Studies on Industrial Digesters and Cooking Performance: Methods and Applications

摘要

Industrial pulp cooking reactors, digesters, were introduced in the early stagesof chemical pulping technology for chemical liberation of fibres from wood chips and other lignocellulosic materials. With cooking temperatures of 20-80degC above the boiling point of water and strong chemical such as sodium hydroxide, sulphide or sulphite, digesters had to be sturdy and big. When the first rotating digesters were replaced by stationary batch digesters or continuous chip plug digesters, the digester content was no longer mixed during the cooking process. Because of the harsh process conditions and stationary chip material it has been very difficult to make observations of the physical and chemical conditions prevailing inside industrial digesters. As a result, very little attention has been paid to gaining a more thorough understanding of the performance of industrial digesters.