The Measurement Of The Effective Interfacial Area In Rotating Packed Bed And Its Cavity Zone

Nowadays, the existing research on the rotating packed bed (RPB), mainly focused on the mass transfer of the packing zone and the mass transfer of the cavity zone as a whole, which hardly exhibites the exactly contribution of the mass transfer of the packing to the RPB. Based on the chemical absorption of CO2in NaOH and the molecular diffusion theory, we established a detection method of the effective interfacial area in a RPB and the effective interfacial area in the cavity zone, which can distinguish the mass transfer in the cavity zone from that in the whole RPB.Under the operational conditions, the measurements of the effective interfacial area in rotating packed bed and its cavity zone were based on chemical absorption of CO2in NaOH, which can be treated as a pseudo-first-order reaction. We found the effective interfacial area in the cavity zone was about1.5×102. Meanwhile, almost1/4the overall mass transfer took place in the cavity zone under our experimental conditions. As the effective interfacial area in the packing zone was very closed to the surface area of the packing, the mass transfer of the packing zone can be separated from that of the cavity zone when measuring the effective interfacial area.The experiments detected the effect of the temperature, the mixed gas flow rate, the rotational speed and the liquid spray density on the effective interfacial area of the RPB and its cavity zone. The effective interfacial area in the rotating packed bed and its cavity zone was measured by fixing the other three variations at the temperature ranged from278.15K to303.15K, the mixed gas flow rate ranged from550L·h-1to800L·h-1, the rotational speed ranged from300r·min-1to1500r·min-1and the liquid spray density ranged from212L·m-2·h-1to390L·m-2·h-1. It was found that the four variations have the same effect on the effective interfacial area in rotating packed bed and its cavity zone under the operational conditions. The experimental results showed the temperature and the gas flow rate had no effect on the effective interfacial area. The effective interfacial area increased with the rotational speed and the liquid spray density.The experiments proved that the four variations have the effect on the effective interfacial area in rotating packed bed by removing parts of the packing.