10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Large Scale PM2.5 Cleaning System for Targeted Area with Several Square Kilometers
SHENG-CHIEH CHEN, Min Tang, Qingfeng Cao, David Y. H. Pui, University of Minnesota
Abstract Number: 1665 Working Group: Control and Mitigation
Abstract The Xi’an 60 m (L) x 45 m (W) x 60 m (H) first generation SALSCS has been successfully evaluated and results showed that it can effectively pull urban polluted air containing high PM2.5 into the tower by the nature convective flow created by solar irradiation. The high concentration PM2.5 was efficiently removed by well-equipped filter bank before the airflow being released back to the ambient. This first generation SALSCS is intended to be scaled up to create a large quanity of clean air to clean up a large urban area. In the second generation SALSCS, the cleaning mechanism of the filtration was modified to raindrop scavenging, a considered green technique. Theoretical calculations have shown that a higher PM2.5 removal efficiency could be achieved by reducing the size of water droplets. However, in practical application a reasonable droplet size should be controlled to around 100 to 500 µm for avoiding their reentrainment into the tower. This second generation SALSCS has 20 m x 20 m x 14 m in size and has been built in Salt City of Jiangsu province, China. Experimental evaluation showed that the PM2.5 can be collected with >80% efficiency. The PM2.5 laden water will be drained into a collecting pond where the water will be processed to remove the PM2.5, and the clean water can be recycled and supplied to the sprayers. This will then provide a low cost and sustainable operation for the SALSCS. To be mentioned that the second generation SALSCS is designed to accommodate the use of solar induced convective flow or electrical powered fan as flow driving force. When the nature convective flow is applied, its size also needs to be enlarged. A third generation SALSCS is being developed for a targeted area in densely populated urban area. It has a reduced size but high clean air delivery with the aid of large array of high powered fan. Besides, a special feature of this SALCSC is that the clean air will directly deliver to ground level, a reverse flow direction then the first and second generation SALSCSs. Theoretical calculations showed that a 20 m x 20 m x 20 m third generation SALSCS can produce clean air of ~1000 m3/s flow rate with 80% PM2.5 removal. It is able to clean up an area of 1 km2 effectively.