Abstract: A process for the formation of fiberboard where the fiber stock suspension is dewatered on two sides between wires or felts, a top wire being provided in the main dewatering zone.

Abstract: A process for the formation of fiberboard where the fiber stock suspension is dewatered on two sides between wires or felts, a top wire being provided in the main dewatering zone.

Abstract: The invention relates to a device for dewatering and washing fibre stock suspensions with two counter-rotating rolls (2, 3), a stock feed (4, 5) and a stock discharge (6). It is mainly characterized by the headbox (4, 5) at the two rolls (2, 3) being arranged separately in the lower section of the rolls (2, 3), and a discharge screw (6) being foreseen for discharge of the filter mat below the gap between the two rolls (2, 3) and a washing zone (9″, 10″) in the upper part of the rolls (2, 3).

Abstract: A process and apparatus for treating and particularly bleaching pulp contacts a pulp with a gaseous reaction medium in a reactor tower. The pulp is fluffed and refined before being added to the pulp bed and then homogeneously permeated with the gaseous reaction medium to produce a uniformly treated pulp. A distribution device is included in the reactor to uniformly distribute the pulp in the reactor and form a homogenous pulp bed having a substantially even upper surface uniform bed depth.

Abstract: A process and apparatus for treating and particularly bleaching pulp contacts a pulp with a gaseous reaction medium in a reactor tower. The pulp is fluffed and refined before being added to the pulp bed and then homogeneously permeated with the gaseous reaction medium to produce a uniformly treated pulp. A distribution device is included in the reactor to uniformly distribute the pulp in the reactor and form a homogenous pulp bed having a substantially even upper surface and uniform bed depth.

Abstract: A mixer for fluffing and mixing pulp with treatment additives includes a disc rotor, an annular stator, a pulp feed channel, a ribbon feeder and a baffle, the axially rotating disc rotor including a shaft and a grinding segment. The stator includes a grinding segment which opposes the rotor grinding segment. The feed channel is coaxial with the rotor axis, has a discharge end which confronts the rotor and has an inlet end for receiving pulp. The ribbon feeder is coaxially disposed within the feed channel and has a hollow axially rotating shaft. This feeder discharges pulp at the rotor toward the mixing and fluffing zone. The baffle is carried on the feeder shaft and guides the pulp toward the fluffing and mixing zone. Treatment additives are introduced as the pulp moves toward the discharge end of the channel.

Abstract: A process and apparatus for controlling and/or regulating a solids-liquid separation process, such as in a dewatering or drying device includes at least two photodetectors, each associated with a light source, a detector to detect light of the associated light source reflected from the surface of the solids-liquid mass, a controller generating an output signal as a function of the detected light and converting and processing the output signals of the photodetectors into correcting variables for controlling and/or regulating at least one process parameter of the separation process. At least one of the photodetectors is associated with at least one second photodetector for detecting light reflected into the photodetector at an angle, preferably an angle of 30.degree. to the main direction of reflection. The output signals of the photodetectors are advantageously processed into correcting variables for the step-wise adjustment of the at least one process parameter to optimize the separation process.

Abstract: A process and apparatus for controlling and/or regulating a solids-liquid separation process, such as in a dewatering or drying device includes at least two photodetectors, each associated with a light source, a detector to detect light of the associated light source reflected from the surface of the solids-liquid mass, a controller generating an output signal as a function of the detected light and converting and processing the output signals of the photodetectors into correcting variables for controlling and/or regulating at least one process parameter of the separation process. At least one of the photodetectors is associated with at least one second photodetector for detecting light reflected into the photodetector at an angle, preferably an angle of 30.degree. to the main direction of reflection. The output signals of the photodetectors are advantageously processed into correcting variables for the step-wise adjustment of the at least one process parameter to optimize the separation process.

Abstract: The invention relates to a method and device for the washing of a medium consistency fibrous slurry, especially a chemical pulp slurry in which the slurry is fed at an inclined angle onto a substantially horizontal portion of circulating filter belt, and then distributed over substantially the entire working width of the filter belt. The distributed slurry is then washed with a washing liquid under localized pressure to produce a slurry having a medium consistency range, i.e., about 8 to 15 percent. In order to increase the consistency to 20 to 40 weight percent, preferably about 30 to about 35 weight percent, the washed slurry is passed to a pressing zone.

Abstract: A process for the comminution, in particular defibrillation, and reaction of fibrous materials having a high dry solids content with the addition of a circulating medium, preferably a carrier gas and/or reaction agent, as well as optionally of chemicals. The invention is mainly characterized in that the circulating medium is recycled after leaving the comminuting device, by changing its temperature, and is then recycled to the comminuting device. Another embodiment of the invention is characterized in that the fibrous materials and liquid reaction agent are separated from the carrier gas and reaction agent vapors, which are then recycled back to comminuting device. A plant for carrying out this process is mainly characterized in that the comminuting device and route for recycling and treatment of the circulating medium form a closed system.

