Mixer and exhaust aftertreatment system

1. A mixer for an exhaust aftertreatment system, comprising:

a shell, an injection port, a first baffle, a second baffle, a deflector, and an impactor, wherein

the first baffle is provided with a gas inlet, the second baffle is provided with a gas outlet, the first baffle and the second baffle are disposed opposite each other, and the first baffle, the second baffle and the shell provide a flow space for an exhaust gas to flow in the mixer; and

in the flow space, the first baffle, the shell, the deflector and the impactor provide a mixing space, the deflector comprises a first deflecting surface opposite the first baffle, the deflector is disposed adjacent to the impactor, and the impactor is disposed opposite the injection port for impacting a liquid injected from the injection port into the mixing space;

wherein the injection port, the first baffle, the deflector, and the impactor are arranged and shaped such that, during use and after the exhaust gas enters the flow space of the mixer through the gas inlet, most of the exhaust gas impacts with the liquid injected from the injection port and is driven by the liquid to the impactor, and the exhaust gas not impacting with and not being driven by the liquid flows to the deflector, under a drive of the flow velocity of the liquid nearby, is also deflected along the deflector to the impactor at which the exhaust gas divides into multiple flows.

2. The mixer of claim 1 , wherein the impactor has a circular arc shape.

3. The mixer of claim 1 , wherein the deflector further comprises a second deflecting surface and a third deflecting surface respectively extending from two lateral ends of the first deflecting surface toward the first baffle.

4. The mixer of claim 3 , wherein the first deflecting surface is a circular arc surface, and the second deflecting surface and the third deflecting surface are planes parallel to each other.

5. The mixer of claim 1 , wherein the gas inlet and the injection port are disposed on the same side with respect to an axis of the flow space.

6. The mixer of claim 1 , wherein a radial gap is provided between the impactor and an inner wall of the shell, the radial gap and the first baffle jointly provide a heating space, and the first baffle is provided with a gas inlet opening for the exhaust gas to flow into the heating space.

7. The mixer of claim 1 , wherein the first baffle and/or the second baffle have a plurality of plug welds, and the impactor and/or the deflector are connected to the first baffle and/or the second baffle via the plug welds.

8. The mixer of claim 1 , wherein the liquid injected into the mixing space is a urea solution.

9. An exhaust aftertreatment system, comprising a mixer, wherein the mixer comprises:

a shell, an injection port, a first baffle, a second baffle, a deflector, and an impactor, wherein

the first baffle is provided with a gas inlet, the second baffle is provided with a gas outlet, the first baffle and the second baffle are disposed opposite each other, and the first baffle, the second baffle and the shell provide a flow space for an exhaust gas to flow in the mixer; and

in the flow space, the first baffle, the shell, the deflector and the impactor provide a mixing space, the deflector comprises a first deflecting surface opposite the first baffle, the deflector is disposed adjacent to the impactor, and the impactor is disposed opposite the injection port for impacting a liquid injected from the injection port into the mixing space;

wherein the injection port, the first baffle, the deflector, and the impactor are arranged and shaped such that, during use and after the exhaust gas enters the flow space of the mixer through the gas inlet, most of the exhaust gas impacts with the liquid injected from the injection port and is driven by the liquid to the impactor, and the exhaust gas not impacting with and not being driven by the liquid flows to the deflector, under a drive of the flow velocity of the liquid nearby, is also deflected along the deflector to the impactor at which the exhaust gas divides into multiple flows.

10. The exhaust aftertreatment system of claim 9 , wherein the impactor has a circular arc shape.

11. The exhaust aftertreatment system of claim 9 , wherein the deflector further comprises a second deflecting surface and a third deflecting surface respectively extending from two lateral ends of the first deflecting surface toward the first baffle.

12. The exhaust aftertreatment system of claim 11 , wherein the first deflecting surface is a circular arc surface, and the second deflecting surface and the third deflecting surface are planes parallel to each other.

13. The exhaust aftertreatment system of claim 9 , wherein the gas inlet and the injection port are disposed on the same side with respect to an axis of the flow space.

14. The exhaust aftertreatment system of claim 9 , wherein a radial gap is provided between the impactor and an inner wall of the shell, the radial gap and the first baffle jointly provide a heating space, and the first baffle is provided with a gas inlet opening for the exhaust gas to flow into the heating space.

15. The exhaust aftertreatment system of claim 9 , wherein the first baffle and/or the second baffle have a plurality of plug welds, and the impactor and/or the deflector are connected to the first baffle and/or the second baffle via the plug welds.

16. The exhaust aftertreatment system of claim 9 , wherein the liquid injected into the mixing space is a urea solution.