Abstract: A screw conveyor for mixing a gas into a liquid and a mixing apparatus including the screw conveyor are disclosed. The screw conveyor includes a helical element having a screw core having a longitudinal axis, a primary spiral including a plurality of primary coils and a secondary spiral supported on the primary spiral and including a plurality of secondary coils. The primary spiral and secondary spiral include a plurality of primary coils and second coils in succession. The secondary spiral is slidably rotatable on the primary spiral. The screw conveyor includes at least one deflector spanning each pair of consecutive primary and secondary coils, wherein the longitudinal axis of each deflector is parallel to the longitudinal axis of the screw core, the deflectors are simultaneously rotatable while maintaining their longitudinal axis parallel to the longitudinal axis of the screw core.

Abstract: A liquid (2), such as wastewater, is filtered using a liquid-permeable filtering element (9) having first and second faces (10, 11) so as to produce filtered liquid (4) having total suspended solids of no more than 10 mg/L. The method comprises cycling the liquid-permeable filtering element through the liquid whereby, in a first position, an area of the first face of the filtering element is subjected to liquid under pressure and a pressure across the filtering element is greater than 0 and less than or equal to 5.9 kPa (60 cm H2O), and, in a second position, the area is not subjected to liquid under pressure or is subjected to liquid at a lower pressure, and solids accumulated on the first face of the filtering element can be removed by directing at least one jet at the second face of the filtering element through the filtering element towards the first face.

Abstract: A screw conveyor (90, 91, 92) for a drying apparatus (1) or a fermentation system is disclosed. The screw conveyor includes a helical element (11) having a longitudinal axis (x) and including a primary spiral (12) and a secondary spiral (13) mounted on the primary spiral and rotatable with respect to the primary spiral around the longitudinal axis; and a set of elongated members (20) spanning the primary and secondary spirals.

Abstract: A liquid (2), such as wastewater, is filtered using a liquid-permeable filtering element (9) having first and second faces (10, 11) so as to produce filtered liquid (4) having total suspended solids of no more than 10 mg/L. The method comprises cycling the liquid-permeable filtering element through the liquid whereby, in a first position, an area of the first face of the filtering element is subjected to liquid under pressure and a pressure across the filtering element is greater than 0 and less than or equal to 5.9 kPa (60 cmH2O), and, in a second position, the area is not subjected to liquid under pressure or is subjected to liquid at a lower pressure, and solids accumulated on the first face of the filtering element can be removed by directing at least one jet at the second face of the filtering element through the filtering element towards the first face.

Abstract: A device for separating and lifting solids from waste water has a stationary drum provided with a first filter screen and a screw conveyor. An auger shaft has a lower portion located inside the stationary drum, which is partially surrounded by a second filter screen. The lower portion is connected to a cleaning apparatus of the first filter screen formed by a plurality of comb-holder arms mounted on a cross shaped element. The comb-holder arms are integral at the opposite end to an anti-skid ring sliding in a sliding seat integral with the support frame. Each comb-holder arm has an elongated comb facing the first filter screen and in contact with the first filter screen. The comb-holder arms are connected to the auger shaft by an epicyclic secondary gear.

Abstract: A device for separating and lifting solids from waste water has a stationary drum provided with a first filter screen and a screw conveyor. An auger shaft has a lower portion located inside the stationary drum, which is partially surrounded by a second filter screen. The lower portion is connected to a cleaning apparatus of the first filter screen formed by a plurality of comb-holder arms mounted on a cross shaped element. The comb-holder arms are integral at the opposite end to an anti-skid ring sliding in a sliding seat integral with the support frame. Each comb-holder arm has an elongated comb facing the first filter screen and in contact with it. The comb-holder arms are connected to the auger shaft by means of an epicyclic secondary gear.