摘要 |
<p>A method of defibring lignocellulose-bearing raw material with a polysulphide-bearing cooking liquor in a continuous digester. According to the present invention, cooking liquor is mixed into the raw material which is to be defibred before the cooking, and the cooking liquor is allowed to absorb into the raw material at a temperature which is at maximum approximately 130 °C. After that, cooking liquor used for the absorption is separated from the raw material which is treated in this way, the separated cooking liquor is heated to a temperature of approximately 140-170 °C, after which the generated hot cooking liquor is mixed back into the treated raw material, possibly together with a fresh feed of cooking liquor fresh feed, and the raw material is defibred by means of the hot cooking liquor in a continuous digester in order to generate pulp which has a desired kappa number. Thus, in the cooking stage, alkaline cooking liquor which was originally dosed into the absorption process, and only the temperature of which was increased, is used; liquor to be absorbed is not removed, nor is any fresh liquor fed into the cooking, or if it is, only small amounts of it.</p> |