醋酸乙烯精馏塔3D594/595工况分析及改造措施

Work conditions analysis and improvement of vinyl acetate rectifying tower 3D594/595

对醋酸乙烯精馏塔 3D5 94 / 5 95工况存在的问题进行了考察 ,结果发现 ,该塔进料状态与塔径不相配 ,提馏段液相负荷过大 ,近液泛状态操作 ,返混严重。精馏段上升气流较小 ,回流比接近最小回流比 ,导致在进料板附近形成恒浓区。在该区域内醋酸乙烯停留时间延长 ,聚合物生成加快使筛孔堵塞加重。通过增加进料加热器 ,相应改变了灵敏板的位置及控制温度 ,从而延长了该塔的运行周期 ,并为今后此塔的改扩建提供了参考。

The work conditions of vinyl acetate rectifying tower 3D594/595 were inspected and analyzed.It was found that the feed in state didnt match case with tower diameter,stripping section being liquid phase over charge and operating under near liquid flooding state with heavy backmixing.The up gas stream of rectifying section was small and reflux ratio was near minimum reflux ratio that brought on the formation of concentration constant zone closed to charge plate.In this zone,the residence time of vinyl acetate prolonged and the accelerated formation of polymer made the blocking of sieve pores heavier.By the means of increasing heater for feed and correspondingly changing sensitive plate position and control temperature,the operating cycle of the tower was prolonged.This can give a reference to the renovation and expansion of the tower for the future.