[11] Referring to FIG. 1, there is shown an engine exhaust aftertreatment canister assembly 10 in which embodiments of the present disclosure may be provided. The assembly 10 comprises a canister body 12 having a first open end 14 and a second open end 16. The canister body 12 may be generally cylindrical, for example, as shown, with a central length axis X. One or more aftertreatment devices such as permeable bodies 100 may be arranged in the canister body 12, as shown in FIG. 3.

[12] The assembly 10 further comprises a first end can 18 provided at the first open end 14 of the canister body 12 and a second end can 20 provided at the second open end 16 of the canister body 12. After assembly, the first and second end cans 18, 20 close the first and second open ends 14, 16, respectively.

[13] Each of the first and second end cans 18, 20 comprises an end plate 22 and a wall 24 extending from a periphery of the end plate 22. The wall 24 may extend as shown generally in the axial direction of the canister body 12. Each wall 24 may include a lip 25 which is shaped to mate with the canister body 12.

[14] Each of the first and second end cans 18, 20 also has an opening 32 provided therein to form an inlet or outlet of the assembly 10. Either or both of the openings 32 may be provided in the wall 24 of the respective end can 18, 20 to extend away from the central length axis X of the canister body 12 for connection with the respective, upstream and downstream exhaust system components of the engine at an angle which is defined by the rotational position of the first and second end cans 18, 20 relative to each other about the central length axis X.

[15] The assembly defines a flowpath F which extends through the canister body 12 between the openings 32 of the end cans, from the respective inlet opening 32 through the one or more aftertreatment devices 100 within the canister body 12 to the respective outlet opening 32. In the illustrated example, the flowpath carries an exhaust gas in the flow direction indicated by the arrow, so that the inlet is in the second can 20 and the outlet is in the first end can 18. It will be appreciated that the flow direction could be reversed if desired.

[16] The assembly further includes a first pressure port 26 and a second pressure port 26’, the pressure ports being spaced apart in fluid communication with the flowpath F so that the fluid pressure of the exhaust gas can be sensed at two different points along the flowpath. The flowpath may extend through one or more permeable bodies 100 or other aftertreatment devices which are arranged in-between the two pressure ports 26, 26’ so that the sensed differential pressure between the first and second pressure ports 26, 26’ provides an indication of the pressure drop across the intervening aftertreatment device or devices.

[17] The first pressure port 26 is arranged generally centrally in the end plate of the first end can 18, and as shown, may be arranged on the central length axis X of the canister body 12.

[18] The second pressure port 26’ may be arranged in the second end can 20 as shown for example in the arrangement of Figs. 1 and 2.

[19] Alternatively, as shown for example in the variant arrangement of Fig. 3, first

-4and second permeable bodies 100 may be arranged in the canister body 12 in series relation in the flowpath F, with the second pressure port 26’ being arranged in the canister body 12 in fluid communication with the flowpath F between the first and second permeable bodies 100. This arrangement makes it possible to sense the differential pressure across only one of the permeable bodies 100. Thus, for example, where one body 100 is a diesel particulate filter and the other body 100 is a catalyst, the ports 26, 26’ may be arranged on either side of the filter to provide an indication of its flow resistance. In the example of Fig. 3 the first pressure port 26 is downstream of the second pressure port 26’ with respect to the flow direction; however, if desired, the first pressure port could be arrange upstream of the second pressure port.

[20] The first pressure port 26 may be in fluid connection with a first input 29 of a pressure sensor 28 via a first conduit 30, while the second pressure port 26’ may be in fluid connection with a second input 29’ of the pressure sensor 28 via a second conduit 30’, each conduit 30, 30’ comprising for example a flexible hose or a rigid tube. The pressure sensor 28 may be a differential pressure sensor 28 having both first and second inputs 29, 29’ and configured to measure a pressure drop across all or part of the flowpath F within the assembly 10. The pressure sensor 28 may be attached to a mounting plate (not shown) to which the canister body 12 may also be mounted using straps (also not shown) which extend around the canister body 12 in a use position of the assembly 10. Other forms of mounting for the assembly 10 may also be used.

