Claims:
WE CLAIM:
1. An exhaust gas after-treatment assembly (200), for an engine of an automobile, configured for reducing air pollutants escaping into the atmosphere, said assembly (200) comprising a Diesel-Oxidation-Catalyst (DOC) unit (210) mounted on a transmission housing (211) of the automobile in proximity to and spaced apart from the engine, a Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit (230) attached to the underbody of the automobile, and a conduit (215) configured to facilitate fluid communication between said Diesel-Oxidation-Catalyst (DOC) unit (210) and said Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit (230).
2. The exhaust gas after-treatment assembly (200) as claimed in claim 1, wherein said conduit (215) is coupled to said Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit (230) via a flange (227) configured to act as a mechanical fuse, and said flange (227) is a split flange.
3. The exhaust gas after-treatment assembly (200) as claimed in claim 1, wherein said conduit (215) is a flexible bellow.
4. The exhaust gas after-treatment assembly (200) as claimed in claim 1, wherein said after-treatment assembly (200) includes a heat shield (231) enveloped around said conduit (215).
5. The exhaust gas after-treatment assembly (200) as claimed in claim 4, wherein the material of said heat shield (231) is selected from the group consisting of steel, aluminium, carbon-fibre, a composite material, a polymer, and a plastic capable of withstanding shocks and vibrations.
6. The assembly (200) as claimed in claim 1, wherein said Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit (230) is attached to the underbody of the automobile via a plurality of rubber insulators (226) and a plurality of hangers (225).
7. The assembly (200) as claimed in claim 1, wherein said assembly comprises a dosing module (220) arranged between said Diesel-Oxidation-Catalyst (DOC) unit (210) and said Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit (230) for injecting urea solution in the stream of exhaust gas received from said Diesel-Oxidation-Catalyst (DOC) unit (210).
8. The assembly (200) as claimed in claim 7, wherein said assembly comprises a mixer (228) arranged between said dosing module (220) and said Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit (230) and configured to facilitate mixing of the urea with said exhaust gas.
9. The assembly (200) as claimed in claim 1, wherein said dosing module (220) is an air cooled module and is configured to receive high velocity ambient air flowing along the outer surface of said Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit (230).
, Description:FIELD
The present disclosure relates to the field of exhaust gas after-treatment.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
The exhaust gases usually contain substantial amounts of air pollutants such as nitrogen oxides (NOx), carbon oxides (COx), hydrocarbons (HC), and particulate matter (PM), the treatment of which is very critical for emission control. This is called as aftertreatment process, which uses Diesel Oxidation Catalyst (DOC), Selective Catalytic Reduction (SCR) catalyst, and Diesel Particulate Filter (DPF). DOC helps in converting carbon monoxide (CO) and hydrocarbons (HC) present in exhaust into carbon dioxide (CO2) and water. SCR helps in conversion of NOx to N2 and O2. DPF helps to remove diesel particulate matter or soot from the exhaust gas.
Therefore, it is imperative to control the amount of pollutants being emitted out to the atmosphere, which is done by means of an after-treatment system for the treatment and removal/reduction of the pollutants present in the exhaust gas. The after-treatment unit is typically mounted on the vehicle engine. It is mandatory to adhere to stringent emission standards.
A conventional exhaust gas after-treatment unit comprises a Diesel-Oxidation-Catalyst (DOC) unit, a Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit, a dosing module, and a mixer packaged into a single housing. While packing all these components in a single housing, the size and volume of the assembled exhaust gas after-treatment unit increases significantly. Till recent times, the whole exhaust gas after-treatment unit which is packed in a single housing is mounted into the engine compartment.
The space available in the engine compartment is limited. Therefore, placing the exhaust gas after-treatment unit for a 1-ton utility automobile/vehicle is a challenge. Further, due to the enclosed nature of the engine compartment, cooling the components of the after-treatment unit requires a separate cooling arrangement, such as water cooling jackets or water cooled dosing module. This results in an increase in the weight and the cost of the automobile.
There is, therefore, felt a need of an exhaust gas after-treatment unit for an engine of an automobile 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 object of the present disclosure is to provide an exhaust gas after-treatment unit for an engine of an automobile.
Another object of the present disclosure is to provide an exhaust gas after-treatment unit that is air cooled.
Yet another object of the present disclosure is to provide an exhaust gas after-treatment unit that is fixed to an operative bottom of the floor of the automobile.
Still another object of the present disclosure is to protect the exhaust gas after-treatment unit from damage due to shocks.
