Abstract: Methods for producing chemical pulp from lignocellulose-containing material in processes for kraft pulp production are disclosed including charging the lignocellulose-containing material to a digester, initially treating the lignocellulose-containing material with an impregnation liquor, and then treating the impregnated lignocellulose-containing material with hot liquor and displacing calcium-containing spent liquor from the digester during that treatment, heating and cooking the heated lignocellulose-containing material to produce cooked lignocellulose-containing material and cooking liquor and displacing the cooking liquor from the digester using at least a portion of the displaced calcium-containing spent liquor.

Abstract: A method for producing chemical pulp from cellulosic material by means of alkaline cooking, including cooking the material to pulp at cooking temperature in a digester, reducing the temperature at the end of the cook, substantially relieving the overpressure in the digester and then discharging the pulp from the digester by means of pumping. The method is characterized in that the pulp is cooled to essentially 85° C. to 70° C. before pumping cooked material as a fluid suspension from the digester, and that the temperature of the cooked material is maintained in the same temperature range and at a pH level being between 10 and 13, between the digester and a first delignification/bleaching stage, thus avoiding mechanical damage of cellulosic material.

Abstract: A method for preparing pulp from lignin-containing cellulosic material is disclosed, including a step for acid cleaning of the lignocellulosic material, followed by alkaline delignification. The acidic step removes undesired components such as metal ions and side groups of polysaccharides, which may have adverse effects on the process especially when extensive recycling of liquors is employed within the plant.

Abstract: A method of sealing the pressure chamber of a shoeless press comprising a roll and a concave counterpart provided with a nip pressure chamber and with a press belt by proportioning the edge radius of the pressure chamber and the radius of the path of the belt to the pressures acting under the belt. A pressure is generated under the press belt, outside the press chamber, with the aid of oil or gas, and a suitable lubrication leak is allowed from the pressure chamber by adjusting the pressure in the right proportion to the chamber pressure. The invention also includes an apparatus for carrying out the method.

Abstract: A press for the dewatering of a fiber web, comprising a roll, a counterpart and and an endless press belt adapted to glide around the counterpart. Into the concave press zone region of the counterpart, a flexible press plate is adapted, anchored to the counterpart at the leading edge of the counterpart, relative to web motion. Beneath the press plate, hydrostatic pressure chambers are provided, separated from each other by means of flexible pressure lines. By individually controlling the pressures of the chambers, the leads and optionally the press plate edges, a desired pressure profile is obtained across the extended pressure zone.