| 摘要 |
The present invention relates to a process for preparing pulp by means of a so-called displacement process in batchwise cooking, in which process chips are fed, using feeding devices, into the digester, in which air between the chip pieces is removed, the digester is filled with black liquor, which preheats and impregnates the chips and removes the remainder of the air from the digester, the digester is pressurized and hot black liquor and white liquor are pumped into the digester in a suitable sequence and proportion, at the same time displacing the black liquor which was previously fed in, the temperature in the digester is raised to the final cooking temperature using steam, the cooking liquid is displaced with cool washing liquid after the cooking reactions have achieved the desired degree of cooking, and the cooked pulp is removed from the digester by pumping it to a discharge container; and in which process a gas space G is arranged in the upper part of the digester 10, or in connection with this upper part, in which gas space G the gas which has been removed from the chip pieces and the fibres, and has arisen during the cooking processes, is collected and evacuated therefrom through a pipe connection 48. <IMAGE>
|
