WO2015026305A2

WO2015026305A2 - An exhaust gas reducer

Info

Publication number: WO2015026305A2
Application number: PCT/TR2014/000287
Authority: WO
Inventors: Ismail Hakkı SAVCI; Emre OZ; Omer KAYA; Sinan EROGLU; Gokhan HISAR; Onur DEMIR; Tolga SENOGUZ; Aydın PEKIN
Original assignee: Ford Otomotiv Sanayi Anonim Sirketi
Priority date: 2013-08-22
Filing date: 2014-08-22
Publication date: 2015-02-26
Also published as: WO2015026305A3; DE112014003842T5; DE112014003842B4

Abstract

The present invention relates to a exhaust gas reducer having a plurality of catalysts the flow and temperature distribution of which is almost uniform and thus which enables to carry out flow in optimum value and therefore wherein homogeneity is realized in heat distribution and the thermal breaks are decreased structurally.

Description

DESCRIPTION

AN EXHAUST GAS REDUCER Field of the Invention

The present invention relates to a exhaust gas reducer having a plurality of catalysts the flow and temperature distribution of which is almost uniform and thus which enables to carry out flow in optimum value.

Background of the Invention

When the maximum temperature in the combustion chamber in internal combustion engines exceeds a certain value, the nitrogen and oxygen in the air are combined chemically and transform into a gas called nitrogen oxide (NOx) which is harmful for human health and environment. The diesel engines operating with excess air increases the potential to form NOx relative to gasoline engines. Catalysts are used for releasing the nitrogen oxide to the environment safely. These catalysts which increase or decrease the speed of a chemical reaction have an effect of unbinding the bonds of the reactants and thus enable reaction to take place faster. Today, it is not possible to maintain the catalysts present inside the catalyzers used for cleaning exhaust gases and other equipments realizing this process effectively in a compact structure. In case more than one catalyst is used, the positioning of these catalysts should be performed accurately in order to provide full heat distribution. In the previous art, the catalysts and the chambers are placed inside the exhaust gas reducer by considering the packing and temperature distribution effects, and then additional equipments and many optimization studies are required in order to enable the gases to be distributed homogenously and mixed well before entering into the catalysts.

United States Patent Document no US2012260635, an application known in the state of the art, discloses a diesel exhaust treatment system comprising at least one diesel particulate filter, at least one diesel exhaust fluid mixing chamber and at least one selective catalytic reduction converter (SCR). This application does not disclose how the catalysts will be positioned according to the mixer, the distances of the catalysts from the mixer and that the mixer can be placed symmetrical according to the catalyst.

In the current embodiments, it is not disclosed where the catalysts will be positioned exactly according to the mixer. The features such as what ratio will be used for determining the distance between the catalysts and the mixer, being able to provide homogeneity with the distances being symmetrical and close are not present in the previous art. Furthermore, it is not disclosed how the catalysts will be placed according to the mixer and the distances from the mixer will be equal and symmetrical when the number of the catalysts is increased.

The Objective of the Invention

The objective of the present invention is to provide an exhaust gas reducer which has catalysts positioned symmetrical in order to distribute the flow homogenously.

Another objective of the present invention is to provide an exhaust gas reducer which enables the flow and temperature distributions to be realized in optimum values. Yet another objective of the present invention is to provide an exhaust gas reducer which does not have difference in heat distribution since symmetrical placement is performed and thus enables to decrease thermal breaks structurally.

A further objective of the present invention is to provide an exhaust gas reducer which enables to maintain flow balance continuously since the gas inlet and outlet chambers are symmetrical. Detailed Description of the Invention

An exhaust gas reducer developed to fulfill the objective of the present invention is illustrated in the accompanying figures, in which:

Figure 1 is the perspective view of the exhaust gas reducer.

Figure 2 is the perspective view of the exhaust gas reducer from the other side.

Figure 3 is the side view of the exhaust gas reducer.

