WO2016013794A1 - Device for purifying exhaust gas - Google Patents

Abstract

In an exhaust gas processing system comprising an oxidation catalyst device and a selective catalyst reduction device which are sequentially installed in an exhaust pipe through which exhaust gas from an internal combustion engine is exhausted, a device for purifying exhaust gas comprises: at least one carrier through which exhaust gas passes, the at least one carrier being installable on at least one of the position ahead of the oxidation catalyst device and the position between the oxidation catalyst device and the selective catalyst reduction device; and a wash coat, which coats the surface of the carrier, for collecting impurities included in the exhaust gas or oxidative material deviated from the oxidation catalyst device.

Description

Exhaust gas purification device

The present invention relates to an exhaust gas purification apparatus. More particularly, the present invention relates to an exhaust gas purification apparatus for maintaining the performance of the selective reduction catalyst apparatus and the oxidation catalyst apparatus.

The exhaust gas treatment system of an internal combustion engine may include exhaust gas aftertreatment devices such as oxidation catalyst (OC) and selective catalyst reduction (SCR) to reduce pollutants contained in the exhaust gas. Can be.

In the selective reduction catalyst device, nitrogen oxide is reduced to nitrogen gas and water by catalytic reaction with nitrogen oxide (NOX) by spraying urea water or the like from a reducing agent injection module.

However, when the temperature of the exhaust gas rises or misfire occurs, precious metal or oxide material in the oxidation catalyst device may be separated and attached to the front end of the selective reduction catalyst device. This may cause a problem that the efficiency of nitrogen oxide conversion of the selective reduction catalyst device is lowered.

On the other hand, the oxidation catalyst device may oxidize carbon monoxide and hydrocarbons contained in the exhaust gas. However, the exhaust gas may include engine oil leaked during the fuel combustion process, and if low quality fuel is used, impurities such as sulfur (S) may be included. Engine oil and impurities in the exhaust gas may act as a poisoning material for the oxidation catalyst, which may reduce the performance of the oxidation catalyst device.

An object of the present invention to provide an exhaust gas purification apparatus for maintaining the performance of the selective reduction catalyst device.

Another object of the present invention is to provide an exhaust gas purification apparatus for maintaining the performance of the oxidation catalyst device.

In order to achieve the above object of the present invention, in the exhaust gas treatment system including an oxidation catalyst device and a selective reduction catalyst device which is sequentially installed in the exhaust pipe from which the exhaust gas is discharged from the internal combustion engine, exemplary embodiments The exhaust gas purifying apparatus according to claim 1 may be mounted at at least one position in front of the oxidation catalyst device or between the oxidation catalyst device and the selective reduction catalyst device and at least one carrier through which the exhaust gas passes, and the carrier It may include a washcoat layer coated on the surface to collect the impurities contained in the exhaust gas or the oxide material released from the oxidation catalyst device.

In exemplary embodiments, the oxide material may be Pt, Pd, Rh, Ir, Ag, Sn, Ru, or the like.

In exemplary embodiments, the carrier may be cordierite, silicon carbide, pecaloy, NiCrAl, NiFeCrAl, or the like.

In exemplary embodiments, the carrier may have a honeycomb shape.

In exemplary embodiments, the carrier may be canned together with the oxidation catalyst device.

In exemplary embodiments, the carrier may be installed inside the exhaust pipe.

In example embodiments, the carrier may be integrally formed with the oxidation catalyst device.

In example embodiments, the washcoat layer may be Al 2 O 3, SiO 2, TiO 2, CeO 2, ZrO 2, V 2 O 5, La 2 O 3, zeolite, or the like.

In example embodiments, the washcoat layer may increase a contact area with the exhaust gas.

In example embodiments, the washcoat layer may have a surface area of 50 to 60 m ² / g.

In example embodiments, the carrier may have a metal fiber structure.

In example embodiments, the carrier may be in the form of a metal foam.

In exemplary embodiments, the impurity may be engine oil.

However, the problem to be solved by the present invention is not limited to the above-described problems, and may be variously expanded within a range without departing from the spirit and scope of the present invention.

The exhaust gas purifying apparatus according to the exemplary embodiments may collect precious metals or oxides separated from the oxidation catalyst apparatus. Accordingly, the oxide material can be prevented from flowing into the selective reduction catalyst device to maintain the performance of the selective reduction catalyst device.

In addition, when the exhaust gas purification device is installed upstream of the oxidation catalyst device, the performance of the oxidation catalyst device can be maintained by collecting impurities such as engine oil contained in the exhaust gas.

However, the effects of the present invention are not limited to the above-mentioned effects, and may be variously expanded within a range without departing from the spirit and scope of the present invention.

