DISPERSION DEVICE

Technical Field of the Present Invention

The present invention relates to an exhaust outlet system with exhaust gas dilution and dispersion components suitable for evacuation of exhaust gas stream from a combustion engine.

Prior Art Background of the Present Invention Generally, an exhaust system guides exhaust gases formed due to the controlled combustion inside the engine of a vehicle. Diesel engines differ from spark- ignition gasoline engines due to the ignition of the fuel by the high temperature in compressed state. Typically, hazardous chemical components are present in a diesel exhaust such as nitrogen oxides (NO _x ), carbon monoxide, and hydrocarbons.

The main function of the exhaust system is to reduce the CO, (NO _x ) and hydrocarbons, to decrease the noise level to a desired acceptable level. Therefore, it is of utmost importance to ensure appropriate operation of the exhaust system so as to fulfill the above-mentioned functions.

Exposure to exhaust gases is a common problem in the modern world and therefore the emitted gases from the engines and the amounts thereof are regulated by legal requirements. For diesel engine-vehicles, compliance with regulations to reduce exposure to exhaust gases emitted as such is ensured by exhaust aftertreatment systems which include components such as diesel particulate filters (DPF), diesel oxidation catalysts (DOC) and selective catalytic reduction (SCR) component so as to diminish the toxicity effect of the exhaust gas.

Diesel oxidation catalysts (DOC) is responsible for converting the CO, hydrocarbons and the organic residues in the diesel oil, which are in the gaseous state, to carbon dioxide and water. Diesel particulate filter (DPF) is a mechanical element holding the diesel particles and reducing emission. Selective catalytic reduction (SCR), on the other hand, transforms the (NOJ emissions into nitrogen and water vapor via using the urea in the system.

The exhaust outlet pipe structurally forms an outer part of the exhaust system, where the exhaust gases are released to the outer environment after their emissions are reduced. The temperature of the released exhaust gas is extremely important in the respect that it must be harmless for the outer environment and it should not cause a fire due to the high temperature of the released gases. It is to be noted that animals and human beings can be affected by the released gases. There is also a risk needed to be considered for the vehicle components surrounding the exhaust system, these parts in the proximity of the exhaust outlet may burn or melt at high temperatures.

Further, the exhaust outlet pipe is alone responsible for the transmission of the noise generated inside the engine. To this end, its physical structure is decisive overcoming transmission of the noise and effecting noise reduction emitted to the outer environment.

In order for ensuring effective operation of the exhaust outlet system, heat insulation is applied to the components thereof, resulting in that the exhaust gases almost completely preserve their heat as they reach the tailpipe of the exhaust outlet system. Therefore, the exhaust gases should be effectively cooled as they leave the tailpipe so that potentially harmful impacts for the surrounding components or vehicles close to the exhaust outlet and as well as fire hazards can be prevented.

There are various exhaust diluting and dispersing systems in the state of the art, certain applications making use of a wider surface area tailpipe design in an effort to provide cooling effect. Alternatively, cool air is received from the outside through appropriate openings for the same purpose.

A prior art publication in the technical field of the present invention may be referred to as DEI 02008048218 Al, which discloses an exhaust silencer with a channel having individual outlets, where the channel is formed from separately formed individual channels. One end of the individual channel forms the individual outlets and another end of the individual channels exhibits a cross- sectional shape. The individual channels form a circular connection to an outlet of an exhaust silencer. The individual channels are connected with each other at front sides at the circular connection of the exhaust silencer by welding in a material-fit and form-fit manner, where the outlet is formed in the form of a rounded square. The present invention provides an exhaust gas outlet system with exhaust gas dilution and dispersion components suitable for evacuation of exhaust gas stream from a combustion engine.

It is to be noted that the present invention is devised under the recognition that improving the exhaust outlet structure remains a need to ensure an effective and reliable exhaust dilution and dispersing device. The exhaust dilution and dispersing device of the invention effectively eliminates the fire risk originating from burning of various pieces such as sticks, straw etc. on the ground or road surface while at the same time effectively protecting parts of the vehicle surrounding the exhaust dilution and dispersing device. It is also to be noted that the velocity of the exhaust gases leaving the tailpipe may have a strong effect to raise dust to the extent that the sight of a driver in a vehicle behind may be curtailed. The present invention provides a structurally improved exhaust dilution and dispersing device generating an effective cooling effect through supplying atmospheric cool air in the environment by mixing it with the hot exhaust gas stream. A structurally improved tailpipe having a specifically structured closed volume in flow communication with a particularly configured outlet area ensures a much expedient and uniform cooling for the outlet gas in a short distance.

