Gas-liquid stirring and mixing device of urea solution metering injection system

Abstract

The invention relates to a gas-liquid stirring and mixing device of a urea solution metering injection system, comprising a metering valve, a compressed air inlet, a mixing cavity and an injection outlet, wherein the metering valve injects a reducing agent; the mixing cavity is used for gas-liquid stirring and mixing; the compressed air inlet is arranged on the side wall of the mixing cavity and tangent to the inner wall of the mixing cavity; and the injection outlet is arranged at the bottom of the mixing cavity. The invention has ingenious design, ensures good uniformity of a stirred and mixed suspension and can effectively solve the problems of deposition and crystallization inside the mixing cavity.

Description

technical field [0001] The invention relates to a post-treatment and purification system for diesel vehicle exhaust, in particular to a gas-liquid stirring and mixing device in a urea solution metering injection system. Background technique [0002] With the continuous improvement of motor vehicle emission standards, vehicle exhaust purification systems have increasingly attracted the attention of motor vehicle manufacturers, and various technical routes have gradually matured. [0003] It is now known that selective catalytic reduction technology (SCR) is a main way to reduce NOx emissions from diesel vehicles, that is, the reducing agent (urea aqueous solution) is atomized and quantitatively injected into the exhaust pipeline, and then undergoes a series of physical and chemical reactions. , Convert the main harmful gas NOx in the exhaust gas into nitrogen and water to discharge, so as to achieve the purpose of exhaust gas purification. Among them, the transportation of u...

AI Technical Summary

Problems solved by technology

Affected by factors such as the structure of the mixing chamber, air pressure, blowing direction, urea injection volume and temperature, the actual effect is not ideal, the suspension is not uniform enough, and deposition and crystallization tend to occur in the mixing chamber, which may cause blockage of the injection pipeline in severe cases

[0005] In addition, in actual work, due to the sudden interruption of compressed air, the residual liquid in the pipeline is not purged, and the backflow of liquid in the pipeline may also cause crystallization and blockage, affecting the normal operation of the injection system

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