Technical Field The present invention relates to a multi-manifold pipe, which prevents the formation of deposits that may result after the injection of a reductant mixture in the exhaust systems using the technics of active selective catalytic reduction-SCR.

Background Art

In internal combustion engines, some waste gases are formed after combustion. There are also harmful gases for environment but also for human health within the exhaust gases formed after combustion. It is dangerous and forbidden, that the harmful gases are expelled directly out of the exhaust of a vehicle, which endanger the environment and human health. The harmful gases formed after combustion are tried to be eliminated by several steps such as filtering, re-burning, improving the combustion process. In this way it is prevented, that the harmful gases are thrown directly out of the exhaust system, whereas the emission values are reduced.

There are some applications in order to reduce the emission values whereby the function and quality of the combustion is improved. In some of these applications the amount of oxygen is increased and the quality of combustion is improved by adding air into the exhaust system. In recent years different catalysts (reductant gases and/or liquids) have been injected into the exhaust system especially in order to reduce the emission values in heavy commercial vehicles. The gases and liquids, which are injected, should be mixed with the exhaust gas homogeneously, so that they can react effectively with the exhaust gas. In case that sufficient and effective mixing cannot be achieved, a part of the reductant liquids and gases are thrown out without entering the chemical reaction. In such applications it is very of importance that the exhaust gas in the exhaust system is homogeneous. The more homogeneous the exhaust gas is in the system, the more efficient the reaction with the catalysts will be. In such applications it is a very important detail and technical problem that the exhaust gas proceeds homogeneous in the system. Because, if the exhaust gas is not homogeneous, sufficient air cannot be obtained from the air, gas and reducers, which are injected into the system and the emission values cannot be reduced to the desired levels.

In the exhaust systems, the exhaust gas coming from the engine is not conveyed through straight pipes. The parts and pipes used in exhaust system are arranged in places, which are suitable for the vehicle body design. Design of pipes of the exhaust system are made according to body design and to other parts and also according to the position of pipes and of equipments like injector, which are attached to the pipes. For that reason, there are returns, decreases and increases in diameters of the pipes in the exhaust systems. Changes to the pipes of the exhaust system directly affect the gas flow and the homogeneity of the exhaust gas.

Nowadays, there are some applications for decreasing the emission levels of the combustion gases and decreasing the exhaust gas emission by increasing the combustion quality.

The system used to reduce NOx emissions below regulatory limits is generally referred to as the active SCR system. In the active SCR systems, an urea-water solution is used for the regulation of the NOx emissions, which is referred to as "Ad blue". The urea-water solution is sprayed in liquid form by means of an injector into the mixing zone. This urea-water mixture evaporates in high temperatures in the exhaust line and enters reaction, then is converted into ammonia (NH3). In the catalysts (SCR catalyst) in which the active SCR system is applied, ammonia reacts with NOx, reducing the NOx emissions to the desired level. In active SCR systems, the Ad blue mixture coming out from the injector is striking the pipeline walls in low engine loads due to low exhaust flows and low temperature. The solution hitting the wall draws heat from the wall in order to evaporate and so decreases in temperatures of the wall are observed. The injected ad blue starts to solidify in the low temperature zone formed on the wall, instead of evaporating. Since the solution does not evaporate, the target value for NOx emission cannot be achieved. Due to the solidification of the solution, an increase in the target pressure drop value in the exhaust pipe is observed. Furthermore, the solidified parts damage the catalysts in the exhaust line.

United States patent document US20120263632, which is in the state of the art, discloses a system developed for use in exhaust systems. There is a doser in this system. In this system, the doser transfers the UWS (Urea-Water Solution) required for the final process to the exhaust aftertreatment system. It is described, that materials like urea etc. In the system cause the problem of solidification on the walls. In order to avoid this problem, the exhaust gas is guided to the aftertreatment system from more than one point with a certain angle. As a result, the exhaust gas mixes with UWS in areas that are remote from the walls. The invention makes it possible to avoid the problem of accumulation of liquid particles in the doser as well as in the exhaust pipe. In the invention, which is the subject of the application, the exhaust gas is divided into three different lines. The first one of these lines is a flow conduit, the other two are the separating lines positioned symmetrically to each other. Thanks to these separating lines it is possible to obtain a more stable mixture in the mixing zone.