The present invention provides a system by which low temperature air from the environment is effectively received into the closed volume of the exhaust dilution and dispersing device in flow communication with the outlet area and is effectively mixed with the hot exhaust gas inside the outlet pipe.

While cooling of the exhaust gas in the outlet pipe is effected, it can be more reliably discharged to the atmosphere while the exhaust gas communicates with an effectively wider discharging plane. It is thus ensured that the exhaust gas is cooled in a quicker manner during distribution due to the created vortex inside the outlet pipe, which provides the exhaust gas to be more effectively mixed with the gas taken from the atmosphere and to be sufficiently cooled down before it moves out from the exhaust system. It is further to be noted that the structure of the outlet pipe allows created vortexes continue to create an efficient pattern of circulation even after the exhaust gases leave the outlet pipe.

It is also to be noted that the structural efficiency of the outlet pipe ensures much slower discharging velocity for the same amount of exhaust gas mass, which in turn effectively eliminates the effect of raising dust by the discharging exhaust gases. Objects of the Present Invention

Primary object of the present invention is to provide a structurally improved exhaust dilution and dispersing device generating an effective cooling effect through supplying atmospheric cool air in the outer environment by mixing it with the hot exhaust gas stream of the exhaust system.

Brief Description of the Figures of the Present Invention Accompanying drawings are given solely for the purpose of exemplifying an exhaust delivering and dispersing device with an outlet pipe. The drawings exemplify the associated components, whose advantages over prior art were outlined above and will be explained in brief hereinafter. The drawings are not meant to delimit the scope of protection as identified in the claims nor should they be referred to alone in an effort to interpret the scope identified in said claims without recourse to the technical disclosure in the description of the present invention. Fig. 1 demonstrates a general perspective view of an exhaust diluting and dispersing device in unmounted condition according to the present invention.

Fig. 2 demonstrates a general perspective view of the exhaust diluting and dispersing device in mounted condition according to the present invention.

Fig. 3 demonstrates a general perspective view of an alternative connection element between an inner pipe and an outlet enclosure according to an alternative embodiment of the present invention. Fig. 4 demonstrates another perspective view of the exhaust diluting and dispersing device with an upstream pipe according to the present invention. Fig. 5 demonstrates a horizontal cross-sectional view of the asymmetrical outlet plane lobes of the outlet enclosure according to the present invention. Fig. 6 demonstrates different gas streams within the asymmetrical lobes of the outlet enclosure and the upstream pipe according to the present invention.

Fig. 7 demonstrates tangential pressure distribution regions formed on the inner surface of the outlet enclosure's first lobe according to the present invention.

Fig. 8 demonstrates another horizontal cross-sectional view of the asymmetrical outlet plane lobes of the outlet enclosure with respective radiuses according to the present invention. Fig. 9 demonstrates a cross-sectional view taken along the longitudinal axis of the inner pipe in parallel with the outlet plane of the exhaust diluting and dispersing device, by which the eccentricity of the first lobe with respect to the longitudinal axis of the inner pipe is shown according to the present invention. Fig. 10 demonstrates another horizontal cross-sectional view of the asymmetrical exhaust diluting and dispersing device within which swirling motion of the gas streams occur according to the present invention.

Fig. 11 demonstrates motion of the gas streams discharging from different lobes of the outlet enclosure according to the present invention.

Fig. 12a and 12b respectively demonstrate cross-sectional and perspective side view of the exhaust diluting and dispersing device with the upstream pipe according to the present invention.

Fig. 13 demonstrates a cross-sectional side view of the exhaust diluting and dispersing device within which motion of the gas streams are shown according to the present invention.

Fig. 14 demonstrates another cross-sectional side view of the exhaust diluting and dispersing device within which motion of the gas streams are shown according to the present invention.

Fig. 15 demonstrates longitudinal configuration of a vehicle with an exhaust dilution and dispersion device having a first larger and a second smaller lobe according to the present invention.