1 is a diagram illustrating an exhaust gas treatment system according to example embodiments.

2 is a view showing the exhaust gas purification device of FIG.

3 is a cross-sectional view taken along the line AA ′ of FIG. 2.

4 is a view showing the oxidation catalyst device of FIG.

FIG. 5 is a cross-sectional view taken along the line BB ′ of FIG. 4.

6 is a graph showing the NOx conversion efficiency of the selective reduction catalyst when the exhaust gas purification apparatus is not used.

7 is a graph showing NOX emissions and NOX conversion efficiency with and without an exhaust gas purification device.

8 is a diagram illustrating an exhaust gas treatment system according to example embodiments.

9 is a diagram illustrating an exhaust gas treatment system according to example embodiments.

10 is a diagram illustrating an exhaust gas treatment system according to example embodiments.

FIG. 11 is a cross-sectional view taken along the line CC ′ of FIG. 10.

12 is a diagram illustrating an exhaust gas treatment system according to example embodiments.

FIG. 13 is a cross-sectional view taken along the line D-D 'of FIG. 12.

14 is a diagram illustrating an exhaust gas treatment system according to example embodiments.

15 is a diagram illustrating an exhaust gas treatment system according to example embodiments.

16 is a diagram illustrating an exhaust gas treatment system according to example embodiments.

17 is a cross-sectional view taken along the line E-E 'of FIG. 16.

18 is a diagram illustrating an exhaust gas treatment system according to example embodiments.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, and the following examples can be modified in various other forms, and the scope of the present invention is It is not limited to an Example. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In addition, the thickness or size of each layer in the drawings is exaggerated for convenience and clarity of description.

Throughout the specification, when referring to one component "located", "connected", or "coupled" to another component, the above-described one component directly on another component " It may be interpreted that there may be other components that are in contact with, or “in connection with,” or “coupled to”. On the other hand, when one component is said to be located on another component "directly on", "directly connected", or "directly coupled", it is interpreted that there are no other components intervening therebetween. do. Like numbers refer to like elements. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items.

Although the terms first, second, etc. are used herein to describe various members, parts, regions, and / or parts, it is obvious that these members, parts, regions, and / or parts should not be limited by these terms. Do. These terms are only used to distinguish one member, part, region or part from another region or part. Thus, the first member, part, region, or portion, which will be described below, may refer to the second member, component, region, or portion without departing from the teachings of the present invention.

Also, relative terms such as "top" or "above" and "bottom" or "bottom" may be used herein to describe the relationship of certain elements to other elements as illustrated in the figures. It may be understood that relative terms are intended to include other directions of the device in addition to the direction depicted in the figures. For example, if the device is turned over in the figures, elements depicted as present on the face of the top of the other elements are oriented on the face of the bottom of the other elements described above. Thus, the exemplary term "top" may include both "bottom" and "top" directions depending on the particular direction of the figure. If the component faces in the other direction (rotated 90 degrees with respect to the other direction), the relative descriptions used herein may be interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. Also, as used herein, "comprise" and / or "comprising" specifies the presence of the mentioned shapes, numbers, steps, actions, members, elements and / or groups of these. It is not intended to exclude the presence or the addition of one or more other shapes, numbers, acts, members, elements and / or groups.

Embodiments of the present invention will now be described with reference to the drawings, which schematically illustrate ideal embodiments of the present invention. In the figures, for example, variations in the shape shown may be expected, depending on manufacturing techniques and / or tolerances. Accordingly, embodiments of the inventive concept should not be construed as limited to the specific shapes of the regions shown herein, but should include, for example, changes in shape resulting from manufacturing. The following embodiments may be configured by combining one or a plurality.

1 is a diagram illustrating an exhaust gas treatment system according to example embodiments. 2 is a view showing the exhaust gas purification device of FIG. 3 is a cross-sectional view taken along the line AA ′ of FIG. 2. 4 is a view showing the oxidation catalyst device of FIG. FIG. 5 is a cross-sectional view taken along the line BB ′ of FIG. 4. 6 is a graph showing the NOx conversion efficiency of the selective reduction catalyst when the exhaust gas purification apparatus is not used. 7 is a graph showing NOX emissions and NOX conversion efficiency with and without an exhaust gas purification device.

1 to 7, the exhaust gas treatment system 10 is installed in the exhaust pipe P to remove carbon monoxide and hydrocarbons in the exhaust gas F (Oxidation Catalyst 200), an oxidation catalyst. Selective Catalyst Reduction (300) installed in the exhaust pipe (P) downstream of the device (200) to reduce NOx, and between the oxidation catalyst device (200) and the selective reduction catalyst device (300). It may include an exhaust gas purification device 100 is mounted to the exhaust pipe (P) of the capacitive particles that can be separated from the oxidation catalyst device 200.

