Hydraulic flocculators are principally characterized by their volume (which determines the time of flocculation) and the water level difference between inlet and outlet (which determines the average energy dissipation). Within these constraints, however, the designer has many degrees of freedom, such as the average water depth, the number and spacing of baffles, the length of the gap at the baffle ends, and the degree to which adjoining baffles overlap. In an earlier paper (Haarhoff 1998), these variables were systematically reduced to a number of critical ratios, and a comprehensive mathematical framework was presented whereby hydraulic flocculators can be designed once these ratios are fixed. In this paper, these ratios are further investigated by computational fluid dynamics (CFD) to find their optimal values. The validity of CFD modelling is first verified by comparing experimentally measured velocities in two flocculators against modelled velocities for similar hydraulic conditions. CFD is then used to systematically optimize the three critical design ratios for flocculator design. The optimal ratios are considered to be those that cause the least deviation from the average G-value; addressing the concern that there may be large G-value differences at different points in the flocculator.
Skip Nav Destination
Close
Close
Article navigation
Research Article|
May 01 2001
Towards optimal design parameters for around-the-end hydraulic flocculators
Johannes Haarhoff;
1Department of Civil and Urban Engineering, Rand Afrikaans University, PO Box 524, 2006 Auckland Park, South Africa
Fax: + 27 11 489 2148; E-mail: jh@ing1.rau.ac.za
Search for other works by this author on:
Jeremia J. van der Walt
Jeremia J. van der Walt
2Magalies Water, Private Bag X82327, 0300 Rustenburg, South Africa
Search for other works by this author on:
Journal of Water Supply: Research and Technology-Aqua (2001) 50 (3): 149–160.
Citation
Johannes Haarhoff, Jeremia J. van der Walt; Towards optimal design parameters for around-the-end hydraulic flocculators. Journal of Water Supply: Research and Technology-Aqua 1 May 2001; 50 (3): 149–160. doi: https://doi.org/10.2166/aqua.2001.0014
Download citation file:
Close
Citation
Johannes Haarhoff, Jeremia J. van der Walt; Towards optimal design parameters for around-the-end hydraulic flocculators. Journal of Water Supply: Research and Technology-Aqua 1 May 2001; 50 (3): 149–160. doi: https://doi.org/10.2166/aqua.2001.0014
Download citation file:
Close
Impact Factor 1.319
CiteScore 2.0
27
Views
0
Citations