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 exhaust gas after-treatment assembly for an engine of an automobile for reducing air pollutants escaping into the atmosphere. The exhaust gas after-treatment assembly has various components such as a Diesel-Oxidation-Catalyst (DOC) unit mounted on a transmission housing of the automobile in proximity to and spaced apart from the engine, a Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit attached to the underbody of the automobile, and a conduit configured to facilitate fluid communication between the Diesel-Oxidation-Catalyst (DOC) unit and the Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit.
According to an aspect of the present disclosure, the conduit of the exhaust gas after-treatment assembly is coupled to the sDPF unit via a split flange. The split flange is configured to act as a mechanical fuse.
According to an aspect of the present disclosure, the conduit is a flexible bellow.
According to an aspect of the present disclosure, the after-treatment assembly includes a heat shield that is enveloped around the conduit.
According to an aspect of the present disclosure, the material of the heat shield is selected from the group consisting of steel, aluminium, carbon-fibre, a composite material, a polymer, and a plastic that is capable of withstanding shocks and vibrations.
According to an aspect of the present disclosure, the Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit is attached to the underbody of the automobile via a plurality of rubber insulators and a plurality of hangers.
According to an aspect of the present disclosure, the assembly further comprises a dosing module, arranged between the Diesel-Oxidation-Catalyst (DOC) unit and the Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit, for injecting urea solution into the stream of exhaust gas received from the Diesel-Oxidation-Catalyst (DOC) unit.
According to an aspect of the present disclosure, the assembly comprises a mixer module arranged between the dosing module and the Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit, such that the mixer is configured to facilitate mixing of the urea with the exhaust gas.
According to an aspect of the present disclosure, the Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit is configured to receive high velocity ambient air that is flowing along the outer surface of the Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
An exhaust gas after-treatment assembly for an engine of an automobile of the present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates an isometric view of a conventional exhaust gas after-treatment assembly mounted on an automobile;
Figure 2 illustrates a detailed isometric view of an exhaust gas after-treatment assembly of an automobile in accordance with the present disclosure;
Figure 3 illustrates an isometric view of the exhaust gas after-treatment assembly of an automobile;
Figure 4 illustrates a side view of a Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit;
Figure 5 illustrates a sectional view of the sDPF unit along a plane B-B shown in Figure 4; and
Figure 6 illustrates an isometric view of a Diesel-Oxidation-Catalyst (DOC) unit mounted on a transmission housing of the automobile.
LIST OF REFERENCE NUMERALS
100 – Conventional exhaust gas after-treatment assembly
101 – Chassis
102 – Cross beams
120 – Conventional after-treatment unit
124 – Rubber insulators
125 – Hangers
140 – Muffler
150 – Tail pipe
200 – Exhaust gas after-treatment assembly
201 – Chassis
202 – Cross beams
210 – Diesel-Oxidation-Catalyst (DOC) unit
211 – Transmission housing
212 – DOC unit support bracket
215 – Conduit
220 – Dosing module
225 – Hangers
226 – Rubber insulators
227 – Flange
227a – DOC outlet flange
227b – sDPF inlet flange
228 – Mixer
230 – Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit
231 – Heat Shield
240 – Muffler
250 – Tail pipe
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, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, 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.
The present disclosure envisages an exhaust gas after-treatment assembly 200 for an engine of an automobile, as illustrated in Figure 2 to Figure 5. The exhaust gas after-treatment assembly 200 is depicted in an isometric view in Figure 2 and Figure 3.
A conventional exhaust gas after-treatment assembly 100 for an engine of an automobile is illustrated in Figure 1. All the necessary components required for treatment of the exhaust gas, that comprises a Diesel-Oxidation-Catalyst (DOC) unit, a Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit, a urea dosing module, and a mixer for efficient mixing of a dosing solution with the exhaust gas are packaged into a single housing. The exhaust gas after-treatment unit 120 is placed near the engine and within the engine compartment. A conduit such as a flexible bellow fluidly connects the exhaust gas after-treatment unit 120 with a muffler 140 from where the exhaust gas exits to the surroundings via a tail pipe 150. The muffler 140 is fixed to the chassis 101, and a plurality of cross beams 102 of the automobile via a plurality of hangers 125 and a plurality of rubber insulators 124. A special cooling arrangement (not shown in figures), such as water cooling is employed for maintaining the optimum working temperature of the components of the exhaust gas after-treatment unit 120. The water cooling arrangement requires separate conduits, water jackets, a pump, electrical cables, temperature sensors, and a control unit. This increases the cost and space requirement, which is a challenge, during the assembly of different components of the automobile.
