Sinking behavior

Settling behavior describes how particles, droplets, or agglomerates sink in a fluid (gas or liquid) under the influence of gravity. It is determined by density differences between particles and fluid, particle size and shape, fluid viscosity, and flow conditions.

In process engineering, settling behavior is an important parameter for separation processes, suspensions, sedimentation, fluidization, and pneumatic conveying. For powders, it influences, for example, the behavior in fluidized beds, mixers, reactors, and separators. Differences in settling behavior can lead to segregation, classification, or sedimentation.

Settling behavior is often described by the settling velocity, which in laminar flow can be approximately determined by Stokes' law. In technical applications, it is a central parameter for the design of separation and mixing processes.