Abstract: The invention relates to a method and device for the washing of a medium consistency fibrous slurry, especially a chemical pulp slurry in which the slurry is fed at an inclined angle onto a substantially horizontal portion of circulating filter belt, and then distributed over substantially the entire working width of the filter belt. The distributed slurry is then washed with a washing liquid under localized pressure to produce a slurry having a medium consistency range, i.e., about 8 to 15 percent. In order to increase the consistency to 20 to 40 weight percent, preferably about 30 to about 35 weight percent, the washed slurry is passed to a pressing zone.

Abstract: The invention relates to a crushing or grinding element for drum refiners having an engine-driven rotor for the crushing or grinding of fibrous materials. The element is attachable to the rotor shell and has crushing or grinding surfaces of increasing diameter and optionally crushing or grinding surfaces of steeper inclination to the rotor axis immediately adjacent the crushing or grinding surfaces inclined to the rotor axis provided on the rotor shell. The grinding surfaces are symmetrical to the median plane of the material feed. The invention is characterized in that the crushing or grinding element(s) is (are) formed as (a) segment(s) placed around the circumference of the rotor having anchoring projections of hammerhead-like cross section on the side facing the rotor axis and which are engageable in corresponding rotor grooves of hammerhead-like cross section.

Abstract: A drum refiner for grinding fibrous material, preferably chips, has an engine-driven drumshaped rotor which is placed on a horizontal shaft. The rotor has grinding surfaces extending parallel to the rotor axis and corresponding opposing grinding surfaces arranged on the housing. The grinding elements are placed symmetrically about at least one material feeds which are conveniently evenly distributed around the circumference of the rotor. The grinding surfaces begin parallel to the axis and contiguously increasing in inclination forming a grinding gap inclined towards the rotor axis at an angle of approximately 5.degree. to 45.degree., preferably 15.degree.. The second embodiment includes grinding surfaces contiguously increasing in inclination and ending with an angle of inclination of approximately 90.degree. to the rotor axis.

Abstract: A double screen belt press for dewatering mixtures of fibrous material suspensions has a wedge compression zone comprising rolls and perforated plates supporting generally upper and lower screen belts. For dewatering mixtures of fibrous material suspensions having a high dry solids content, at least one sealed material feed empties into the wedge compression zone with a high pressure. A generally vertically gravity tower with an outlet port is provided to feed material into the entrance of the wedge compression zone above the lower screen belt and in front of the front roll supporting the upper screen belt. The outlet port area of the material feed is sealed on at least the side facing the lower screen belt and optionally on the side facing the upper screen belt and on the other side of the material feed facing away from the wedge compression zone between the material feed and the lower screen belt.

Abstract: A grinding element for a drum refiner for the crushing or grinding of fibrous material. The drum refiner includes an engine driven rotor having a generally horizontal rotor axis and at least one material feed. A rotor jacket is positioned on the rotor and has a surface of revolution. The grinding element is attachable to the rotor jacket on the surface of revolution and has a diameter increasing away from the material feed. A housing receives the rotor and rotor jacket therein, and has an opposing inner wall with a corresponding grinding element thereon. The grinding element on the rotor jacket includes a channel spaced from the material feed for the discharge of steam. The channel has one end in fluid communication with the grinding gap and a second end in fluid communication with a bore extending generally normally to the channel. The bore is in fluid communication with a cavity in the housing. The improvement comprises the grinding element on the rotor jacket being generally formed of a segment.

Abstract: The invention relates to an apparatus for the crushing or grindign of fibrous material, in particular fibrous material wet or mixed with water, preferably chips, in particular to drum refiners.The invention is mainly characterized in that channels for the discharge of steam are provided spaced from at least one material feed extending radially to the rotor axis or tangentially to the rotor jacket or housing shell on the grinding surfaces and optionally on the jacket supporting them, the channels piercing the grinding surfaces and optionally their supports and being provided in the working area of the grinding element provided on the surfaces, conveniently surfaces of revolution, in particular frustoconical surfaces, inclined to a rotor axis or extending normally thereto, and emptying into channels optionally provided in the bottoms of the supports and extending normally to the channels and conveniently being connected to cavities in the housing.

Abstract: A process for the comminution, in particular defibrillation, and reaction of fibrous materials having a high dry solids content with the addition of a circulating medium, preferably a carrier gas and/or reaction agent, as well as optionally of chemicals. The invention is mainly characterized in that the circulating medium is recycled after leaving the comminuting device, by changing its temperature, and is then recycled to the comminuting device. Another embodiment of the invention is characterized in that the fibrous materials and liquid reaction agent are separated from the carrier gas and reaction agent vapors, which are then recycled back to comminuting device. A plant for carrying out this process is mainly characterized in that the comminuting device and route for recycling and treatment of the circulating medium form a closed system.