Tail gas after-treatment mixing device

Abstract

The invention discloses a tail gas after-treatment mixing device. The device comprises a shell and a mixing assembly positioned in the shell. The mixing assembly comprises a first space, a second space and a third space, the top of the first space communicates with the third space, and the top of the second space communicates with the third space. The mixing assembly is provided with a first bulgepart which protrudes into the third space from the bottom and a second bulge part which is positioned below the first bulge part, and a fourth space is formed between the first bulge part and the second bulge part. By means of the arrangement, the distance of urea evaporation is extended, the time of the urea evaporation is prolonged, and uniformity of airflow mixing is improved.

Description

technical field [0001] The invention relates to an exhaust gas aftertreatment mixing device, which belongs to the technical field of engine exhaust aftertreatment. Background technique [0002] Studies have shown that the uniformity of ammonia distribution in the exhaust gas after-treatment system (such as selective catalytic reduction system, SCR system) pipeline has an important impact on the overall performance and durability of the system. If the distribution of ammonia is not uniform, it will lead to excessive ammonia in local areas, which will easily cause ammonia leakage, while in other ammonia-lean areas, the conversion efficiency of nitrogen oxides (NOx) will be too low. The uneven distribution of ammonia over a long period of time can lead to uneven catalyst aging, which affects the overall performance of the catalyst. In addition, the uneven distribution of urea droplets will cause the temperature of the local pipe wall or mixing structure to be too low, forming ...

AI Technical Summary

Problems solved by technology

If the distribution of ammonia is not uniform, it will lead to excessive ammonia in local areas, which will easily cause ammonia leakage, and the conversion efficiency of nitrogen oxides (NOx) will be too low in other ammonia-lean areas.

Uneven distribution of ammonia over a long period of time can lead to uneven catalyst aging, which affects the overall performance of the catalyst

In addition, the uneven distribution of urea droplets will cause the temperature of the local pipe wall or the mixing structure to be too low, forming crystallization, which will block the exhaust pipe in serious cases, resulting in a decrease in engine power performance

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