Keywords
airflow velocity,
flour recovery,
bran–flour mixture,
particle classification,
separation efficiency,
pneumatic separator,
flour-milling technology.
How to Cite
Abstract
This study aimed to determine the optimal airflow velocity for recovering flour particles from bran–flour mixtures using pneumatic separation. A laboratory-scale pneumatic separator equipped with an air compressor, receiver, regulating valve, rotameter, separation chamber, and fraction collection system was designed and tested. Experiments were conducted using 100 g samples of bran–flour mixture obtained from the final stage of industrial flour milling, with airflow velocities ranging from 0.56 to 0.70 m/s. The results showed that flour recovery efficiency strongly depends on airflow velocity. At 0.56 m/s, fine-particle entrainment was incomplete, whereas excessive velocities above 0.65 m/s reduced separation selectivity due to turbulence and coarse-particle carryover. The highest efficiency was achieved at 0.62 m/s, where flour recovery reached approximately 73%. The findings confirm that optimized airflow velocity improves separation efficiency, reduces mechanical loading on sieving surfaces, and enhances the technological performance of pneumatic flour classification systems.
References
Kasymov, F.O.; Yunusov, B.I. Application of pneumatic separation methods for flour extraction from bran mixtures. In Proceedings of the Young Chemists Conference; Tashkent, 2010; pp. 248–252.
Kasymov, F.O.; Artykov, A.A. Mathematical modeling of pneumatic separation of bulk materials. In Proceedings of the Republican Scientific Competition; Samarkand, 2008; pp. 117–119.
Kasymov, F.O.; Yunusov, B.I. Determination of drag coefficient in pneumatic separation of bulk materials. In Proceedings of the Young Chemists Conference; Tashkent, 2009; pp. 134–137.
Rhodes, M. Introduction to Particle Technology, 2nd ed.; Wiley: Hoboken, NJ, USA, 2008.
Geldart, D. Gas Fluidization Technology; Wiley: Chichester, UK, 1986.
Kunii, D.; Levenspiel, O. Fluidization Engineering; Butterworth-Heinemann: Oxford, UK, 2013.
Perry, R.H.; Green, D.W. Perry’s Chemical Engineers’ Handbook, 9th ed.; McGraw-Hill: New York, NY, USA, 2018.
Jaworek, A.; Krupa, A. Modern pneumatic separation techniques. Powder Technology 2021, 389, 15–29.
Yang, W.C. Handbook of Fluidization and Fluid-Particle Systems; CRC Press: Boca Raton, FL, USA, 2017.
Zhao, Y.; Chen, X. Pneumatic classification of fine particles in food-processing industries. Powder Technology 2022, 398, 117–126.
Li, J.; Wang, H. CFD investigation of airflow behavior in pneumatic separators. Chemical Engineering Research and Design 2021, 169, 241–252.
Kumar, P.; Singh, R. Energy-efficient pneumatic conveying systems for powder materials. Advanced Powder Technology 2023, 34(4), 103–115.
Zhang, L.; et al. Experimental analysis of particle–fluid interactions in pneumatic classifiers. Separation and Purification Technology 2020, 251, 117326.
Silva, M.; Rocha, F. Modern trends in aerodynamic particle separation systems. Powder Technology 2024, 421, 119–134.
This work is licensed under a Creative Commons Attribution 4.0 International License.