| Rotating Packed Bed(RPB) has been demonstrated to be a new type of high-efficient gas-liquid contactor by providing the centrifugal fields of several hundreds or thousands times gravity. The results shows that RPB intensely enhanced the liquid controlled mass transfer which can be up to the power of 1~2 orders of magnitude larger than that in a conventional packed bed. Cross flow and counter flow are the most common two kinds of structure in typical rotating packed bed, because of the difference of gas-liquid contact mode. In addition the flow field distribution of the internal fluid is not the same. The size of the mass transfer intensity is closely related to the unique characteristics of the flow field. Studying the effect of gas-liquid contact on mass transfer characteristics of RPB can provide further insight into the designing and application of RPB equipment.The performance of the high gravity equipment were usually studied and affected by the factors including the rotational speed, gas and liquid quantity. In this paper, design and development of two similar rotor size crossflow and countercurrent RPB, the gas flow can be up to 1200 m3/h. Using CO2~NaOH as the absorption system. Studying the effect of gas velocity, liquid spray density, gravity factors, gas residence time on the mass transfer surface area ae, liquid phase volumetric mass transfer coefficient kLa, liquid transfer unit height HOL and akPL?/. The mass transfer performance of the cross flow and counter flow with wire mesh packing and new star packing structure was studied.With the same operating conditions, the comparative study of the mass transfer characteristics of the cross flow and counter flow were studied. When the liquid spray density is less than 9m3/(m2·h), the mass transfer performance of the cross flow bed is better than that of the countercurrent flow. When the liquid spray density is greater than 9 m3/(m2·h), the mass transfer performance of the countercurrent bed is better than that of the cross flow bed. When the gas residence time is less than 0.17 s, the cross flow bed k La is larger than that of the countercurrent flow; when the gas residence time is more than 0.17 s, the flow bed kLa is less than that of the countercurrent flow. The mass transfer coefficients of the RPB with different references were compared and analyzed, and the experimental results were obtained. The totalvolumetric mass transfer coefficient of the same operating condition size similar to that of the counter current bed is 1.21-1.92 times of that of the flow bed. The comprehensive performance of two kinds of structure rotating packed bed is compared: When the gas velocity is greater than 0.71m/s, the comprehensive performance akPL?/ of the cross flow bed is better than that of the countercurrent flow. The counter flow bed is suitable for the treatment of small gas flow, and the cross flow bed is more suitable for industrial application.Research on the mass transfer characteristics in countercurrent Star packing RPB and crossflow Star packing RPB with the same operating conditions. At the same operating conditions, values of ae and k La of wire mesh were more than those of Star packing, the value of HOL was less than that of star packing, which demonstrated that mass transfer performance of wire mesh is better than that of star packing. This is mainly related to the wetting properties of the two packings. Comprehensive performance comparison: akPL?/ of star packing is smaller than wire packing, the overall performance of star packing is better than that of wire mesh. Comparison of different literature ae and kLa, this experiment used two fill the cross-flow and countercurrent RPB ae literature about four times, kLa about 3.44- 4.30 times the literature used in the experiments described in this cross-flow and countercurrent. This experiment used the two kinds of cross flow and countercurrent packing structure of RPB ae is about 4 times of the literature, while kLa is about 3.44~4.30 times of literature. The rotating packed bed is suitable for the amplification of the equipment.Values of ae and kLa of same size cross-flow and countercurrent RPB were correlated, a dimensionless correlation was established with the liquid Reynolds ReL, liquid Grashof number GrL, liquid Schmidt number ScL, liquid Froude number Fr L, liquid Weber number WeL.The results of this study may provide theoretical and practical basis for the selection and application design RPB... |
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