Theory of Filtering
A complete solution through theorical procedures of of filtering comes out the theory to be extremely difficult. There are too many imponderable factors which can come up and which consist especially in the nature of the solid particles contained within the liquid and and in the physical characteristic of the liquid itself Moreover, the successive stopping of the particles down to a certain minimum diameter is not actually caused by the filtering septum, but rather by the initial deposit of solid material on the filter. We can consider the panel of thickness 1 as a whole of capillary tubes through which the liquid passes with a velocity which is maintained within the laminar rante. For this,then, Poiseuille s law is valid: