Research On Classification Mechanism Of SCX Superfine Classifier And Equipment Design

Superfine classifier is one of the most important basic operation in the powder industry. With the rapid development of materials science ,high requirements are proposed for the preparation of powder,such as lower limits on diameter size,narrower standard deviations on size distribution, and the like. Classifier seems very important as a final equipment of dominating product size, grade width and distribution of size. Based on CFD and theory of air solid two-phase, SCX superfine classifier was designed considering dispersion, classification jet, and seal, through analyzing flow field characteristic of superfine classification and numerical simulation was used.The physical and chemical characteristics of powder have important effect with classification,GCC of Bao Xing factory was chose, through test analysis, its characteristics such as composition, size, density, whiteness etc. were found.The quality of particle dispersing is directly influencing the classifying effect of classifier's. Based on the mechanism of particles agglomeration, discuss the ways of the dispersion of particles, bring up a air dispersion way of bottom feeding. FLUENT code was used to simulate its geometric parameters, made the correlative curve of local particle concentration and average particle concentration to explain the quality of particle dispersing. Acquires a group optimum objectives.Recognize and master the flowing characteristics of classifying flow field have great valuable significance with designing classifier. In this study, numerical simulation was adopted to investigate the flowing characteristics of between blades, annular region and the flow distributing of rotor rate, based on tradition turbo classification, acquires the preferably design goals of blades quantity, annular region width.The classifying efficiency would fall easily due to carry-under in the side wall since the thinning of powder. Jet classifying was drew into set up complex classifier flowing according to Coanda Effect in turbo flowing, and the motion track produce angle deflexion in the light of particle size, reduce the carry-under , and numerical simulation was adopted to analyze the structure of jet.The quality of the seal has much influence on the final product of the classifier. A new type of seal equipment of initiative airflow was developed to aim at the leakage phenomenon of mechanical labyrinth seal of the classifier and FLUENT code was used to simulate its geometric parameters and operational parameters. Through statistical analysis of X-Y plot data which were obtained from numerical simulation to discuss the connections between velocity standard deviation,pressure standard deviation of spill airflow and each structure paramater of seal area,inlet pressure and acquires the critical dimensions of seal structure and the prussure controls parameters.Complete SCX400 prototype manufacturing, by contrast experiments show that make use of air dispersion structure, jet structure , seal structure of initiative airflow can achieve better efficiency grading and classification accuracy, the correctness of the numerical simulation results was verified. Another machine experimental data show that SCX400 classifier grading an average average classification efficiency was about 86%, can get high classification efficiency and classification accuracy.