| 摘要 |
The invention relates to a process for the continuous digestion of finely divided cellulosic material, such as wood chips. The finely divided material is passed, in a liquid-filled vessel (11), in the form of a continuous column of chips through an intake zone (B), a heating and impregnating zone (C), a digestion zone (D) and a washing zone (E), the temperature in the heating and impregnating zone (C) being kept lower than that in the digestion zone (D). In order to maintain a stable temperature profile and a stable chemical profile in these zones, the liquid (41) fed in with the chips is caused to flow through the column of chips in the intake zone (B) in the feeding direction of the chips at such a velocity, before the said liquid is drawn off (21), that the said column of chips is passed through the downstream impregnating zone (C), where impregnating liquid (42) is adjusted in counter-current to the column of chips moving forward in such a way that the heat capacity flux of the said impregnating liquid is at least equal to the heat capacity flux of the column of chips moving forward (Fig. 1). <IMAGE>
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