Figure 4 is the side view of the exhaust gas reducer from the other side. Figure 5 is the perspective view of the exhaust gas reducer and its outlet chamber. The components shown in the figures are each given reference numbers as follows:

1. Exhaust gas reducer

2. Exhaust inlet

3. First catalyst

4. Filter

5. Router

6. Mixer

7. Separator

8. Second catalyst

9. Outlet chamber

10. Exhaust outlet

K. Mixer central axis

The distance of the second catalyst to the mixer central axis

b. The distance of the other second catalyst to the mixer central An exhaust gas reducer (1), which has catalysts positioned symmetrically in order to distribute the flow homogenously and wherein the homogeneity is provided in heat temperature in this way and furthermore the thermal breaks are decreased structurally, essentially comprises

- at least one first catalyst (3) which is used in controlling contaminants caused by exhaust gas and decreases the mass of the diesel particle emissions, at least one filter (4) which allows the exhaust gases to pass and does not allow the solid and liquid particles to pass,

at least one mixer (6) wherein the exhaust gas is mixed preferably with an urea solution,

- at least one separator (7) which enables the gas moving inside the mixer (6) to be transferred in almost equal flow rate in more than one direction,

at least two second catalysts (8) to which the gas passing through the separator (7) is transferred and the distances (a, b) of which to the center of the mixer (6) are almost equal and symmetrical or the difference between the distances of which is located such that it will not exceed ±10% of the bigger distance, and thus wherein the flow rate of the gas moving therein is equal.

The exhaust gas reducer (1) is designed for cleaning the harmful gases generated as a result of combustion in the engine. In one embodiment of the invention, an exhaust inlet (2) from which the harmful gases generated due to combustion in the engine is located in the exhaust gas reducer (1). The gases and the particles generated as a result of combustion are transferred inside the exhaust gas reducer (1) through the said exhaust inlet (2). The gas and the particles (2) are directed to the first catalyst (3) from the exhaust inlet (2). The first catalyst (3) is a diesel oxidation catalyst (DOC) which is used in controlling contaminants generated as a result of the combustion such as CO, HC and PM and in which oxidizing elements, preferably platinum and/or palladium, are used. The carbon monoxide and hydrocarbons are transformed into carbon dioxide and water in the first catalyst (3) and the toxic effect of gas and particles caused by combustion is slightly decreased. The gas and the particles are directed to the filter (4) from the first catalyst (3). The filter (4) is preferably a diesel particle filter (DPF), it allows the exhaust to pass, but does not allow the particles to pass. By this means, the mixture entering inside the filter (4) as gas and particle comes out of the filter (4) only as gas, the particles are oxidized and thus the said particles are prevented from being discharged to outer environment. In order that the exhaust gas reducer (1) has a compact structure, a router (5) which has the structure to direct the flow preferably 180 degrees to the outlet of the filter (4). The gas purified from the particles in the filter (4) is turned around nearly 180 degrees via the router (5) and transferred into the mixer (6). Preferably urea is injected to the gas directed into the mixer (6) and an ammonium solution (NH3) and carbon dioxide (CO2) is enabled to be formed. At the outlet end of the mixer (6) there is a separator (7) which is designed to direct the gas in more than one direction homogenously and in equal flow rate. The separator (7) separates the gas passing through the mixer (6) equally in more than one ratio, and enables to transfer the flow into each second catalyst (8) in equal flow rate. In this preferred embodiment of the invention, there is a second different catalyst (8) with the same characteristics. The distance of one of the second catalyst (8) to the mixer axis (K) is defined as (a). The distance of the other second catalyst (8) to the mixer axis (K) is defined as (b) (Figure 3). In the preferred embodiment of the invention, distance (a) of the second catalysts (8) to the mixer axis (K) and distance (b) of the other second catalyst (8) to the mixer axis ( ) are equal. In another preferred embodiment of the invention, the difference between distance (a) of the second catalysts (8) to the mixer axis (K) and distance (b) of the other second catalyst (8) to the mixer axis (K) is as much as it will not exceed 10% maximum. Half of the gases coming to the separator (7) from the mixer (6) move in direction of a second catalyst (8) in equal flow rate, and the other half moves in direction of the other second catalyst (8). The second catalyst (8) is preferably selective reducing catalyst (SCR) and it enables the ammonium solution (NH3) to react with the nitrogen oxide (NOx). By this means, nitrogen (N2) and water (H2O) are enabled to be released to the outer environment. The gases entering inside two separate second catalysts (8) in almost equal flow rate go out of both second catalysts (8) in almost equal flow rate as a result of the reaction taking place in here. These gases exiting in equal flow rate move towards the exhaust outlet (10) wherein the gases coming out of the second catalysts (8) are collected, and which is positioned symmetrical and in almost equal distance to the second catalysts (8) so that the gases coming out of more than one second catalyst (8) come out in equal flow rate. These harmless gases generated in the second catalyst (8) are discharged to outer environment from the outlet chamber (9) via the exhaust outlet (10). Similar to the mixer (6), the exhaust outlet (10) is also located symmetrical and in equal distance to the second catalysts (8). By this means, the fluids coming out of the second catalysts (8) move towards the exhaust outlet (10) in equal flow rate and thus each one of the second catalysts (8) can function with same characteristics.

