PURPOSE: To easily and inexpensively improve the crushing performance of a jet mill by providing an automatic valve which is repeatedly opened and closed on this side of a nozzle for jetting a crushed raw material at high speed along with pressure air and intermittently supplying the pressure air to the nozzle.
CONSTITUTION: An accelerating pipe 2 for jetting a granular raw material at high speed is inserted into a casing 1, a raw material feed port 3 and a nozzle 4 are provided in an ejector 2a, and an automatic valve 5, which is repeatedly opened and closed, is connected to the nozzle 4. In this case, one end of the valve 5 is opened, the other end is closed by a cylindrical valve 6, and an open hole 7 is bored in the periphery of the cylindrical valve 6. Further, a rotating shaft 9 and a pulley 10 are furnished to the closed end and connected to a motor 13 through a belt 11 and a pulley 12. The cylindrical valve 6 is rotated and communicated with the nozzle 4, when the open hole 7 is matched with the discharge port 8 of the valve 5. Consequently, the pressure air is intermittently discharged, and the crushing performance of the jet mill is improved.
HATORI TOSHIO
URAYAMA KIYOSHI
KATO MASASHI
