Abstract: The filter system includes a plurality of porous metal filter tubes and is used in a method for extracting high purity solid para-xylene crystals from a mother liquor feed slurry of mixed xylenes in liquid and crystal form utilizing a separation unit which includes a crystallization stage where the mother liquor slurry is cooled in at least one crystallizer to crystallize liquid para-xylene into solid crystals, an isomerization stage where xylenes, such as ortho-xylene and meta-xylene, are reacted over a catalyst bed to convert these xylenes into para-xylene, and a distillation stage where the mixed xylenes are separated from the impurities from which byproducts are obtained.