E-curve and F-curve for the Tanks-in-Series Model of MacMullin and Weber
The residence time distribution curve (RTD-curve or E-curve) is the response to a pulse experiment. On the other hand, the response to a step experiment is called the F-curve.
This Demonstration plots both the E-curve and the F-curve for a number of tanks in series.
The E-curve and F-curve are given by the following relationships (MacMullin and Weber, 1935):
where is dimensionless time and is the number of tanks in series. For a single tank, the E-curve and the F-curve correspond to the mixed tank case, while when is very large, for example equal to 100, the E-curve and the F-curve correspond to the plug flow reactor case.