Effect Of Liquid Atomization On Mass Transfer Intensification In Rotating Packed Beds

Previous studies by the author has shown that gas-liquid mass transfer intensification in a rotating packed bed (RPB) is in large part the result of intense atomization of the liquid that occurs when the liquid strikes the rotating bed and is pulled through the packing by the intense centrifugal field. The objective of this dissertation is to further understand the phenomena of gas-liquid mass transfer intensification in a RPB by means of modeling, mass transfer experiments, and highspeed strobe light photography.A special RPB machine is designed and constructed. Its liquid distributor can rotate independently in either direction at any speed up to 1450RPM. The rotor is a 12mm thick bed with three windows on both sides for photography. The packing employed is a reticulated Ni-Cr alloy wire gauze. The wire has as a diameter of 0.264mm. The packing is of 240mm inner diameter, 400mm outer diameter and 12mm axial thickness. The packing mass is 216.5g, with a specific surface area of 436m²/m³ and porosity of 93%.The water is deareated by N₂ flowing counter-currently to the liquid. The range of the operational parameters in the mass transfer experiments are listed below:* : (+) for clock-wise direction; (-) for counter-clock-wise direction.** : to the reference of rotor: (absolute rotating speed of liquid distributor - rotating speed of rotor)The rotating of liquid distributor has remarkable influence on mass transfer: (l)Mass transfer performance will significantly deteriorate when liquid distributor rotates synchronously with the rotor. For instance, at 0.75m³/hr liquid flow rate, 2.5m³/hr gas flow rate and 800RPM rotor rotating speed, synchronously rotating of liquid distributor can decrease average K₁a_e as much as about 13% comparing with the conditions when there is 200RPM in rotating speed between distributor and rotor. (2)The greater the relative rotating speed between the liquid distributor and rotor, the higher average mass transfer coefficient. More than 6% increase at average K₁a_e can be found when relative rotating speed between rotor and distributor rises from 900RPM to 1200RPM at 0.5m³/hr liquid flow rate, l.0m³/hr gas flow rate and 600RPM rotor rotating speed. (3)The higher absolute rotating speed of liquid...