降低腈纶溶剂NaSCN系统含杂的研究

针对超滤技术在腈纶溶剂二步法硫氰酸钠系统应用中存在的问题开展试验研究,主要考察了不同类型超滤膜(内、外压膜差异以及膜丝固定形式差异)的投用效果、产料反冲洗及进料方式对膜运行周期的影响等。通过试验可知:投用超滤膜对二步法料液中水不溶物有一定的去除效果;采用新型超滤膜(膜丝一端固定),其过滤周期是传统两端固定超滤膜的2.5倍;内压式超滤膜不适用于处理二步法硫氰酸钠料液;增加产料反冲洗能显著提高过滤时间、过滤总流量。经过优化,基本解决了存在的膜通量无法恢复、过滤时间短、通量衰减过快等问题,为产业化改造提供依据。

Study on Reducing Impurity Content in Acrylic Fiber Solvent NaSCN System

An experimental study was carried out on the problems existing in the application of ultra filtrationtechnology in acrylic fiber solvent two-step NaSCN system. The differences between different types of ultrafiltration membranes(internal and external pressure membranes and the difference of fixed type of membranewire) application effect, backwashing of production material and influence of feeding mode on membraneoperation cycle, etc were researched. The experiments result show that the ultra filtration membrane has acertain removal effect on water insoluble substances in the feed liquid of the two-step process. A new ultrafiltration membrane is adopted(one end of membrane wire is fixed), and the filtration period is 2.5 times ofthat of the traditional ultra filtration membrane fixed at both ends. Internal pressure ultra filtration membraneis not suitable for treating NaSCN feed liquid in two-step process. Increasing the backwashing of the producedmaterials can significantly improve the filtration time and the total filtration flow. After optimization, theexisting problems such as unrecoverable membrane flux, short filtration time and too fast flux attenuation arebasically solved, which provids a basis for industrial transformation.