Post-processor structure of detachable integrated urea nozzle

Abstract

The invention relates to a post-processor structure of a detachable integrated urea nozzle. A mixing cavity is formed in a post-processor shell of the structure; an air inlet unit is fixed on the front end cover of the post-processor shell, and the opening port part of the air inlet unit extends into the post-processor shell; a mixing unit is installed on the side surface of the post-processor shell, and a urea nozzle base welding assembly of the mixing unit is connected with an external urea nozzle and is connected with a liquid path assembly through a V-shaped clamp assembly; the liquid pathassembly is connected with a urea mixer assembly, and the urea mixer assembly is positioned in the mixing cavity; a SCR unit is positioned in the post-processor shell, the front end of the SCR unit is connected with the mixing cavity, and the rear end of the SCR unit is close to the rear end cover of the post-processor shell; silencing units are arranged on the periphery of the SCR unit, and an air outlet unit is arranged to the rear end cover position close to the, post-processor shell. The post-processor structure is high in integration level and can be disassembled at any time to check whether the inside of the post-processor and the mixer generate urea crystallization, and the urea crystals generated inside can be disassembled and cleared any time.

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 China IV, China V and China 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 simultaneously reduce the above two exhaust pollutants in the engine, and 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 to mix ...

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, it is required that 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, and 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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