Claims:
WE CLAIM:
1. An engine exhaust after-treatment apparatus (100) comprising:
• a shell (101) having an inlet and an outlet;
• a first perforated baffle plate (106) disposed at the inlet;
• a second perforated baffle plate (111) disposed at the outlet;
• said shell (101) divided into two sections (105, 109), a first section (105) adjoining said first baffle plate (106) and a second section (109) adjoining said second baffle plate (111);
• a diesel oxidation catalyst element (107) located in said first section (105); and
• a perforated muffling element (110) located in said second section (109); wherein,
the dimensions and the density of the perforations (106a, 111a, 110a) of the baffle plates (106, 111) and the muffling element (110) are predetermined to obtain a predetermined signature sound for the vehicle and a normalized back pressure for the engine.
2. The apparatus (100) as claimed in claim 1, wherein said shell (101) has a converging section (101b) between said DOC section (105) and said muffler section (109).
3. The apparatus (100) as claimed in claim 1, wherein said first perforated baffle plate (106) is positioned upstream of said diesel oxidation catalyst element (107).
4. The apparatus (100) as claimed in claim 1, wherein diesel oxidation catalyst element (107) comprises a diesel oxidation catalyst substrate coated with a diesel oxidation catalyst.
5. The apparatus (100) as claimed in claim 1, wherein said muffling element (110) is disposed inside said second section (109) in a latitudinal orientation with respect to the direction of inward flow of the exhaust gases in said shell (101).
6. The apparatus (100) as claimed in claim 5, wherein the outlet pipe (103) of said apparatus (100) is connected to said muffling element (110) at a lateral surface of said second section (109) of said shell (101).
7. The apparatus (100) as claimed in claim 1, wherein said shell (101) is fitted with an end cap (112) at the longitudinal end opposite to the inlet side of said shell (101).
8. The apparatus (100) as claimed in claim 7, wherein said shell (101) is provided with an end cap insulation (113) on the inner side of said end cap (112).
9. The apparatus (100) as claimed in claim 8, wherein said second baffle plate (111) is fitted between between said end cap insulation (113) and said muffling element (110).
10. The apparatus (100) as claimed in claim 1, wherein said apparatus (100) has a flexible outlet pipe (103).
11. The apparatus (100) as claimed in claim 10, wherein said outlet pipe (103) has a first outlet pipe section (103a) and a second outlet pipe section (103b), and a flexible bellow (115) is inserted between said first outlet pipe section (103a) and said second outlet pipe section (103b).
12. The apparatus (100) as claimed in claim 1, wherein said apparatus (100) is configured to facilitate exhaust after-treatment of a naturally aspirated engine.
13. The apparatus (100) as claimed in claim 12, wherein the back pressure generated by the apparatus (100) for naturally aspirated engines is in the range of 150-170 mbar.
14. The apparatus (100) as claimed in claim 1, wherein said apparatus (100) is configured to facilitate exhaust after-treatment of a turbocharged engine.
15. The apparatus (100) as claimed in claim 14, wherein the back pressure generated by the apparatus (100) for turbocharged engines is in the range of 230-250 mbar.
Dated this 10th Day of September, 2019

_______________________________
MOHAN DEWAN, IN/PA - 25
of R.K.DEWAN & CO.
Authorized Agent of Applicant

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT MUMBAI
, Description:FIELD
The present disclosure relates to the field of exhaust gas after-treatment systems of vehicles.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
The transition of regulations into stricter regimes of engine emission norms necessitates use of after-treatment systems for the exhaust gases emitted out of vehicle engines. Exhaust after-treatment systems include diesel oxidation catalysts (DOCs), diesel particulate filters (DPFs), selective catalytic reducers (SCRs) and the like.
The exhaust after-treatment systems need to be incorporated in combination with an existing muffler component. A diesel oxidation catalyst (DOC) occupies a significant volume to increase constraints in packaging within the hood of an existing arrangement of a vehicle such as a tractor. Further, assembly of a DOC in the system introduces an additional step in the engine assembly during manufacturing of the vehicle. Moreover, a separate space needs to be dedicated in the storage of the manufacturing facility for the DOCs.
There is, therefore, felt a need for providing an engine exhaust after-treatment system which ameliorates the aforementioned issues.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An objective of the present disclosure is to provide an exhaust after-treatment apparatus for a vehicle engine.
Another objective of the present disclosure is to provide an exhaust after-treatment apparatus for a vehicle engine, which occupies minimum space within the engine compartment.
Yet another objective of the present disclosure is to provide an exhaust after-treatment apparatus for a vehicle engine, which requires minimum storage space.
Still another objective of the present disclosure is to provide an exhaust after-treatment apparatus for a vehicle engine, which is easy to assemble.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages an engine exhaust after-treatment apparatus. The engine exhaust after-treatment apparatus comprises a shell having an inlet and an outlet. A first perforated baffle plate is disposed at the inlet and a second perforated baffle plate is disposed at the outlet of the shell. The shell is divided into two sections: a first section adjoining the first baffle plate, a second section adjoining the second baffle plate. A diesel oxidation catalyst element is located in the first section and a perforated muffling element is located in said second section. The dimensions and the density of the perforations of the baffle plates and the muffling element are predetermined to obtain a predetermined signature sound for the vehicle and a normalized back pressure for the engine.
