Patent ID: 8017002

Claim:
Device for filtering a fluid, particularly a liquefied plastic, the device comprising: a housing ( 1 ) of a filter changer, the housing having a feed channel ( 2 ) and a discharge channel ( 3 ); a filter slide ( 4 , 4 a ) that is arranged in the flowpath of the fluid to be filtered and is slidable transverse to a flow direction of the fluid, so as to open and close a flowpath between the feed channel and the discharge channel; at least one filter element ( 5 , 6 ), each one filter element arranged in a corresponding filter chamber ( 7 , 8 ) in the filter slide; a storage space ( 11 ) arranged in the flowpath of the feed channel, upstream of the filter slide, the storage space equipped with a displacing piston ( 10 ); and a pressure generator ( 12 ) arranged in the flowpath of the feed channel, wherein, during normal operation, a pressure generator output is at a first operating level; a sensor (S) associated with the discharge channel; and a controller adapted to affect the operation of the displacing piston and the pressure generator in response to a signal from the sensor; wherein, when a pressure drop is sensed at the discharge channel, the pressure generator output is increased to a second operating level that is higher than the first operating level, such that interaction of the pressure generator and the displacing piston counterbalances a pressure drop in the discharge channel.