Study On Enhancement Of Mass Transfer Process And Performance Of Dust Collection In A Water-sparged Aerocyclone

Water-sparged aerocyclone(WSA)is a new type of gas-liquid mass transfer equipment with the breakup and atomization process of liquid jet in gas cyclone and the high-gravity effect of the cyclone field.To further enhance the gas-liquid mass transfer process in WSA and to explore the application of WSA in the field of air pollution control,the effect of separation space configuration,bottom baffles,air inlet position and solid particles in liquid phase on mass transfer performance of a water-sparged aerocyclone was comparatively studied by air stripping of ammonia from waste water and numerical simulation.Meanwhile,the total collection efficiency of a water-sparged aerocyclone for fine solid particles was studied by experiment of wet dust collection,in addition,the effects of velocity of air inlet,liquid jet velocity and average dust concentration on dust removal performance in the high pressure drop area of gas phases was investigated by theoretical analysis and experimentsThe research results indicated that the WSA with a conical structure exhibited better mass transfer performance and higher gas pressure drop,which was probably caused by a comprehensive effect of the better jet atomization,forming larger interfacial area between gas and liquid phase.The axial air inlet position has no effect on mass transfer performance,but moving air inlet position downward could reduce the gas pressure drop in WSA by about 10%,which was probably caused by abating the friction loss between the gas cyclone and the wall.The bottom standard baffles in the WSA could improve the mass transfer performance,and the effect is more pronounced with the increase of air inlet velocity,which was probably caused by intensifying the mixing effect between gas and liquid phases.The non-adsorptive solid particles could intensify gas-liquid mass transfer performance,mass transfer coefficient of liquid side kL,specific mass transfer area a,volumetric mass transfer coefficient kLa and mass transfer intensification factor E increase initially and decrease afterwards with the increase of solid concentration cs,in addition,kL,a,kLa increase with the increase of gas inlet velocity and liquid jet velocity,E decreases with the increase of gas inlet velocity and liquid jet velocity,further study show that the solid particles could increase a,kL and the surface renew frequency S,increasing the surface renew frequency S was the major mechanism.When the WSA was used to treat the dusty gas in which the content of PM 2.5 is 66.44%,the total efficiency of dust collection in a WSA is more than 93%,in the high pressure drop area of gas phase,the emprirical formula was developed correlating total efficiency of dust collection with operational parameters,?=98.67×Reg-0.013×Rel0.011,the total efficiency of dust collection increase initially and decrease afterwards with the increase of gas inlet velocity and liquid jet velocity,which was probably caused by decreasing penetration depth of liquid jet and reducing the probability of interaction between dust and liquid phase.The results of this paper could be used as a guide for the design of WSA with good mass transfer performance and optimizing the operating parameters.And also,the paper provided a pioneering work for the application of the WSA in the field of PM2.5 capture from air.