JP2018087497A - Exhaust gas purifying apparatus - Google Patents
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Abstract
Description
本発明は、ディーゼルエンジン等の内燃機関に使用される排ガス浄化装置に関するものである。 The present invention relates to an exhaust gas purification device used for an internal combustion engine such as a diesel engine.
従来、自動車、船舶、発電機等の各種内燃機関から発生する排気ガスには、有害物質が含まれており、有害物質に対応した排ガス浄化装置を用いることにより、外部に排出される有害物質は減少しつつある。特にディーゼルエンジンは、固体状炭素微粒子や、液体又は固体状の高分子量炭化水素微粒子などの粒子状物質（ＰＭ：Ｐａｒｔｉｃｕｌａｔｅ Ｍａｔｔｅｒ）や窒素酸化物が排出されることから、複数の排ガス浄化装置を組み合わせて有害物質を減少させている。たとえば、ＰＭを除去する方法の一つとして、セラミックハニカム、セラミックフォーム、金属発泡体等の耐熱性の排ガス浄化フィルタを用いる方法が開発されている。この方法では、まず排ガス浄化フィルタで排ガス中のＰＭを捕集する。 Conventionally, exhaust gas generated from various internal combustion engines such as automobiles, ships, and generators contains harmful substances. By using an exhaust gas purification device that supports harmful substances, harmful substances discharged outside are It is decreasing. In particular, diesel engines emit particulate matter (PM: Particulate Matter) such as solid carbon particulates, liquid or solid high molecular weight hydrocarbon particulates, and nitrogen oxides. Reducing harmful substances. For example, as one method for removing PM, a method using a heat-resistant exhaust gas purification filter such as a ceramic honeycomb, a ceramic foam, or a metal foam has been developed. In this method, first, PM in exhaust gas is collected by an exhaust gas purification filter.
そして、ＰＭの捕集によりフィルタの圧力損失が上昇した場合には、バーナー又はヒーター等で排ガス浄化フィルタを加熱し、堆積したＰＭを燃焼させ、炭酸ガスに変えて外部に放出することにより、フィルタを再生することができる。 When the pressure loss of the filter rises due to PM collection, the exhaust gas purification filter is heated by a burner or a heater, and the deposited PM is burned, converted into carbon dioxide gas, and discharged to the outside. Can be played.
また、触媒を排ガス浄化フィルタに担持し、ＰＭを触媒作用により燃焼させることで、バーナー又はヒーターなどによる燃焼操作を軽減して、フィルタを再生する方法もある。例えば、耐熱性セラミックからなるフィルタ基材に予めＰＭ燃焼触媒を担持させておき、ＰＭの捕集と共に燃焼反応を行わせる方法が研究されている。現在、ＰＭ燃焼触媒には白金、パラジウム等の白金族金属が広く使用されている。これは白金族金属を用いた触媒が、良好なＰＭ燃焼性能と耐久性能とを持つためである。 There is also a method of regenerating the filter by supporting the catalyst on an exhaust gas purification filter and burning PM by catalytic action to reduce the combustion operation by a burner or a heater. For example, a method has been studied in which a PM combustion catalyst is supported in advance on a filter base made of a heat-resistant ceramic, and a combustion reaction is performed together with PM collection. Currently, platinum group metals such as platinum and palladium are widely used for PM combustion catalysts. This is because a catalyst using a platinum group metal has good PM combustion performance and durability performance.
