THERMAL SCIENCE

International Scientific Journal

INFLUENCE OF SECONDARY AIR ON THE FLOW FIELD OF NGZF CLASSIFIER

ABSTRACT
Aiming at the problems of uneven material dispersion of traditional air classifier, NGZF classifier with downward air inlet fabric method is designed. In order to investigate the classification law of the classifier and the effect of secondary air on the flow field of the classifier, this paper utilizes ANSYS-FLUENT 19.2 software to simulate the internal flow field and conducts material experiments using the response surface method. The simulation results demonstrate that with the rise of the secondary air volume, the overall flow field distribution tends to be appropriate, and the washing flow field created by the secondary air does not interfere with the primary flow field. However, when the secondary air is too big, it will generate turbulence in the axial velocity in the guide cone zone. The discrete phase model indicated that the secondary air would re-screen the misclassified fine particles. Response surface experiments with calcined petroleum coke showed that by setting the cut particle size at 50 μm and maximizing the classification accuracy, the ideal operating parameters were a rotor speed of 1037.4 rpm, a primary air volume of 429.6 m3 per hour, and a secondary air volume of 50.2 m3 per hour. This work not only provides a novel approach for the design and development of air-flow classifiers but also gives theoretical direction for their implementation in industrial production.
KEYWORDS
PAPER SUBMITTED: 2024-03-24
PAPER REVISED: 2024-05-12
PAPER ACCEPTED: 2024-05-23
PUBLISHED ONLINE: 2024-08-18
DOI REFERENCE: https://doi.org/10.2298/TSCI240324170Z
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2024, VOLUME 28, ISSUE No. 6, PAGES [4637 - 4653]
REFERENCES
[1] Karunakumari, L., et al., Experimental and Numerical Study of a Rotating Wheel Air Classifier, AIChE Journal, 51 (2005), 3, pp. 776-790, 10.1002/aic.10349
[2] Shapiro, M., Galperin, V., Air Classification of Solid Particles: a Review, Chemical Engineering and Processing, 44 (2005), 2, pp. 279-285, 10.1016/j.cep.2004.02.022
[3] Guizani, R., et al., Effects of the Geometry of Fine Powder Outlet on Pressure Drop and Separation Performances for Dynamic Separators, Powder Technology, 314 (2017), June, pp. 599-607, 10.1016/j.powtec.2016.10.025
[4] Yu, Y., et al., Analysis of Numerical Simulation Models for the Turbo Air Classifier, Materialwissenschaft und Werkstoffechnik, 53 (2022), 5, pp. 644-657, 10.1002/mawe.202100130
[5] Sun, Z., et al., The CFD Simulation and Performance Optimization of a New Horizontal Turbo Air Classifier, Advanced Powder Technology, The International Journal of the Society of Powder Technology, 32 (2021), 4, pp. 977-986, 10.1016/j.apt.2021.01.041
[6] Liu, R., et al., Matching of Air Inlet Velocity and Rotor Cage's Rotating Speed of Turbo Air Classifier (in Chinese), Chemical Engineering, 43 (2015), 3, pp. 41-45
[7] Zeng, Y., et al., Numerical and Experiment Investigation on Novel Guide Vane Structures of Turbo Air Classifier, Processes, 10 (2022), 5, 844, 10.3390/pr10050844
[8] Ren, W., et al., Design of a Rotor Cage with non-Radial Arc Blades for Turbo Air Classifiers, Powder Technology, 292 (2016), May, pp. 46-53, 10.1016/j.powtec.2016.01.024
[9] Yu, Y., et al., Effect of the Rotor Cage Chassis on Inner Flow Field of a Turbo Air Classifier, Materialwissenschaft und Werkstofftechnik, 52 (2021), 7, pp. 772-780, 10.1002/mawe.202000153
[10] Liu, R., et al., Effects of Axial Inclined Guide Vanes on a Turbo Air Classifier, Powder Technology, 280 (2015), Aug., pp. 1-9, 10.1016/j.powtec.2015.04.034
[11] Zhao, H., et al., Effects of the Impeller Blade Geometry on the Performance of a Turbo Pneumatic Separator, Chemical Engineering Communications, 205 (2018), 12, pp. 1641-1652, 10.1080/00986445.2018.1464918
