Abstract: A new approach to determining bubble point or dew point of a binary mixture has been proposed. From an equilibrium still operating steadily at a constant pressure, a portion of the equilibrium binary solution (its composition x1(0) to be evaluated) is replaced by an equal amount of solution having a known composition x1(1). If the equilibrium temperature before and after the replacement remains unchanged, i. e. T(0) - T(1)=0, then x(0)=x1(1) and the bubble point[T(1), x1(1)] is thus obtained. On the contrary, an inequality of T(0) and T(1) indicates x1(0)≠x1(1). In the latter case, pure component 1 or 2 is added in successive small increments to adjust the temperature in the still to the neighborhood of T(0), and then the replacement is repeated by a new solution of composition x1(2). The foregoing procedure is repeated until | T(n-1)-T(n)| or | x1(n-1)-x1(n)| comes up to the desired precision and the final point[T(n), x1(n)] is the bubble point of the system. In a similar way, the dew point could be obtained by replacement of the equilibuium vapor in the still.

摘要： 用已知组成为x_1~(1)的溶液对恒压下稳定运行的平衡釜中的平衡液相(其组成x_1~(0)为待求量)作等质量代换.若代换前后的相平衡温度差T~(0)-T~(1)=0,则x_1~(0)=x_1~(1),即得一泡点(T~(1),x_1~(1));否则,x_1~(0)≠x_1~(1),此时向釜中加入组分1或组分2使温度回到T~(0)附近,改用已知组成为x_1~(2)的溶液作代换.如此反复,直至|T~(n-1)-T~(n)|或|x_1~(n-1)-x_1~(n)|达到所需精度,最后的点(T~(n),x_1~(n))即为泡点.对平衡汽相作同样代换可得到露点值.