| 摘要 |
<p>The present invention provides a pneumatic impact pulverizer, a fine powder production apparatus and a process of producing toner for developing electrostatic images. According to the present invention, a pneumatic pulverizer comprises an accelerating tube for carrying and accelerating powder to be pulverized with high-pressure gas and a pulverizing chamber for pulverizing the powder to be pulverized. Herein, the back end of the accelerating tube is provided with a pulverization powder feed port for feeding powder to be pulverized to the accelerating tube, the pulverizing chamber is equipped with an impact member having an impact surface opposed to the opening plane of the outlet of the accelerating tube, the pulverizing chamber has a side wall against which the powder to be pulverized that has been pulverized with the impact member collides to further pulverize, and the closest distance from the side wall to a margin of the impact member, L1, is shorter than the closest distance from the front wall of the pulverizing chamber opposed to the impact surface to the margin of the impact member, L2. Thus, the pulverizer successfully prevents pulverized powder from fusing, coagulating, and getting coarser, and from causing localized abrasion of an impact surface of an impact member and of an accelerating tube. Thereby, pulverization efficiency improves. This realizes continuous stable operation and thus provides toner showing sharp distribution of particle sizes. <IMAGE></p> |
