Research On Structural Parameters And Industrial Application Of Water-Only Cyclone

In order to improve the separating coefficient, new structures for the overflow pipe and the taper of cyclone are explored and the effecting parameters are studied systematically applying a self-developed Water-only cyclone of 50mm in diameter. In addition, the cyclone was enlarged and applied successfully in industry.Structure parameters such as overflow diameter, underflow diameter and inserting depth of overflow pipe were modified as well as operating parameters as inlet pressure and feed concentrate. Consequently, it was studied how the yield and ash content of overflow vary regularly according to each parameter. It was found that the yield and ash content of overflow increased with the increasing of overflow diameter and feed concentrate, while decreased with the increasing of underflow diameter. An increase in feed pressure caused a slight decrease in the yield and ash content of overflow, too.Dimensional analysis was employed to determine the order of these structure parameters according to their effecting difference. The conclusion is: overflow diameter > underflow diameter > insert depth of overflow pipe. An empirical Model is built concerning the overflow yield and all the structure and operating parameters employing nonlinear regression. This model is proved to have a fairly high fitting accuracy and can be used in predicting theoverflow yield of cyclone with a relatively high accuracy.Tapers, including two single cones of 120 and 135 , two compound cones of 120-60 and 60-120 , and seven taper faces such as stepped and grooved cone, were designed. Accordingly the influence of these different taper shapes and taper faces were studied on the separating effect of cyclone. The results show that the increase of the taper angle causes an increase in the yield and ash content of overflow and the separation density. The compound cone of 120-60 showed a significant decrease in the yield and ash content of overflow comparing with that of 120 . Moreover, grooved and stepped cones can influence the practical separation density in a certain range.Likewise the effects of overflow pipes with upward-horn, downward-horn, and double-horn are compared with that of common overflow pipe. The conclusion is that the overflow pipe with double-horn gives higher yield and low ash content in clean coal, thus gives better separating effectOn the basis of primary assessment on the separating efficient of 120 single-cone, the possible deviation Ep is indicated to be about 0.14, and the imperfection I about 0.23. The low limit of effective separation can reach 0.074mm, and the desulfuring coefficient of pyrite can exceed 90%.The water-only cyclone was enlarged on the basis of structure study of 50mm cyclone. The enlarged cyclone of 150mm was applied in separation of low-ash clean coal and the re-separation of fine coal, and 350mm cyclone in the re-separation of middlings of Tun-Lan coal preparation plant. It is proved that the system operates properly and the economic benefit followed is significant.