Sieve changing unit, comprises a housing with at least two sieve bolt receiving bores, melt inlet and outlet regions and branch channels which are connected to the bores

摘要

A sieve changing unit for continuously filtering a plastic melt stream, comprises a housing (10) with at least two sieve bolt receiving bores, a melt inlet region (14) which splits into branch channels (11) leading to the bores and a melt outlet region (15). A sieve changing unit for continuously filtering a plastic melt stream, comprises: (1) a housing (10) with at least two sieve bolt receiving bores; (2) a melt inlet region (14) which splits into branch channels (11) leading to the bores; and (3) a melt outlet region (15). Outlet channels (12) from the bores flow into the outlet region. The unit also has a return flow channel (13) and at least two sieve bolts (20,30) which can slide in the bores. Sieve elements are located in sieve chambers and each chamber splits into two bolt flow channels behind the sieve element. The sieve chamber is opposite the return flow channel when in the back flushing position. The bolt flow channels are connected to the outer circumference of the bolt via a groove. The bolt flow channels have the same cross section.