Experimental Study Of New Hydro-classification Cyclone Enlargement

Hydro-clones are mostly used in industrial production for thickening and classifying operations,but when used as classifying equipment,there is often a problem of bottom-fine entrainment,which significantly affects the separation effect of coarse coal slurry including CSS sorter,and the high ash and fine mud in the bottom flow can also cause pollution of fine coal products.In this thesis,based on the small cyclone which has been successfully applied in the industrial field,we develop a large fine classification hydro-cyclone and explore the influence of its structure and operation on the classification effect through industrial experimental research,in an attempt to reduce the bottom-fine entrainment and overflow coarse running.The specific research contents are as follows:Based on the similar theory,the design of fine classifying cyclone was scaled up,and the industrial test system for coarse coal slurry and the online monitoring system based on PLC and Configuration King were built to provide software and hardware guarantee for the industrial test.Three fitting models of the distribution curve were compared,and the compound hyperbolic tangent model was selected to evaluate the distribution curve in terms of the goodness of fit and relative error;it was concluded that the content of fine particle level,i.e.-0.2 mm particle level,in the bottom flow could be reduced to 23.83%,and the content of +0.2 mm particle level in the overflow could be reduced to 0.05% under the optimal bottom flow port and overflow port aperture.On the basis of determining the basic structure of the cyclone,the influence of the main operating parameters on the classification effect of the cyclone was investigated.The test results show that,when the content of-0.2mm in the feed is 67.03% and the concentration is 140.52g/L,the classification size tends to decrease first and then increase with the increase of the feed pressure,and the lowest classification size is224.02μm;the classification accuracy and classification efficiency tends to increase first and then decrease,and the highest classification efficiency can reach 83.6%.The classification accuracy and classification efficiency showed a trend of increasing first and then decreasing,and the highest classification efficiency could reach 83.6%,with the best classification accuracy at the inlet pressure of 0.16 MPa.The flushing water plays the role of secondary dispersion and cleaning for the materials in the near wall layer of the cone to a certain extent,and along with the gradual increase of the flushing water pressure,the grading size first increases and then decreases;the grading efficiency first increases and then decreases,and the best flushing water pressure is0.185 MPa flushing water when the content of-0.2mm in the feed material is 53.09%and the concentration is 149.12g/L,and the lowest possible deviation is 61.99μ m;the highest classification efficiency is 73.77%.The classification efficiency of the new fine classification hydro-cyclone is 25 percentage points higher than that of the original traditional classification cyclone,and the-0.2mm particle content in the bottom stream is 20 percentage points lower.