FILTERING DEVICE Russian patent published in 2002 - IPC

FIELD: filtration technique. SUBSTANCE: proposed filtering device includes container with intake passage for introduction of liquid to be treated, circular multi-layer sectional structure made from lattice members which is filled preliminarily with filtering material and provided with outlet passage for discharge of treated liquid. Sectional structure made from lattice members includes three or more cylindrical lattice members of different diameters; lattice members are located coaxially in container and their axes run vertically. Circular gap is formed between respective cylindrical lattice members. Each circular gap between cylindrical lattice members is filled with one or more filtering materials used as different filtering fractions. Outer cylindrical lattice member of sectional structure is just cylindrical lattice member with wedge-shaped grates and slot and hole on external surface which are widened radially from slot inside lattice member. EFFECT: enhanced efficiency of filtration at reduced frequency of flushing operations. 9 cl, 19 dwg