Novel urea mixer

Abstract

The invention discloses a novel urea mixer. The novel urea mixer comprises a mixing pipe used for gathering urea and tail gas and a urea spraying nozzle vertically connected with one end of the mixing pipe in an inserted mode. A first baffle surrounding the urea spraying nozzle is arranged in the mixing pipe. A notch is formed in the lateral surface, opposite to the spraying direction of the urea spraying nozzle, of the first baffle. A second baffle opposite to the spraying direction of the urea spraying nozzle is further arranged in the portion, on one side of the first baffle, of the mixing pipe and is an arc baffle which extends upwards from the bottom of a turning surface of the mixing pipe, inclines in the direction away from the first baffle and then is gently bent in the tail gas flowing direction. The edges of two sides of the second baffle are in butt joint with the turning surface of the mixing pipe. An airflow passage for tail gas circulation is formed above the second baffle. The novel urea mixer is simple in structure, the problem of urea crystallization near the spraying nozzle and inside the mixer is solved, and the production cost is lowered.

Description

technical field [0001] The invention relates to the field of power machinery, more specifically, it relates to a novel urea mixer. Background technique [0002] The SCR injection system is used in the aftertreatment system of the diesel engine to eliminate the exhaust pollutant NO X system. The parts included in the SCR injection system are: Tianlan tank, air filter, metering injection pump, antifreeze solenoid valve, DCU components, nozzles and connecting pipelines. The system is controlled by the DCU. The metering injection pump will pass through the air filter. The clean compressed air, the antifreeze liquid passed through the antifreeze solenoid valve and the preheated blue liquid are mixed, sprayed into the mixer through the nozzle according to actual needs, and mixed with NO X A reduction reaction occurs to generate ammonia and water. The role of the mixer in the whole system is very important, which determines the mixing effect of urea and exhaust gas, thus affecti...

AI Technical Summary

Problems solved by technology

[0004] 1. Since there is no structure that can promote the mixing of urea and exhaust gas, the entire injection system has higher requirements on the atomization ability of the nozzle, which makes the manufacture of the nozzle more difficult and increases the manufacturing cost of the nozzle;

[0005] 2. In order to make the mixing time of urea and exhaust gas fully mixed, the length of the mixer will be designed to be very long. Moreover, because urea is highly corrosive, the material of the mixing tube must be stainless steel with high corrosion resistance , resulting in large consumables for the mixer, high cost, and larger system volume;

[0006] 3. Since the mixer is a straight-through long pipe, the exhaust gas in the mixer flows very slowly, and the exhaust gas is easy to form crystals on the surface of the urea nozzle or the inner wall of the mixing tube, causing the problem of pipeline blockage

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