A feeding arrangement comprising a transportation means (3) for transportation of material from a material supply to at least a first chute (7) and a second chute (8), a plug screw feeder (11) for feeding the material to the treatment stage. The plug screw feeder (11) is provided with a first inlet opening (12) connected to the first chute (7), which first chute (7) is provided between the transportation means (3) and the plug screw feeder (11). Further, the transportation means (3) comprises at least selectively openable first and second outlets (4, 5) arranged at different axial positions along the transportation means (2), which first outlet (4) is in connection with the first chute (7) and the second outlet (5) is in connection with the second chute (8).

A system for treatment of a biomass material and a method for transporting biomass material, said system comprising: —a first vessel (3) in which said biomass material is treated at a first pressure;—a second vessel (5) in which said biomass material is collected at a second pressure which is lower than the first pressure; and—a transporting pipe (7) connecting an outlet (9) of the first vessel (3) with an inlet (11) of the second vessel (5) for transporting the biomass material from the first vessel to the second vessel, wherein said transporting pipe (7) comprises at least one restriction (13) for control of the flow in the transporting pipe and hereby providing a pressure drop to the transported biomass material, wherein at least one of said at least one restriction (13) is provided somewhere in the second half of the length of the transporting pipe (7) starting from the first vessel (3) and ending at the second vessel (5).

A system for treatment of a biomass material and a method for transporting biomass material, said system comprising: —a first vessel (3) in which said biomass material is treated at a first pressure;—a second vessel (5) in which said biomass material is collected at a second pressure which is lower than the first pressure; and—a transporting pipe (7) connecting an outlet (9) of the first vessel (3) with an inlet (11) of the second vessel (5) for transporting the biomass material from the first vessel to the second vessel, wherein said transporting pipe (7) comprises at least one restriction (13) for control of the flow in the transporting pipe and hereby providing a pressure drop to the transported biomass material, wherein at least one of said at least one restriction (13) is provided somewhere in the second half of the length of the transporting pipe (7) starting from the first vessel (3) and ending at the second vessel (5).

The invention relates to a system and a method for feeding comminuted cellulosic material from a low-pressure zone (P.sub.L) to a high-pressure zone (P.sub.E) with at least 1 bar higher pressure. The invention uses a screw 7 feeder having a feeding screw (1) arranged in a feeding pipe (2). Back blow pulses from the high-pressure zone that may blow 7 backwards from the high-pressure zone (P.sub.E) can be ventilated (Vent.sup.II) in an intermediate part (P.sub.c) of the feeding pipe (2), and thus not reach the low 7-pressure zone.

The invention relates to a system and a method for feeding comminuted cellulosic material from a low-pressure zone (P.sub.L) to a high-pressure zone (P.sub.E) with at least 1 bar higher pressure. The invention uses a screw 7 feeder having a feeding screw (1) arranged in a feeding pipe (2). Back blow pulses from the high-pressure zone that may blow 7 backwards from the high-pressure zone (P.sub.E) can be ventilated (Vent.sup.II) in an intermediate part (P.sub.c) of the feeding pipe (2), and thus not reach the low 7-pressure zone.

The invention relates to a system (1) comprising a feeding device (2) comprising a channel (6) having an inlet (8) and an outlet (10) and a feed screw (12) for conveying biomass material through the channel. The feed screw comprises a screw flight (12b) that extends from a first end (12c) to a second end (12d) and is adapted to form a gas impermeable plug of biomass. The system comprises at least one primary measuring unit (14; 16) adapted to continuously measure a primary variable indicative of the gas permeability of the plug, which primary measuring unit is connected to said feeding device between the first end of the screw flight and the outlet; and a control unit (3) adapted to use said primary variable values to monitor the gas permeability of the plug. The invention also relates to a method for preventing blow back in the above described system.

