A Study On The Characteristics Of Mass Transfer In Rotating Packed Bed

Rotating Packed Bed (RPB), which takes centrifugal force as high-gravity force to intensify the mass transfer and chemical reaction processing between gas and liquid phases, is so new efficient a equipment that it has a bright prospect in industry.In this paper, the water is used to absorb SO2 in the air, several self-made conductance sensors are set in the packing to pick up the concentration information of the liquid, and an online measurement computer system is set up. The concentration distribution of liquid along the radius direction was measured the first time. The experiment includes both counter-current flow and parallel-current flow , the influence of gas flow rate, liquid flow rate, rotating speed, SO2 concentration at gas inlet on the concentration distribution and volume mass transfer coefficient distribution along the radius direction are investigated in the paper. The results indicate that: 1. Both the concentration distribution and the volume mass-transfer coefficient distribution along the radius direction are non-liner. In counter-current flow flow, they increase rapidly near the outer edge of packing and tardily near the inner edge of packing, where it is on the other way round in parallel-current flow flow. 2. The liquid concentration inside packing of RPB increases when gas flow rate, rotating speed or the SO2 concentration at gas inlet increases, but decreases when the liquid flow rate increases. 3. In counter-current flow, the volume mass-transfer coefficient increases from the inner to the outer of packing, except it is larger at the No. 1 measured point than that at No. 2 point, and it increases rapidly near the outer edge of packing but tardily near the inner edge. In parallel-current flow flow, the volume mass-transfer coefficient decreases from the inner to the outer of packing, except that of No. 1 measured point is lower than that of No. 2, and it varies rapidly near No. 2 measured point but tardily near the outer edge of packing. 4. The volume mass-transfer coefficient inside packing of RPB increaseswhen gas flow rate, liquid flow rate, or rotating speed increases, while decreases slightly when the SO2 concentration at gas inlet increases.According to the experimental values, an empirical correlation of the volume mass-transfer coefficient along the radius direction inside packing is given: incounter-current flow, while in parallel-current flow,Based on the Surface Renewal Theory, a mass transfermodel is established to simulate the mass transfer processing inside packing of RPB, and the calculated values fit well with the experimental values.