Counter-impact Jet Milling Mechanism and Jet Mill Using the Same

A counter-impact jet milling mechanism, comprising a housing (1), rotating members (8) capable of rotating around an axis being arranged in the housing (1), and a material inlet and a material outlet being arranged on the housing (1), and characterized in that at least 4 circumferentially distributed grinding areas (2-1, 2-2, 2-3) are arranged in the rotating members (8), a channel (23) is formed between the outer edge of each of the grinding areas and the inner wall of the housing (1), through paths (3) are formed at both ends of each of the channels (23), a material-containing airflow is defined as a two-phase flow which is ejected into negative pressure zones (6) of the corresponding grinding areas through the through paths (3), negative pressure blades (4-1, 4-2, 4-3, 4-4), positive pressure blades (5-1, 5-2, 5-3, 5-4, 5-5, 5-6, 5-7) and two-phase flow diverters are arranged in each of the grinding areas, the sectional area of a stress surface of each of the positive pressure blades is N times that of each of the through paths (3), N>1, negative pressure zones (6) are formed between adjacent negative pressure blades and between the negative pressure blades and walls of the grinding areas, positive pressure zones (7) are formed between adjacent positive pressure blades and between the positive pressure blades and walls of the grinding areas, the positive pressure zones (7) are arranged at the left and right sides of any of the negative pressure zones (6), the negative pressure zones (6) are arranged at the left and right sides of any of the positive pressure zones (7), wherein the axial direction of the rotating members (8) is defined as the front-back direction, and the horizontal direction perpendicular to the front-back direction is defined as the left-right direction;

• when the rotating members (8) spinning, the negative pressure zones (6) produce negative pressure with the rotation of the negative pressure blades, and the positive pressure zones (7) produce positive pressure with the rotation of the positive pressure blades, thus producing airflows;
• the two-phase flow formed by the material-containing airflow at least flows out of the positive pressure zone (7) of the current grinding area from the left-right direction;
• the two-phase flow discharging from the right out of the positive pressure zone (7) of the current grinding area is ejected into the negative pressure zone (6) on the right side of the positive pressure zone (7) and adjacent thereto through the channel (23) and the through paths (3), and the negative pressure zone (6) is arranged in the current grinding area;
• the two-phase flow flowing to the left out of the positive pressure zone (7) of the current grinding area is ejected into the negative pressure zone (6) on the left side of the positive pressure zone (7) and adjacent thereto through the channel (23) and the through paths (3), and the negative pressure zone (6) is arranged in the next grinding area adjacent to the left side of the current grinding area;
• and the two-phase flow flowing into the negative pressure zone (6) is diverted by a two-phase flow diverter to the positive pressure zone (7) of the same grinding area, forming a circulation;
• For the same negative pressure zone (6), two two-phase flows are ejected into the negative pressure zone (6) through the left and right through paths (3) respectively, the speed of the two-phase flows ejected through the through paths (3) is N times that of total airflows produced by the positive pressure blades, the two two-phase flows ejected through the left and right through paths (3) respectively form a counter-impact jet at the inlet of the negative pressure zone (6), resulting in collision and crushing of materials in the two streams of the two-phase flows.