The present disclosure envisages an exhaust gas after-treatment assembly 200. A detailed isometric view of the exhaust gas after-treatment assembly 200 in accordance with the present disclosure is depicted in Figure 2 and Figure 3. Various components of the exhaust gas after-treatment assembly 200 are fixed to a chassis 201 and a plurality of cross beams 202 of the automobile. The exhaust gas after-treatment assembly 200 comprises a Diesel-Oxidation-Catalyst (DOC) unit 210, a Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit 230, a dosing module 220, and a mixer 228. The DOC unit 210 is in fluid communication with the sDPF unit 230 via the conduit 215. The exhaust gas, after passing through the sDPF unit 230, exits to the surrounding through a tail pipe 250 which is in fluid communication with the sDPF unit 230. The DOC unit 210 is mounted on a transmission housing 211 through a DOC support bracket 212. The sDPF unit 230 and the muffler 240 are fixed to the chassis 101 and the cross beams 202 via a plurality of hangers 225 and rubber insulators 226. A flange 227 is used for connecting the DOC unit 210 to the sDPF unit 230.
According to an embodiment of the present disclosure, the flange 227 is a split flange which also acts as a mechanical fuse to prevent damage to the assembly 200 due to shocks or a collision.
As shown in Figure 4, the sDPF unit 230 comprises a sDPF inlet flange 227b at one end and which is configured to be coupled with a DOC outlet flange 227a (shown in figure 6). The dosing module 220 is fixed on the external surface of an inlet passage to the sDPF unit 230. The dosing module 220 comprises an injector for injecting a calculated amount of urea solution into the stream of the exhaust gas, intermittently. A heat shield 231 surrounds the conduit 215 and other components of the assembly 200 for reducing the heat losses to the surrounding.
Figure 5 illustrates a sectional view of the sDPF unit 230 along a plane B-B shown in Figure 4. The mixer 228 is incorporated in the inlet passage downstream the dosing module 220. The mixer 228 is configured for reducing the mixing length of the urea and the exhaust gas, before the gas enters the sDPF unit 230.
According to an embodiment of the present disclosure, the mixer 228 is a dual mixer, a swirl mixer, a vortex mixer, a plate type mixer, a helix mixer, a mesh mixer, and the like.
Figure 6 illustrates an isometric view of the DOC unit 210 mounted on the transmission housing 211 of the automobile. The DOC unit 210 is mounted on the DOC support bracket 212 provided on the transmission housing 211. The DOC outlet flange 227a is provided at the outlet end of the DOC unit 210.
The sDPF unit 230 placed under the floor of the automobile receives free flowing ambient air which passes over the sDPF unit 230. The volume flow rate and speed of the ambient air is proportional to the speed of the automobile. This facilitates air cooling of the sDPF unit 230. There is no need of a separate cooling arrangement that uses water or a synthetic coolant. This further reduces the weight and cost of the after-treatment assembly 200.
The dosing module 220 is oriented away from the tire kick-up of the automobile. In this configuration, the dosing module 220 is least affected by water splashes and stone hitting. The heat shield 231 is provided around the conduit 215 and the inlet passage carrying the exhaust gas from the DOC unit 210 to the sDPF unit 230. The heat shield 231 also protects the conduit 215 and the inlet passage to the sDPF unit 230 from damages due to stones and water splashes.
According to an embodiment of the present disclosure, the Diesel-Oxidation-Catalyst (DOC) unit has a primary mounting inside exhaust manifold in case of a naturally aspirated engine and in the turbocharger in case of a boosted engine. A secondary mounting is provided on engine crankcase and the transmission housing and in proximity to and spaced apart from the engine with the help of brackets. The Diesel-Particulate-Filter with Selective Catalytic Reduction coating (sDPF) unit is attached to the underbody of the automobile and a conduit is provided for facilitating fluid communication between the DOC unit and the sDPF unit.
According to an embodiment of the present disclosure, the heat shield 231 is made from steel, aluminium, carbon-fibre, a composite material, polymer, or a plastic capable of withstanding shocks and vibrations.
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 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 gas after-treatment assembly for an engine, which:
• ensures an effective packaging of the exhaust gas after-treatment units;
• ensures that lesser space is required for mounting of the exhaust gas after-treatment units;
• is cooled by ambient air;
• does not require special cooling arrangement;
• is cost effective;
• expedites the automobile manufacturing by reducing the assembly time of the exhaust gas after-treatment assembly; and
• is easy to assemble and service.
The foregoing disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
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 documents, acts, 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.