Exhaust gas purification device

Abstract

[OBJECT] To provide an exhaust gas emission purifying device in a more compact size, and to prevent a decrease in catalytic performance due to the adsorption of intermediates such as ammonium sulfate even if the fuel contains a large quantity of sulfur compounds. [MEANS] An exhaust gas emission purifying device 1 provided with an exhaust manifold 6 which collects an exhaust gas discharged from exhaust connection pipes 3 connected to exhaust ports 2a of an engine 2, and which leads the exhaust gas into an exhaust passageway 5 upstream of a turbine 4a of a turbocharger 4, and further provided with a denitration catalyst apparatus 7 disposed in the exhaust passageway 5, and also provided with an evaporation tube 8 disposed within the exhaust manifold 6, the evaporation tube 8 having one end 8a connected to the exhaust passageway 5 and the other end 8b opening into the exhaust manifold 6. In addition, there is provided a nozzle 9 that sprays an aqueous solution of urea 9a into the exhaust gas as it passes through the evaporation tube 8. [ADVANTAGEOUS EFFECTS] The wall surface of the evaporation tube 8 provided within the exhaust manifold 6 is heated by the high-temperature exhaust gas immediately after it is discharged from the exhaust connection pipes 3, thereby preventing the formation of intermediates, and also conserving space.

Description

technical field [0001] The present invention relates to an exhaust gas purification device, which makes the nitrogen oxides (hereinafter referred to as "NOx" in the exhaust gas discharged from the internal combustion engine) x ”) react with a reducing agent under a denitrification catalyst such as SCR (Selective Catalytic Reduction: Selective Catalytic Reduction) to be reduced and removed. Background technique [0002] Conventionally, a technique has been used in which, for example, a denitrification reactor using an SCR catalyst is installed downstream of the exhaust pipe of a diesel engine, and a nozzle is installed on the upstream side of the denitrification reactor. The aqueous solution of the reducing agent composition of ammonia is sprayed into the exhaust gas, and the NOx in the exhaust gas is removed by the denitrification reactor x decomposed into nitrogen and water to make it harmless (such as patent document 1 figure 1 ). [0003] Also, in the past, in such F...

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Problems solved by technology

[0012] The problem to be solved by the present invention is that in the existing exhaust gas purification device, the exhaust manifold and the evaporator tube occupy a large volume, so the problem of poor space efficiency; and when the fuel contains sulfur, ammonium sulfate or hydrogen sulfate is produced The intermediate products such as ammonium are adsorbed on the SCR (Selective Catalytic Reduction) catalyst, which leads to the problem of degradation of catalytic performance

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