Preferably, the first perforated baffle plate is positioned upstream of the diesel oxidation catalyst element.
In an embodiment, the shell of the engine exhaust after-treatment apparatus has a converging section between the DOC section and the muffler section.
The diesel oxidation catalyst element comprises a diesel oxidation catalyst substrate coated with a diesel oxidation catalyst.
In an embodiment, the muffling element is disposed inside the first section in a latitudinal orientation with respect to the direction of inward flow of the exhaust gases in the shell. An outlet pipe of the apparatus is connected to the muffling element at a lateral surface of the second section of the shell.
The shell of the engine exhaust after-treatment apparatus is fitted with an end cap at the longitudinal end opposite to the inlet side of the shell. In an embodiment, the shell is provided with an end cap insulation on the inner side of the end cap. The second baffle plate is fitted between between the end cap insulation and the muffling element.
In an embodiment, the apparatus has a flexible outlet pipe. The outlet pipe preferably has a first outlet pipe section and a second outlet pipe section, and a flexible bellow is inserted between the first outlet pipe section and the second outlet pipe section.
In an embodiment, the engine exhaust after-treatment apparatus is configured to facilitate exhaust after-treatment of a naturally aspirated engine, wherein the back pressure generated by the apparatus is in the range of 150-170 mbar. In another embodiment, the engine exhaust after-treatment apparatus is configured to facilitate exhaust after-treatment of a turbocharged engine, wherein the back pressure generated by the apparatus is in the range of 230-250 mbar.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The exhaust after-treatment apparatus of the present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a top view of an exhaust handling subassembly of prior art;
Figure 2 illustrates a top view of an exhaust handling subassembly of the present disclosure;
Figure 3 illustrates a sectional view of a DOC-muffler unit of the present disclosure;
Figure 4 illustrates an isometric view of the DOC-muffler unit of Figure 3; and
Figure 5 illustrates an isometric view of the DOC-muffler unit of Figure 3.
LIST OF REFERENCE NUMERALS
1000’ exhaust handling subassembly of prior art
100’ muffler unit of prior art
1000 exhaust handling subassembly of the present disclosure
100 DOC-muffler unit of the present disclosure
101 shell
101a shell insulation
101b converging section
102 inlet pipe
103 outlet pipe
103a first outlet pipe section
103b second outlet pipe section
104 inlet cone
105 first section, i.e., DOC section
106 inlet baffle plate (first perforated baffle plate)
107 DOC element
108 support mat
109 second section, i.e., muffler section
110 muffling element
111 outlet baffle plate (second perforated baffle plate)
112 end cap
113 end cap insulation
114 second layer of insulation
115 bellow
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises”, “comprising”, “including” and “having” are open-ended transitional phrases and therefore specify the presence of stated features, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
When an element is referred to as being “mounted on”, “engaged to”, “connected to” or “coupled to” another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Terms such as “inner”, “outer”, “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
The present disclosure envisages an exhaust after-treatment apparatus which is an integrated DOC-muffler unit 100 as shown in the exhaust handling system 1000 of Figure 2, which does not consume more space than the erstwhile muffler unit 100’ as shown in the exhaust handling system 1000 of Figure 1, and which does not need an additional step for assembly.
The DOC-muffler unit 100 of the present disclosure integrates two functional units – a DOC unit and a muffler unit. The DOC-muffler unit 100 has a shell 101 which has two sections: a diesel oxidation catalyst (DOC) section 105 and a muffler section 109. The DOC section 105 is configured at an upstream side relative to the muffler section 109 within the shell 101 of the DOC-muffler unit 100. The DOC section 105 encloses a DOC element 107. The muffler section 109 encloses a muffling element 110.
The shell 101 is preferably made of stainless steel.
The DOC section 106 further comprises a support mat 108 for firmly supporting the DOC element 107. The shell 101 preferably has a cylindrical configuration, although the other cross-sections are also feasible. The shell 101 is provided with a shell insulation sheet 101a for insulating the contents of the shell 101 from the high heat emanating from the engine.
An inlet cone 104 is provided at the inlet side of the shell 101. An inlet pipe 102 is coupled to the inlet cone 104.
According to an aspect of the present disclosure, an inlet baffle plate 106 is positioned upstream of the DOC element 107. The inlet baffle plate 106 is configured to distribute uniformly the flow of incoming exhaust gases into the DOC element 107.
The DOC element 107 is a substrate structure which is coated with an oxidation catalyst. The catalyst is selected from a group consisting of palladium, platinum. The catalyst oxidizes any unburnt hydrocarbons or any partially oxidized molecules such as those of carbon monoxide (CO) that escape with the exhaust gas coming from the engine, to generate CO2 and water vapour. The substrate usually has a monolith honeycomb-type structure having a plurality of fine parallel channels, which effectively provide a large contact area with the coated catalyst for the exhaust gases flowing therethrough.
