Urea Urea-SCR mixer of diesel internal combustion engine after-treatment system

Abstract

The invention discloses a urea Urea-SCR mixer of a diesel internal combustion engine after-treatment system. The mixer comprises a spiral mixing cavity at the front end and a flow equalizing cavity at the rear end. The spiral mixing cavity comprises an air inlet end panel, an air outlet end panel and a spiral rotational flow guide plate, the flow guide plate forms a vortex convergence type airflow channel from an air inlet to an air outlet, a convex peak type flow guide plate is arranged in the channel in the flowing direction of fluid, a plurality of groups of splitter plates are arranged, and a flow equalizing disc is arranged in the flow equalizing cavity in the radial direction of a cylinder body. According to the mixer, hot tail gas flow is distributed and guided, and a urea aqueous solution is strongly crushed and atomized, so that the urea aqueous solution is quickly and fully atomized and pyrolyzed. A mixed gas flows at a high speed in the spiral vortex convergence type airflow channel, so that uniform and sufficient mixing is achieved. The convex peak type flow guide plate and the splitter plates are used for distributing, guiding, crushing and disturbing hot air flow which is mixed and flows at a high speed. The flow equalizing disc is used for distributing and guiding the high-speed rotational flow entering the rear cavity, so that the conversion rate of ammonia is greatly improved.

Description

technical field [0001] The invention discloses a urea selective catalytic reduction (Urea-SCR) mixer for a post-treatment system of a diesel internal combustion engine, and relates to a post-treatment technology of hot exhaust gas of a diesel internal combustion engine, in particular to a Urea-SCR mixing system for a hot exhaust post-treatment system of a diesel internal combustion engine The structure of the device. Background technique [0002] As the country pays more and more attention to environmental protection and the implementation of the national VI emission regulations for diesel internal combustion locomotives, urea is widely used in the hot exhaust aftertreatment system of diesel internal combustion engines to reduce and eliminate NO in the hot exhaust. X ; During the working process of the aftertreatment system, the urea aqueous solution needs to be hydrolyzed after spraying, and ammonia gas can be generated to discharge the NO in the hot exhaust gas with the in...

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Problems solved by technology

[0003] Aiming at the general problems and design defects in the Urea-SCR mixer technology for the existing diesel internal combustion engine aftertreatment system, the purpose of the present invention is to overcome and solve the performance deficiencies of the existing Urea-SCR mixer, including the Insufficient atomization, formation of urea crystals, low ammonia conversion rate, etc.

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