Sediment-containing sewage separation using intermittent-discharge columnar hydrocyclones

Abstract

Traditional hydrocyclones can be used for the concentration of sewage-containing sediments, but the low underflow concentration and the high content of fine particles result in a large subsequent dehydration workload. This study aimed to investigate the effect of columnar hydrocyclone column height on separation performance and the change in the internal flow field after the underflow orifice of the hydrocyclone was closed, so as to provide a theoretical basis for improving the ability to treat the sewage of the hydrocyclone. Numerical simulation was used to examine the change in the separation performance of the hydrocyclone and the effect of column height on the separation performance of the hydrocyclone in the case of the closed underflow orifice during intermittent discharging. The results indicate that a proper increase in column height was beneficial to improve the separation performance of the hydrocyclone. With the increase in the closing time of the underflow orifice, the particle content at the bottom of the hydrocyclone increased significantly. The experiment proves the feasibility of the intermittent discharge method in practice, and this working method can effectively increase the underflow concentration.