Filtration facilitated by filter aids

Abstract

To the producers of liquid products; in which class are included manufacturers of chemicals, dyes, glues and adhesives, paints and varnishes, beverages, sugars and syrups, animal, vegetable and mineral oils, and many other commodities; one of the major problems of production is clari,fication, i.e. the manufacture of a clear, brilliant and pure liquid, free from suspended, emulsified or flocculent impurities. These impurities may be present in particles of sizes varying from those quite easily discernible to the unaided eye, down to the colloidal size which puts the impurity almost, but not quite into solution in the liquid medium, resulting in a marked departure from clarity and brilliance in the appearance of the product. The impurities which may occur in any liquid product vary, of course, according to the nature of the product, but those most frequently occurring . in organic liquids of vegetable origin consist chiefly of resins, gums, albuminoids, etc., which are of such amorphous nature that they are not removable by settling or simple filtration. They can sometimes be eliminated by centrifugation, but where the volume handled is large, the investment cost of centrifugal equipment is sometimes prohibitive, the power charges being also a handicap when, as above stated, the volume is large.