Abstract:Working pressure P which directly influenced separation performance of grit separation module was the most important control parameter. Experimental results show that with the increasing of the working pressure, the processing capacity increases significantly linearly (R2=0.988 9) and the split ratio exponentialy (R2=0.993 1). Separation efficiency and enrichment ratio increase first and then remain stable. Boltzmann function model was emploged to fit the trend, the R2 being 0.975 7 and 0.987 8, respectively. Better separation performance can be obtained when the work pressure controls between 0.15~0.2 MPa, and the best separation performance can be obtained when the working pressure is 0.175 MPa. The separation efficiency η of the grit separation module is 48% and the split rate g is 0.17 under the condition that the cone angle is 20°, the overflow hole diameter Φ 22 mm, underflow port diameter Φ 13 mm and the working pressure is 0.175 MPa. If we drain the underflow sludge, which can increase grit discharge, thus the grit problem can be relieved.