SCR urea solution mixer

Abstract

The invention discloses an SCR urea solution mixer. The mixer is a gas through structure cylinder arranged at a motor vehicle tail gas outlet, and after the urea solution in the mixer is sprayed and is mixed with the tail gas for the first time, the urea solution is continuously mixed with the tail gas for at least one time, wherein the first-time mixing is that the urea solution is tangentially sprayed along the tail gas flow direction and then is radially and spirally mixed, and the subsequent mixing is that the first-time mixed gas flow is sprayed along the radial direction and is remixed with the tail gas for at least one time. According to the mixer, the atomized urea solution and the tail gas entering the mixer are guided and subjected to first-time atomization decomposition by adopting a spiral flow guide plate, then subjected to second-time atomization thermal decomposition and guided into a flow equalizing pipe, tail gas flow is supplemented through the outer side, and third-time decomposition is conducted through the flow equalizing plate. According to the mixer, the mixing stroke is more reasonable, the mixing path of the urea solution and the tail gas is prolonged, mixing is more uniform and sufficient, urea thermal decomposition is better, the crystallization risk is avoided, and the conversion efficiency of NOx in the tail gas is improved.

Description

technical field [0001] The invention belongs to the technical field of motor vehicle tail gas purification treatment and relates to an SCR urea solution mixer in the motor vehicle tail gas purification treatment technology. Background technique [0002] With the increasingly stringent requirements of exhaust emission regulations, in order to meet the requirements of the National IV emission standards, "SCR" technology is adopted in the exhaust aftertreatment system of heavy-duty diesel engines. The so-called "SCR" technology is the use of selective catalytic reduction chemistry. The principle is to realize the technology of after-treatment and purification of exhaust gas. The SCR treatment technology can effectively reduce the NOx emission of diesel engines and meet the emission standards. [0003] In SCR technology, the mixer is the main mixing device used for the atomization and decomposition of diesel engine exhaust and sprayed urea solution. The existing mixer uses spira...

AI Technical Summary

Problems solved by technology

[0003] In SCR technology, the mixer is the main mixing device used for the atomization and decomposition of diesel engine exhaust and sprayed urea solution. The existing mixer uses spiral blades to guide the atomization and decomposition of the urea solution and diesel engine exhaust entering the mixer. The stroke path of the helical blade is short, and this structure is prone to urea crystallization, and the mixing uniformity of urea solution and exhaust gas is poor, resulting in low NOx conversion efficiency

Images