一方、窒素酸化物の浄化システムとしては尿素ＳＣＲシステムが知られている。尿素ＳＣＲシステムでは、排ガス通路に窒素酸化物を選択的に還元する還元触媒と、その上流において排ガスに還元剤（尿素水）を噴射する噴射装置が備えられている。噴射された尿素水は排ガス中でアンモニアを生成して、アンモニアの作用により窒素酸化物を窒素と水に分解することで窒素酸化物を除去するものである。還元触媒による窒素酸化物の浄化を効果的に行うためには、噴射された還元剤が還元装置に一様に供給される必要がある。例えば噴射装置と還元装置の間にミキサー（旋廻流板）を設置して、還元剤が還元触媒に到達するまでの経路を長く取ることで、還元剤の拡散させることができる（例えば、特許文献１参照）。 On the other hand, a urea SCR system is known as a nitrogen oxide purification system. The urea SCR system includes a reduction catalyst that selectively reduces nitrogen oxides in an exhaust gas passage and an injection device that injects a reducing agent (urea water) into the exhaust gas upstream thereof. The injected urea water generates ammonia in the exhaust gas, and removes nitrogen oxides by decomposing nitrogen oxides into nitrogen and water by the action of ammonia. In order to effectively purify nitrogen oxides by the reduction catalyst, it is necessary to uniformly supply the injected reducing agent to the reduction device. For example, a reducing agent can be diffused by installing a mixer (rotating flow plate) between the injection device and the reducing device and taking a long path until the reducing agent reaches the reduction catalyst (for example, Patent Documents). 1).
ところで、この種の排気浄化システムにおいて、ＰＭ燃焼触媒として広く使用される白金族金属を含む触媒は、添加する還元剤を酸化してしまうことが知られている。還元剤の酸化を防ぐために、添加する還元剤の噴射装置は、燃焼装置と還元装置の間に設置する必要があった。 By the way, in this kind of exhaust purification system, it is known that a catalyst containing a platinum group metal widely used as a PM combustion catalyst oxidizes a reducing agent to be added. In order to prevent oxidation of the reducing agent, it is necessary to install the injection device for the reducing agent to be added between the combustion device and the reducing device.
また、噴射弁から噴射された還元剤は、噴射直後には濃度に偏りがあり、想定した以上の濃度で還元剤が還元装置に到達すると、窒素酸化物の還元に寄与しない還元剤が還元装置下流側に放出されるスリップという現象を発生してしまうこともあった。そこで還元装置前段にミキサー等を設置して、還元装置の前で拡散させる必要があった。 In addition, the reducing agent injected from the injection valve is uneven in concentration immediately after injection, and when the reducing agent reaches the reducing device at a concentration higher than expected, the reducing agent does not contribute to the reduction of nitrogen oxides. In some cases, a phenomenon called slip released downstream occurs. Therefore, it has been necessary to install a mixer or the like in front of the reducing device and diffuse it in front of the reducing device.
その結果、還元装置上流側の経路を長くした効果は得られるが装置間の距離が長くなり、排ガス浄化装置が大きくなり、車両の容量を圧迫していた。 As a result, the effect of lengthening the path on the upstream side of the reduction device can be obtained, but the distance between the devices becomes longer, the exhaust gas purification device becomes larger, and the capacity of the vehicle is pressed.
そこで本発明は、上記従来の課題を解決するものであり、燃焼装置および還元装置の性能を確保しつつ、排ガス浄化装置を小型化することを目的とする。 SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to downsize an exhaust gas purification device while ensuring the performance of a combustion device and a reduction device.
そして、この目的を達成するために、本発明は、内燃機関の排気ガス通路に配置させることができる排ガス浄化装置であって、還元触媒を塗布した還元装置と、その前段に燃焼触媒を塗布した燃焼装置と、前記還元装置を通過させる排気ガスに還元剤を噴射する噴射装置とを備え、前記燃焼装置は、ウォールフロー型の構造でありセル壁で区画された複数のセルを備え、前記燃焼触媒がアルカリ金属と遷移金属の複合酸化物を含み、前記噴射装置は、燃焼装置の上流に配置されているものであり、これにより所期の目的を達成するものである。 In order to achieve this object, the present invention is an exhaust gas purifying apparatus that can be disposed in an exhaust gas passage of an internal combustion engine, wherein the reducing apparatus is applied with a reducing catalyst, and the combustion catalyst is applied to the preceding stage. A combustion device; and an injection device that injects a reducing agent into the exhaust gas that passes through the reduction device. The combustion device has a wall flow structure and includes a plurality of cells partitioned by cell walls, and the combustion The catalyst includes a composite oxide of an alkali metal and a transition metal, and the injection device is disposed upstream of the combustion device, thereby achieving the intended purpose.