[21] Either or each of the first and second conduits 30, 30’ may be connected to the the respective pressure port 26, 26’ and input 29, 29’ of the differential pressure sensor 28 in a freely draining orientation, for example, as shown in each of Figs. 1, 2 and 3. The freely draining orientation is arranged so that the respective conduit 30 or 30’ can drain freely towards the respective pressure port 26 or 26’ along substantially all of the length of the conduit in the use position of the assembly 10.

[22] For this purpose the respective conduit 30, 30’ may be arranged so that it extends in the freely draining orientation in a generally downward direction towards the respective pressure port 26 or 26’ and does not reverse direction along its length. In particular, the conduit 30, 30’ may be arranged to not reverse direction in an upward direction when the assembly 10 is installed in its use position, indicated in the drawings by arrow A. Such an arrangement may prevent air locks forming in the conduit 30, 30’ caused

-5by condensed fluid which, if the conduit were not arranged to drain freely towards the pressure port 26, 26’, could accumulate in a ‘U’ bend and interfere with measurements by the pressure sensor 28.

123] The first end can 18 may be assembled to the canister body 12 and the second end can 20 at a selected angle of rotation about the central length axis X of the cylindrical canister body 12 with respect to the second end can 20, the angle of rotation being selectively adjustable during assembly, as illustrated for example in FIG.2. As discussed above, this makes it possible to adjust the angular orientation of the inlet and outlet connections to suit the exhaust system configuration of the particular engine to which the 10 assembly 10 is to be mounted.

[24] The first conduit 30 may be connectable to the first pressure port 26 on the central length axis X of the cylindrical canister body 12 and in the freely draining orientation, irrespective of the selected angle of rotation.

[25] One or more aftertreatment devices, which may include one, two or more 15 permeable bodies 100, may be provided in the canister body 12. For example, in the arrangement shown in Fig. 3, two permeable bodies 100 are arranged in series relation in the flowpath F, so that exhaust gases may enter the assembly 10 via the opening 32 forming an inlet, flowing through each of the permeable bodies 100 in turn, and then exit the assembly 10 via the opening 32 forming an outlet. Any suitable aftertreatment device 20 known to the skilled person may be used; for example, either or both of the permeable bodies 100 may be formed as a block to function respectively as a filter and/or a catalyst.

[26] In the embodiment illustrated in the drawings, the first pressure port 26 is provided generally centrally on the end plate 22 of the first end can 18, as best seen in FIG.

2. The second pressure port 26’ may similarly be provided generally centrally, optionally 25 on the central length axis X of the canister body 12, on the end plate 22 of the second end can 20, or alternatively on the wall 24 of the second end can 20.

[27] The first end can 18 may be mountable to the canister body 12 in any of a plurality of alternative angular orientations corresponding to a plurality of angles of rotation about the central length axis X of the cylindrical canister body 12, as illustrated in

FIG.2 by the dashed lines showing alternative orientations of the opening 32 of the first end can 18. Since the pressure port 26 is provided generally centrally on the end plate 22 of the first end can 18, the same conduit 30 can be used to connect the pressure port 26 of the

-6first end can 18 to the pressure sensor 28 irrespective of the orientation of the first end can

18. This may enable the assembly 10 with the first end can 18 to be used in engines with different configurations without requiring the first end can 18 to be redesigned. Redesigning the first end can 18 for each engine configuration is undesirable since it does not permit reduction of manufacturing costs.

[28] While the foregoing description has been made with reference to the canister body 12 being generally cylindrical, ie having a generally circular cross-section, other configurations may be used. For example, the canister body 12 may have a hexagonal, octagonal, dodecagonal cross-section, and the first end can 18 may be shaped to mate with the canister body 12 to provide 6, 8 or 12 orientations, respectively. It will be appreciated that these configurations are exemplary only and that other configurations are possible.

[29] It will be appreciated by those skilled in the art that while the foregoing description has been made with reference to the first end can 18 being mountable to the canister body 12 in a plurality of orientations, either or both the first and second end can 18, 20 may be adjustably connectable to the canister body 12 so as to provide angular adjustment of the first end can relative to the second end can.

