Patent ID: 7530463

Claim:
A backwashable filtering device for thermoplastic plastics material, comprising: a housing having at least one feed channel configured as an inlet of the material to be filtered and at least one delivery channel configured as an outlet for the filtered material, at least one carrying body configured to be movable between a filtering and a backwashing position inside the housing, at least two nests of screens disposed inside carrying body, said nests of screens being configured for the filtering position and the backwashing position, a distribution chamber arranged on the inflow side of each nest of screens, said distribution chamber being fluidically connected to the at least one feed channel via inflow channels, a collecting chamber arranged on the outflow side of each nest of screens, said collecting chamber being fluidically connected to the at least one delivery channel via outflow channels, wherein in the backwashing position a portion of the filtered material flows: from the collecting chamber of one nest of screens, through a backwashing channel arranged in the carrying body, into the collecting chamber of another nest of screens, through the backwashed nest of screens, thus removing impurities from the backwashed nest of screens, into the distribution chamber of the backwashed nest of screens, into a backwashing outlet channel fluidically connecting the distribution chamber to at least one control body, into at least one control opening of the at least one control body, into a discharge channel of the at least one control body, and further out of the device, wherein the at least one control body: is movable relative to the carrying body and relative to other control bodies in the longitudinal or the rotational direction, is configurable for backwashing either an entire nest of screens or a selectable portion of the nest of screens, and is in the flow path only in the backwashing position, and out of the flow path in the filtering position.