本発明によれば、内燃機関の排気ガス通路に配置させることができる排ガス浄化装置であって、還元触媒を塗布した還元装置と、その前段に燃焼触媒を塗布した燃焼装置と、前記還元装置を通過させる排気ガスに還元剤を噴射する噴射装置とを備え、前記燃焼装置は、ウォールフロー型の構造でありセル壁で区画された複数のセルを備え、前記燃焼触媒がアルカリ金属と遷移金属の複合酸化物を含み、前記噴射装置は、燃焼装置の上流に配置されている構成にしたことにより、噴射装置と還元装置の経路を長くとることができ、還元剤が拡散しやすくなる。 According to the present invention, there is provided an exhaust gas purification device that can be disposed in an exhaust gas passage of an internal combustion engine, wherein a reduction device coated with a reduction catalyst, a combustion device coated with a combustion catalyst in the preceding stage, and the reduction device An injection device for injecting a reducing agent into exhaust gas to be passed, the combustion device having a wall flow type structure and a plurality of cells partitioned by cell walls, wherein the combustion catalyst is made of an alkali metal and a transition metal. Since the injection device includes a complex oxide and is arranged upstream of the combustion device, the path between the injection device and the reduction device can be made long, and the reducing agent can easily diffuse.
特に、還元剤を燃焼装置に通すことで還元剤の分散を推進することができるため、ミキサーを備えることは不要になる。また、アルカリ金属と遷移金属の複合酸化物を含む燃焼触媒は還元剤との相互作用がないため、還元剤が燃焼装置を通ることによる燃焼装置および還元装置の性能への影響を排除することができる。 In particular, since the dispersion of the reducing agent can be promoted by passing the reducing agent through the combustion device, it is not necessary to provide a mixer. In addition, since a combustion catalyst containing a composite oxide of an alkali metal and a transition metal has no interaction with the reducing agent, it can eliminate the influence on the performance of the combustion device and the reducing device due to the reducing agent passing through the combustion device. it can.
したがって、燃焼装置および還元装置の性能を確保しつつ、排ガス浄化装置を小型化することができる。 Therefore, the exhaust gas purification device can be downsized while ensuring the performance of the combustion device and the reduction device.
本発明の請求項１記載の排ガス浄化装置は、内燃機関の排気ガス通路に配置させることができる排ガス浄化装置であって、還元触媒を塗布した還元装置と、その前段に燃焼触媒を塗布した燃焼装置と、前記還元装置を通過させる排気ガスに還元剤を噴射する噴射装置とを備え、前記燃焼装置は、ウォールフロー型の構造でありセル壁で区画された複数のセルを備え、前記燃焼触媒がアルカリ金属と遷移金属の複合酸化物を含み、前記噴射装置は、燃焼装置の上流に配置されている構成を有する。これにより、噴射装置から還元装置までの経路を長くとることができ、還元剤を拡散させやすくすることができる。さらに、還元剤を燃焼装置に通すことで還元剤の分散を推進することができるので、燃焼装置および還元装置の性能を確保しつつ、排ガス浄化装置を小型化することができる。 The exhaust gas purifying apparatus according to claim 1 of the present invention is an exhaust gas purifying apparatus that can be disposed in an exhaust gas passage of an internal combustion engine, and is a reduction apparatus that applies a reduction catalyst, and a combustion that applies a combustion catalyst to the preceding stage. And an injection device that injects a reducing agent into exhaust gas that passes through the reduction device, and the combustion device has a wall flow type structure and includes a plurality of cells partitioned by cell walls, and the combustion catalyst Includes a composite oxide of an alkali metal and a transition metal, and the injection device has a configuration arranged upstream of the combustion device. Thereby, the path | route from an injection apparatus to a reduction | restoration apparatus can be taken long, and it can make it easy to diffuse a reducing agent. Furthermore, since the reducing agent can be dispersed by passing the reducing agent through the combustion device, the exhaust gas purification device can be downsized while ensuring the performance of the combustion device and the reducing device.
