The Influence Of Plate Structure On Mass Transfer Efficiency For Cross-Type Valve Tray

Mass transfer efficiency of cross-type valve tray was investigated in a rectifying column with diameter of0.75m and four trays under total reflux condition. The influences of operating parameters such as heating, reflux temperature, and equipment parameters such as overflow weir height, hole area percent, heat loss on the efficiency of the second and third tray and the full column efficiency were studied. The experimental results showed that, as the heating increased, the trends of efficiency curve were different for trays with different hole area percent. The whole column efficiency for the reflux temperature of73-76℃was about6%higher than that of61-66℃. When overflow weir height increased from30mm to50mm, mass transfer efficiency was improved by10%, and the effect was particularly obvious in the foam situation, but the growth would gradually reduce and the instability would increase while the overflow weir height continuously increased to70mm. The tray efficiency was stable for the second and the third tray in the column, their mean value can be used as the criteria to the tray efficiency. The tray efficiency was high and relatively stable when its hole area percent was8.22%or13.56%. Under50mm weir height, the tray efficiency of cross-type valve was about5%higher than that of F1valve, and it was more stable than that of wave-directed floating valve. The comparison of model results of AIChE and Garcia-Fair with experiment value was carried out. Smaller heat loss ratio of main equipment was more beneficial to the mass transfer process.