In the exhaust gas reducer (1) present in another preferred embodiment of the invention, there are three separate second catalysts (8). The distances of the second catalysts (8) to the mixer (6) are equal, and the angle between two different second catalysts (8) is almost 120°±10. The geometry of the separator (7) is positioned such that it can direct the gas from the mixer (6) to those three second catalysts (8) in equal flow rate. By this means, exhaust gas can be distributed to three second catalysts (8) in equal ratio.

In the exhaust gas reducer (1) present in another preferred embodiment of the invention, there are four separate second catalysts (8). The distances of the second catalysts (8) to the mixer (6) are equal, and the angle between two different second catalysts (8) is almost 90°±10. The geometry of the separator (7) is positioned such that it can direct the gas from the mixer (6) to those four second catalysts (8) in equal flow rate. By this means, exhaust gas can be distributed to four second catalysts (8) in equal ratio.

In the exhaust gas reducer (1) present in another preferred embodiment of the invention, there are more than four second catalysts (8). The distances of the second catalysts (8) to each other and the angle between them are almost equal as well as their distances to the mixer (6) are almost equal. Besides, the separator (7) also has the geometrical features that can transfer the gas coming from the mixer (6) to the said more than four second catalysts (8) homogenously and in equal flow rate. By this means the gases transferred from the mixer (6) to the separator (7) are transferred to all second catalysts (8) in equal ratio.

In another preferred embodiment of the invention, more than one first catalyst (3) and more than one filter (4) are used for cleaning the harmful gas and particles coming from the exhaust inlet (2). The filter (4) can be positioned right after the exhaust inlet (2) in order to clean the particles first as well as the first catalyst (3) can be positioned right after the exhaust inlet (2). In this embodiment of the invention, more than one second catalyst (8) symmetries and distances can be adjusted and positioned inside the exhaust gas reducer (1) when it is preferred as well as single second catalyst (8) can be used.

In the inventive exhaust gas reducer (1), the mixer (6) and the exhaust outlet (10) are positioned on the mixer central axis (K) as in Figure 3. Furthermore, one of the second catalysts (8) which are preferably two of them are distant from the mixer central axis (K) as far as the distance (a) in Figure 3, and the other second catalyst (8) is distant as (b) distance in the same way. The difference between the distance of the second catalyst (8) to the mixer central axis (a) and the distance of the other second catalyst (8) to the mixer central axis (b) is as much as it will not exceed +/-10% of the distance which is larger. In the preferred embodiment of the invention, (a) distance and (b) distance are almost equal, and the positions of the second catalysts (8) are symmetrical relative to the mixer central axis (K).

In the preferred embodiment of the inventive exhaust gas reducer (1), the mixer (6) and the exhaust outlet (10) are positioned on the mixer central axis (K) as in Figure 3. Furthermore, one of the second catalysts (8) which are preferably two of them are distant from the mixer central axis (K) as far as the distance (a) in Figure 3, and the other second catalyst (8) is distant as (b) distance in the same way. The difference between the distance of the second catalyst (8) to the mixer central axis (a) and the distance of the other second catalyst (8) to the mixer central axis (b) is as much as it will not exceed +/-10% of the distance which is larger. In other words, the ratio of the (a) distance to (b) distance is between 0.9 and 1.1 1.