[12] Yu, Y., et al., A New Volute Design Method For the Turbo Air Classifier, Powder Technology, 348 (2019), Apr., pp. 65-69, 10.1016/j.powtec.2019.03.015
[13] Zhao, D., Zhang, S., Effect of Volute Structure on Classification Performance of O-Sepa Classifiers(in Chinese), China Powder Science and Technology, 21 (2015), 6, pp. 20-24
[14] Ren, C., et al., Influence of Air Guide Vanes on the Flow Field in a Vortex Air Classifier, Chemical Industry and Engineering Progress, 38 (2019), 9, pp. 3988-3994
[15] Elsayed, K., Lacor, C., The Effect of Cyclone Inlet Dimensions on the Flow Pattern and Performance, Applied Mathematical Modelling, 35 (2011), 4, pp. 1952-1968, 10.1016/j.apm.2010.11.007
[16] Yu, Y., et al., Design of the New Guide Vane for The Turbo Air Classifier Design eines neuen Austrittsleitrads fur Turbo-Luftsichter, Materialwissenschaft und Werkstofftechnik, 54 (2023), 2, pp. 196-206, 10.1002/mawe.202200108
[17] Yu, Y., et al., The Influence of Air Inlet Lay-Out on the Inner Flow Field for a Vertical Turbo Air Classifier, Physicochemical Problems of Mineral Processing, 59 (2023), 6, 175859, 10.37190/ppmp/175859
[18] Yu, Y., et al., Influence of Guide Vane on Dispersion of Aggregates Near the Guide Vane in a Turbo Air Classifier, Powder Technology, 434 (2024), 119344, 10.1016/j.powtec.2023.119344
[19] Lin, T., et al., Exploring the Factors Affecting the Efficiency of the O-Sepa Separator, China Cement, (2020), 7, pp. 95-97
[20] Li, B., et al., Development and Application of DS-M Type Ultra-Subdivisional Sorting Machine, Cement Engineering, 3 (2020), pp. 33-35
[21] Sun, J., et al., Structural Analysis And Improvement of the O-Sepa Powder Separator, Cement, 2 (2013), pp. 35-37
[22] Ren, C., et al., Effect of Air Guide Vanes on the Flow Field in a Vortex Air Classifier, Chemical Progress, 38 (2019), 9, pp. 3988-3994
[23] Xu, H., Improvement of Unreasonable Air Inlet Duct Arrangement of O-Sepa Separator, Cement, 10 (2012), 10, pp. 61-62
[24] Li, Q., et al., Effects of a Guide Cone on the Flow Field and Performance of a New Dynamic Air Classifier, Processes, 10 (2022), 5, 874, 10.3390/pr10050874
[25] Mou, X., et al., The CFD-Based Structural Optimization of Rotor Cage for High-Efficiency Rotor Classifier, Processes, 9 (2021), 7, 1148, 10.3390/pr9071148
[26] Jia, F., et al., A New Rotor-Type Dynamic Classifier: Structural Optimization and Industrial Applications, Processes, 9 (2021), 6, 1033, 10.3390/pr9061033
[27] Braun, R. M., et al., Fine Dry Comminution of Calcium Carbonate in a Hicom Mill with an Inprosys Air Classifier, Minerals Engineering, 15 (2002), 3, pp. 123-129, 10.1016/s0892-6875(01)00217-5
[28] Zeng, C., et al., Effects of Secondary Air on the Classification Performances of LNJ-36A Air Classifier, Chemical Industry and Engineering Progress, 34 (2015), 11, pp. 3859-3863
[29] Wei, L., Sun, M., Numerical Studies of the Influence of Particles' Size Distribution Characteristics on the Gravity Separation Performance of Liquid-Solid Fluidized Bed Separator, International Journal of Mineral Processing, 157 (2016), Dec., pp. 111-119, 10.1016/j.minpro.2016.10.004
[30] Sun, Z., et al., Experimental and CFD Study on a Cyclonic Classifier with New Flow Pattern, Advanced Powder Technology, The International Journal of the Society of Powder Technology, 30 (2019), 10, pp. 2276-2284, 10.1016/j.apt.2019.07.007
[31] Petit, H. A., et al., Evaluation of the Performance of the Cross-Flow Air Classifier in Manufactured Sand Processing Via CFD-DEM Simulations, Computational Particle Mechanics, 5 (2018), 1, pp. 87-102, 10.1007/s40571-017-0155-6
[32] Sun, Z., et al., The CFD Simulation and Optimization of the Flow Field in Horizontal Turbo Air Classifiers, Advanced Powder Technology, 28 (2017), 6, pp. 1474-1485, 10.1016/j.apt.2017.03.016

© 2026 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence