Research On Performance Of Hydrodynamics Of Double Swirl-Flow High-Velocity Column

Aiming at improving the throughput of gas phase, this paper devises a new plate device called high-velocity column. It takes advantage of cyclone tube, which has high gas velocity and high separation efficiency of gas and liquid, transplants cyclone tube onto the plate and designs new passage for liquid to enter the center of blades directly. So that, the liquid can contact and transfer mass with gas immediately after discharging from the exit, and make use of the centrifugal force, resulting from the rotating gas, to achieve separation. This new structure changes jet type for bubbling type, which is the tranditional way of contacting between gas and liquid. It means the gas maintains for continue phase during the contact process, while the liquid becomes dispersed phase. Also, the separation proceeds at the same time of contact, as a result, the space in the tower is fully used.At first, this paper carries out numerical simulation analysis of gas flow field in single cyclone tube, and gets some properties:(1) Because of the diversion effect of blades, the gas velocity distribution is very conductive to the gas-liquid contact and separation. The circumfluence emerges in the axial direction contributes to the repeatedly mixing, contacting and mass transferring of gas and liquid; high tangential velocity aids in the separation of droplets, reducing the entrainment; small radial velocity provides more contact time for gas and liquid;(2) Under the joint effect of low pressure area in the center of the blade outlet and static pressure of liquid level in the downcomer, the liquid could successfully enter the cyclone tube With the increasing capacity of gas phase, the downcomer minimum level increases; the pressure drop of cyclone tube mainly concentrates on blade outlet.Then, the specific structure of the high-velocity column is designed based on the results of simulation. The experiment study of performance on dry plate pressure drop and wet plate pressure drop are conducted, after machining the equipment and putting up the platform. The following conclusions can be drawn:(1) The dry pressure drop of this column improves with the increasing of gas flow rate, and the pressure drop of different layers of plate decrease from the bottom to the top;(2) With the gas flow rate growing, the wet pressure drop significantly increases, while with the liquid flow rate growing, it increases slightly; when the gas flow rate is low, wet pressure drop of the three layers of plate are almst the same,when the gas flow rate is high, the wet pressure of bottom tray is larger than the middle tray, of which it is larger than the top tray.On the basis, the load performance of high-velocity column is studied further. Experiment studies of the flooding、weeping and dry plate are conducted, the conclusions below can be obtained:(1) With the growth of liquid flow, the flooding velocity decreases gradually, while the weeping velocity almost stays unchanged;(2) There is no obvious lower limit of liquid flow, while the upper limit decreases slightly when the gas flow increases.