In the United States patent document US20100212301A1 known in the art, a flow system for exhaust systems is described. There is a system in the invention with multiple exhaust gas inlet ways. The invention has a doser developed for SCR systems. The exhaust gas coming from multiple inlets is mixed with fluids coming out from the doser. It is described, that thanks to the invention the formation of deposits is avoided. The invention uses a tube-like reflector too. In the invention according to the application though, there are several separator lines. The gas coming from the exhaust inlet through the said separating lines is divided into several lines and the part coming from the interior of the separating lines is angularly directed to the flow conduit. This prevents the reductant from accumulating after hitting the walls of the flow conduit.

In the United States patent document US8079211 B2, which is in the known state of the art, an invention is described, which is developed for the use in the SCR systems and prevents the formation of reducing deposit. In that invention, the exhaust gas coming from the exhaust pipe is directed to an inlet through a path-like element. It can enter through this inlet, whereas it can be mixed with the fluids injected by the injector. The system, which utilizes high pressure, prevents in this way the formation of deposit on the pipe walls. In the invention according to the application though, the exhaust gas is angularly directed to the flow conduit through the separator line. In this way, a good mixture is obtained in the mixing zone and also reductant accumulation on the walls of the flow conduit is prevented.

In the United States patent document US 8079211 B2, which represents the known state of the art, a compact radial outer exhaust auxiliary reactor tube is described. In the related invention, the exhaust has an external pipe geometry. In this document, a system is described, which is developed for the purpose of reacting with exhaust reducing fluids for a longer period of time by reducing the speed of the exhaust gas. In this document, it is also mentioned, that the system prevents the formation of deposits on the walls. In the present invention according to the application, the exhaust gas is separated by means of two symmetrical separator lines and of a flow conduit and then the exhaust gas separated into the separator lines, is transferred angularly to the mixing zone. In this way, the injected reductant is mixed with exhaust gas without hitting the walls of flow conduit and reduced. In the known state of the art, there is not a multi- manifold pipe, which has multiple lines, directs the exhaust gas coming from the exhaust pipe from top to bottom, keeping away the reductant from the walls of the pipe, which is coming out of the injector, whereas the flow in the lines can be adjusted.

Objectives of the Invention The object of the present invention is to provide a multi-manifold pipe which transfers the exhaust gas from the exhaust gas pipe to the conventional pipe system via a plurality of channels. Another object of the present invention is to provide a multi- manifold pipe which allows the flow direction of the reductant liquid sprayed from the injector to be changed.

Yet another object of the present invention is to realize a multi-manifold pipe in which the flow of the exhaust gas is changed by increasing in areas, where the risk of accumulation is higher, thereby preventing the liquid from hitting the wall and causing the accumulation to occur.

A further object of the present invention is to provide a multi-manifold pipe in which the amount of flow to each line can be adjusted. Brief Description of the Invention

A multi-manifold pipe provided to achieve the object of the present invention and disclosed in the first claim and other depended claims comprises a flow conduit positioned between an inlet port and an outlet port and further comprises two separator lines. A part of the exhaust gas coming out of the exhaust pipe is distributed to the flow conduit and another part to the separator lines. The separator lines are arranged around the injector, which is positioned on the elbow outside the flow conduit. Separator lines guide the exhaust gas they carry in an angular direction to the flow conduit. The ducts of the separator lines are connected to the contact surface of the flow conduit. Thus, the exhaust gas carried by the separator lines is directed angularly to the flow conduit. The exhaust gas entering the flow conduit from the separator lines prevents the reducing liquid sprayed by the injector from contacting the inner walls. The exhaust gas and the reducing liquid enter the reaction in the mixing zone within the flow conduit and so the emission levels in the exhaust gas are reduced. Exhaust gas with reduced emissions is directed to be transferred from the exhaust output to the outside atmosphere.

Detailed Description of the Invention

A multi- manifold provided to achieve the object of the present invention is shown in the accompanying figures, in which; Figure 1 is a perspective view of the multi- manifold pipe from an angle of view.

Figure 2 is a perspective view of the multi- manifold pipe from another angle of view.

Figure 3 is a perspective view of the multi- manifold pipe from yet another angle of view.

Figure 4 is a perspective view of the multi- manifold pipe from a further angle of view.

Figure 5 is front view of the multi- manifold pipe.

Figure 6 is the rear view of the multi- manifold pipe from an angle of view. Figure 7 is the rear view of the multi- manifold pipe from yet another angle of view.

