Abstract:
In a method and control system for controlling a conveyor system comprising a plurality of conveyors, each of which is allocated a control unit (44, 46, 48), the conveyors are controlled in accordance with status data from the conveyors. Each conveyor is brought to communicate (via 50, 52, 53, 54) only with its adjacent conveyors, which are in turn brought to communicate only with their adjacent conveyors, etc. The communication comprises the control units (44, 46, 48) of each conveyor transmitting and receiving control information, said information being created on the basis of the conveyor's own status data and control information from its adjacent conveyors. Control signals for controlling the conveyor are created on the basis of the conveyor's own status data and the control information received by the conveyor's control unit from control units of adjacent conveyors. The control units can be standardized and dimensioned for a maximum number of adjacent conveyors. A plant for baling paper pulp comprises a conveyor system having such a control system.
Abstract:
A method of oxygen delignification of pulp from lignocellulosic material at medium concentration in two steps. An extended delignification is obtained in that the temperature in the first step is hel d below 90 .degree.C, that the difference in temperature between the steps is lower than 20 .degree.C. The pressure in the first step is 4-10 bar and i n the second step 2-5 bar, and the pressure in the first step is higher than in the second step. The oxygen addition to the first step is high, 25-50 kg/ton pulp, that alkali is added only to the first step for obtaining high alkalinity in the pulp, 25-50 kg alkali per ton pulp. The stay-time in the first step is 10-30 min and in the second step 45-180 min.
Abstract:
A METHOD FOR THE CONTINUOUS MANUFACTURE OF BOARD FROM LIGNOCELLULOSIC MATERIAL, WHERE THE MATERIAL IS DISINTEGRATED TO PARTICLES AND/OR FIBERS, DRIED, GLUE-COATED AND FORMED TO A MAT AND PRESSED TO A FINISHED BOARD. THE FORMED MAT IS HEATED WITH STEAM AND THERE-AFTER COMPRESSED TO NEAR FINAL THICKNESS, WHEREAFTER IT IS PRESSED TO A MANAGEABLE BOARD IN A CALIBRATION SECTION.(FIG. 1)
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 .degree.Celsius. In this way, the spring back characteristics of the fiber m at is reduced so that its resistance to compression is reduced and the thickness can be reduced more in the pre-compression while the temperature i s not so high to initiate a curing process.
Abstract:
A method for the continuous manufacture of board from lignocellulosic material, where the material is disintegrated to particles and/or fibers, dried, glue-coated and formed to a mat and pressed to a finished board. The formed mat is heated with steam and thereafter compressed to near final thickness, whereafter it is pressed to a manageable board in a calibration section.
Abstract:
A method of controlling oxygen delignification of pulp, i.e. reduction of th e kappa number of the pulp, where the delignification is carried out in two stages, and the main portion of the chemicals required fo r the delignification is added to the first stage. The ingoing kappa number of the pulp prior to the delignification and the reduction of t he kappa number of the pulp during the total delignification in the two stages are used for adjusting the chemical addition to the first stage. The control is carried out so that higher ingoing kappa number yields lower charge and higher kappa number reduction yields higher charge, calculated per reduced kappa number unit. Said chemical addition to the first stage in its tum is used for control the temperature i n the second stage.
Abstract:
A device for admixing a processing agent to a pulp suspension. The device co mprises a cylindric lower portion (10) of a vessel with an agitator (11) fitted into the wall of said vessel portion, which agitator is intended to bring about a pulp flow across the vesse l portion (10). Means are provided (13) for the supply of the processing agent to the pulp f low. A flow divider (15) is located in the vessel portio n (10) diametrically opposite the agitator (11). Said flow divider (15) comprises a substantially vertical front distribution edge (16) and are-shaped surfaces (17) extending from the distribution edge (16) one in each directio n, which surfaces are substantially vertical and join th e wall of the vessel portion (10).
Abstract:
A pair of co-operating refining elements (10, 11) intended for a disc refiner for finely disintegrating and refining lump-shaped lignocellulosic material in a refiner gap (5, 6) between two opposed refining discs (1, 2). The outer portion (6) of the refiner gap is angular in relation to the radial plane, and the refining disc (2) located outside the outer portion (6) of the refiner gap is rotary. The refining elements (10, 11) are intented to be placed directly in front of each other on opposed refining discs in this outer portion (6) of the refiner gap. The refining element (10) located inside is provided with at least one wing (14) freely projecting in the direction to the inner portion (5) of the refiner gap. The refining element (11) located outside has an inlet portion (15) located directly in front of the wing (14) which is formed with a concavely curved surface (16). The wing is provided to throw the material against the curved surface (16) for changing the direction of movement of the material into the outer angular portion (6) of the refiner gap.
Abstract:
A refining segment for a disc refiner fox defibering and processing lignocellulose-containing fiber material. The refining segment has the shape of a circle sector and a refining surface with bars and intermediate grooves, which extend across substantially the entire refining surface. The bars are oblique in relation to the radius of the refining segment, and the angle of the bars in relation to said radius is greatest closest to the centre and thereafter decreases in radial outward direction. The angle closest to the centre shall be in the interval 20-45.degree. and farthest out in the interval -10.degree. to +20.degree..