Other

Sunds Defibrator Aktiebolag

Sunds Defibrator Ab

Sunds Defibrator Industries Aktiebolag

Defibrator Aktiebolag

American Defibrator, Inc.

Cell Develop, Inc.

Rolf B Reinhall

Inge J Johansson

Johan G Johansson

Anders Mukvist

Anders V Mokvist

Lars Elander

Ake Sandstron

Johan I Johansson

Device for treating material mixtures

The present invention provides a regulator for a refiner or grinding apparatus having opposed relatively rotatable grinding discs. Each grinding disc carries a grinding segment, and a predetermined gap or grinding space is defined between the grinding segments. The regulator, which is provided to compensate for axial variations in the predetermined grinding space due to variations of the load, includes a piston axially movable in a cylinder and a calibrated resilient element acting on the piston. The regulator is coupled to a hydraulic servo motor for the grinding discs, and the dimensions of the piston and cylinder of the regulator are selected to correspond to that of the servo motor, but in reduced scale. By calibrating the resilient element of the regulator to correspond to the axial load applied to the grinding discs, the displacement of the regulator piston corresponds to the relative displacement of the grinding disc and thus to a variation in the grinding space between the grinding discs. Variations in the grinding space are instantaneously and continuously counteracted by the regulator to maintain the grinding space at its predetermined value.

Stress regulator for pulp grinding apparatus and method

A method and apparatus is provided for conjoint or simultaneous adjustment of the gap spaces of the inner and outer grinding zones of a pulp refiner apparatus in a single step. The inner grinding zone is generally radially oriented, and merges into an outer inclined grinding zone. Pulp stock to be ground is introduced into a central inlet position and is accelerated through the inner and outer grinding zones by centrifugal forces generated by a pair of grinding members which rotate relative to one and other. The opposed surfaces of the relatively rotating members each carry a plurality of concentric rows of teeth, and the gap spacing of the inner grinding zone is defined between adjacent surfaces of the teeth. The adjacent teeth defining the inner grinding zone are arranged so that adjustment of the gap space of the outer grinding zone simultaneously controls the gap spacing of the inner grinding zone without the need for separate adjustment. Retarding rings are provided adjacent to the concentric rows of teeth to prevent pulp from by-passing the grinding spaces between adjacent teeth.

Apparatus and method for conjoint adjustment of both the inner and outer

Apparatus for treatment of fibre suspensions

Apparatus for feeding lignocellulose-containing material through a steam

Combined hydrostatic/hydrodynamic bearing system for a grinding apparatus in which the material is ground in a grinding space defined between a pair of relatively rotating grinding members and in which at least one of the grinding members is carried by an axially displaceable rotatable shaft. One or more cylindrical pistons are mounted on the rotatable shaft to rotate therewith within a pressure chamber defined within a stationary cylindrical housing permitting the piston or pistons to be displaced axially therein. Fluctuations in axial thrust forces acting on the displaceable rotatable shaft are counteracted by applying a fluid pressure medium to one or both of the piston ends of the cylindrical piston or pistons in a controlled manner so as to maintain a predetermined clearance range of the grinding space.

Combined hydrostatic/hydrodynamic bearing system for grinding apparatus

Method and apparatus for manufacturing fibre pulp

A system for mixing and refining pulp in which the raw material is conveyed into a cylindrical drum and propelled therethrough in linear/spiral direction by a co-axial rotor comprising a plurality of mixing/refining elements. The raw material is mixed and refined during the relative rotation between the rotor and the drum in a plurality of co-axially extending grinding areas defined between rotatable grinding elements on the rotor and a facing grinding surface on the interior of the drum while being simultaneously compressed therein and alternately decompressed in areas between the grinding areas. The rotatable elements are adjustably mounted to the rotor so as to vary the spacing between the grinding surface on the interior of the drum and a rotatable grinding surface on the grinding elements, while simultaneously adjusting the material feeding angle of the grinding areas. The adjustment can be achieved mechanically or by a hydraulic system during the operation of the apparatus to control and vary the flow of the pulp material as it passes through the grinding areas to insure optimum and even mixing and refining of the pulp.