In exemplary embodiments, the exhaust gas F exhausted from the engine of the internal combustion engine (not shown) is oxidized catalyst 200, exhaust gas purification apparatus 100 and selective reduction along the exhaust pipe P. It may be discharged to the outside through the catalytic device 300 in sequence. The exhaust gas purification device 100 may be located downstream of the oxidation catalyst device 200, and the selective reduction catalyst device 300 may be located downstream of the exhaust gas purification device 100. At this time, being located "downstream" indicates that the exhaust gas F discharged from the engine is relatively closer to the outside.

As shown in FIGS. 2 and 3, the exhaust gas purification apparatus 100 may include a first washcoat layer 120 coated on the first carrier 110 and the first carrier 110.

The first carrier 110 can have at least one first passageway 112 extending in the axial direction. The exhaust gas discharged from the engine passes through the first passage 112, and then may be discharged to the outside via the selective reduction catalyst device 300. For example, the first carrier 110 may be formed in a honeycomb shape by extruding a raw material of a ceramic material. Examples of the first carrier include cordierite, silicon carbide, pecaloy, NiCrAl, NiFeCrAl, and the like.

Since the first carrier 110 is made of a ceramic material, it is easily broken by an external impact. Thus, it can be wrapped and canned in a relatively soft mat to protect it from external impacts.

Alternatively, the first carrier 110 may be formed to have a porous structure using a metal. For example, the first carrier may be formed of a metal fiber structure in which metal fibers are woven like a net, or in the form of a metal foam having a myriad of pores.

The first washcoat layer 120 may be coated on the surface of the first passage 112 of the first carrier 110 to capture the oxide material released from the oxidation catalyst device 200. Examples of the first washcoat layer include Al 2 O 3, SiO 2, TiO 2, CeO 2, ZrO 2, V 2 O 5, La 2 O 3, zeolite, and the like. The first washcoat layer 120 may be coated on the surface of the first carrier 110 by immersing one end of the first carrier 110 in a washcoat solution and forming a negative pressure at the other end.

In exemplary embodiments, the first carrier 110 may be mounted upstream of the selective reduction catalyst device 300. Therefore, the exhaust gas purification apparatus 100 may collect the oxide particles separated from the oxidation catalyst device 200 and prevent the inflow into the selective reduction catalyst device 300.

In detail, when the temperature of the exhaust gas rises or misfire occurs, the oxidation catalyst device 200 may be exposed to a high temperature of 850 ° C. or more. At this time, the oxide material may be separated from the oxidation catalyst device 200 and discharged downstream together with the exhaust gas F. The discharged oxide material may be attached to and removed from the surface of the first washcoat layer 120 while passing through the first passage 112 of the exhaust gas purification apparatus 100. Examples of the oxides include Pt, Pd, Rh, Ir, Ag, Sn, Ru, and the like.

By coating the first washcoat layer 120 on the surface of the first carrier 110, the contact area with the exhaust gas F may be increased. For example, the surface area per unit weight of the uncoated first carrier is about 0.00643 m ² / g, whereas when the first washcoat layer is coated, the surface area per unit weight may be 50 to 60 m ² / g. have. That is, by coating the first washcoat layer 120 on the surface of the first carrier 110, the surface area contacting the exhaust gas F may be increased by about 7700 to 9300 times. As a result, an oxide material such as the noble metal separated from the oxidation catalyst device 200 may be greatly increased to prevent the inflow into the selective reduction catalyst device 300 by greatly increasing the chance of encountering the exhaust gas purification device 100.

As shown in FIG. 4 and FIG. 5, the oxidation catalyst device 200 includes a second washcoat layer 220 coated on the second carrier 210 and the second carrier 210 and including the oxidation catalyst. can do.

The second carrier 210 can have at least one second passage 212 extending in the axial direction. The exhaust gas discharged from the engine passes through the second passage 212, and then may be discharged to the outside through the exhaust gas purification device 100 and the selective reduction catalyst device 300 in sequence. The second carrier 210 may be formed in a honeycomb shape by extruding a raw material of a ceramic material. Examples of the second carrier include cordierite, silicon carbide, pecaloy, NiCrAl, NiFeCrAl, and the like.

Since the second carrier 210 is made of a ceramic material, it is easily broken by an external impact. Therefore, it can be wrapped and canned in a relatively soft mat to protect it from external impacts.

Alternatively, the second carrier 210 may be formed to have a porous structure using a metal. For example, the second carrier may be formed of a metal fiber structure in which metal fibers are woven like a net, or in the form of a metal foam having numerous pores.