According to an aspect of the present disclosure, the shell 101 of the DOC-muffler unit 100 has a converging section 101b between the DOC section 105 and the muffler section 109. The converging section 101b facilitates pressurized entry of the catalyst-treated gases into the muffler section 109.
According to an aspect of the present disclosure, the muffling element 110 is disposed inside the muffler section 109 in a latitudinal orientation with respect to the direction of inward flow of the exhaust gases in the shell 101. The muffling element 110 is a cylindrical perforated tube. The muffling element 110 is supported on opposing surfaces of the muffler section 109 of the shell 101. An outlet pipe 103 of the DOC-muffler unit 100 is connected to the muffling element 110 at a lateral surface of the muffler section 109 of the shell 101.
At the longitudinal end opposite to the inlet side of the shell 101, an end cap 112 is fitted. An end cap insulation 113, preferably made of glass wool, is inserted in the shell 101 on the inner side of the end cap 112. An outlet baffle plate 111 is positioned between the end cap insulation 113 and the muffling element 110. An additional second layer of insulation 114 can be provided beneath the end cap insulation 113.
In an embodiment, the outlet pipe 103 of the DOC-muffler unit 100 is a flexible pipe. The outlet pipe 103 has a first outlet pipe section 103a and a second outlet pipe section 103b. A flexible bellow 115 is inserted between a first outlet pipe section 103a and a second outlet pipe section 103b of the outlet pipe 103. Having the flexible pipe and the flexible bellow 115 allows having a compact packaging of the exhaust handling assembly 1000.
The DOC-muffler unit 100 is mounted on surrounding rigid members of the vehicle chassis using mounting flanges and clamps.
The DOC-muffler unit 100 of the present disclosure requires a single step in the assembly of components in the exhaust handling subassembly 1000 of the engine assembly of the vehicle. Also, the unit 100 occupies minimum space within the engine compartment as also requires minimum storage space in the vehicle manufacturing plant. Hence, the engine compartment under the hood of the vehicle, say, a tractor, does not require either rearrangement of the layout or redesigning or expansion of the hood. The DOC-muffler unit 100, thus, fulfills the new engine emission requirements without requiring additional space which would have otherwise been required for a DOC unit mounted separately from the existing muffler unit.
While the integration of the DOC unit with the muffler unit to obtain a combined DOC-muffler unit such as the one of the present disclosure would have effectively increased the back-pressure generated by the unit as faced by the incoming exhaust gases, the combined effect of the muffling element 110 together with the inlet baffle plate 106, which is positioned upstream of the DOC element 107, and the outlet baffle plate 111 results in normalizing the back pressure given by the DOC-muffler unit 100 to the incoming exhaust gases.
The DOC-muffler unit 100 of the present disclosure can be implemented with naturally aspirated engines as well as turbocharged engines of varying capacities. In an exemplary embodiment, the back pressure generated by the DOC-muffler unit for naturally aspirated engines of 55 hp and 60 hp power output capacities is in the range of 150-170 mbar, while that generated by the DOC-muffler unit for turbocharged engines of 65 hp, 71 hp and 75 hp power output capacities is in the range of 230-250 mbar. These back pressure values remain unchanged as compared to a muffler-only engine, after the implementation of the combined DOC-muffler unit of the present disclosure.
While the back-pressure values thereof have been retained within the desired ranges, the DOC-muffler unit 100 of the present disclosure is also tunable for the desired acoustic frequencies produced for various engine RPM values, so as to achieve the predetermined signature sound for the vehicle. The tuning of the DOC-muffler unit 100 is achieved by varying the density and size of the holes in the muffling element 110 as well as the holes in the baffle plates 106, 111.
For naturally aspirated engines of 55 hp and 60 hp power output capacities, the tuned orders of the frequencies versus RPM values are reproduced in the table below:
RPM Overall noise
(dB) 1st order
(Hz) 2nd order
(Hz) 3rd order
(Hz) 4th order
(Hz) 6th order
(Hz) 8th order
(Hz) 500-3000 Hz
850 89 16.5 60 40 72 85.5 76 81
1200 91 31 65 52 84 77 75 84.5
1700 97 41 70 66 90 80 83 91
2100 97 44 76 68 85 81 79 94
2300 100 48 80 71 87 84 76 96
Table 1
For turbocharged engines of 65 hp, 71 hp and 75 hp power output capacities, the tuned orders of the frequencies versus RPM values are reproduced in the table below:
RPM Overall noise
(dB) 1st order
(Hz) 2nd order
(Hz) 3rd order
(Hz) 4th order
(Hz) 6th order
(Hz) 8th order
(Hz) 500-3000 Hz
850 83 20 53 35 56 68 64 81
1200 87 30 54 47 71 72 76 82
1700 93 37 70 58 75 82 70 92
2100 97 41 76 62 79 81 75 95
2300 99 45 79 65 84 80 77 98
Table 2
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of an exhaust after-treatment apparatus for a vehicle engine, which:
• occupies minimum space within the engine compartment;
• requires minimum storage space; and
• requires minimum steps during assembly and hence is easy to assemble.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.