[30] Industrial Application [31] Embodiments of the present disclosure have been described that provide an engine exhaust aftertreatment canister assembly which may accommodate different engine configurations without requiring re-designed parts for each configuration. Such embodiments may enable reduced manufacturing costs. The engine exhaust aftertreatment canister assembly of the present disclosure provides the first pressure port generally centrally on the end plate of the first end cap, enabling the first end cap to be mounted in alternative angular orientations relative to the second end cap without affecting the configuration or orientation of the first conduit which connects the first pressure port to the pressure sensor. Further, the or each conduit connecting a respective one of the pressure ports to the pressure sensor may be arranged to drain freely towards the respective pressure port, which may prevent or reduce air locks forming in the conduit. By arranging for the first conduit 30 to be connectable to the first pressure port 26 on the central length axis X of the cylindrical canister body 12 and in the freely draining orientation, the connection may be accomplished irrespective of the selected angle of rotation of the first end cap in

-7the use position of the assembly. Thus, the assembly may conveniently be adapted to suit the exhaust system configuration of the engine, while providing reliable pressure sensing, without adaptation of the configuration of the first conduit 30.

[32] While aspects of the present disclosure have been particularly shown and 5 described with reference to the embodiments above, it will be understood by those skilled in the art that many further adaptations are possible within the scope of the claims.

[33] In the claims, reference numerals and characters are provided in parentheses, purely for ease of reference, and should not be construed as limiting feature.

Claims

1. An engine exhaust aftertreatment canister assembly (10), comprising:

a canister body (12) having a first end (14) and a second end (16);

a first end can (18) provided at the first end (14) of the canister body;

a second end can (20) provided at the second end (16) of the canister body; and first and second pressure ports (26, 26’);

each of the first and second end cans comprising:

an end plate (22), a wall (24) extending from a periphery of the end plate (22), and an opening (32) forming an inlet or outlet of the assembly;

the assembly defining a flowpath (F) extending through the canister body between the openings (32) of the first and second end cans, the first and second pressure ports (26, 26’) being spaced apart in fluid communication with the flowpath (F);

wherein the first pressure port (26) is arranged generally centrally in the end plate of the first end can (18).

2. The assembly of claim 1, wherein the canister body (12) is generally cylindrical, and the first pressure port (26) is arranged on a central length axis (X) of the canister body.

3. The assembly of claim 1 or claim 2, wherein the second pressure port (26’) is arranged in the second end can (20).

4. The assembly of claim 1 or claim 2, wherein first and second permeable bodies (100) are arranged in the canister body (12) in series relation in the flowpath (F), and the second pressure port (26’) is arranged in the canister body in fluid communication with the flowpath (F) between the first and second permeable bodies (100).

5.

The assembly of claim 2, wherein the respective opening (32) of the first end can

-9(18) is formed in the wall (24) of the first end can (18).

6. The assembly of claim 2, further comprising:

a differential pressure sensor (28) having first and second inputs (29, 29’), a first conduit (30) fluidly connecting the first pressure port (26) to the first input (29) of the differential pressure sensor (28), and a second conduit (30’) fluidly connecting the second pressure port (26’) to the second input (29’) of the differential pressure sensor (28).

7. The assembly of claim 6, wherein the first conduit (30) has a length and is connected to the the first pressure port (26) and the first input (29) of the differential pressure sensor (28) in a freely draining orientation; and wherein in the freely draining orientation, the first conduit (30) is arranged to drain freely towards the first pressure port (26) along substantially all of its length in a use position of the assembly (10).

8. The assembly of claim 7, wherein the first end can (18) is assembled to the canister body (12) and the second end can (20) at a selected angle of rotation about the central length axis (X) of the cylindrical canister body (12) with respect to the second end can (20), the angle of rotation being selectively adjustable during assembly; and the first conduit (30) is connectable to the first pressure port (26) in the freely draining orientation irrespective of the selected angle of rotation.