以下、本発明の実施の形態について図面を参照しながら説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
（実施の形態１）
図１に示すように、排ガス浄化装置１は、例えば、ディーゼルエンジン等の内燃機関の排気通路に設けることができる。前記排気通路を流れる排ガス中の粒子状物質（以下、ＰＭと記載）および窒素酸化物を除去するものである。
(Embodiment 1)
As shown in FIG. 1, the exhaust gas purification device 1 can be provided in an exhaust passage of an internal combustion engine such as a diesel engine, for example. Particulate matter (hereinafter referred to as PM) and nitrogen oxides in the exhaust gas flowing through the exhaust passage are removed.
排ガス浄化装置１は、ＰＭを除去する燃焼装置２と、窒素酸化物を除去する還元装置３とを有し、燃焼装置２の上流側に接続された第一排気ガス管４と、燃焼装置２と還元装置３を繋ぐ第二排気ガス管５と、還元装置３の下流側に接続された第三排気ガス管６とを備えている。 The exhaust gas purification device 1 includes a combustion device 2 that removes PM and a reduction device 3 that removes nitrogen oxides, a first exhaust gas pipe 4 connected to the upstream side of the combustion device 2, and a combustion device 2. And a second exhaust gas pipe 5 connecting the reduction device 3 and a third exhaust gas pipe 6 connected to the downstream side of the reduction device 3.
第一排気ガス管４には、第一排気ガス管４内部に還元剤（尿素水、ＮＨ４）を噴射する噴射装置７が備えられている。 The first exhaust gas pipe 4 is provided with an injection device 7 that injects a reducing agent (urea water, NH 4) into the first exhaust gas pipe 4.
噴射装置７は、第一排気ガス管４内壁から排ガス中へと還元剤を噴射できるように配置され、還元剤は液体やミスト状で排ガス中へと噴射される。還元剤の加水分解を促進させ、アンモニアの生成を促進するためにヒーター等を設けてもよい。 The injection device 7 is arranged so that the reducing agent can be injected from the inner wall of the first exhaust gas pipe 4 into the exhaust gas, and the reducing agent is injected into the exhaust gas in a liquid or mist form. A heater or the like may be provided to promote hydrolysis of the reducing agent and promote production of ammonia.
燃焼装置２は、ＰＭを捕集する多孔質の排ガス浄化フィルタ８と、ＰＭを燃焼して浄化する燃焼触媒９とを備える。 The combustion apparatus 2 includes a porous exhaust gas purification filter 8 that collects PM, and a combustion catalyst 9 that combusts and purifies PM.
排ガス浄化フィルタ８は、ウォールフロー型の構造であり、セル壁で区画された複数のセルを備え、隣接するセルの端部が交互に目封じされている。これにより、排ガスの上流側を開口し、下流側が閉塞した排ガス流入セルと、排ガスの上流側が閉塞し、下流側が開口した排ガス流出セルとが、セル壁を介して隣接した構成となっている。なお、排ガス浄化フィルタ８の形状は上記のような形状に限定されるものではなく、ウォールスルー型、フロースルーハニカム型、金属あるいはセラミックスの発泡体型などでもよい。 The exhaust gas purification filter 8 has a wall flow type structure, includes a plurality of cells partitioned by cell walls, and ends of adjacent cells are alternately sealed. Thereby, the exhaust gas inflow cell which opened the upstream side of exhaust gas, and the downstream side obstruct | occluded, and the exhaust gas outflow cell which obstruct | occluded the upstream side of exhaust gas and opened the downstream side become the structure adjacent via the cell wall. The shape of the exhaust gas purification filter 8 is not limited to the above shape, and may be a wall-through type, a flow-through honeycomb type, a metal or ceramic foam type, or the like.