The second washcoat layer 220 may be coated on the surface of the second passage 212 of the second carrier 210 and may include an oxidation catalyst. Examples of the oxidation catalyst include Pt, Pd, Rh, Ir, Ag, Sn, Ru, and the like. The second washcoat layer 220 may be coated on the surface of the second carrier 210 by immersing one end of the second carrier 210 in a washcoat solution and forming a negative pressure at the other end.

The exhaust gas F discharged from the engine (not shown) may enter the oxidation catalyst device 200 along the exhaust pipe P and pass through the second passages 212 formed in the second carrier 210. have. In this case, the oxidation catalyst included in the second washcoat layer 220 may oxidize carbon monoxide and hydrocarbons in the exhaust gas F to carbon dioxide and water. The exhaust gas F passing through the oxidation catalyst device 200 may be discharged to the outside via the exhaust gas purification device 100 and the selective reduction catalyst device 300 in sequence.

In exemplary embodiments, the oxidation catalyst device 200 may include an oxidation catalyst device for oxidizing carbon monoxide and hydrocarbons included in exhaust gas of a diesel engine or a compressed natural gas engine.

For example, in an internal combustion engine using a diesel engine, a diesel oxidation catalyst may be used to purify harmful carbon monoxide, hydrocarbons, and soluble organic fractions in the exhaust gas.

In example embodiments, the oxidation catalyst device 200 may include a diesel particulate filter for removing particulate matter in the exhaust gas F.

The diesel particulate filter may comprise a carrier having at least one passage extending in the axial direction. The carrier may be formed in a honeycomb shape by extruding a raw material of a ceramic material. Examples of the carrier include cordierite, silicon carbide, pecaloy and the like.

The passages of the diesel particulate filter may have a structure that is alternately blocked over one. That is, the downstream may be blocked in the passage upstream and the downstream may be open in the passage blocked upstream. Accordingly, the exhaust gas F introduced into the passage in which the upstream is opened may pass through the pores formed in the carrier and flow into the passage in which the neighboring downstream is opened. In this process, particulate matter in the exhaust gas F can be filtered through the carrier.

After traveling a certain distance, it is necessary to regenerate the diesel particulate filter. This is because the filter may be clogged by the filtered particulate matter. In the regeneration process, a method of increasing the exhaust gas (F) temperature above the ignition temperature of the particulate matter to burn the particulate matter or adding an additive such as cerium may reduce the oxidation temperature of the particulate matter. Can be.

As shown in FIG. 1, in the exemplary embodiments, the selective reduction catalyst device 300 may include a reducing agent injection module 320 and at least one selective reduction catalyst device. For example, the selective reduction catalyst device may include first to third selective reduction catalyst devices 312, 314, and 316. The reducing agent injection module may be installed upstream than the first to third selective reduction catalyst devices.

The reducing agent injection module 320 may inject a reducing agent such as urea water into the exhaust pipe P. Since the temperature of the exhaust gas F discharged from the engine is a high temperature of several hundred degrees Celsius, the reducing agent injected in the exhaust pipe P can be vaporized immediately. The vaporized reducing agent may be mixed with the exhaust gas F and supplied to the first to third selective reduction catalyst devices 312, 314, and 316.

The first to third selective reduction catalyst devices (312, 314, 316) may be installed downstream than the reducing agent injection module 320, by reducing the nitrogen oxides (NOX) by the following reaction schemes 1 to 3 Can be converted to nitrogen (N2), which is harmless to humans.

Scheme 1

Scheme 2

Scheme 3

Urea ((NH 2) 2 CO) may produce ammonia (NH 3) by hydrolysis. The ammonia thus produced can be converted to nitrogen (N 2), which is harmless to the human body by reducing NO and NO 2.

At this time, the oxide material released from the oxidation catalyst device 200 may lower the performance of the selective reduction catalyst device 300.

As shown in FIG. 6, in the second and third selective reduction catalyst devices 314 and 316 attached to the rear end of the selective reduction catalyst device 300, the NOX reduction reaction is normally performed, and the NOX conversion efficiency is positive. Can have However, in the case of the first selective reduction catalyst device 312 attached to the front end of the selective reduction catalyst device 300 may exhibit a negative NOx conversion efficiency. This is because the oxide material released from the oxidation catalyst device 200 is attached to the first selective reduction catalyst device 312 to oxidize the ammonia to NOx. In this case, the NOx conversion efficiency may be calculated by Equation 1 below.

