▎ 摘　　要

NOVELTY - A filtering device for filtering a fluid, containing dissolved and optionally colloidal substances, and/or further impurities like bacteria and virus, comprises at least one first filter unit (12) to remove substances in a first filtering step by membrane filtration, where removed substances have molecular weight above a defined limit value; second filter unit (19) for treating permeate of first filtering unit and disposed downstream of first filtering unit; and third filter unit (20) comprising porous membrane, through which the fluid to be filtered flows in a cross-flow, where third unit is disposed downstream of second unit. USE - A filtering device for filtering fluid containing dissolved and optionally colloidal substances, and further impurities like bacteria and/or virus, where liquid is selected from beverages, pharmaceutical products, chemical products, and/or cosmetic products, for the purpose of recovery of flavorings (terpenes), recovery of organic acids (malic acid), filtration of sugars, purification of hemicellulosic hydrolysates, recovery of polyphenolic substances, purification of drugs as antipyretics, selection or purification of natural drug-like substances, recovery or purification of resveratrol, recovery of plant or algae extracts, and filtration or purification of glycolic, salicylic, or retinoic acid (all claimed). ADVANTAGE - The filtering device is capable of effectively filtering the fluid containing dissolved and optionally colloidal substances with high efficiency, and prevents clogging of the filter unit. DETAILED DESCRIPTION - A filtering device for filtering a fluid, containing dissolved and optionally colloidal substances, and/or further impurities like bacteria and virus, comprises at least one first filter unit (12) to remove substances in a first filtering step by membrane filtration, where removed substances have molecular weight above a defined limit value; second filter unit (19) for treating permeate of first filtering unit and disposed downstream of first filtering unit; and third filter unit (20) comprising porous membrane, through which the fluid to be filtered flows in a cross-flow, where third unit is disposed downstream of second unit. The second filter unit comprises a filter bed comprising at least one filter material selected from graphene, modified graphene (fully or partially exfoliated), graphite, activated carbon, chemical carbon or chemically activated powdered or granular carbon, vegetable carbon, vegetable carbon of organic origin activated either chemically or via steam, zeolite compound, natural or synthetic polymers, nanoporous polymeric materials, polyvinylpolypyrrolidone (PVPP), polyvinylpyrrolidone (PVP), polyether sulfone (PES), polysulfone (PS), polyvinylidene fluoride (PVDF), polypropylene (PP), (polymeric or metal) foam, borophene, silicone, phosphorene, hexagonal boron nitride, white graphite, germanene, stannine, titanium oxide, diatomaceous earth, iodine pellets, nanoiodine pressed into pellets, noble metals, gold, platinum, silver, other metals or alloys, textile fiber, yarn, thread, fiber, woven or non-woven fabric, glass, ceramic material, and/or sol-gel, where these various media and substances may be associated, combined, or blended with each other via different techniques, particularly by impregnation, coating, doping, functionalization, or activation of materials. An INDEPENDENT CLAIM is included for process for filtering a fluid. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of a filtering device. First filter unit (12) Product collection tank (14) Receptacle (18) Second filter unit (19) Third filter unit (20)