排ガス浄化フィルタ８の材質は、耐熱性セラミックスや金属材料等からなる多孔質材料であればよい。耐熱性セラミックスとしては、例えば炭化ケイ素（ＳｉＣ）、コージェライト、窒化ケイ素、チタン酸アルミニウム等を用いることができる。金属材料としては、例えばステンレス合金、Ｆｅ−Ｃｒ−Ａｌ合金等を用いることができる。これらの中でも、耐熱性および触媒塗工性の観点から、炭化ケイ素が好ましい。セル壁に設けられた細孔の平均細孔径は特に限定されないが、例えば５μｍ〜５０μｍとすることができる。平均細孔径が５μｍ以上の場合には、ＰＭが堆積しても圧力損失の過度の上昇を抑制することができる。また、平均細孔径が５０μｍ以下の場合には、ＰＭの過度の素抜けを抑制することができる。セルの断面形状は特に限定されないが、触媒とＰＭの接触面積を大きくできる観点から、４〜８角形のうちのいずれかであることが好ましい。またセルの形成密度は特に限定されないが、上記と同様の観点から、セルの数は１平方インチあたり２００〜４００セルであることが好ましい。セル数を２００セル以上とすることで、触媒とＰＭの接触面積を十分に確保することができる。また、セル数を４００セル以下とすることで、セルへのＰＭ堆積による目詰まりを生じにくくすることができる。 The material of the exhaust gas purification filter 8 may be a porous material made of heat resistant ceramics or metal material. As the heat-resistant ceramic, for example, silicon carbide (SiC), cordierite, silicon nitride, aluminum titanate, or the like can be used. As the metal material, for example, a stainless alloy, an Fe—Cr—Al alloy, or the like can be used. Among these, silicon carbide is preferable from the viewpoints of heat resistance and catalyst coatability. The average pore diameter of the pores provided in the cell wall is not particularly limited, but can be, for example, 5 μm to 50 μm. When the average pore diameter is 5 μm or more, an excessive increase in pressure loss can be suppressed even if PM is deposited. Moreover, when the average pore diameter is 50 μm or less, excessive removal of PM can be suppressed. The cross-sectional shape of the cell is not particularly limited, but is preferably any one of 4 to 8 octagons from the viewpoint of increasing the contact area between the catalyst and PM. The cell formation density is not particularly limited, but from the same viewpoint as described above, the number of cells is preferably 200 to 400 cells per square inch. By making the number of cells 200 or more, a sufficient contact area between the catalyst and PM can be ensured. Further, by setting the number of cells to 400 cells or less, clogging due to PM deposition on the cells can be made difficult to occur.
燃焼触媒９は、アルカリ金属と遷移金属の複合酸化物を含む触媒である。燃焼触媒９はＰＭ燃焼性能が高くかつ、アンモニアの分解や吸着等の相互作用が少なければよい。また、ＰＭ燃焼性能を向上させるために、酸化物等の酸化物を担体として用いてもよい。 The combustion catalyst 9 is a catalyst containing a composite oxide of an alkali metal and a transition metal. The combustion catalyst 9 should have high PM combustion performance and less interaction such as ammonia decomposition and adsorption. In order to improve PM combustion performance, an oxide such as an oxide may be used as a carrier.
例えば、ＰＭ燃焼性能が高くするものとしてセリウム含有酸化物を含む担体は、比表面積が大きく、ＰＭと触媒の接触率向上させることができるため好ましい。 For example, a carrier containing cerium-containing oxide as a PM combustion performance is preferable because it has a large specific surface area and can improve the contact rate between PM and the catalyst.