Claims

1. An exhaust gas reducer (1), which has catalysts positioned symmetrically in order to distribute the flow homogenously and wherein the homogeneity is provided in heat temperature in this way and furthermore the thermal breaks are decreased structurally, essentially characterized by

at least one first catalyst (3) which is used in controlling contaminants caused by exhaust gas and decreases the mass of the diesel particle emissions, at least one filter (4) which allows the exhaust gases to pass and does not allow the solid and liquid particles to pass (4),

at least one separator (7) which enables the gas moving inside the mixer (6) to be transferred in almost equal flow rate in more than one direction,

at least two second catalysts (8) to which the gas passing through the separator

(7) is transferred and the distances (a, b) of which to the center of the mixer (6) are almost equal and symmetrical or the difference between the distances of which is located such that it will not exceed ±10% of the bigger distance, and thus wherein the flow rate of the gas moving therein is equal.

2. An exhaust gas reducer (1) according to claim 1, characterized by exhaust inlet (2) to which the harmful gas and particles generated as a result of the combustion in the engine enter.

An exhaust gas reducer (1) according to claim 1, characterized by first catalyst (3) which is used in controlling contaminants generated as a result of the combustion such as CO, HC and PM and wherein oxidizing elements, preferably platinum and/or palladium, are used.

An exhaust gas reducer (1) according to claim 1, characterized by first catalyst (3) which enables to decrease the toxic effect of the gas and particles caused by combustion by transforming carbon monoxide and hydrocarbons into carbon dioxide and water.

5. An exhaust gas reducer (1) according to claim 1, characterized by first catalyst (3) which is preferably a diesel oxidation catalyst (DOC).

6. An exhaust gas reducer (1) according to claim 1, characterized by filter (4) which allows the exhaust gases to pass but does not allow the particles to pass, thus enables the mixture entering therein as gas and particle to go out only as gas and enables the particles to be oxidized.

7. An exhaust gas reducer (1) according to claim 1, characterized by filter catalyst (4) which is preferably a diesel particle filter (DPF). 8. An exhaust gas reducer (1) according to claim 1, characterized by router (5) which is positioned at the outlet of the filter (4) and which has the structure to direct the flow preferably 180 degrees and transfers the flow into the mixer

(6) . 9. An exhaust gas reducer (1) according to claim 1, characterized by separator

(7) which is located at the outlet end of the mixer (6) and separates the gas passing therein almost equally in more than one ratio, and enables to transfer the flow into each second catalyst (8) in almost equal flow rate. 10. An exhaust gas reducer (1) according to claim 1, characterized by second catalyst (8) which is preferably a selective reducing catalyst (SCR).

11. An exhaust gas reducer (1) according to claim 1, characterized by second catalyst (8) which forms the basis for ammonium solution (NH₃) and nitrogen oxide (NOx) to react and enables to discharge nitrogen (N2) and water (H2O) to the outer environment.

12. An exhaust gas reducer (1) according to claim 1, characterized by exhaust outlet (10) wherein the gases coming out of more than one catalyst (8) are collected, and which is positioned symmetrical and in equal distance to the second catalysts (8) so that the gases coming out of more than one second catalyst (8) go out in equal flow rate. 13. An exhaust gas reducer (1) according to claim 1, characterized by exhaust outlet (10) which is positioned symmetrical and in equal distance to the second catalysts (8) an thus enables to discharge the fluids coming out of the second catalysts (8) to the outer environment in equal flow rate. 14. An exhaust gas reducer (1) according to claim 1, characterized by first catalyst (3) which is positioned right after the exhaust inlet (2) or the filter (4).

15. An exhaust gas reducer (1) according to claim 1, characterized by filter (4) which is positioned right after the exhaust inlet (2) or the first catalyst (4).

16. An exhaust gas reducer (1), which has catalysts positioned symmetrically in order to distribute the flow homogenously and wherein the homogeneity is provided in heat temperature in this way and furthermore the thermal breaks are decreased structurally, essentially characterized by

at least two second catalysts (8) which are more than one and the distances to the mixer (6) are almost equal and the angle between one of them and the other one is almost equal or ±10°, and which are positioned around the mixer

(6) in this way.

17. An exhaust gas reducer (1) according to claim 16, characterized by second catalysts (8) which are three of them and the distances of which to the mixer (8) are almost equal and the angle between each one of them is almost 120°±10° and which are positioned around the mixer (6) in this way.

18. An exhaust gas reducer (1) according to claim 16, characterized by second catalysts (8) which are four of them and the distances of which to the mixer (8) are almost equal and the angle between each one of them is almost 90°±10° and which are positioned around the mixer (6) in this way.