IMPACT TYPE PNEUMATIC PULVERIZER AND PRODUCTION OF ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER

摘要

PURPOSE: To effectively pulverize a powder raw material by making the directions of a primary carrier air current on the upstream side of the outer peripheral impact surface in a pulverizing chamber and of a primary carrier air current on the downstream side different from each other. CONSTITUTION: On the impact surface of an impact member 4, a projection central part 14 protruded in the shape of a conic body is provided. Around the projection central part 14, an outer peripheral impact surface 15 for further subjecting the primarily pulverized material of the finely pulverized material pulverized by the projection central part 14 to secondary pulverization with impact is provided. The pulverizing chamber 8 is provided with a side wall 6 for subjecting the secondarily pulverized material subjected to secondary pulverization by the outer peripheral impact surface 15 to tertiary pulverization with impact. The side wall 6 has such a shape that a discharge port 5 is installed behind the impact member 6 in order to eliminate the channeling of a carrier air current and the directions of a primary carrier air current on the upstream side of the outer peripheral impact 7 surface 15 in the pulverizing chamber 8 and of a secondary carrier air current on the downstream side are made different from each other. In this way, a solid-gas mixture flow jetted from an accelerating pipe 3 is made to effectively collide with the impact member 9.