分级旋流器分选作用与分选旋流器分级作用的试验研究

Experimental study on the separation effect based on density in hydrocyclone and the classification effect based on size in water-only cyclone

为考查颗粒粒度与密度对旋流器分级、分选的影响,采用20°锥角的分级旋流器与130°锥角的分选旋流器对<3 mm粒级的煤泥进行了分离试验,对其产品进行筛分及分粒级浮沉,得到了不同粒度、密度颗粒在旋流器产品中的分配规律。结果表明:20°锥角旋流器以分级为主,但对各粒级均存在一定的分选作用,其中对<0.125 mm粒级分选作用最强,这是导致溢流低灰精煤跑粗及底流细泥夹带的根源;130°锥角旋流器以分选为主,对较低密度颗粒不存在分级作用,随密度的增大,分级作用开始显现,对高密度颗粒存在明显的分级作用,这是导致溢流高灰细泥污染的根源。

In order to study the effect of particle size and density on the classification and separation of cyclones, sepa- ration experiments of 〈3 mm coal slimes were carried out on a hydroeyelone with 20~ cone and a water-only cyclone with 130° cone. Screen and sink-and-float analysis of each size fraction were conducted and the distribution law of particles with different size and density was obtained. The results show that classification predominates in hydrocyelone with 20° cone, while density-based separation effect does exist in each size fraction, and the density-based separation effect is especially significant for 〈0. 125 mm fraction, which is the origin of low ash coarse coal loss into the vortex finder and fine coal slime entrainment in the underflow. Density-based separation predominates in water-only cyclone with 130° cone while significant classification does occur for particles of higher density ,which is the origin of high ash contaminate in the vortex finder. This size-based classification does not occur for low density particles, but becomes apparent for higher density.