精馏过程多定态现象及其分析

精馏传质过程存在多定态现象 ,而产生多定态的原因有多种 .文中针对流量之间非线性转换产生的多定态 ,进行研究和分析 .当操作处于多定态区域时 ,塔内各塔板的温度与组成等参数的分布 ,以及塔顶和塔底产品浓度等参数都存在多种可能的数值 .对于一个处于多定态区域操作的工业塔 ,当某些操作参数产生波动或受外界微扰时 ,塔内各塔板的温度与组成等参数可能由正常的分布向不正常的分布突跃迁移 ,使塔的正常操作遭到破坏 .对多定态的实验结果和产生原因进行分析 ,结果表明理论上在一定条件下存在多定态的可能性 ,不同定态下的组成参数均能满足物料衡算和塔的分离能力检验

Phenomenon of Multiple Steady-State during Process of Rectification and Its Analysis

During processes of rectification transfer and mass transfer, there exists phenomenon of multiple steady state, which had been discovered and studied just in the recent decades. There are different types of multiple steady states, the multiple steady states caused by nonlinear conversion of flow rates is studied and analysed here. When the operation is in the zone of multiple steady state, the distribution of such parameters as temperature and composition at each tray within rectifying column as well as such parameters as product concentration at top and bottom of the column exhibit various possible values. With regard to a column where the operation is in a zone of multiple steady state, such parameters as temperature and composition at each tray within the column may jump abruptly from normal to abnormal distribution and thus the normal operation within the column may be destroyed whenever certain operating perameter fluctuates or encounters external perturbation. In this paper, an analysis is made on the experimental results and the contributing factors of multiple steady state. The analysis shows theoretically the possibility of the existence of multiple steady state under definite condition, it shows also that the composition parameters are able to meet the material balance and the test of separating power of the column.