Abstract: A pulper for pulping a fiber suspension includes a vessel, an extraction plate assembly and a rotor. The extraction plate assembly is disposed within the vessel and includes a metal plate with a plurality of holes extending therethrough. A plurality of metal inserts are respectively disposed within the holes and project from the plate. Each insert is removably attached to the plate. A rotor is disposed within the vessel adjacent to the extraction plate assembly. The inserts are removably attached to the plate by brazing the inserts within the holes, or slightly shrinking the inserts using liquid nitrogen and placing the inserts in the holes.

Abstract: An apparatus for continuously loading fibers in a fiber suspension with a chemical compound includes a deflocculating vessel having an interior chamber, a fluid inlet connected with the interior chamber, a fluid outlet connected with the interior chamber, and a high shear imparting device disposed within the interior chamber for imparting high shear forces to and thereby deflocculating the fiber suspension. A mixing container has an interior compartment, a fluid inlet connected with both the interior compartment and the fluid outlet of the deflocculating vessel, a fluid outlet connected with the interior compartment, and a low shear imparting device within the interior compartment for imparting low shear forces to the fiber suspension. A gas supply is connected with the interior chamber of the deflocculating vessel and/or the interior compartment of the mixing container. The gas supply is configured for supplying a gas to and pressurizing each of the deflocculating vessel and the mixing container.

Abstract: An apparatus for continuously loading fibers in a fiber suspension with a chemical compound includes a deflocculating vessel having an interior chamber, a fluid inlet connected with the interior chamber, a fluid outlet connected with the interior chamber, and a high shear imparting device disposed within the interior chamber for imparting high shear forces to and thereby deflocculating the fiber suspension. A mixing container has an interior compartment, a fluid inlet connected with both the interior compartment and the fluid outlet of the deflocculating vessel, a fluid outlet connected with the interior compartment, and a low shear imparting device within the interior compartment for imparting low shear forces to the fiber suspension. A gas supply is connected with the interior chamber of the deflocculating vessel and/or the interior compartment of the mixing container. The gas supply is configured for supplying a gas to and pressurizing each of the deflocculating vessel and the mixing container.

Abstract: A pulper for pulping a fiber suspension includes a vessel, an extraction plate assembly and a rotor. The extraction plate assembly is disposed within the vessel and includes a metal plate with a plurality of holes extending therethrough. A plurality of metal inserts are respectively disposed within the holes and project from the plate. Each insert is removably attached to the plate. A rotor is disposed within the vessel adjacent to the extraction plate assembly. The inserts are removably attached to the plate by brazing the inserts within the holes, or slightly shrinking the inserts using liquid nitrogen and placing the inserts in the holes.

Abstract: A pulper for pulping a fiber suspension includes a vessel, an extraction plate assembly and a rotor. The extraction plate assembly is disposed within the vessel and includes a metal plate with a plurality of holes extending therethrough. A plurality of metal inserts are respectively disposed within the holes and project from the plate. Each insert is removably attached to the plate. A rotor is disposed within the vessel adjacent to the extraction plate assembly. The inserts are removably attached to the plate by brazing the inserts within the holes, or slightly shrinking the inserts using liquid nitrogen and placing the inserts in the holes.

Abstract: An apparatus providing process water used for making or processing a fiber suspension includes a multi-compartment tank with a top, a bottom wall, and a plurality of exterior sidewalls. Each compartment has an inlet positioned near the top, an outlet positioned near the bottom wall, and at least one intervening wall common with an adjacent compartment. Each intervening wall has a height defining an overflow weir whereby the compartments are arranged with sequentially decreasing maximum fluid levels. Each intervening wall also has a backflow device positioned near the bottom wall. The backflow device is selectively openable to allow flow from one compartment to an adjacent compartment in a direction opposite to a flow direction over the corresponding overflow weir.