水相喷雾干燥法制取聚碳酸酯粒料

The Preparation of PC Pellet by Water Phase Spray-drying

为了从光气化缩聚液中脱除溶剂并制取粒状聚碳酸酯,本研究对水相喷雾干燥法提出了独具特色的改进:(1)油相雾化流与载热水流的旋转方向呈逆向对流;(2)载热水流由浓缩塔的雾化段流入,由汽液分离段流出,消除了载热水流的短路现象;(3)浓缩液在冷却下发生凝胶化与固化作用,悬浮固体在旋切浆作用下发生淬碎作用;(4)含少量溶剂的淬碎物在简单水汽蒸馏作用下容易地脱除剩余溶剂,而制取无油的粒状聚磷酸酯。

In order to seperate solvent and prepare PC pellet from phosgenation polycondensation solution, an improvement withcharacteristics was made on water phase spray-drying process. (1)Oil phase spray flow and heat carrier water flow are contra-flow; (2)Heat carrier water flow gets into the tower at spraying section and gets out from the steam-liquid separating section,eliminating the short-pass of the water flow; (3)Concentrated liquid gelated and cured by cooling, suspended solid was breakeddown by a special screw; (4)The little solvent contained in the broken particles was removed easily by distillation, thus the oil-free PC pellet was prepared.