Affinity of the main separation barameters in laminar and transient regimes

Abstract

The main determining parameters of the process are the separation curves. They can be of two types. Firstly, these are graphical dependencies in coordinates, linking the value of extraction of a narrow size class into a fine product with the flow rate. Secondly, graphs linking the extraction with the particle sizes at a fixed flow rate. All information about the process is concentrated in these curves. Therefore, their mathematical analysis based on physical concepts is the basis for understanding the mechanism of the process and developing methods for its calculation. An attempt was made to apply partial differential equations similar to the Navier-Stokes equations to the classification process. It gave a positive result for turbulent modes of moving flows. Based on the analysis of these equations, the Froude criterion was determined, which ensured reliable affinity of the separation curves in turbulent modes. It should be noted that turbulent modes are typical only for the separation of relatively large powders. When separating fine powders, the flow rates decrease and under these conditions the Froude criterion does not provide affinity of the separation curves. The task is to determine the affinity criteria for separating such powders in laminar and transitional flow regimes. Ill. 4. Ref. 3.