Equation 1

When the temperature of the exhaust gas rises or misfire occurs, precious metal or oxide particles inside the oxidation catalyst device 200 may be separated and attached to the first selective reduction catalyst device 312. Accordingly, a reaction as in Schemes 4 to 6 may occur, and the ammonia generated in Scheme 1 may be oxidized in the first selective reduction catalyst device 312.

Scheme 4

Scheme 5

Scheme 6

NOx may be further generated through the reactions, and secondary products such as N 2 O and greenhouse gases may also be generated. This is because the ammonia supplied from the reducing agent injection module 320 is not used as a reducing agent for reducing NO x to N 2, but rather is oxidized to NO x by the oxide material. This may cause a problem that the NOx conversion efficiency of the selective reduction catalyst device 300 is reduced.

As illustrated in FIG. 7, the exhaust gas purification apparatus 100 according to the exemplary embodiments may improve the performance of the selective reduction catalyst 300 by capturing oxide material.

In the case of the exhaust gas treatment system which does not use the exhaust gas purification apparatus 100, when the operation time is 50 hours, the NOX emission through the exhaust pipe P increases rapidly and the NOX conversion efficiency decreases rapidly. This is because the oxides released from the oxidation catalyst device 200 are attached to the selective reduction catalyst device 300, thereby degrading the performance of the selective reduction catalyst device 300.

In contrast, in the case of the exhaust gas treatment system using the exhaust gas purification device 100, even after 1000 hours of operation time, the North American NOX emission standard of 0.20 g / hp · hr can be satisfied and the NOX conversion efficiency It can maintain more than 70%. This is because the oxidized materials separated from the oxidation catalyst device 200 are filtered out of the exhaust gas purification device 100, so that the selective reduction catalyst device 300 can perform the NOx reduction function properly.

In exemplary embodiments, the exhaust gas treatment system 10 may further include an ammonia slip catalyst device 400. For example, the ammonia slip catalyst device 400 may be installed in the exhaust pipe P downstream of the selective reduction catalyst device 300 to remove ammonia.

The ammonia generated by the urea injected from the reducing agent injection module 320 may reduce nitrogen oxides in the exhaust gas F. In this case, in order to maximize the conversion efficiency of the nitrogen oxides, ammonia may be supplied in an amount larger than the stoichiometric amount. For this reason, the ammonia may be released into the atmosphere without being completely consumed through the catalytic reaction, which may cause air pollution. This is called an ammonia slip phenomenon. The ammonia slip catalyst device 400 may prevent the ammonia slip phenomenon by removing the ammonia that is not consumed by the selective reduction catalyst device 300.

As described above, the exhaust gas purification apparatus 100 according to the exemplary embodiments prevents the oxide material separated from the oxidation catalyst device 200 and the exhaust pipe P from flowing into the selective reduction catalyst device 300. can do. Accordingly, the selective reduction catalyst device 300 may perform a NOx reduction action without degrading the performance, and may reduce the amount of NOx discharged to the exhaust pipe (P).

8 is a diagram illustrating an exhaust gas treatment system according to example embodiments. The exhaust gas treatment system is substantially the same as or similar to the exhaust gas treatment system described with reference to FIG. 1 except that the exhaust gas purification apparatus is canned together with the oxidation catalyst apparatus. Accordingly, the same components are denoted by the same reference numerals, and repeated descriptions of the same components are omitted.

Referring to FIG. 8, in exemplary embodiments, the exhaust gas treatment system 11 may include an exhaust gas purification apparatus 100 canned together with the oxidation catalyst device 200.

Since the first and second carriers are made of a ceramic material, they are easily broken by an external impact. Thus, the canning process is carried out by wrapping it in a relatively soft mat to protect the carriers from external impact. In this case, the first carrier 110 may be placed directly behind the second carrier 210 to be canned at a time. Alternatively, the first carrier 110 may be canned separately from the second carrier 210, respectively.

9 is a diagram illustrating an exhaust gas treatment system according to example embodiments. The exhaust gas treatment system is substantially the same as or similar to the exhaust gas treatment system described with reference to FIG. 1 except where the exhaust gas purification apparatus is installed. Accordingly, the same components are denoted by the same reference numerals, and repeated descriptions of the same components are omitted.

Referring to FIG. 9, in the exemplary embodiments, the exhaust gas treatment system 12 may purify the exhaust gas installed inside the exhaust pipe P connecting the oxidation catalyst device 200 and the selective reduction catalyst device 300. Device 100 may be included.

The exhaust gas purification device 100 may maintain the performance of the selective reduction catalyst device 300 by collecting the oxide material separated from the oxidation catalyst device 200. Therefore, the exhaust gas purification apparatus 100 may be installed at various positions between the oxidation catalyst device 200 and the selective reduction catalyst device 300. For example, the exhaust gas purification apparatus may be installed inside the exhaust pipe connecting the oxidation catalyst apparatus and the selective reduction catalyst apparatus without separately canning.

