Process for preparing cellulose solution and equipment therefor

The present invention provides a process for preparing a cellulose solution. NMMO with a relatively low concentration and non-activated pulp are continuously mixed online， the mixed premix is dewatered in evaporation dewatering equipment until an NMMO concentration suitable for swelling is achieved， then， sufficient swelling is carried out under this condition， and the uniformly-mixed and sufficiently swelled pre-swelling solution is subjected to depressurized evaporation dewatering and dissolving by thin-film-evaporation equipment thereby obtaining a high-concentration， uniformly-dissolved and excellently-uniformity cellulose solution. The present invention further provides continuous preparation equipment for the process for preparing a cellulose solution. According to the present invention， the conflict between uniform mixing and sufficient swelling during the preparation of a high-concentration cellulose solution is solved， and problems in storage and transportation safety caused by using high concentration NMMO in the conventional technologies are prevented.

本发明提供了一种纤维素溶液的制备工艺。将低浓度N-甲基吗啉-N-氧化物（NMMO）与未活化浆粕进行在线连续混合，所得混合预混料经蒸发脱水设备脱水至适合溶胀的NMMO浓度后，在该条件下进行充分溶胀；随后将混合均匀且充分溶胀的预溶胀料液送入薄膜蒸发设备中，通过减压蒸发脱水与溶解工序，最终得到高浓度、溶解均匀且均一性优异的纤维素溶液。本发明还提供了适配上述纤维素溶液制备工艺的连续化制备设备。本发明解决了高浓度纤维素溶液制备过程中均匀混合与充分溶胀之间的矛盾，同时规避了传统工艺中使用高浓度NMMO所引发的储运安全隐患。