A post-processor structure with detachable integrated urea nozzle

Abstract

The invention relates to a post-processor structure with detachable and integrated urea nozzles. The post-processor housing of the structure has a mixing cavity; Inside the post-processor housing; the mixing unit is installed on the side of the post-processor housing, and its urea nozzle seat welding assembly is connected to the external urea nozzle and connected to the liquid circuit assembly through the V-shaped clamp assembly; the liquid circuit assembly It is connected with the urea mixer assembly, which is located in the mixing chamber; the SCR unit is located in the afterprocessor housing, its front end is connected with the mixing chamber, and the rear end is close to the rear end cover of the afterprocessor housing; noise reduction The unit is arranged on the periphery of the SCR unit; the air outlet unit is arranged near the rear end cover of the afterprocessor housing. The invention has high integration, and can be disassembled at any time to check whether urea crystals are generated inside the post processor and the mixer, and can be disassembled and cleaned at any time to clean the urea crystals generated inside.

Description

technical field [0001] The invention relates to a post-processor structure with a square detachable integrated urea nozzle, which is suitable for diesel commercial vehicles meeting the regulations of National IV, National V and National VI. Background technique [0002] The limit value of exhaust pollutants (mainly particles and nitrogen oxides NOx) in the national IV, national V and national VI emission regulations of diesel engines is much lower than that of national III emission regulations. It is difficult to reduce the above two exhaust pollutants in the engine at the same time. The SCR (Selective Catalytic Reduction) system can effectively reduce the content of nitrogen oxides in the exhaust pollutants, so that the exhaust pollutants of the engine meet the requirements of emission regulations. [0003] With the extensive application of SCR technology, urea aqueous solution as a reducing agent needs to be sprayed into the exhaust pipe through the urea nozzle in advance ...

AI Technical Summary

Problems solved by technology

It is difficult for the elbow and pipeline welding process of the existing pipeline layout scheme to meet the above requirements;

[0005] 2. The urea nozzle is arranged on the pipeline. Since urea is corrosive, all pipelines in contact with urea must be made of stainless steel, and the cost is high;

[0006] 3. The urea aqueous solution may produce urea crystallization, and the urea crystallization of the pipeline in the existing pipeline layout scheme may cause leakage and corrosion, which greatly affects the aesthetics;

[0007] 4. The urea aqueous solution may produce urea crystals. The urea crystals in the existing pipeline layout scheme may be generated and accumulated inside the pipeline and post-processor, affecting the back pressure of the exhaust system, and even blocking the pipeline and post-processor;

[0008] 5. The urea aqueous solution may produce urea crystallization. If urea crystallization occurs, this part of urea cannot be used as the reducing agent of the SCR reaction, ammonia gas, to participate in the selective catalytic reduction reaction, which may cause excessive nitrogen oxides in the vehicle, and even limit the output torque of the vehicle. ;

[0009] 6. The urea aqueous solution may produce urea crystallization, and the existing pipeline layout scheme cannot observe whether crystallization occurs inside the post-processor at any time;

[0010] 7. Urea aqueous solution may produce urea crystals

The existing pipeline layout scheme is not conducive to generalization, integration and modularization

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