通过对泡点温度面具有代表性的两个三元共沸系统的连续精馏实验，考察了在进料组成位于泡点温度面脊（谷）上的情况下沿塔高的浓度分布，结果表明浓度分布曲线越过了脊（谷），馏出液和釜液组成落在脊（谷）的两侧．本文采用非线性常微分方程对共沸精馏塔的浓度分布进行模拟，提出了靠近脊（谷）的积分曲线求解方法，并从理论上对实验结果进行了讨论． Through the continuous rectification experiment of two ternary azeotropic systems with bubble point temperature surfaces, the concentration distribution along the tower height with the feed composition at the bubble point surface temperature (valley) was investigated. The results Indicating that the concentration profile crosses the ridges (valleys) and the distillate and caustic composition fall on either side of the ridges (valleys). In this paper, the non-linear ordinary differential equation is used to simulate the concentration distribution of azeotropic distillation tower. The integral curve solution near the ridges (valleys) is proposed. The experimental results are discussed theoretically.