As described above, the exhaust gas purification apparatus 100 according to the exemplary embodiments may be installed at various positions between the oxidation catalyst device 200 and the selective reduction catalyst device 300. That is, the exhaust gas purification apparatus 100 may be canned at one time with the oxidation catalyst apparatus 200 or may be separately canned. Alternatively, the exhaust gas purification apparatus 100 may be mounted inside the exhaust pipe P.

10 is a diagram illustrating an exhaust gas treatment system according to example embodiments. FIG. 11 is a cross-sectional view taken along the line CC ′ of FIG. 10. The exhaust gas treatment system is substantially the same as or similar to the exhaust gas treatment system described with reference to FIG. 1 except that the exhaust gas purification apparatus is integrally formed with the oxidation catalyst apparatus. Accordingly, the same components are denoted by the same reference numerals, and repeated descriptions of the same components are omitted.

10 and 11, in exemplary embodiments, the exhaust gas treatment system 13 may include an exhaust gas purification apparatus 100 formed integrally with the oxidation catalyst device 200.

For example, one carrier may be formed in a honeycomb shape so as to have at least one passage extending in the axial direction by extruding a raw material of ceramic material. Subsequently, a first washcoat layer 121 may be coated on the rear end 111 of the carrier, and a second washcoat layer 221 may be coated on the front end 211 of the carrier. In this case, the first and second washcoat layers 121 and 221 may be formed by dip coating in which one end of the carrier is immersed in the washcoat solution and then taken out.

The exhaust gas F discharged from the engine (not shown) may pass through the second washcoat layer 221 and the first washcoat layer 121 in order to be discharged downstream. The second washcoat layer 221 may oxidize carbon monoxide and hydrocarbons in the exhaust gas F to carbon dioxide and water. The first washcoat layer 121 may collect an oxide material such as a noble metal separated from the second washcoat layer 221.

As described above, the exhaust gas purifying apparatus 100 according to the exemplary embodiments may be zone-coated with the first washcoat layer 121 at the rear end of the oxidation catalyst apparatus 200 to integrate with the oxidation catalyst apparatus 200. Can be formed. In this case, the first washcoat layer 121 may collect the oxide material released from the second washcoat layer 221 to maintain the performance of the selective reduction catalyst 300.

12 is a diagram illustrating an exhaust gas treatment system according to example embodiments. FIG. 13 is a cross-sectional view taken along the line D-D 'of FIG. 12. The exhaust gas treatment system is substantially the same as or similar to the exhaust gas treatment system described with reference to FIG. 1 except that the exhaust gas purification apparatus is installed upstream of the oxidation catalyst apparatus. Accordingly, the same components are denoted by the same reference numerals, and repeated descriptions of the same components are omitted.

Referring to FIG. 12, an exhaust gas treatment system 14 is installed in an exhaust pipe P, and an oxidation catalyst device 200 to remove carbon monoxide and hydrocarbons in the exhaust gas F and an oxidation catalyst device 200. ) Installed in the exhaust pipe (P) downstream to reduce the nitrogen oxides (NOX) (Selective Catalyst Reduction, 300), and the exhaust pipe (P) upstream of the oxidation catalyst device 200 to remove impurities It may include an exhaust gas purification device 102 that can be collected. That is, the exhaust gas purification device 102 may be located upstream than the oxidation catalyst device 200 and the selective reduction catalyst device 300.

Referring to FIG. 13, the exhaust gas purification apparatus 102 may include a third carrier 115 having a third passage 117 and a third washcoat layer 125 coated on the third carrier 115. Can be. In this case, the third carrier 115 and the third washcoat layer 125 may be formed in substantially the same shape and material as the first carrier 110 and the first washcoat layer 120, respectively.

The exhaust gas discharged from the engine passes through the third passage 117, and then may be discharged to the outside through the oxidation catalyst device 200 and the selective reduction catalyst device 300 in order. In this case, the contact area with the exhaust gas F may be increased by coating the third washcoat layer 125 on the surface of the third carrier 115. As a result, it is possible to greatly increase the chance that impurities such as engine oil contained in the exhaust gas meet with the exhaust gas purification device 102, thereby preventing the inflow into the oxidation catalyst device 200.

14 is a diagram illustrating an exhaust gas treatment system according to example embodiments. The exhaust gas treatment system is substantially the same as or similar to the exhaust gas treatment system described with reference to FIG. 12 except that the exhaust gas purification apparatus is canned together with the oxidation catalyst apparatus. Accordingly, the same components are denoted by the same reference numerals, and repeated descriptions of the same components are omitted.

