Abstract: Cross flow filter device comprising a longitudinal first filter element (1) having a first width (w1) and a longitudinal central axis (8), a longitudinal second filter element (2) having a second width (w2) and being longitudinally installed substantially concentrically inside said first filter element (1), a housing (3) surrounding said first filter element (1), said cross flow filter device having respectively a raw material inlet (4), a concentrate outlet (5), and a first filtrate outlet (6) connected to said first filter element (1). The ratio between the second width (w2) and the first width (w1) is 65%, preferably at least 70% and more preferably about 75%.

Abstract: Cross flow filter device comprising a longitudinal first filter element (1) having a first width (w1) and a longitudinal central axis (8), a longitudinal second filter element (2) having a second width (w2) and being longitudinally installed substantially concentrically inside said first filter element (1), a housing (3) surrounding said first filter element (1), said cross flow filter device having respectively a raw material inlet (4), a concentrate outlet (5), and a first filtrate outlet (6) connected to said first filter element (1). The ratio between the second width (w2) and the first width (w1) is 65%, preferably at least 70% and more preferably about 75%.

Abstract: A filter system includes a back-flush unit to back-flush a filter unit, the filter including a housing and a first filter element separating a raw material compartment from a filtrate compartment. The filter unit has a first filtrate outlet and is in communication with the filtrate compartment. The back-flush unit includes a first expansion vessel. The filter system also includes a pressurizing system to pressurize the filtrate when in the second compartment. The filter unit includes a second filtrate outlet spaced apart from the first filtrate outlet. The first filtrate outlet is in communication with the filtrate compartment and with the expansion vessel by a first back-flush nozzle.

Abstract: The invention concerns a method for producing a lens (6), one side of which (9, 10) has a complex multifocal or progressive or regressive multifocal surface (7). This method comprises the following steps: 1—forming a mold (1) composed of two parts (2, 3), each having an imprint (4, 5); 2—machining at least one of the imprints (4, 5), via a first machining with a digitally controlled, micrometrically precise machine using a computer file of tool movement points defining a complex surface (7), and a nanometric finish machining with a digitally controlled diamond turning tool; 3—injecting a thermoplastic polymer-based material into the mold (1). The invention also concerns a complex lens made of injected thermoplastic polymer, particularly methyl polymethacrylate.

Abstract: Cross flow filter device comprising a longitudinal first filter element (1) having a first width (w1) and a longitudinal central axis (8), a longitudinal second filter element (2) having a second width (w2) and being longitudinally installed substantially concentrically inside said first filter element (1), a housing (3) surrounding said first filter element (1), said cross flow filter device having respectively a raw material inlet (4), a concentrate outlet (5), and a first filtrate outlet (6) connected to said first filter element (1). The ratio between the second width (w2) and the first width (w1) is 65%, preferably at least 70% and more preferably about 75%.

Abstract: Filter system comprising a back-flush unit (B) provided to back-flush said filter unit (F). The filter unit (F) has at least a housing (3) and at least a first filter element (1) separating a raw material compartment (34) from a filtrate compartment (35). The filter unit (F) has a first filtrate outlet (6) and is in communication with the filtrate compartment (35). The back-flush unit (B) comprises a first expansion vessel (17). The filter system also comprises pressurising means (11,12,13,23) to pressurise the filtrate when in the second compartment. The filter unit (F) also comprises a second filtrate outlet (7) different and spaceded apart from said first filtrate outlet (6). The first filtrate outlet (6) is in communication with the filtrate outlet (6). The first filtrate outlet (6) is in communication with the filtrate compartment (35) and with the expansion vessel (17) by means of a first back-flush nozzle (29).