It is shown from CFD simulation and particle image velocimetry (PIV) measurements that the flow field around ring packing is impacted by their height/diameter ratio and inclination. The results indicate that it is better to decrease the height/diameter ratio of ring packing to intersify the separation processes in the packing bed. Baded on a systematic study, a new Plum Flower Mini Ring (PFMR) was developed to meet the demands of separation column intensification. A comparison of the PFMR, Pall Ring and Intalox Saddle in a 600mm diameter column with an air-oxygen-water system over a wide range of liquid loads is presented. It was shown from the experiments that the PFMR had a much lower pressure drop, much larger throughput and better mass transfer efficiency than Pall Rings and Intalox Saddles.

To characterize the flow instability in mechanically agitated vessels, digital particle image velocimetry (DPIV) was used to measure the near-instantaneous flow fields in a baffled, stirred vessel, equipped with a Rushton turbine impeller of large diameter ratio of impeller to vessel. From the measured near-instantaneous flow fields, distinct large-scale flow patterns were identified and the formation mechanisms of the patterns were explored via multi-scale analysis. Further investigations show that the flow patterns are rather complex. Macro-instability (MI) appears as a swith among those flow patterns. Spectral distribution function P(ƒ), equivalent to probability distribution function from a purely mathematical point of view, was introduced to extract information on MI fron the time series of the vorticity of the fluctuation velocity field. The two-dimensional distribution of MI and its dependence on Reynolds number were studied. Results show that probability analysis via spectral distribution function can be successfully used to quantify the relative intensity of macro-instabilities. Low-frequency, large-scale fluctuations of flow patterns were much more intensive in the lower and upper corner of the vessel than in the rest parts of the vessel. The fluctuations of flow patterns also had an offset to the core of the vessel due to the influence of baffles. Compared with visual observation technique, this new analysis method via DPIVis more objective and can be used to give deep understanding to the spatio-temporal properties of macro-instability.

The Pulsed packed column (PPC) uses pultation to enhance mass transfer. Systermat expertments (Spaay et al., 1971; Bender et al., However, only comentional packion such as Rasching rings and Pall rings were used in these experirenus. Packing types have been shown to inlluence the hydrodynumics and mass transfer characteristics of PPC (Bender et al., 1979; Simans et al., 1986). Several kinds of high efficiency packing, including randosn packing and structured packing, have been developed in recent years, but there are only a few studies on the characteristies of PPC (Hoting and Vogelpohl, 1996a, b) with these new packings. SMRs (Fei et al, 1991) are newfy devetoped mini rings with an elaborate geometrical design A photo of the SMR is shown in Figure 1. It has three afches and a lower height/diameter ratio (about 0.3), which has been shown to enhance the dispersion-coalescence cycle and contral the non-ideal flow of the two phases in the packing elements. Experiments (Fei et al., 1993) showed that the SMR has lower axial mixing and higher mass transfer etficiency than many corwentional packing, This, studies on the hydrodynamics and ruass transter characteristics of PPC with stainless steel SMR is presented in thas work. Experiments with cenamic and starless steel Rasching rings were also done for comparison.