CASSETTE FILTER Russian patent published in 2001 - IPC

FIELD: purification of natural water and sewage, specifically, purification of water from iron and tertiary treatment of sewage cleared from hard impurities in advance. SUBSTANCE: cassette filter has frame housing separable cassettes with filtering elements of elastic porous material. Cassettes are mounted in parallel one another for vertical reciprocating motion. Each cassette has flexible screens interconnected by elastic couplings between which filtering material in placed, pressing out rolls are located in intervals between cassettes. Pressing out rolls come in the form of perforated cylinders coaxially positioned one inside another and communicating with pipe-line for removal of washing water. Outer cylinder is perforated and is mounted for rotation along direction of flow of treated fluid in cassettes carrying separate pieces of elastic porous material. Impermeable diaphragm partially shutting off filtering element of cassette secures uniform filtration of fluid over entire area of this element. During conditioning of iron-containing underground water and tertiary treatment of sewage cleared from hard impurities in advance fouling is sorbed in pores of elastic filtering material and its regeneration is carried out without disconnection of filter. In this case usage of purified water for regeneration is prevented and discharge of waste water is substantially decreased. EFFECT: improved operational characteristics of filter. 2 dwg