Efficient anti-crystallization SCR mixer and automobile comprising same

Abstract

The invention discloses an efficient anti-crystallization SCR mixer and an automobile comprising the same. The efficient anti-crystallization SCR mixer comprises a post-processor mixer barrel, a U-shaped mixing pipe and a baffle are arranged in an inner cavity of the post-processor mixer barrel, and the U-shaped mixing pipe is obliquely arranged in the inner cavity of the post-processor mixer barrel; the baffle is arranged on the U-shaped mixing pipe in a sleeved manner and divides the post-processor mixer barrel into a first cavity and a second cavity; and a plurality of hydrocyclones are also arranged in the second cavity. The U-shaped mixing pipe is designed, and a rotational flow plate is designed on one side of the U-shaped pipe, so that urea mist beams and exhaust gas are fully mixed, and the requirement for uniformity of ammonia in the mixer is met; by adjusting the urea spraying angle, the situation that the urea mist beams collide with the wall too early is reduced, and therefore the risk of crystallization is avoided; a perforated pipe is designed on the other side of the mixing pipe to promote diffusion and mixing of urea and injection; and the hydrocyclones are designed on the rear side of the U-shaped mixing pipe, so that the mixing uniformity of urea and air is further promoted.

Description

technical field [0001] The invention relates to the technical field of denitrification, in particular to an SCR mixing system and an SCR mixer thereof, in particular to a high-efficiency anti-crystallization SCR mixer and an SCR exhaust aftertreatment system containing the high-efficiency anti-crystallization SCR mixer. Background technique [0002] Selective Catalytic Reduction (SCR) refers to the use of reducing agents (such as NH3, liquid ammonia, urea) to selectively react with NOx in the flue gas under the action of a catalyst to generate non-toxic and pollution-free N 2 and H 2 O. Automotive exhaust systems include injection systems that inject diesel exhaust fluid (DEF) or a reductant, such as a solution of urea and water, upstream of a selective catalytic reduction (SCR) catalyst. A mixer is positioned upstream of the SCR catalyst and mixes engine exhaust gases and urea conversion products. [0003] The Chinese invention patent with the authorized notification nu...

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Problems solved by technology

[0006]However, the above-mentioned technical solution has the following defects: 1. The design of the post-processor mixer is not compact enough, resulting in a larger overall size of the vehicle post-processor, which increases the cost and occupies a relatively large area. The control is installed on a large vehicle chassis; 2. The mixing distance of the mixer is short, which may easily cause urea to enter the SCR carrier behind without being fully mixed in the mixer, resulting in carrier blockage; 3. The urea solution in the mixer still exists in the early stage of urea spraying Risk of hitting the wall at the first stage, thus causing the risk of urea crystallization blockage

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