In secondary dispersions, the droplets are so small they do not readily wet a surface or settle under gravity - typical drop sizes are in the range of 1 to 30 microns. In cartridge form with the liquid flowing from the center radially outwards, the Dusec Coalescer is made up from a selection of fiber materials

Adhesion forces capture intercepted droplets onto the fiber surface at selective points where clusters form until coalescence takes place and the droplets grow. Viscous drag forces increase until they exceed the adhesion forces, causing the droplets to separate from the fiber and move
further into the coalescer fiber bed, where the process is repeated.

  Eventually the droplets reach primary dispersion size - i.e. predominantly >60 microns. The outer layer of the cartridge is the same composite
construction as an Enhanced DC (primary) Coalescer which accelerates separation and avoids jetting and re-entrainment.