A New Rotor-Type Dynamic Classifier: Structural Optimization and Industrial Applications

Abstract

Due to the inadequate pre-dispersion and high dust concentration in the grading zone of the turbo air classifier, a new rotor-type dynamic classifier with air and material entering from the bottom was designed. The effect of the rotor cage structure and diversion cone size on the flow field and classification performance of the laboratory-scale classifier was comparatively analyzed by numerical simulation using ANSYS-Fluent. The grinding process performance with an industrial classifier was also tested on-site. The results revealed that an inverted cone-type rotor cage is more suitable for the under-feed classifier. When the rotor cage’s top-surface diameter to bottom-surface diameter ratio was too large or too small, the radial velocity and tangential velocity at the outer surface of the rotor cage greatly fluctuated. Furthermore, the diameter of the diversion cone also affected the axial velocity and radial velocity of the flow field. Models T-C(1-0.8) and T-D(1-0.7) were determined as the best rotor cage structures. Under stable operating conditions, the classification efficiency of the industrial classifier was 87% and the sharpness of separation was 0.58, which meet the industrial requirements for classification efficiency and energy consumption. This present study provides theoretical guidance and engineering application value for air classifiers.

Design of a shelf pneumatic classifier for separating a polydisperse mixture of granulated superphosphate

“…Centrifugal pneumatic classifiers are used to separate finely dispersed materials with a particle size of not more than 50-100 µm [7]. For the separation of granular materials with a particle size of 1-4 mm, these classifiers are not suitable since they require increased energy costs for pumping air flow through the working volume of the device.…”

Research and Optimization of Operating Parameters of a Rotor Classifier for Calcined Petroleum Coke

“…Aiming at the problems of uneven material dispersion and serious wear of guide vanes, some scholars researched and designed a new rotor classifier and carried out numerical simulation and optimization of the internal structure [25][26][27]. To date, although many studies have been carried out to optimize the operating parameters, the results presented showed that there are differences in the optimum operating parameters for different classifiers and materials, and few studies have been reported on the calcined petroleum coke classification experiments.…”