Figure 8 is a cross-sectional view of the multi- manifold pipe from an angle of view.

The parts in the figures are individually numbered and the counterparts of these numbers are given below.

1. Multi- manifold pipe

2. Inlet opening

3. Outlet opening

4. Injector

5. Flow conduit

51. Contact surface

52. Mixing zone

6. Separator line

61. Conveying channel

62. Conducting channel

63. Rotation axis

E. Exhaust pipe In the exhaust systems using the technics of active selective catalytic reduction (SCR), a multi- manifold pipe (1) in its most basic form, which prevents the potential formation of deposits after the injection of a reductant mixture, comprises,

- at least one inlet opening (2) through which the exhaust gas is transferred from the exhaust pipe (E),

- at least one outlet opening (3), through which the exhaust gas coming from the inlet port, proceeds to be transferred to the outside atmosphere,

-at least one injector (4), which ensures that the reductant reducing the emission values of exhaust gas can reach the preferred zone, -at least one flow conduit (5) carrying a part of the exhaust gas coming from the exhaust pipe (E) and in which the entire exhaust gas conducted from the exhaust pipe (E) is also mixed with the reductant coming from the injector (4),

-at least two separator lines (6), which are positioned symmetrically to the central axis of the mixing zone (52) of the flow conduit (5) and carrying the other part of the exhaust gas conducted from the exhaust pipe (E), which is not carried through the flow conduit (5), in addition preventing the contact of the reductant sprayed from the injector (4) the inner walls of the mixing zone (52) of the flow conduit (5) whereby directing the exhaust gas angularly to the central axis of the mixing zone (52) of the flow conduit (5). In one embodiment of the invention, there is an inlet opening (2) at the contact point of the exhaust pipe (E) with the multi- manifold pipe (1). Inlet opening (2) opening (2) is also close to the part where the flow conduit (5) and the separator lines (6) are separated. Exhaust gas transferred from the inlet opening (2) to the multi- manifold pipe (1) is conveyed through the outlet opening (3) to be conducted to outer atmosphere.

In one embodiment of the invention, an injector (4) is provided. The injector (4) injects the emission reducing mixture into the mixing zone (52) contained in the multi- manifold pipe (1) by atomizing it. Injector (4) sprays the reductant mixture towards the flow conduit (5). The injector (4) is positioned preferably onto the flow conduit (5). There is a preferred amount of spraying holes on the injector (4). In this embodiment of the invention, the injector (4) comprises three spraying holes. The spraying holes spray the reductant liquid in such a way that it will preferably form a conical geometry. In this way the reductant sprayed from the injector (4) forms a conical line and proceeds on this line. The spray holes of the injector (4) are located below the axis of rotation (63) of the separator lines (6).

In one embodiment of the invention, a flow conduit (5) is provided. The flow conduit (5) is a line, through which the exhaust gas coming from the exhaust pipe (E) is conveyed and which is exposed to a reductant. Flow conduit (5) can be of elbow- shape or a flat pipe. In this embodiment of the invention the flow conduit (5) is a pipe of elbow-shape. On the flow conduit (5), there is located the injector (4), which injects reductant to the exhaust gas passing through the flow conduit (5). In this embodiment, the injector (4) is arranged on the elbow part of the flow conduit (5). The contact surface (51) forms the outer section of the flow conduit (5). The conducting channels (62) of separator lines (6) are connected to the flow conduit (5) via contact surface (51). The conducting channels (62) are connected to the contact surface (51) in an angularly manner. Reductant injected from the injector (4) and exhaust gas coming with exhaust pipe through the separator lines (6) are mixed in the mixing zone (52) located in the flow conduit (5) and conveyed to be transferred to outer atmosphere through the outlet opening (3). At one end of the flow conduit (5), the outlet opening (3) is arranged.

