Abstract:
Process and apparatus for removing solids from an aqueous fiber suspension in a flotation container that includes a drainage section. The process includes adding gas bubbles to the fiber suspension entering the flotation container, and collecting a flotation foam formed within the flotation container. The flotation foam includes the solids to be removed. The process also includes laterally moving the flotation foam in the drainage section, such that at least a portion of fluid within the flotation foam is drained from the flotation foam, collecting the drained fluid in the drainage section, discharging the drained fluid from the drainage section, discharging the flotation foam as a rejects material, and discharging a purified fiber suspension as an accepted stock suspension. The apparatus includes a flotation container, and a drainage section coupled to the flotation container. The drainage section is arranged to drain at least a portion of fluid from a flotation foam. The apparatus also includes a rejects outlet coupled to the drainage section, an accepts outlet coupled to the flotation container, and a fluid collector coupled to the drainage section for collecting the fluid drained from the flotation foam.
Abstract:
The process is designed for the flotation of interfering materials from an aqueous fibrous pulp suspension and is in particular used in the processing of printed or used paper that is otherwise contaminated. The separation of gas bubbles of the suspension occurs in a flotation layer that has a maximum thickness of approximately 100 mm. The process also achieves good flotation results in fibrous pulp suspensions that have a fiber pulp content significantly larger than 1% by weight, for example around 2% by weight. A flotation apparatus is provided for performing the flotation process. The apparatus includes a flotation vessel, an inlet, an outlet, and a skimmer device.
Abstract:
Process for increasing the water retaining ability of fibrous paper stocks. The process includes knead dispersing a fibrous paper stock having a stock concentration of at least about 20% and a temperature greater than about 45° C. A treatment for the knead dispersing is at least about 10 seconds. The process further includes completing a post-treatment phase to a machine tub of a paper machine in a reaction time of no longer than about 30 minutes.
Abstract:
A method and a dispersing machine for hot dispersing a highly consistent fibrous stock. The machine includes at least one stationary stator that includes a plurality of annular concentric rows of stator teeth. At least one rotating rotor is provided that includes a plurality of annular concentric rows of rotor teeth. An annular dispersing zone is formed by the stator teeth and the rotor teeth whereby the rotor teeth are adapted to rotate adjacent the stator teeth such that a distance is maintained between the stator teeth and the rotor teeth in the annular dispersion zone. An inlet is provided that allows the fibrous stock to enter the dispersion machine. A milling element is centrally arranged on the rotor. The milling element is arranged near the inlet and defines a milling zone. An annular chamber is arranged between the dispersion zone and the milling zone. At least one conduit allows a heating medium to enter the annular chamber. At least one rotatable annular centrifugal row of teeth is arranged between the milling element and the annular chamber. The method includes transporting the fibrous stock via the inlet to the milling zone, rotating the milling element to subject the fibrous stock to milling, allowing the fibrous stock to pass by the at least one rotatable annular centrifugal row of teeth, subjecting the fibrous stock to the heating medium in the annular chamber, and moving the fibrous stock through the dispersion zone.
Abstract:
Process for dispersing a fibrous paper web which comprises a substantially consistent fibrous paper material. The process includes loosening and pulverizing a fibrous paper material into a fine, friable fibrous material; guiding the fine, friable fibrous material into a vapor chamber in which at least one of a gaseous and vaporous heating medium mixes, calefies, and disperses the fine, friable fibrous material; and dispersing the fine, friable fibrous material in a disperser zone, the disperser zone and the vapor chamber being located in one device. A device for dispersing a fibrous paper web which comprises a substantially consistent fibrous paper material. The device includes an inlet for fibrous paper material, a stationary stator, and at least one rotatable rotor. The stator and the at least one rotor form a pulverizing zone including a pulverizing element located near the inlet for the fibrous paper material, the pulverizing element including least one of scrapers and knives for pulverizing the fibrous material into a fine, friable material; a vapor chamber forming a ring about the pulverizing zone, the vapor chamber being for calefying the fine, friable material formed by the pulverizing element; and a dispersing zone including at least one row of teeth on the stator and at least one row of teeth on the at least one rotor which can be moved relative to the at least one row of teeth of the stator.
Abstract:
A process is disclosed that is utilized in particular in the preparation of fibrous material of used paper. Hot fibrous pulp friable materials, which are especially suitable for dispersing, are first formed in a compact, high-consistency fibrous material in the form of a plug. In a preferred embodiment, the plug of materials is pushed against a rotor that is equipped with pulverization elements. The pulverization elements remove the fibrous pulp friable materials and distribute them in a disintegrated condition in a processing chamber. In the processing chamber, super-heated vapor is supplied via vapor supply lines, which calefies the fibrous pulp friable materials, for example, by condensation.
Abstract:
Process and device for dispersing a fibrous paper web which comprises a substantially consistent fibrous paper material. The device includes an inlet for fibrous paper material, a stationary stator, and at least one rotatable rotor. The stator and the at least one rotor form a pulverizing zone including a pulverizing element located near the inlet for the fibrous paper material, the pulverizing element including least one of scrapers and knives for pulverizing the fibrous material into a fine, friable material; a vapor chamber forming a ring about the pulverizing zone, the vapor chamber being for calefying the fine, friable material formed by the pulverizing element; and a dispersing zone including at least one row of teeth on the stator and at least one row of teeth on the at least one rotor which can be moved relative to the at least one row of teeth of the stator.