ABSTRACT
The study of particle flow concerns the relative motion between a particle and the fluid within which it is suspended. The particle is often considered to be a solid having a small diameter but equally, it may be considered as a small liquid droplet in a gas or, conversely, a small gas bubble in a liquid. Particles may be the product emanating from a process waste stream, such as dirt, dust, smoke, soot, fumes, aerosols, mists, and sprays. There are many examples of fluids that transport or carry particles. Industrial examples include settling tanks used for clarifying dirty water, centrifuges, dust handling and collection in electro-static precipitators, cyclones, particle size analysis, sprays of liquids including spray dryers and oil burners, and hydraulic flocculation. Most engineering design calculations are based on the terminal velocity of a particle. This is the point in which a single particle falling through a fluid under the influence of gravity or some other force reaches the point where it is balanced by frictional resistance and where there is no acceleration.
