| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for stably keeping Kappa number of blow pulp within the predetermined target value range in a columnar vessel type continuous digester. SOLUTION: The columnar vessel type continuous digester is supplied with a cooking agent and a pulp raw material comprising finely ground lignocellulose material from the top of a columnar vessel V, and comprises, in the vessel V from the upper position, a penetration zone A for penetrating the cooking agent into the pulp raw material, a digestion zone B for dissolving/separating lignin components into the cooking agent and a washing zone C for washing the cellulose components in the pulp raw material, wherein the black liquor produced by containing lignin components separated from the pulp raw material into the cooking agent is extracted from an extraction strainer 4 installed at the middle section of the vessel V and cellulose components are taken out from an outlet device 6 installed at the lower section of the vessel V. The Kappa number of the cellulose component is adjusted to keep within the predetermined range of the number by controlling the dissolved lignin concentration, H factor, remaining alkali content and sulfidity of the black liquor in each of the penetration zone A, the digesting zone B and the washing zone C. COPYRIGHT: (C)2005,JPO&NCIPI
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