Optimization of Hydrocyclone Performance in Sand Removal from Well Water (A Case Study of Drinking Water Wells in Mashhad)

Hydrocyclones are used for removing suspended solids such as silt and sand from water. In this study, all the factors involved in the performance of hydrocyclones were initially identified and listed before they were optimized using the Taguchi experiment design method. It was the objective of the present study to optimize the efficiency of hydrocyclones in removing sand from water. For this purpose, 18 hydrocyclones were designed and constructed to test all the variables affecting their performance including hydrocyclone inlet, overflow, apex, and body diameters as well as cylindrical, total, and vortex finder heights. Minimum (20 mg/l) and maximum (100 mg/l) concentrations of total suspended solids (sand) in the samples from the water wells in Mashhad city along with the observed particle distribution were used in the optimization. Statistical analysis of the results showed that the ratio of the inlet and overflow diameters to that of the hydrocyclone was 0.225 and that the ratio of the apex diameter to that of the hydrocyclone was 0.15. Also, the ratios of the cylindrical and vortex finder heights to the total height of the hydrocyclone were 0.12 and 0.08, respectively. Under optimum conditions, sand removal efficiency varied from 95.9% to 98.4% in different experiments. This is while a value of 97.2±1.1% was obtained as the result of three tests in the hydrocyclone optimized in this experiment. Comparison of the mass removal efficiencies predicted by the Taguchi method and the values measured in the optimal hydrocyclone tests showed that both sets of data were very close and substantially high. Moreover, it was found that the geometric elements obtained in this study were generally in the range of minimum and maximum ratios proposed for hydrocyclones used in mining. These ratios may, therefore, be recommended for use in the construction of real-scale hydrocyclones for sand removal from water.