Particles larger than about 0.3 micron are caused by their inertia not to follow the air current in the fibre bed. These particles are caught by the fibres and filtered out. For filtration with separating capacity down to 0.3 micron, filter systems acting on the basis of inertia effect are adequate.
Figure 4.5.2.1
During flow around the fibre, the line of gas flow circumvents the fibre in a curve and the heavy particle is caused by its inertia at higher speeds to proceed in a straight line so that, under favourable conditions, it can impinge upon the fibre. This effect is proportional to the square of the particle size and flow velocity. Temperature effect is reflected in the viscosity of the gas.