Referring to FIG. 14, in the exemplary embodiments, the exhaust gas treatment system 15 is an exhaust gas canned together with the oxidation catalyst device 200 and the oxidation catalyst device 200 upstream of the oxidation catalyst device 200. The purification device 102 may be included.

Since the second and third carriers are made of a ceramic material, they are easily broken by an external impact. Thus, the canning process is carried out by wrapping it in a relatively soft mat to protect the carriers from external impact. In this case, the third carrier 115 may be placed directly in front of the second carrier 210 to be canned at a time.

15 is a diagram illustrating an exhaust gas treatment system according to example embodiments. The exhaust gas treatment system is substantially the same as or similar to the exhaust gas treatment system described with reference to FIG. 12 except for the position where the exhaust gas purification apparatus is installed. Accordingly, the same components are denoted by the same reference numerals, and repeated descriptions of the same components are omitted.

Referring to FIG. 15, in the exemplary embodiments, the exhaust gas treatment system 16 may include an exhaust gas purification device 102 installed inside the exhaust pipe P in front of the oxidation catalyst device 200. .

The exhaust gas purification device 102 can maintain the performance of the oxidation catalyst device 200 by collecting impurities such as engine oil contained in the exhaust gas. Therefore, the exhaust gas purification device 102 may be installed at various positions in front of the oxidation catalyst device 200. For example, the exhaust gas purification apparatus may be installed inside the exhaust pipe in front of the oxidation catalyst apparatus without separately canning.

16 is a diagram illustrating an exhaust gas treatment system according to example embodiments. 17 is a cross-sectional view taken along the line E-E 'of FIG. 16. The exhaust gas treatment system is substantially the same as or similar to the exhaust gas treatment system described with reference to FIG. 12 except that the exhaust gas purification apparatus is integrally formed with the oxidation catalyst apparatus. Accordingly, the same components are denoted by the same reference numerals, and repeated descriptions of the same components are omitted.

16 and 17, in exemplary embodiments, the exhaust gas treatment system 17 may include an exhaust gas purification apparatus 102 formed integrally with the oxidation catalyst device 200.

For example, one carrier may be formed in a honeycomb shape so as to have at least one passage extending in the axial direction by extruding a raw material of ceramic material. Subsequently, a second washcoat layer 222 may be coated on the rear end 215 of the carrier, and a third washcoat layer 126 may be coated on the front end 116 of the carrier. In this case, the second and third washcoat layers 222 and 126 may be formed by dip coating by dipping one end of the carrier into the washcoat solution.

The exhaust gas F exhausted from the engine (not shown) may pass through the third washcoat layer 126 and the second washcoat layer 222 in order to be discharged downstream. The third washcoat layer 126 may collect impurities such as engine oil included in the exhaust gas F. The second washcoat layer 221 may oxidize carbon monoxide and hydrocarbons in the exhaust gas F to carbon dioxide and water.

As described above, the exhaust gas purification apparatus 102 according to the exemplary embodiments may be installed at various positions upstream of the oxidation catalyst apparatus 200. That is, the exhaust gas purification device 102 can be canned at one time with the oxidation catalyst device 200 or separately canned. Alternatively, the exhaust gas purification device 102 may be mounted inside the exhaust pipe P. In some cases, the exhaust gas purification device 102 may be integrally formed with the oxidation catalyst device 200 by zone coating the third washcoat layer 126 on the front end of the oxidation catalyst device 200. Accordingly, the exhaust gas purification device 102 may maintain the performance of the oxidation catalyst device 200 by removing impurities such as engine oil contained in the exhaust gas.

18 is a diagram illustrating an exhaust gas treatment system according to example embodiments. The exhaust gas treatment system is an exhaust gas treatment system described with reference to FIGS. 1 and 12, respectively, except that a plurality of exhaust gas purification apparatuses are installed upstream of the oxidation catalyst apparatus and between the oxidation catalyst apparatus and the conversion catalyst apparatus. Is substantially the same or similar to Accordingly, like reference numerals refer to like elements, and repeated descriptions of like elements are omitted.

Referring to FIG. 18, an exhaust gas treatment system 18 is installed in an exhaust pipe P, and an oxidation catalyst device 200 to remove carbon monoxide and hydrocarbons in exhaust gas F and an oxidation catalyst device 200. And a selective reduction catalyst (300), and an exhaust gas purification device (104) installed in the exhaust pipe (P) downstream to reduce nitrogen oxides (NOX). The exhaust gas purification device 104 includes a first exhaust gas purification unit 105 mounted on the exhaust pipe P between the oxidation catalyst device 200 and the selective reduction catalyst device 300, and the oxidation catalyst device 200 upstream. It may include a second exhaust gas purification unit 106 mounted on the exhaust pipe (P) of the.

