The Study Of Mass Transfer Performance For The Cross-type Valve Tray At Partial Reflux

In this experiment, the feed was cyclohexane and n-heptane mixture and the column diameter was 0.75 m with tower height of 4 m, having 40 m2 plate reboiler and 30 m2 condenser plate. We researched the open porosity, the valve hole kinetic energy factor, reflux ratio and other factors versus Murphree tray efficiency of the cross-type valve tray. The open porosity was 8.22%,11% and 13.56%. Valve hole kinetic energy factor was 4～16 (m/s)(kg/m3)0.5. Reflux ratio variable was ∞,15,10,8.At the corresponding experimental operating conditions, the tray efficiency of cross-type valve tray and F1 type valve were compared. In addition, the experimental value,calculated value of AIChE efficiency model, Chen-Chuang efficiency model and improved of Chen-Chuang efficiency model were compared. Through the above experiment,we find that on the third tray, the tray efficiency is more stable than other trays; at the same reflux ratio, with the valve hole kinetic energy factor increases, the greater is the opening porosity, The smaller is the tray efficiency and the greater is the fluctuations in tray efficiency; under the experimental conditions, the tray efficiency for the opening porosity of 11% is more stable and less volatile; at the same opening porosity, the reflux ratio decreases, the tray efficiency fluctuation increases; the tray efficiency for cross-type valve tray is better than F1 type valve tray. We find that AIChE efficiency model does not fit the cross-type valve tray and improved of Chen-Chuang efficiency model is found more suitable in 11% of the tray opening porosity. For the industry to predict the efficiency of cross-type valve trays, it provides a reference experience.