Research On Performance Of Continuously Tridimensional Mass-Transfer Parallel Flowtrays

Tower is the equipment of gas-liquid what can achieve separate operation such as rectifying and absorbing, etc. It is widely used in the field of chemical industry, petroleum chemical industry, petroleum. A new structure of parallel flow composite trays was presented to exploit high mass transfer efficiency tray suited for big column diameters, based on the mechanism that parallel flow trays can improve plate efficiency. New trays used characteristic configuration of downcomer, and they were combined with LLCT which has good performance. The hydrodynamics of new trays, such as the effect of liquid flux,gas speed,clear liquid height on dry-pressure-drop, wet-pressure-drop, entrainment, weeping, etc, and mass-transfer efficiency were measured and relevant correlations were obtained.Experiment's conclusion and analysis shows that pressure-drop of new trays which didn't refer to the distribution of cap, increased with the increasing gass speed and the increasing liquid flux. In the range of 88±25 m3·(m·h)-1 of liquid flux, entrainment depend on the clear liquid height and F-factor, and the effect of liquid flux on entrainment can be neglected. The weeping of new trays decreased with the increasing gass speed. If the weeping is less than 0.1kg/kg , liquid flux should be neglected. When the gas speed go down to critical point (gas speed in plate hole is about 12m/s), the weeping of ring flow start earlier than converged flow. If gas speed go on to decrease,the weeping will increased crazy. When the gas speed in the plate hold is lower than 8~9m/s, the weeping will beyond 0.1kg/kg. These hydrodynamics and mass-transfer efficiency taken together, liquid flux can be 100 m3·(m·h)-1 which is 30 percent higher than LLCT because of the parallel flow trays avoid form liquid stagnation zone of common countercurrent trays. And structure of several downcomer shorten the passageway and reduce the gradient of liquel level. The plate efficiency of ring flow and converged flow increased with the increasing gass speed and decreased with the increasing liquid flux. The plate efficiency are close to 90% with the increasing gas speed. And the efficiency of ring flow is higher than converged flow because of the different of length of passageway.