Filter unit for liquid plastics has filter screen chambers spaced to ensure that when a filter screen carrier is moved transverse to flow a melt connection always exists between feed and take-off lines

摘要

A transverse moving filter screen carrier(4) has two or more filter screens(5,6), each located in a filter screen chamber(7,8). Each chamber tapers in the flow direction to form an extended outlet channel(9) leading to a take-off channel(3) which at its free end is circular. A transverse moving filter screen carrier(4) has two or more filter screens(5,6), each located in a filter screen chamber(7,8). Each chamber tapers in the flow direction to form an extended outlet channel(9) leading to a take-off channel(3) which at its free end is circular. The spacing of the filter screen chambers in the transverse movement direction of the filter carrier is such that when a filter screen is pushed out of the external housing(1) another moves into a position which ensures a connection always remains between a melt feed channel(2) and the take-off channel. The feed channel(2) is divided into two branches, each comprising two part channels(11,12;14,15) which lead to the filter elements(5,6). The feed channel is machined in a plate which is mounted on the housing. The take-off channel(3) is machined in an additional plate(10) which is mounted on the housing(1). Both the outlet channel(9) and take-off channel may consist of a row of single bores.