Controlling the turbulence intensity helps to reduce the energy consumption of the hydrocydone. In de-foulant hydrocyclone (DFH), reducing the energy consumption can improve the overflow kinetic energy to suck and flush away the foulants at underflow. In this study, a conical surface (CS) is inserted near the locus of zero vertical velocity (LZVV) to control the turbulence intensity of DFH. We investigated the effects of different sizes and positions of CS and the inlet velocity on the separation performance. The results showed that, owing to the presence of CS, the energy consumption of the NH was decreased by approximately 40% whereas the separation efficiency increased by approximately 5%. Moreover, the separation efficiency first decreased and then increased with the increase in inlet velocity, which was different from that of the NH without CS. Furthermore, we also found that radial particle migration mainly occurred at the cone bottom of the DFH. (C) 2020 Elsevier B.V. All rights reserved.