The first exhaust gas purification unit 105 may prevent the oxide material separated from the oxidation catalyst device 200 and the exhaust pipe P from flowing into the selective reduction catalyst device 300. Accordingly, the selective reduction catalyst device 300 may perform a NOx reduction action without degrading the performance, and may reduce the amount of NOx discharged to the exhaust pipe (P).

In this case, the first exhaust gas purification unit 105 may be canned at one time with the oxidation catalyst device 200 or may be integrally formed with the oxidation catalyst device 200. In some cases, it may be mounted in the exhaust pipe P between the oxidation catalyst device 200 and the selective reduction catalyst device 300.

The second exhaust gas purification unit 106 may prevent impurities such as engine oil and sulfur (S) contained in the exhaust gas from flowing into the oxidation catalyst device 200. Accordingly, the oxidation catalyst device 200 may oxidize carbon monoxide and hydrocarbons in the exhaust gas F to carbon dioxide and water without degrading performance.

In this case, the second exhaust gas purification unit 106 may be canned at one time with the oxidation catalyst device 200 or may be integrally formed with the oxidation catalyst device 200. In some cases, it may be mounted in the exhaust pipe (P) upstream of the oxidation catalyst device 200.

As described above, the exhaust gas purification apparatus 104 according to the exemplary embodiments may collect impurities in the exhaust gas to prevent performance degradation of the oxidation catalyst apparatus 200, and may prevent the oxidation catalyst apparatus 200 and the exhaust gas. The performance of the selective reduction catalyst device 300 may be prevented by collecting the oxide material separated from the pipe P.

Although the above has been described with reference to the embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. It will be appreciated.

* Explanation of the sign

F: exhaust gas P: exhaust pipe

10, 11, 12, 13, 14, 15, 16, 17, 18: exhaust gas treatment system

100, 102, 104: exhaust gas purification device 105: first exhaust gas purification unit

106: second exhaust gas purification unit 110: first carrier

111, 215: Rear end of carrier 112: First passage

115: third carrier 116, 211: carrier front end

117: third passage 120, 121: first washcoat layer

125 and 126: third washcoat layer 200: oxidation catalyst device

210: second carrier 212: second passage

220, 221, 222: second washcoat layer 300: selective reduction catalyst device

312: first selective reduction catalyst device 314: second selective reduction catalyst device

316: third selective reduction catalyst device 320: reducing agent injection module

400: ammonia slip catalyst unit

Claims (13)

1. An exhaust gas treatment system comprising an oxidation catalyst device and a selective reduction catalyst device which are sequentially installed in an exhaust pipe through which exhaust gas is discharged from an internal combustion engine,

   At least one carrier that is mountable in at least one position in front of the oxidation catalyst device or between the oxidation catalyst device and the selective reduction catalyst device, and through which the exhaust gas passes; And

   And a washcoat layer coated on the surface of the carrier to collect impurities contained in the exhaust gas or oxides released from the oxidation catalyst device.
2. The exhaust gas purification apparatus according to claim 1, wherein the oxide material comprises Pt, Pd, Rh, Ir, Ag, Sn, and Ru.
3. The exhaust gas purification apparatus according to claim 1, wherein the carrier comprises at least one selected from the group consisting of cordierite, silicon carbide, pecaloy, NiCrAl, and NiFeCrAl.
4. The exhaust gas purification apparatus according to claim 1, wherein the carrier has a honeycomb shape.
5. The exhaust gas purification apparatus according to claim 1, wherein the carrier is canned together with the oxidation catalyst device.
6. The exhaust gas purification apparatus according to claim 1, wherein the carrier is installed in an exhaust pipe.
7. The exhaust gas purification apparatus according to claim 1, wherein the carrier is formed integrally with the oxidation catalyst device.
8. The apparatus of claim 1, wherein the washcoat layer comprises at least one selected from the group consisting of Al 2 O 3, SiO 2, TiO 2, CeO 2, ZrO 2, V 2 O 5, La 2 O 3 and zeolite.
9. The exhaust gas purification apparatus according to claim 1, wherein the washcoat layer increases the contact area with the exhaust gas.
10. The exhaust gas purification apparatus according to claim 1, wherein the washcoat layer has a surface area of 50 to 60 m ² / g.
11. The exhaust gas purification apparatus according to claim 1, wherein the carrier has a metal fiber structure.
12. The exhaust gas purification apparatus according to claim 1, wherein the carrier has a metal foam shape.
13. The exhaust gas purification apparatus according to claim 1, wherein the impurities are engine oil.

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