Blanket Dynamics in Upflow Suspended Bed

• Main Authors: Shu Hsin Tuan, 蘇信團
• Other Authors: D J Lee
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/74855700530712755782

碩士 === 國立臺灣大學 === 化學工程學研究所 === 91 === A one-dimensional model for the spatio-temporal variation of solids fraction in the blanket considering both the hydrodynamic dispersion and the convection effects was proposed in this study. The model equation was a wave equation whose solution presented shock-wave like characteristic. The model output predicted that the distribution of the solids fraction in the blanket would firstly evolve to a uniform distribution at a lower solids fraction. Afterward the blanket would compact itself to another uniform distribution at a higher solids fraction. Experimental works with synthetic raw water coagulated with PACl suspended in a lab-scale suspended bed confirmed the theoretical predictions. The solids flux plot was constructed with underdosed, optimal, and overdosed suspensions. Change in coagulant dose would affect the blanket height and the response time. The solids flux curve was shifted accordingly. The “optimal’ operational condition for the upflow suspended bed that produced the lowest effluent turbidity was discussed.