例えば、アンモニアの分解や吸着等の相互作用が少なくするものとしてバナジウムに対するセシウムのモル比（Ｃｓ／Ｖ）が１．０≦Ｃｓ／Ｖ≦１．５である触媒を塗布することが好ましい。 For example, it is preferable to apply a catalyst having a molar ratio of cesium to vanadium (Cs / V) of 1.0 ≦ Cs / V ≦ 1.5 so as to reduce the interaction such as decomposition and adsorption of ammonia.
また、図示していないが、第一排気ガス管４には、排気ガス中の有害物質成分の一つであるＨＣやＣＯを浄化する酸化触媒（ＤＯＣ：Ｄｉｅｓｅｌ Ｏｘｉｄａｔｉｏｎ Ｃａｔａｌｙｓｔ）等が配置されることがある。この場合ＤＯＣによりアンモニアが酸化してしまうため、噴射装置７はＤＯＣと、燃焼装置２の間に配置することが好ましい。 Although not shown, the first exhaust gas pipe 4 is provided with an oxidation catalyst (DOC: Diesel Oxidation Catalyst) for purifying HC and CO which are one of the harmful substance components in the exhaust gas. There is. In this case, since the ammonia is oxidized by the DOC, the injection device 7 is preferably disposed between the DOC and the combustion device 2.
還元装置３下流には、過剰なアンモニアを浄化するＡＳＣ（Ａｍｍｏｎｉａ Ｓｌｉｐ Ｃａｔａｌｙｓｔ）等が配置されることもある。この場合、還元装置３へと流れ込むアンモニアに影響がないため、還元装置３下流にＡＳＣを配置してもよい。 An ASC (Ammonia Slip Catalyst) or the like that purifies excess ammonia may be disposed downstream of the reducing device 3. In this case, since the ammonia flowing into the reducing device 3 is not affected, an ASC may be arranged downstream of the reducing device 3.
上記構成において、ディーゼルエンジンから排出された排ガスは、排ガス浄化装置１において、まず第一排気ガス管４を通り、噴射装置７から噴射された還元剤を含むこととなる。続いて、排ガスは、燃焼装置２へと流れ込み、排ガスからＰＭが取り除かれ、次に、還元剤を含んだ状態で第二排気ガス管５を通り、還元装置３へと流れる。 In the above configuration, the exhaust gas discharged from the diesel engine first contains the reducing agent injected from the injection device 7 through the first exhaust gas pipe 4 in the exhaust gas purification device 1. Subsequently, the exhaust gas flows into the combustion device 2, PM is removed from the exhaust gas, and then flows into the reduction device 3 through the second exhaust gas pipe 5 in a state containing the reducing agent.
還元装置３内部では、窒素酸化物（ＮＯｘ）と還元剤から生成されたアンモニア（ＮＨ３）との還元反応、例えば、下記（式１）、（式２）、（式３）の還元反応を起こし、窒素酸化物を除去する。 In the reducing device 3, a reduction reaction between nitrogen oxide (NOx) and ammonia (NH3) generated from the reducing agent, for example, the following reduction reactions (Formula 1), (Formula 2), and (Formula 3) are caused. Remove nitrogen oxides.
４ＮＯ＋４ＮＨ３＋Ｏ２→４Ｎ２＋６Ｈ２Ｏ ・・・（式１）
６ＮＯ２＋８ＮＨ３→７Ｎ２＋３Ｈ２Ｏ ・・・（式２）
ＮＯ＋ＮＯ２＋２ＮＨ３→２Ｎ２＋３Ｈ２Ｏ ・・・（式３）
そして、還元装置３から排出された排ガスは第三排気ガス管６を通り車両外に排出される。
4NO + 4NH3 + O2 → 4N2 + 6H2O (Formula 1)
6NO2 + 8NH3 → 7N2 + 3H2O (Formula 2)
NO + NO2 + 2NH3 → 2N2 + 3H2O (Formula 3)
The exhaust gas discharged from the reduction device 3 passes through the third exhaust gas pipe 6 and is discharged outside the vehicle.