The invention relates to a system (1) comprising a feeding device (2) comprising a channel (6) having an inlet (8) and an outlet (10) and a feed screw (12) for conveying biomass material through the channel. The feed screw comprises a screw flight (12b) that extends from a first end (12c) to a second end (12d) and is adapted to form a gas impermeable plug of biomass. The system comprises at least one primary measuring unit (14; 16) adapted to continuously measure a primary variable indicative of the gas permeability of the plug, which primary measuring unit is connected to said feeding device between the first end of the screw flight and the outlet; and a control unit (3) adapted to use said primary variable values to monitor the gas permeability of the plug. The invention also relates to a method for preventing blow back in the above described system.

Disclosed is a screw feeder (10) comprising a pipe (3) enclosing a feed screw 4 arranged on a rotatory shaft (5) running parallel with the length direction of the pipe (3), said pipe (3) further comprising a number of dewatering holes (6). The screw feeder (10) also comprises a number of anti-rotation bars (7) provided on, and extending along, the inside of said pipe (3), said anti-rotation bars (7) protruding in a direction towards said feed screw (4), and an inlet (1) for receiving a solid-liquid mixture arranged at a first end of said pipe (3), and an outlet (2) arranged at a second end of said pipe (3) for discharging an at least partially dewatered solid from said pipe (3). The pipe (3) includes at least one longitudinal pipe section (31) having a first peripheral zone (9) provided in the vertically lower area of said longitudinal pipe section (31) and provided with dewatering holes (6) but no anti-rotation bars (7) and a second peripheral zone (90) provided in the vertically upper area of said longitudinal pipe section (3) provided with anti-rotation bars (7), the overall pipe profile of said pipe section (31) is composed of two differently shaped pipe profiles, a first pipe profile (P1) and a second pipe profile (P2), said first pipe profile (P1) defining the shape of the first peripheral zone (9) and is a profile selected from a square shaped profile, a profile having a partly circular cross-section with a squashed end or a circle segment remove or a partly elliptically shaped profile, and the second pipe profile (P2) defining the shape of the second peripheral zone (90), where the shape of said first pipe profile (P) is selected to allow the outer edges of said feed screw (4) to remove material overlying said dewatering holes (6), and where the shape of said second pipe profile (P2) is selected so as to prohibit any contact between said outer edges of said feed screw (4) and the anti-rotation bars (7). Also disclosed is a pipe for use in such a screw feeder.

Disclosed is a screw feeder (10) comprising a pipe (3) enclosing a feed screw 4 arranged on a rotatory shaft (5) running parallel with the length direction of the pipe (3), said pipe (3) further comprising a number of dewatering holes (6). The screw feeder (10) also comprises a number of anti-rotation bars (7) provided on, and extending along, the inside of said pipe (3), said anti-rotation bars (7) protruding in a direction towards said feed screw (4), and an inlet (1) for receiving a solid-liquid mixture arranged at a first end of said pipe (3), and an outlet (2) arranged at a second end of said pipe (3) for discharging an at least partially dewatered solid from said pipe (3). The pipe (3) includes at least one longitudinal pipe section (31) having a first peripheral zone (9) provided in the vertically lower area of said longitudinal pipe section (31) and provided with dewatering holes (6) but no anti-rotation bars (7) and a second peripheral zone (90) provided in the vertically upper area of said longitudinal pipe section (3) provided with anti-rotation bars (7), the overall pipe profile of said pipe section (31) is composed of two differently shaped pipe profiles, a first pipe profile (P1) and a second pipe profile (P2), said first pipe profile (P1) defining the shape of the first peripheral zone (9) and is a profile selected from a square shaped profile, a profile having a partly circular cross-section with a squashed end or a circle segment remove or a partly elliptically shaped profile, and the second pipe profile (P2) defining the shape of the second peripheral zone (90), where the shape of said first pipe profile (P) is selected to allow the outer edges of said feed screw (4) to remove material overlying said dewatering holes (6), and where the shape of said second pipe profile (P2) is selected so as to prohibit any contact between said outer edges of said feed screw (4) and the anti-rotation bars (7). Also disclosed is a pipe for use in such a screw feeder.

The present invention relates to an improved method and device for treating biomass in which thermally treated biomass is discharged from a pressurized reactor and introduced into a blow tank, wherein the absolute pressure in the blow tank is maintained below atmospheric pressure. The slurry of biomass separated in the blow tank is then enzymatically treated.