Tail gas aftertreatment mixing device

Abstract

The invention discloses a tail gas aftertreatment mixing device which comprises a shell, a mixing component positioned in the shell and a partition plate, wherein the partition plate divides the shellinto a first cavity and a second cavity; the mixing component comprises an inner pipe, a distribution body, an outer pipe and an end cover; the inner pipe is provided with a first pipe body positioned in the first cavity and a second pipe body extending into the second cavity; a plurality of spinning disks are arranged on the wall surface of the first pipe body; a plurality of first through holesfor an air flow to pass through are formed in the wall surface of the second pipe body; a plurality of through holes for an air flow to pass through are formed in the distribution body; the outer pipe is positioned on the periphery of the second pipe body; a plurality of second through holes for an air flow to pass through are formed in the wall surface of the outer pipe; the end cover is positioned at the bottom of the outer pipe and is used for forcing the air flow to flow backward. Therefore, the distance and time of urea evaporation are increased, and the uniformity of air flow mixing isimproved.

Description

[0001] This application is a divisional application of an application with an application date of June 13, 2016, an application number of 201610422729.7, and an invention title of "Exhaust Gas Post-Treatment Mixing Device". technical field [0002] The invention relates to an exhaust gas aftertreatment mixing device, which belongs to the technical field of engine exhaust aftertreatment. Background technique [0003] 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 ...

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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