筛板精馏塔的板效率研究

Research on tray efficiency of sieve tray

在直径为0.75 m,塔高4 m的不锈钢热模塔内,以正庚烷-环己烷为物系、在常压、全回流条件下,进行筛板塔传质效率的研究,选取孔径为13 mm和6 mm,开孔率为3.9%和6.4%的塔板,测试了这些塔板的气液相默弗里板效率,通过排列组合,考察了孔径、不同塔板位置和出口堰高对传质效率的影响,并进行了传质效果对比。此外还运用AIChE传质模型计算了默夫里板效率,并与实验值进行了比较。实验结果表明:在泡沫接触状态下,堰高的增加有利于板效率的提高,孔径6 mm的塔板传质效果较好,喷射接触状态下,堰高对传质效率没有影响;此外模拟计算的塔板效率值接近于实验值,研究结果为工业设计与放大提供了依据。

The mass transfer performance of sieve trays was studied in the distillation column with a diameter of 0.75 m and 4 m high column trays by using cyclohexane-heptane system as working fluid at atmospheric pressure and full reflux.Four kinds of sieve trays with the hole diameter of 13 mm and 6 mm,and the opening area of 3.9% and 6.4% were selected.The effects of structure,pore radius and outlet weir height on tray efficiency were studied.The Murphree tray efficiency for liquid phase in four floors of the column and the overall column efficiency were compared.Besides,the Murphree efficiency values were obtained by AIChE methods.The model values and experimental values for Murphree tray efficiency were compared.The experimental results show that appropriately increasing the outlet weir height can improve the sieve tray efficiency in the froth regime.The tray efficiency of 6 mm hole diameter is higher;the weir height has no influence on the mass transfer performance in the jet regime.AIChE method is more approached to the experimental result.These results can provide a foundation for industrial design and scale-up.