Exhaust gas after-treatment mixing device and package therefor

An exhaust gas after-treatment package comprising a first after-treatment carrier assembly, a second after-treatment carrier assembly downstream of the first after-treatment carrier assembly, and a third after-treatment carrier assembly downstream of the second after-treatment carrier assembly, wherein the exhaust gas after-treatment package further comprises an exhaust gas after-treatment mixing device located between the second after-treatment carrier assembly and the third after-treatment carrier assembly, and the exhaust gas after-treatment mixing device comprises:

• a casing comprising a mounting seat for mounting a urea injector to spray urea;
• and
• a mixing assembly located in the casing, the urea being sprayed to the mixing assembly, the mixing assembly comprising:
• a first plate having a first inlet and a second inlet respectively located at two sides of the first plate;
• a second plate;
• and
• a mixer located between the first plate and the second plate, wherein:
• the mixer comprises a first space in communication with the first inlet, a second space in communication with the second inlet, and a third space located between the first space and the second space, a top portion of the first space being in communication with the third space, and a top portion of the second space being also in communication with the third space;
• wherein
• the mixer comprises a first raised portion protruding from the bottom into the third space and a second raised portion located below the first raised portion, so that a fourth space is formed between the first raised portion and the second raised portion;
• wherein
• the first raised portion comprises a first side and a second side, the first side comprises a plurality of first perforations to communicate the third space with the fourth space, and the second side comprises a plurality of second perforations to communicate the third space with the fourth space;
• wherein
• the second plate is provided with an outlet in communication with the fourth space.