A pulper for circulating a fibrous stock suspension. The pulper includes at least one screen, having a screen surface which is provided with screen openings, and over which a rotor passes. The rotor is formed by a rotor head, to which a plurality of rotor blades are attached on the outer circumference. The rotor circle of the screen, which is passed over by the rotor wings, includes a plurality of bar-shaped elevations. In the process, pulping is to be improved, while wear is to be minimized, in that the angle of intersection between the working edge of the rotor blades pointing in the direction of rotation and the shear edge of the elevations pointing counter to the direction of rotation does not decrease radially outwardly.

The invention relates to a high-concentration mixer (1) for producing a suspension (2), comprising a stationary container (3) and an agitator (8) arranged in the container axis (7), which agitator is connected to a motor via a flange (9) provided in the region of the container bottom (4), which motor is designed for rotationally driving the agitator (8) for mixing the suspension (2) provided in the container (3), wherein the agitator (8) has helical coils (11) which bring about a vertical downward flow (12) of the suspension (2) in the centre of the container (3) and a vertical upward flow (13) of the suspension (2) in the region of the container wall, wherein the flange (9) comprises at least one blade (15) provided on its circumference, which is designed for wiping the suspension (2) from the container (3) and for supporting the vertical upward flow (13) of the suspension (2) in the region of the container wall.

A powered pneumatic system for capturing a rejected tissue sheet on a parent roll for recycling.The parent roll is supported on a powered parent roll back stand, which turns the parent roll to unwind it. The sheet is drawn into the inlet of a wide pneumatic hood. Suction pressure supplied by a material-handling fan draws the sheet through a duct, where the material-handling fanbreaks it up. The air with entrained, broken paper may be supplied either to a dry system, typically including a separator to separate the paper from the air, or to a wet system for pulping the paper. A trim receiver is one example of a dry system separator. A Venturi scrubber is one example of a wet system. In either case, the paper from the parent roll can be recycled without needing to cut the paper from the roll.

A sheet manufacturing apparatus 1 includes a quantitative feeder unit 15 that measures a predetermined amount of a raw material C and feeds the measured raw material C, a defibration unit 31 that defibrates the raw material C fed from the quantitative feeder unit 15 into fibers, a third unit group 103 that deposits and compresses the fibers and forms the fibers into a sheet, a first frame F1 to which the quantitative feeder unit 15 is fixed, and a second frame F2 that is separated from the first frame F1 and to which the defibration unit 31 is fixed.

A device for treating material in a container which is equipped with a stirrer that can be rotated about a central axis has a first deflecting device which is arranged in the container above the stirrer in order to deflect a material flow transported by the stirrer to the container center. The stirrer has a coaxial axle element, the diameter of which in the region of the stirrer is at least a quarter of the diameter of the stirrer. The container has a base below the stirrer, and the distance between the base and the deflecting device is maximally half the maximum diameter of the container between the base and the deflecting device. The base can also be designed as a perforated sheet.

A pulper for circulating a fibrous stock suspension. The pulper includes at least one screen, having a screen surface which is provided with screen openings, and over which a rotor passes. The rotor is formed by a rotor head, to which a plurality of rotor blades are attached on the outer circumference. The rotor circle of the screen, which is passed over by the rotor wings, includes a plurality of bar-shaped elevations. In the process, pulping is to be improved, while wear is to be minimized, in that the angle of intersection between the working edge of the rotor blades pointing in the direction of rotation and the shear edge of the elevations pointing counter to the direction of rotation does not decrease radially outwardly.

Methods for making fire retardant material including fire retardant cellulosic insulation are described. The methods include arrangements for partitioning fibers derived from fiber feedstocks and adding at least a portion of fibers of one or more feedstocks and a fire retardancy chemical compound to a mixer prior to fiber drying. The fibers may be disentangled and/or partitioned prior to mixing with the fire retardancy chemical compound. The fibers may be partially dewatered prior to the drying or other steps of the methods. The feedstock may include old newsprint (ONP), old corrugated containers (OCC), and/or other cellulose-based materials. The method further includes retaining the fibers feedstock and the chemical compound together for enough time to ensure adherence and impregnation of enough of the chemical to and in the fibers after the drying process. Fibers may be partitioned and disentangled prior to, during, and/or after treatment with the fire retardancy compound. The fire retardant cellulose insulation may be a standalone product or may be a component of a finished insulation end product.

The invention relates to a high-concentration mixer (1) for producing a suspension (2), comprising a stationary container (3) and an agitator (8) arranged in the container axis (7), which agitator is connected to a motor via a flange (9) provided in the region of the container bottom (4), which motor is designed for rotationally driving the agitator (8) for mixing the suspension (2) provided in the container (3), wherein the agitator (8) has helical coils (11) which bring about a vertical downward flow (12) of the suspension (2) in the centre of the container (3) and a vertical upward flow (13) of the suspension (2) in the region of the container wall, wherein the flange (9) comprises at least one blade (15) provided on its circumference, which is designed for wiping the suspension (2) from the container (3) and for supporting the vertical upward flow (13) of the suspension (2) in the region of the container wall.

Provided is a pulping device. The pulping device includes a housing, a drive shaft, and an impeller assembly. The housing defines a cavity. The impeller assembly is disposed in the cavity and is configured to be driven to rotate by the drive shaft. A bottom surface of the impeller assembly is disposed opposite to an end surface of the housing, and one of the bottom surface of the impeller assembly or the end surface of the housing is provided with an annular protrusion, and the other one of the bottom surface of the impeller assembly or the end surface of the housing defines an annular groove matching the annular protrusion, and an interference-proof clearance is defined between an outer wall of the annular protrusion and an inner wall of the annular groove.

Methods for making fire retardant material including fire retardant cellulosic insulation are described. The methods include arrangements for partitioning fibers derived from fiber feedstocks and adding at least a portion of fibers of one or more feedstocks and a fire retardancy chemical compound to a mixer prior to fiber drying. The fibers may be disentangled and/or partitioned prior to mixing with the fire retardancy chemical compound. The fibers may be partially dewatered prior to the drying or other steps of the methods. The feedstock may include old newsprint (ONP), old corrugated containers (OCC), and/or other cellulose-based materials. The method further includes retaining the fibers feedstock and the chemical compound together for enough time to ensure adherence and impregnation of enough of the chemical to and in the fibers after the drying process. Fibers may be partitioned and disentangled prior to, during, and/or after treatment with the fire retardancy compound. The fire retardant cellulose insulation may be a standalone product or may be a component of a finished insulation end product.