Detailed Description of the Present Invention

The following numerals are referred to in the detailed description of the present invention:

11) Exhaust dilution and dispersion device

12) Inner pipe

13) Connection element

14) Outlet plane

15) Outlet enclosure

16) Welding line

17) Upstream pipe

18) Dilution gap

19) First lobe

20) Second lobe

21) First lobe opening

22) Second lobe opening

23) Tangential wall

24) Deflection portion

25) Inlet plane The present invention relates to an exhaust dilution and dispersion device (11) for an internal combustion engine of a vehicle, said exhaust dilution and dispersion device (11) comprising an inner pipe (12) in the form of an exhaust passage component in flow communication with the combustion engine components leading to an outlet enclosure (IS) as will be described hereinafter.

The combustion exhaust is received and directed to the outlet enclosure (IS) through the inner pipe (12) generally in the form of a longitudinally extending tubular element. The inner pipe (12) and the inlet of the outlet enclosure (IS) proximate the inner pipe (12) are adapted to be connected with at least one dilution gap (18) effecting air intake into the system. To this end, the inner pipe (12) and said outlet enclosure (IS) communicate with each other by means of a connection element (13) joining the two components while creating air intake gaps substantially contributing to the temperature drop of the exhaust gas streams as will be explained in more detail hereinafter. Preferably, said inner pipe (12) and the inlet of said outlet enclosure (IS) are configured as cylindrical bodies cooperatively fitted to each other with a diametric ratio being specified as 0.9. According to the present invention, a semi-closed gas stream processing chamber is created in the manner that the closed volume increases surface area of metal-gas contact so that enhanced heal transfer is ensured. It is to be noted that gas discharge is appropriately delayed to allow the exhaust gas to interact with free stream air thanks to the structural performance of the outlet enclosure (IS), by which gas flow is directed to a singular outlet plane (14).

The outlet enclosure (IS) of the invention has a semi-closed structure leading to the outlet plane (14) that is oriented to extend parallel to the ground. In other words, the exhaust gases mixed with the atmospheric air is discharged in the manner to be directly facing the road surface the vehicle moves. The closed volume of the outlet enclosure (IS) efficiently directs the exhaust gases to the outlet plane (14) of the outlet enclosure (IS) exit. The outlet enclosure (15) has a first lobe (19) and a second lobe (20), each of the lobes respectively having a first lobe and second lobe openings (21, 22). The exit opening formed by the first lobe and second lobe openings (21, 22) provides that the exhaust flow leaves the system directly facing the ground and in a sufficiently cooled state.

The closed structure of the outlet enclosure (15) is formed between the inlet and the outlet plane (14) thereof. Therefore the outlet enclosure (15) is adapted to extend along the longitudinal axis of the inner pipe (12) and the surface normal of the outlet plane (14) perpendicular to the longitudinal axis of the inner pipe (12). In other words, the outlet plane (14) is perpendicular to the plane of the inlet of the outlet enclosure (15). The outlet enclosure (15) structurally expands in the direction of the outlet plane (14) while the first and second lobes (19, 20) are separated by an inwardly projecting and downwardly expanding deflection portion (24). As can be seen in Fig. 13 or 14, in lateral cross-section, the outlet enclosure (15) as well as the deflection portion (24) is in the form of an arc- shaped extension. The deflection portion (24) is structured to directly face and receive gas streams coming from the inlet pipe (12) through the upstream pipe (17) in the manner that, due to the asymmetry of the first and second lobes (19, 20) with respect to each other, separate vortices are created as demonstrated in Fig. 6.

According to the present invention, the outlet enclosure (15) is structured to have tangential walls (23) which directly receive the upstream hot exhaust gas flow, which is tangentially guided to create vortices due to the asymmetric configuration of the first and second lobes (19, 20). In a more specific manner, the upstream hot exhaust gas hits the tangential walls (23) of the first and second lobes (19, 20) in the manner that bulk flow of the gas is asymmetrically guided to create a higher pressure area along the tangential wall (23) of the first lobe (19) whose projected diameter is greater than that of the second lobe (20) (Fig. 5). The surface pressure distribution graph of the tangential walls (23) of the first and second lobes (19, 20) is seen in Fig. 7. Accordingly, the momentum of the exhaust gas flow is utilized to enhance the mixing process by dividing the exhaust gas flow and creating asymmetrically separated vortex regions as defined by the tangential walls (23) of the first and second lobes (19, 20).

