Effect Of Droplets On Aerosol Particle Collection Efficiency In Wet Dust Removal Processes

Living environment has been improved with the accelerated development of China’s social and economy in the past decades. The requirements of citizen are no longer limited to the temperature, humidity and the speed, good and better indoor and outdoor air quality requirements are now becoming the new requirement of the people. Meanwhile the standards for controlling of pollutants concentration also have been promulgated hy the state, theretore how to remove contammants trom the ambient air becomes an important issue in china. In order to understand the mechanisms of air cleaning and the collecting of fine aerosols in the air, numerical simulation techniques were employed for analyzing and discussing the separation of particles from ambient air by droplets.The classical experimental data in the previous studies for aerosol collecting on droplets was used for the discussions, and gas-solid flow in the laminar and turbulent flow models are employed for the simulations, respectively. The flow field around a single and typical droplet is calculated for the simulation of particle motion, and the comparison of the experimental data and the simulation results in the current study under the same experimental conditions shows acceptable consistency.The numerical simulation and analysis about aerosol particles of the different diameters on the basis of the validated model were conducted. The results shows that factors influencing particle trajectory, concentrations and deposition state, such as droplet diameter, the velocity and particle diameter, have effects on the aerosol concentration distribution and impacting features in laminar flow. The results show that:the capture efficiency of the same diameter particle decreases gradually as droplet diameter increase; when the particle diameter is increased to same diameter of the droplet, the collection efficiency is gradually increased.In addition, the particulate trajectory, concentration distribution and deposition rates were also simulated and analyzed. The results show that the turbulent factors have significant impacts on the particle collection on droplets.The droplet diameter, velocity and particle diameter have different influences on the collection efficiency by droplets.Comparing the numerical simulation results, it can be found that the collection efficiency in the turbulent flow is greater than that of in laminar flow, the difference of the collection efficiency between coarse and fine particles, which varies with the diameter of the drop, is different in laminar and turbulent flows.