In phase-separated synthesis, two fundamental factors control the formation of droplets in a reactor system: the turbulent integral length scale and the rate of droplet breakage and coalescence. In this paper, we report the evaluation and validation of the former in an oscillatory baffled column (OBC) using large eddy simulation (LES) and digital particle image velocimetry (DPIV), respectively. In LES the Navier-Stokes equations are spatially filtered, which eliminates eddies whose scales are smaller than a filter width. Large eddies are directly resolved, while small eddies are modelled using, sub-grid scale models that describe the interactions between the large eddies and the unresolved smaller scales. Eddies are the essential ingredient for mixing in OBC and the methodology of the LES is particularly suited for flows in OBC. In parallel to the LES work, a high-resolution DPIV is also employed. Since it works as a low-pass filtering system, which is analogous to the spacious filtering in LES, it is therefore possible to validate the numerical simulation using the DPIV technique. The results show that the turbulent integral length scale in the OBC is of an order around about 10(-3) m, and the Kolmogorov's time scale of a range from 0.2 to 24 ms depending on the oscillatory Reynolds numbers. Such information is vitally important in controlling chemical processes whose reaction time has an equal or similar value as the time scales shown here. We believe that the drop formation and subsequently size distribution in the OBC are also affected by these scales.