According to the present invention, separated vortex regions provide the atmospheric air to be taken into the outlet enclosure (15) to be effectively mixed with the hot exhaust gas within the closed volume of the outlet enclosure (IS). In other words, due to the asymmetrically guided bulk flow of the exhaust gas, an enhanced vortex flow is generated, which in turn creates secondary vortices to entrain fresh air from outside the outlet enclosure (15). The eccentricity of the first lobe (19) with respect to the longitudinal axis of the inner pipe (12) on the plane along the longitudinal axis of the same in parallel with the outlet plane (14) of the exhaust diluting and dispersing device (11) provides that the bulk flow of the gas is asymmetrically guided to create a higher pressure area along the tangential wall (23) of the first lobe (19). This is primarily achieved thanks to the ratio between diameters of the first and second lobes (19, 20) on the outlet plane (14) of the exhaust dilution and dispersion device (11) with the first and second lobes (19, 20) having a substantially uniformly expanding structure leading to said outlet plane (14). The advantageous ratio is found to be approximately 0.8 and preferably 0.83.

On the other hand, the eccentricity of the first lobe (19) with respect to the longitudinal axis of the inner pipe (12) can be also defined in that the diameter of the inner pipe (12) on the plane along the longitudinal axis of the inner pipe (12) in parallel with the outlet plane (14) of the exhaust diluting and dispersing device (11) (from a section parallel to the ground) is determined to be equal to the diameter of the first lobe (19) on that plane (Fig. 9). Further, the eccentricity of the first lobe (19) with respect to the longitudinal axis of the inner pipe (12) is defined as 0.8 times the radius of the first lobe (19) on that plane (Fig. 9).

The exhaust dilution and dispersion device (11) in accordance with the present invention is mounted to be situated along a longitudinal edge of the vehicle such that the first lobe (19) is configured to be near the longitudinally front side of the vehicle. This is advantageous in that the exhaust gas transferred from the front of the vehicle to the exhaust dilution and dispersion device (11) via the upstream pipe (17) is largely discharged from a more frontal side compared to the second lobe (20) whereby the bulk flow of the exhaust gas being sufficiently cooled thanks to the cooling effect of the secondary vortices created by the first lobe's (19) structural configuration as well as thanks to the effect of the air taken through the dilution gaps (18), even has more time and space to further cool down as it passes along under the second lobe (20).

The structure of the outlet enclosure (15) widening as it closes to the ground provides a wider exit area as diameters of both lobes get larger towards their ends. The first lobe opening (21) as well as the second lobe opening (22) has larger diameters compared to their initial upper parts. As vortex mechanisms are asymmetrical in terms of the gas stream volume, gas discharge from the second lobe opening (22) is less dense in volume compared to the first lobe opening's (21) performance.

The inner pipe (12) and the inlet of the outlet enclosure (15) proximate the inner pipe (12) are connected with each other by a connection element (13) creating a plurality of peripherally distributed dilution gaps (18) around the circular periphery of the inner pipe (12) and within the circular periphery of the projected inlet of the outlet enclosure (15), such dilution gaps (18) effecting air intake into the system. On the other hand, Fig. 3 demonstrates an alternative connection element (13) between an inner pipe (12) and an outlet enclosure (15), such a connection element (13) having a plurality of peripherally distributed radially equally-spaced wings.

The air flowing through the dilution gaps (18) allows atmospheric air to be drawn into the system. It is worthy of note that this gas flow regulating mechanism does not involve a venturi geometry. A welding line (16) can be preferentially created for structuring separate parts of the outlet enclosure (15).

In a nutshell, the present invention proposes an exhaust dilution and dispersion device (11) for an internal combustion engine of a vehicle, said exhaust dilution and dispersion device (11) comprising an outlet enclosure (15) receiving and directing the combustion exhaust to an outlet plane (14).

In one embodiment of the present invention, said outlet enclosure (15) is in the form of a semi-closed gas stream processing chamber adapted to extend between the inlet plane (25) of an inlet portion thereof receiving the upstream hot exhaust gas flow and said outlet plane (14) extending perpendicular to said inlet portion.

In a further embodiment of the present invention, said outlet enclosure (15) has a first lobe (19) and a second lobe (20), each of the lobes respectively having a first lobe and second lobe openings (21, 22).

