Research Of Sieve Tray Efficiencies Under Partial Reflux Condition

In this paper, continuous rectifications were conducted in a pilot distillation column which has4layers of sieve tray and with a size of750mm in diameter and4000mm in height. In this column, cyclo-hexane and n-heptane were chosen as the experimental system to investigate the plate location, pore diameter, hole area rate, F0factor and reflux rate on sieve tray and the whole tower efficiencies. All the operations were conducted with an outlet weir height of50mm. Two sets of Lweis-Matheson calculation were conducted separately under two different reflux rates (15and infinitely great), and fitted equations of the influence of Fo factor on the plate efficiencies are given. Results of the experiments show that: the changes of plate locations would remarkably influence the tray efficiencies, and usually the higher the plate location was, the lower the plate efficiency was; pore diameter and open area ratio not only relate to the processing capacity and applicable scope of sieve trays, but also relate to the plate efficiencies; when the reflux ratio is bigger than15, the regulating effect of R on plate efficiency was quite small. The bigger R was, the smaller the influence was.