In one embodiment of the invention, there are more than one separator line (6) located symmetrically to the central axis of the mixing zone (52) of flow conduit (5). In this embodiment of the invention, two separator lines (6) are arranged. In different embodiments of the invention, more than one separator line (6) may be arranged. In this embodiment of the invention, the separator lines (6) are the external lines, through which the exhaust gas coming from inlet opening (2) is conveyed. Separator lines (6) are located in the area around the injection field of the injector (4). The separator lines (6) in this embodiment of the invention are identical and positioned symmetrically with respect to each other. The separator lines (6) are connected to the exhaust pipe (E) via conveying channels (61). The conveying channels (61) extend the exhaust gas coming from the exhaust pipe (E) up to a certain height and then transfer it to the conducting channels (62). The exhaust gas conveyed to the separator lines (6) is directed from the conducting channels (62) of the separator lines (6) to the mixing zone (52) in the flow conduit

(5) . The separator lines (6) can form a single part with flow conduit (5) or they can be separate parts from the flow conduit (5). In the present embodiment of the invention, the separator lines (6) are integral with the flow conduit (5). The conducting channels (62) of the separator lines (6) are located on the contact surface (51) of the flow conduit (5). These conducting channels (62) of the separator lines (6) are arranged onto the projection or prior to the projection of injection field of the injector (4) on the wall so that this projection will be a reference. Connection of the conducting channels (62) to flow conduit (5) are preferably angled. Thanks to angular geometry, the possibility of collision of the reductant sprayed from the injector (4) against the inner walls of mixing zone (52) of flow conduit (5) is substantially reduced.

The separating lines (6) preferably provide a "curved" geometry. There is an angle between the conveying channels (61) of the separating lines (6) and the conducting channels (62). There is a rotation axis (63) provided in the zone, where the conveying channel (61) of separating line (6) is bend to the conducting channel (62). In the present embodiment of the invention, the axis of rotation (63) is slightly above the contact surface (51) of the flow conduit (5). Rotation axis (63) guides the exhaust gas coming from conveying channel (61) by changing its direction to the conducting channel (62). Thus, the exhaust gas enters the mixing zone (52) of the flow conduit (5) at an angle. The exhaust gas entering the flow conduit from the separating lines

(6) is directed angularly to the exhaust gas coming from the exhaust pipe (E) and to the reductant sprayed from the injector (4). Angled inlet of the exhaust gas from the separator lines (6) into the flow conduit (5) directs the atomized reductant sprayed from the injector (4) to the central axis of flow conduit (5), thus preventing the reductant from impacting the walls of flow conduit (5) and accumulating on the walls. In the present embodiment of the invention, the operation of the multi- manifold pipe (1) is realized as follows; The multi-manifold pipe is placed to the end of the exhaust pipe (E). Exhaust gas from the exhaust pipe (E) is transferred into the multi-manifold pipe (1) through the inlet opening (2). The exhaust gas reaching the inlet port (2) is separated into lines and follows three different routes. The flow conduit (5) forms the one of these lines and separator lines (6) form the further two lines. The separator lines (6) carry the exhaust gas from the outside of the flow conduit (5) and direct the exhaust gas they carry to the mixing zone (52) located in the flow conduit (5). There is an injector (4) provided at the elbow of the flow conduit (5). The injector (4) injects a reductant fluid into the mixing zone (52) of the flow conduit (5). The liquid injected into the flow conduit (5) is of a character reducing the harmful emissions in the exhaust gas. The reductant enters reaction with the exhaust gas in the mixing zone (52). The reductant sprayed from the injector (4) into flow conduit (5) impacts the inner walls of the mixing zone (52) of flow conduit

(5) with low gas flow and low temperature and solidifies on the wall by absorbing temperature from the wall. In order to prevent accumulation on the walls, the separator lines (6) direct the exhaust gas they carry to the mixing zone (52) located in the flow conduit (5) at a certain angle. The exhaust gas guided by the separator lines

(6) to the flow conduit (5) directs the atomized reductant to the center of the mixing zone (52) in the flow conduit (5). Thus, the exhaust gas flow increases in the regions where accumulation is, the pass-through of reductant in the liquid phase is reduced and in addition a better mixture is obtained. The exhaust gas conveyed by flow conduit (5), the exhaust gas coming from the separator lines (6) and the reductant sprayed from the injector (4) are mixed in the mixing zone (52) in the flow conduit (5) and the exhaust gas with lower emission values is directed to the outlet opening (3) to be transferred to outside atmosphere.

With the multi-manifold pipe (1), which is the subject of the present invention the possibility of colliding of the reducer sprayed from the injector (4) against the walls of the flow conduit (5) is minimized cause of low temperature and low exhaust gas flow. By minimizing the possibility of the reducer colliding against the walls, the reductant is prevented from solidifying on the walls at low temperatures, thus an accumulation, that due to solidification occurs, disappears. By this means, it is provided, that the emission values in the exhaust gas are kept in preferred levels, so the catalysts in the exhaust line are not damaged.