In a further embodiment of the present invention, said outlet enclosure (15) structurally expands from the inlet thereof in the direction of the outlet plane (14) while the first and second lobes (19, 20) are separated by an inwardly projecting deflection portion (24) separating the two lobes.

In a further embodiment of the present invention, said first lobe and second lobe openings (21, 22) forming the outlet plane (14) have different diameters. In a further embodiment of the present invention, the outlet plane (14) is oriented to extend parallel to the base of the vehicle. In a further embodiment of the present invention, said first and second lobes (19, 20) are asymmetrical relative to a central surface normal of the inlet plane (25) of the outlet enclosure (15).

In a further embodiment of the present invention, said deflection portion (24) is structured to face and receive upstream hot exhaust gas flow in the manner that the exhaust gas flow is divided and asymmetrically separated vortices are created within the first and second lobes (19, 20).

In a further embodiment of the present invention, said first and second lobes (19, 20) have tangential walls (23) the upstream hot exhaust gas hits in the manner that bulk flow of the gas is asymmetrically tangentially guided to create a higher pressure area along the tangential wall (23) of the first lobe (19).

In a further embodiment of the present invention, projected diameter of the first lobe (19) on the plane the upstream hot exhaust gas hits tangential walls (23) of the first and second lobes (19, 20) is greater than the projected diameter of the second lobe (20).

In a further embodiment of the present invention, the first lobe (19) is eccentric with respect to the central surface normal of the inlet plane (25) on the plane along the same in parallel with the outlet plane (14). In a further embodiment of the present invention, projected diameters of the first and second lobes (19, 20) of the outlet enclosure (15) uniformly widen in the direction of the outlet plane (14).

In a further embodiment of the present invention, an inner pipe (12) in the form of an exhaust passage component in flow communication with an upstream pipe (17) connects the same to the outlet enclosure (15). In a further embodiment of the present invention, the longitudinal axis of the inner pipe (12) is perpendicular to that of the upstream pipe (17). In a further embodiment of the present invention, the inner pipe (12) and the inlet of the outlet enclosure (15) are connected with each other by a connection element (13) creating a plurality of peripherally distributed dilution gaps (18).

In a further embodiment of the present invention, said dilution gaps (18) are created around the circular periphery of the inner pipe (12) and within the circular periphery of the inlet of the outlet enclosure (15).

In a further embodiment of the present invention, said inner pipe (12) and the inlet of said outlet enclosure (15) are configured as cylindrical portions cooperatively fitted to each other with a diametric ratio of approximately 0.9.

In a further embodiment of the present invention, the diameter of inlet of said outlet enclosure (15) is greater than the diameter of the inner pipe (12). In a further embodiment of the present invention, in lateral cross-section, the outlet enclosure (15) and the deflection portion (24) extends in the form of an arc- shaped extension.

In a further embodiment of the present invention, the deflection portion (24) expands in width in the direction of the outlet plane ( 14).

In a further embodiment of the present invention, the first and second lobes (19, 20) have a substantially uniformly expanding structure in the direction of the outlet plane (14).

In a further embodiment of the present invention, the ratio between diameters of the first and second lobes (19, 20) on the outlet plane (14) of the exhaust dilution and dispersion device (11) is in the range of 0.8 to 0.8S.

In a further embodiment of the present invention, said first and second lobes (19, 20) are asymmetrical relative to the longitudinal axis of the inlet pipe (12).

In a further embodiment of the present invention, said first lobe (19) is eccentric with respect to the longitudinal axis of the inlet pipe (12) on the plane along the same axis in parallel with the outlet plane (14).

In a further embodiment of the present invention, the diameter of the inner pipe (12) on the plane along the longitudinal axis of the inner pipe (12) in parallel with the outlet plane (14) of the exhaust diluting and dispersing device (11) is equal to the diameter of the first lobe (19) on the same plane.

In a further embodiment of the present invention, the eccentricity of the first lobe (19) with respect to the longitudinal axis of the inner pipe (12) ion the plane along the longitudinal axis of the inner pipe (12) in parallel with the outlet plane (14) of the exhaust diluting and dispersing device (11) is defined as 0.8 times the radius of the first lobe ( 19) on that plane.

In a further embodiment of the present invention, the exhaust dilution and dispersion device (11) is mountable to be situated along a longitudinal edge of a vehicle such that the first lobe (19) thereof is configured to be near the longitudinally front side of the vehicle.