Placing controlled porosity blockages in unwanted pore sizes of separatingdevice

Abstract From the Canadian patent

Pores that are smaller than or larger than a predetermined range of pore sizes in a porous membrane barrier are blocked with a controlled porosity blocking agent. The pores are first filled with a liquid so as to remove any air therein and then subjected to a transmembrane gas blow a pressure which will clear the larger pores of the liquid. The larger gas filled pores or the smaller liquid filled pores are then blocked by a blocking agent using a polymer-forming chemical reaction a precipitate-forming chemical reaction or the physical deposition of solids.