Experimental data and theoretical analysis of particle removal efficiency in a novel hydraulic separation unit

This research investigates the removal efficiency of a novel hydraulic separation unit - a counter-current upflow column that hydraulically separates sediment particles based on size - for washing contaminated soils with remediation technology. Significant attributes of the new design include the capability for continuous loading and the use of a side-entry tee as a slurry port. Eight tests were performed in a bench-scale model of the hydraulic separation unit to experimentally determine the impact of washwater and slurry flow rates on removal efficiency. After analyzing the experimental results qualitatively, a theoretical residual power approach was used to predict removal efficiency and analyze soil/fluid interaction under the varying flow rates. Optimal separation was obtained for three tests. The residual power analysis revealed two conditions for the optimal tests: (1) the slurry flow rate dominates the approach flow rate at the slurry mixing-jet and the power analysis is a good predictor; and (2) the approach flow rate dominates separation, fluidizing both fine and coarse particles, and agreement with the power analysis is poor.