Cone structure design for improving the separation performance of a water-only cyclone

Abstract

The cone structure of a water-only cyclone is the key factor affecting its separation performance. To improve separation performance, a tri-stage curved-cone (Type Ⅲ/C) water-only cyclone was proposed and designed based on conventional cones. The flow-field characteristics and separation performance of water-only cyclones were analyzed using numerical simulation. Results indicate that the proposed Type Ⅲ/C water-only cyclone has the following superior characteristics: the pressure drop can be reduced by up to 21.43% and tangential velocity by up to 10 m/s; there are three circulating vortex cores and a thicker suspended density layer in its cone section; a continuous 0.18 mm coal particle ascent path forms; and the maximum separation distance from ash particles is 10 mm. The Type Ⅲ/C water-only cyclone had an ash content in the clean coal of 2.34% and an ash content in its underflow of 75.28%; the recovery of clean coal was 35.13%, and the recovery of clean coal combustible was 77.81%. These indicators are better than those of other conventional cyclones.