さて、噴射装置７から噴射された還元剤は、還元装置３に到達するまでに、濃度差により拡散して均一になっていく。噴射装置７の位置を燃焼装置２の上流にすることにより、噴射装置７から還元装置３までの経路を長くすることができるとともに、排ガス浄化フィルタ８を通過することで拡散を促進することができる。 Now, the reducing agent injected from the injection device 7 diffuses and becomes uniform due to the concentration difference before reaching the reduction device 3. By setting the position of the injection device 7 upstream of the combustion device 2, the path from the injection device 7 to the reduction device 3 can be lengthened, and diffusion can be promoted by passing through the exhaust gas purification filter 8. .
なぜなら、図２、３に示すように、排ガス浄化フィルタ８は、ウォールフロー型の構造であり、セル壁１０で区画された複数のセルを備え、隣接するセルの端部が交互に目封じされていることから、排ガス浄化フィルタ８の流入側のセル１１に入った還元剤を含む排ガスは、流出側のセル１２に移る際に強制的に４方向にわかれる。一方、流出側のセル１２では４方向に隣設する流入側セル１１から排ガスが入ってくるため、流出側のセル１２での還元剤の濃度は４方向に隣設する流入側セルの還元剤濃度の平均となる。排ガス浄化フィルタ８の各セルで同様の反応が起こるため、排ガス浄化フィルタ８を通過することで還元剤の拡散が促進される。その結果、下流側の還元装置３において還元剤の濃度を均一な状態とすることができる。 2 and 3, the exhaust gas purification filter 8 has a wall flow type structure, and includes a plurality of cells partitioned by the cell wall 10, and the ends of adjacent cells are alternately sealed. Therefore, the exhaust gas containing the reducing agent that has entered the cell 11 on the inflow side of the exhaust gas purification filter 8 is forcibly divided into four directions when moving to the cell 12 on the outflow side. On the other hand, in the outflow side cell 12, exhaust gas enters from the inflow side cell 11 adjacent in the four directions, so the concentration of the reducing agent in the outflow side cell 12 is the reducing agent in the inflow side cell adjacent in the four directions. This is the average concentration. Since the same reaction occurs in each cell of the exhaust gas purification filter 8, the diffusion of the reducing agent is promoted by passing through the exhaust gas purification filter 8. As a result, the concentration of the reducing agent can be made uniform in the reducing device 3 on the downstream side.
本発明にかかる排ガス浄化装置は、燃焼装置および還元装置の性能を確保しつつ、排ガス浄化装置の小型化を可能とするものであるので、各種内燃機関から発生する排ガスを浄化する排ガス浄化フィルタや、ディーゼルエンジンの排ガスを浄化する排ガス浄化装置等として有用である。 The exhaust gas purifying device according to the present invention enables the downsizing of the exhaust gas purifying device while ensuring the performance of the combustion device and the reducing device, so that the exhaust gas purifying filter for purifying the exhaust gas generated from various internal combustion engines, It is useful as an exhaust gas purification device for purifying exhaust gas from a diesel engine.
１ 排ガス浄化装置
２ 燃焼装置
３ 還元装置
４ 第一排気ガス管
５ 第二排気ガス管
６ 第三排気ガス管
７ 噴射装置
８ 排ガス浄化フィルタ
９ 燃焼触媒
DESCRIPTION OF SYMBOLS 1 Exhaust gas purification device 2 Combustion device 3 Reduction device 4 First exhaust gas pipe 5 Second exhaust gas pipe 6 Third exhaust gas pipe 7 Injection device 8 Exhaust gas purification filter 9 Combustion catalyst
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