Design Characteristics of the Hydrocyclone for the Recovery of Coal Fines

摘要

The relevant design parameters and flow variables of the standard hydrocyclone have been identified. Two experimental systems have been designed and constructed so that the flow rate, inlet area, vortex finder length and diameter, underflow diameter, length of hydrocyclone chamber and cone angle can all be varied, one at a time, while all the other variables are held constant. Dimensional analysis was used to guide the experiments. Initially spheres were used to model solid particles. Data has been taken using spheres ranging in size from 0.03175 m to 0.09525 m with specific gravities varying from 1.05 to 2.10. This range of specific gravities was chosen so as to contain the specific gravity range of coal which varies from 1.2 to 1.6. The specific gravities of the waste materials in gob (clay, shale, pyrite and sandstone) are greater than 2.00. It was later shown that the data taken using spheres compare well with random shaped coal particles with approximately the same mean diameters as the spheres. The sphere data can be used to select a hydrocyclone configuration to perform a specific separation task. In this research, the sphere data was used as a guide to select a configuration to separate coal fines from gob material. Good coal fines recovery from gob samples has been achieved on a batch basis. An an example, Table 1 gives data from one sample showing a combined recovery of 99% by weight with a product rating of 0.95. Another significant finding in this research is that dynamic similitude as predicted by dimensional analysis can be verified using the two experimental systems with hydrocyclones with different diameters. Thus the data taken can be used to scale up or down as the need arises. 10 references, 13 figures, 1 table. (ERA citation 10:009529)