Abstract: A classifier for powdery material has a cylindrical casing formed at an upper portion thereof with an inlet port for introducing the material to be classified into the casing in a tangential direction of an inner wall thereof. The casing has a conical portion formed in its bottom end with an opening connected to a discharge pipe for discharging coarse particles. Further, an outlet pipe protrudes into the casing through its top. The inlet port is located higher than the bottom end of the outlet port. An externally-driven vane wheel is provided under the outlet pipe in a concentric relationship with respect to the casing.

Abstract: The present invention relates to a method and apparatus for pulverizing a material to produce a fine powdery material such as silica powder as a material for a filler for sealing semiconductors. It has a shell and a screw shaft mounted in the shell. A disk having an inverted conical bottom surface is coaxially secured to the bottom of the screw shaft. The disk serves to protect the blade of the screw shaft from wear. Also owing to the inverted conical bottom surface, a centripetal force acts on the screw shaft while in rotation, thus preventing it from running out of true. By providing a plurality of screw shafts in the shell, the fluid in the shell flows in a complicated manner, thus increasing the pulverizing efficiency. A partitioning plate formed with a hole in the upper or lower part thereof may be provided between the adjacent screw shafts to minimize the possibility of shortcircuiting of the material from the inlet of the shell to its outlet.

Abstract: This invention relates to an apparatus for pulverizing quick lime into a slurry form. It has a vertical shell and a rotary shaft mounted in the shell. An agitating layer and a pulverizing layer are formed in the shell at its upper and lower portions, respectively. The material fed from top of the shell is agitated and melted into smaller particles in the agitating layer and then pulverized into fine particles in the pulverizing layer. The fine particles are discharged from a top or middle of the shell. A discharge pipe is provided so as to extend upwardly from the discharge port at the middle of the shell. An agitator may be provided in the discharge pipe. The material to be pulverized is prevented from going from the inlet directly to the outlet without passing through the pulverizing layer.

Abstract: A method and apparatus for pulverizing a material such as sand to a desired particle size. The apparatus has a pulverizing shell in which the material to be pulverized is fed and pulverized. The pulverized fluid-carried material overflows the shell so as to be fed into a settling classifier, where the coarser material settles and is discharged through its bottom opening back into the shell for repulverization. The finer material overflows the classifier and is fed to an intermediate bin, which has its bottom connected to the shell through a valve. When the bin is filled up with the material, the valve is opened so that the material in the bin is returned to the shell. The material is thus circulated through the shell, classifier and intermediate bin. The shell is adapted to be alternately connected to the intermediate bin and a product collector bin by a changeover valve.

Abstract: An improved vertical grinding mill is provided which has a shell, a vertical helically bladed shaft rotatably mounted in the shell, a collector, a drive for the shaft, and a fan or a pump. The shaft is hollow and its lower end is open at the bottom of the shell. This assures a uniform distribution of the material to be treated, the grinding medium and the product particles and thus high production efficiency.