Hydrodynamic model of pneumatic classification of powder materials

Abstract

A pneumatic circulating unit allows carrying out combined processes of powder production e.g. mixing, drying, grinding, and classification. The unit consists of a cylindrical-conical chamber with coaxial pipe. The circulating motion of powder material is realized by the injection of the last by the compressed air feeding through the nozzle block in the bottom of the unit, the conveying of powder through the pipe and the precipitation of particles into the packed bed after the separation stage. For the classification of particles by their sizes a built-in vane rotating classifier is applied. The main element of the classifier is the rotor, which generates a powerful centrifugal field around itself by its rotation and allows to achieve a high performance and sharp classification. The interpenetrating and interacting continua concept is implemented in which it is a suggested that more then one phase can exist at the same location at the same time. This suggestion depends on the ideas of time and space averaging. The phases "share" this space; and they may, as they move within it, interpenetrate. This model is analyzed.