Abstract:
A concentrator press includes a pair of rotatble press rolls (1) which coact with one another. The press rolls have apertured or perforated mantle surfaces (5) for removing liquid from a liquid-drenched material (3) to be concentrated and advanced between the press rolls. A part of the peripheral surface (5) of each press roll (1), including at least those regions in which the press roll acts on material undergoing concentration, is surrounded by a respective endless filter-cloth web (6, 7) which also runs around at least one direction changing roller (10; 10, 17, 18) at a distance from its associated press roll (1) and the still not concentrated, liquid-drenched material (3). The filter-cloth webs (6, 7) extend generally parallel with each other downstream of the press nip, to a concentrated material delivery station (15, 16).
Abstract:
A method for the continuous production of boards of a ligno-cellulosic fiber material wherein the material is broken up into particles and/or fibers. These are dried, glued and formed to a mat. The mat is compressed to a finished board while steam is introduced. According to the present invention, the compression is performed as a single step and the steam is introduced through one or many compression rollers. By injecting steam in this way a sufficient cure is obtained to withstand the spring back characteristics inherent of the fibers so that it is possible to obtain a finished thickness of the board with one single compression step.
Abstract:
A method for the continuous production of boards having a lignocellulosic fiber material wherein the material is broken up into particles and/or fibers that are dried, glued and formed and pressed to a finished board. The mat is pre-compressed while steam is introduced in such a limited amount during the pre-compression that the temperature of the fibrous mat increases to a value within an interval of 60-95 DEG Celsius. In this way, the spring back characteristics of the fiber mat is reduced so that its resistance to compression is reduced and the thickness can be reduced more in the pre-compression while the temperature is not so high to initiate a curing process.
Abstract:
The invention relates to a belt guide for short belt conveyors (1) in which an endless belt is passed over rollers (3, 4) at the ends of the conveyor. A plurality of glide strips (10) which extend generally in the direction of belt movement (7) beneath the upper run of the belt and over a stationary plane or surface (12). They are pivotal along the plane (12) about a respective pivot (11) in the proximity of the conveyor input end (8) and mutually connected for common angular movement around the pivots (11). The upper surface of respective glide strips (10) is proud of the common tangential plane of the end-rollers (3, 4) so that there can be generated between the glide strips (10) and the conveyor belt a contact pressure which is sufficiently great for the frictional force that acts laterall between the strips and the belt to enable lateral displacement of the belt in response to an angular change in the position of the glide strips (10).
Abstract:
A static mixer for mixing together gaseous and/or liquid media, comprising a casing (10) having media inlets and outlet (14-18; 19), and helical mixing elements (20, 21) extending therebetween, said mixing elements being stationary when the mixer is in use. Two or more mixing elements (20, 21) are arranged side-by-side in the casing (10), and each mixing element includes at least one flange (23) which extends helically through two or more turns along the length of the elements. The pitch of the helix is substantially greater than the flange thickness. The flanges (23) on the mixing elements (20, 21) extend helically in mutually the same direction, and the flange turns of each mixing element project into the spaces (24) between the flange turns of mutually adjacent mixing elements (20, 21).
Abstract:
A method of chlorine free bleaching of pulp where the metals in the pulp are removed by means of a chelating agent. The pulp is treated with the chelating agent at a pH 2-7 for a period of 5 minutes to 2 hours. The chelating agent is activated by the addition of an oxidizing agent. After the treatment the pulp is washed.
Abstract:
A device for compressing and processing a material mat at the manufacture of board of lignocellulosic material, comprising rotary compression rolls. At least one of the compression rolls (2) is formed with a perforated shell surface (6) and an axial duct system (7) located inside of the shell surface. A slide shoe (8) abuts sealingly the end wall of the roll (2) for injection of the processing medium to the mat via the duct system (7) in a restricted sector (9) of the roll (2) where the mat is compressed.
Abstract:
A refiner segment for disc refiners for desintegration of lignocellulose-containing material, where the refiner segment (1) is formed with a pattern of bars (2) and grooves (3), and where dams (4) are placed in the grooves. The dams (4) are so arranged that their angle in relation to the radius of the refiner segment (1) is smaller than 30 DEG .
Abstract:
Board of lignocellulose-containing material and a method of manufacturing such board. The material is disintegrated to particles or fibres, dried, glued prior to or after the drying, formed to a mat and finally dried by hot pressing to a finished board. According to the invention, the lignin is modified chemically at least in the surface layer of the particles or fibers prior to the final drying, so that an increased binding reactivity is obtained by the introduction of hydrophilic groups and so that the softening temperature of the lignin is lowered. Thereby the lignocellulose material in the board is partially sulphonated so that the organically combined sulphur exceeds the native sulphur content of the material but is lower than 0.4 %.
Abstract:
A method of treating process water containing metal ions in connection with bleaching pulp of ligno-cellulose-containing material. The process water is brought into contact with an alkaline liquid, which preferably also contains sulphide, whereby metal ions precipitate in the form of difficultly soluble metal compounds. The precipitated metal compounds thereafter are separated from the process water.