Product Description Double piston backflush screen changer with 4 screen cavities for twin screw extruder zb-DP-BF series Automatic backflush screen changer( double piston screen changer with four working positions) In order to considerably increase the lifetime of the filter media GMACH offers automatic backflush screen changers. Working principle (backflush process)of this double piston backflush screen changer with 4 screen cavities for twin screw extruder These systems work as follows: When a pre-defined pollution degree is reached, the backflushing automatically starts. Then the contaminations from the screen pack are led out of the machine via a spillway. The contaminated backflush mass leaves the machine by means of heated backflush outlet pipes which are installed at the screen changer housing. There the small quantity may be removed or collected. With the-channel screen changers additional slide valves are used at the backflush channels. There is no interference of the process during backflushing. Features included 1,Continuously working melt filter 2,Four working stations 3,venting groove can discharge the gas mixed in the raw material 4, no interference during the process of backflushing 5,the screen cleaning reached 85% 6, long life span of the filtration screen pack/mesh , it owning to up to 100 times backflushing at most. The self-cleaning backflush screen changer finished