Rotor/mixer for controlling mixing and refining of pulp material

Method for manufacturing cellulose pulp using plural refining and fiber

Refining apparatus with radial passageways for steam recovery

Apparatus for producing thermo-mechanical pulp from wood chips and the like in which the chips are first heated in a steaming chamber or preheater to a fiber temperature below the softening point of the lignin of middle lamella section of the wood fibers. The thus heated chips are conveyed in a sealed system to the inlet of a defibrating zone enclosed within a housing in a gaseous atmosphere of superatmospheric pressure, where it is compressed by a screw conveyor into a plug which seals the defibrator housing against blow-back of the pressurized gaseous medium. The defibrating space is defined between a pair of grinding discs which rotate relatively to one another in the housing and comprises a first substantially central zone into which the compressed plug is advanced by the compressor screw and broken up and the fibers subjected to an initial defibration step at a fiber temperature below the softening point of the lignin, to cause the fibers to unravel and to expose the different fiber layers without any substantial separation thereof. As the fiber bundles progress radially outwards under the centrifugal force of the rotating discs into a second zone radially surrounding the first zone, the temperature increases by the heat of the grinding friction which converts water accompanying the chips into high temperature, high pressure steam, in which environment the lignin is softened so that the wood structure is broken in the lignin-rich middle lamella section of the fibers to permit the fibers to become completely separated and fibrillated in undamaged condition. The resultant pulp is discharged from the pressurized housing through a blow valve which is adjustable to control the pressure and temperature within the defibrator housing.

Apparatus for producing fiber pulp from fibrous lignocellulose

Method and apparatus for grinding pulp stock in the grinding space of a defibrating apparatus, which space is defined between grinding surfaces carried by a pair of grinding discs, both of which rotate relative to one another within a closed housing, to thereby control the rate of flow of grist through the grinding space. The grinding space includes an inner grinding zone and two outer grinding zones which diverge at an angle to the radial plane of the inner zone. The inner grinding zone is defined between the two facially-opposed rotating discs in a plane substantially perpendicular to the axis of rotation, and the outer grinding zones are defined between portions of the two rotating discs which extend at an angle to the radial plane of the inner zone and correspondingly inclined facing surfaces of a stationary element such as a stator ring encasing the two rotating discs.

Method and apparatus for grinding pulp stock in pulp defibrating

A grinding apparatus in which lignocellulose-containing material such as wood chips is ground in a grinding space defined between cooperating disc segments carried by a rotating disc and a stationary disc in close spacing tolerance. In order to counteract the deflective centrifugal force exerted on the rotating disc segments, the peripheral portion at the rear of the rotating disc is formed with an annular bulge having an annular channel therein for receiving mercury in an amount calculated to generate during the rotation of the bulging disc a counter centrifugal force equal to the deflecting centrifugal force exerted on the rotating grinding segments to thereby maintain the close tolerance spacing between the cooperating grinding segments.

Device in grinding apparatus

Method of producing fiberboard products according to the so-called dry method from lignocellulosic fiber material in which the fiber material discharged from a defibrating apparatus in an environment of steam is propelled in a stream of heated air to remove substantially all moisture therefrom. The thus dried fibers are deposited on an underlying moving perforated screen to form a mat in which the fibers are oriented at random while propellant air is evacuated therefrom. The thus formed mat is wetted by adding water thereto while it is being advanced by the screen into a hot press where the wetted fibers are compressed and bonded in their random orientation, with consequent removal of water. The amount of water added in the wetting step is proportioned to be effective in itself to bond the fibers without use of extraneous bonding or adhesive substance.

Growing community of inventors

Bellevue, WA, United States of America

Rolf B Reinhall