Aerosol Transport – Inertia

:: Section 9

Inertial Impaction

I. Principle

The curvelinear motion is important in separating particles. Take the nozzle in the figure below for example.

The gas stream passes through the narrow nozzle at a high speed. When an obstacle (i.e. impaction plate in this case) is in front of the stream, the stream can easily make a turn to avoid the obstacle. Particles in the stream, however, may have a different fate. Larger particles, due to their higher inertia, won't be able to follow the gas stream well. Therefore, they will deviate from the gas stream, and they will impact on the plate.