A high efficiency parallel plates wet scrubber (PPWS) for acidic gases

• Main Authors: Sheu, Shiang-Ru, 許香茹
• Other Authors: Tsai, Chuen-Jinn
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/42790317179884231038

碩士 === 國立交通大學 === 環境工程系所 === 101 === Wet scrubbing system is widely used in high-tech industries to remove the exhaust gases. However, traditional wet scrubber has poor removal efficiency toward acid-bases gas such as HF, HCl and NH3, etc., especially for those in low concentration and thus fails to meet emission standard promulgated by Taiwan EPA. In this study, a high removal efficiency parallel plate wet scrubber (PPWS) was designed to meet this problem. In the PPWD, traditional packing material was replaced by the multi-parallel plate. The plates were coated with nano-TiO2 gel to enhance its wettability. That will let exhaust passing through the plates with large contact surface area (327 m2/m3) and well absorbency, and further increase its removal efficiency in low pressure drop condition. Simulated exhaust gases (< 2 ppm) in low concentration mixed with HCl, HNO3 and CH3COOH were used for testing the removal efficiency of the PPWS. Results show that when the gas flowrate is 1.62 CCM, gas retention time in the multi-parallel plate (Tg) is 0.5 s and the liquid/gas ratio (L/G) is 18.5 L/m3, the removal efficiency of the PPWS toward HCl, HNO3 and CH3COOH are 99.51 ± 0.48 , 99.13 ± 0.87 and 99.15 ± 0.46 %, respectively, while the gas flowrate is increased to 8.1 CCM, the Tg is decreased to 0.1 s and the L/G is decreased to 3.7 L/m3, the corresponding removal efficiency are decreased to 98.34 ± 1.62, 97.42 ± 2.08 and 94.94 ± 3.48 %, respectively. That is, the removal efficiencies of the PPWS toward the HCl and HNO3 are able to meet the emission standard when the Tg and L/G are 0.1 s and 3.7 L/m3, respectively, while for the CH3COOH, the Tg must be extended to 0.5 s allowing its removal efficiency to achieve the emission standard.