The Impact of Water Distribution System on the Internal Flow Field of EGSB by Using CFD Simulation

Abstract:

The internal flow field of EGSB (Expanded Granular Sludge Bed) reactor was investigated by using CFD simulation. A three-dimensional Eulerian–Eulerian two phase (sewage-granular sludge) fluid model was applied to investigate the impact of water distribution system on the internal flow field by considering the ratio α of hole area to reactor area. Results showed that the flow state of sludge granules changed periodically when the sludge bed reached a stabilization stage, and every cycle included two periods (U period and D period), where U stands for up-flow of the granular sludge and D represents down-flow. Keeping the upward-flow velocity of reactor at 3 m/h and reducing ratio α from 1.44% to 0.25%, the flow state of the two periods changed differently and was closely related to the height of reactor. Besides, the ratio α could affect the homogeneity of sludge granules, which could further influence the performance of the reactor. In addition, a validation experiment was conducted to verify the practical applicability of the fluid model, a good relationship between simulation and experiment was discovered, which further confirmed that the ratio α of water distribution system has significant impact on the internal flow field of EGSB.

• Periodical: Applied Mechanics and Materials (Volume 614)
• Pages: 596-604
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.614.596
• Online since: September 2014
• Authors: Hua Wang, Jie Ding*, Xian Shu Liu, Nan Qi Ren
• Keywords: CFD, EGSB, Internal Flow Field, Water Distribution System

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