Industry News

Summary of Design Theory of Turbo Air Classifier

As is known to all, the Turbo Air Classifier is widely used to the process of classifying the fly-ash, while it still needs to be improved in the area of removing the contradiction between the requests to high grade of particles and the classifying efficiency, classifying accuracy, as well as large handling capacity. What’s more, the problems of high energy consumption and serious abrading of components are also to be solved. Recently, according to some characteristics of the fly-ash relatively to the classification, the domestic experts make some researches on the classifying theory of the particles and put forward the SLK Class Theory based on the gas-solid flow theory. Furthermore, the experts combining the practices make some designs on the SLK classifier structures and some experiments on the model machines, as well as some reaches and analysis on the industrial application examples, through the numerical stimulation analysis of the gas-solid flow.

By the improvement to the forced eddy classification theory, the SLK Class Theory can: make insurance to the high efficiency of classification and the valid reduction of energy consumption; classify quickly to limit the residence time in the class area for the particles, consequently reducing the agglomeration and the particle back-mixing and improving the efficiency and accuracy of the classification, which at the meantime can reduce the velocity gradient of the separating area and the abrading of the components; the preliminary classifying of the inertia can preliminarily separate some of coarse particle and enlarge the throughput of the classifier; the high pressure produced by the gas sealing high-speed rotate vane can increase the accuracy of classifying; the preliminary separating is used to separate the materials preliminarily, which is beneficial to the following classifying, as well as separate some hard sundries to avoid the breakdown of components.

The results of the analysis of SLK show: the “Z” type rotor vane with both inside and outside of 30°can effectively eliminate the inertial anti-cyclone phenomenon easily appearing in the vortex, which can make the classifying field more evenly and steady; the “L” type guide vane makes the speed of the airflow getting into the classifying field be similar to the speed of the edge of the guide vane, which can realize the quick classifying and reduce the speed differences of the airflow in the classifying field, as well as reduce the abrading of the vanes; the “L” type guide vane of 55°can make the path of the airflow deflect to realize the inertial classifying; the airflow sealing structure consisted of the sealing vane of caster angle being 60°and the sealing ring below the vanes by 15 to 20mm can effectively keep the particles from crossing; the airflow preliminary system employed to the scattered of materials in the concave cavity and cleaning facilities of thick powder fluidization, which can realize the segregating the particles and the preliminarily segregating hard sundries.

The domestic experts based on the analysis and numerical simulation results of the classifying theory, design structures of the classifiers, including the “L” type guiding vanes, “Z” type rotor vanes, classifying field structures, circulating spatial structures of the classifying area, cleaning facilities of thick powder fluidization and so on.