Investigation of the Effect of Duct Geometry on Drying Air Flow in Conventional Grain Dryers by Porous Media Approach
Abstract
It is a traditional practice to store many agricultural products after drying, ensuring that they are used all year round. Mixed counter flow air drying is one of the most common and traditional methods in the bulk drying process. In this application, the air flow produced by the air channels placed in the dryer bed is forced to flow through the grains in the opposite direction to the grain flow. The moisture contained in the grains is thrown out of the dryer through forced convection. However, it is expected that the air ducts installed in the dryers should not obstruct the flow of grain and provide the best possible drying performance. In this study, computational fluid dynamics (CFD) modeling for a counter-flow grain dryer was performed and the effect of the geometry of the drying channels on the process was investigated. Fluent 2020 R2 commercial software was used for 2-D flow modeling through the dryer. The airflow in the grain zone, modeled as porous media, was included in the calculation for three different geometries of the dryer air ducts (circular, angular, and straight). A constant temperature boundary condition (37°C) was applied for the air ducts in which the drying air circulated without mixing with the grain. As an output of the analysis, the dryer outlet temperature and differential pressure variation along the flow were calculated for 5 different inlet velocities (between 0.005-0.25) to determine the behavior of different air flow rates in the drying process. The increase in the inlet velocity increased the pressure difference and consequently the stability of the flow for all models. The outlet temperature decreased by about 2.5 °C with a 5-fold increase in velocity. The results showed that the sufficient outlet air for moisture removal depends on the structure of the porous medium and the flow geometry. For this analysis, the best flow was found to be for the circular cross-section model and the outlet temperature could be at acceptable levels.
Keywords
References
- H. Duan, H. Tong, A. Zhu, H. Zhang ve L. Liu, Effects of heat, drought and their combined effects on morphological structure and physicochemical properties of rice, Journal of Cereal Science, Vol. 95, no. 103059, 2020.
- E. Elert, Rice by the numbers: A good grain, Nature, Vol 514, no. 7524, p. S50+, 30 Oct. 2014.
- P. C. Coradi, C. H. P. Fernandes ve &. J. C. Helmich, Adjustment of mathematical models and quality of soybean grains in the drying with high temperatures, Revista Brasileira de Engenharia Agrícola e Ambiental, vol. 20, no. 4, pp. 385-392, 2016.
- Z. M. Shad ve G. Atungulu, Post-harvest kernel discoloration and fungi activity in long-grain hybrid, pureline and medium-grain rice cultivars as influenced by storage environment and antifungal treatment, Journal of Stored Products Research, Vol. 81, no. ISSN 0022-474X, pp. 91-99, 2019.
- B. J. Olorunfemi ve S. E. Kayode, Post-Harvest Loss and Grain Storage Technology- A Review, Turkish Journal of Agriculture-Food Science and Technology, Vol. 9, no. 1, p. 75–83, 2021.
- N. L. de Menezes, L. L. Pasqualli, A. P. Piccinin Barbieri, M. D. Vidal and G. M. Conceição, Drying temperatures on physical integrity, physiological quality and chemical composition of rice seeds, Pesquisa Agropecuária Tropical; Goiânia, Vol. 42, no. 4, pp. 430-436, 2012.
- N. Donla, Y. Matsushita and Y. Ogawa, Influence of postharvest drying conditions on resistant starch content and quality of non-waxy long-grain rice (Oryza sativa L.), Drying Technology, vol. 36, no. 8, pp. 952-964, 2018.
- L. P. Mussi, A. O. Guimarães, K. S. Ferreira ve N. R. Pereira, Spouted bed drying of jambolão (Syzygium cumini) residue: Drying kinetics and effect on the antioxidant activity, anthocyanins and nutrients contents, LWT - Food Science and Technology, cilt 61, no. 1, pp. 80-88, 2015.
- M. K. d. Guzman,S. Parween, V. M. Butardo, C. M. Alhambra, R. Anacleto, C. Seiler, A. R. Bird, C.-P. Chow ve N. Sreenivasulu, Investigating glycemic potential of rice by unraveling compositional variations in mature grain and starch mobilization patterns during seed germination, Nature Publishing Group UK-Scientific reports, vol. 7, no. 1, p. 5854, 2017.
- T. J. Siebenmorgen, R. C. Bautista ve P. A. Counce, Optimal harvest moisture contents for maximizing milling quality of long-and medium-grain rice cultivars, Applied Engineering in Agriculture, Vol.23, no. 4, pp. 517-527, 2007.
- G. H. Lang, B. A. Rockenbach, C. D. Ferreira ve M. & de Oliveira, Delayed drying interval of red rice: Effects on cooking properties, in vitro starch digestibility and phenolics content, Journal of stored products research, Vol. 87, no. 101613, 2020.
- S. Cenkowski, S. Pabis and D. S. Jayas, Grain Drying: Theory and Practice, New York: John Wiley & Sons, 1998.
- Mortaza Aghbashlo et al., Influence of drying conditions on the effective moisture diffusivity, energy, Energy Conversion and Management, p. 2865–2871, 2008.
- M. Danismaz and C. Demirtaş, Investigation of the Relationship Between the Core Temperature of Hazelnuts, International Journal of Computational and Experimental Science and Engineering, pp. Vol. 7-No.1, pp. 29-34, 2021.
- P. C. Coradi, Â. F. C. Lemes, S. J. Ibagé, A. Müller ve C. Z. Alves, Mathematical Modeling of Drying in a New Concept of Silo-Dryer-Aerator and the Quality of Soybean Seeds, 2018.
- P. Coradi ve Â. F. Lemes, Experimental prototype of silo-dryer-aerator of grains using Computational Fluid Dynamics (CFD) system, Acta Scientiarum - Technology, vol. 41, no. e36949, 2019.
- P. Przystupab, W. Wojciech and J. Nowaka, Methods for asssessıng energy effıcıency, Agricultural Engineering, vol. 23, no. 2, pp. 39-47, 2019.
- H. Scaar, G. Franke, F. Weigler, M. Delele and E. T. &. J. Mellmann, Experimental and numerical study of the airflow distribution in mixed-flow grain dryers, Drying Technology, vol. 34, no. 5, pp. pp. 595-607, 2016.
- H. Silva, C. Schepke, C. da Cruz Cristaldo, D. de Oliveira and N. Lucca, "An Efficient Parallel Model for Coupled Open-Porous Medium Problem Applied to Grain Drying Processing," Latin American High Performance Computing Conference, High Performance Computing, vol. 1540, p. pp 250–264, 2021.
- C. W. Cao, D. Y. Yang ve Q. Liu, Research on modeling and simulation of mixed flow grain dryer, Drying Technology, vol. 24, no. 4, pp. 681-687, 2007.
- F. Weigler, H. Scaar ve J. Mellmann, Investigation of particle and air flows in a mixed-flow dryer, Drying Technology, cilt 30, no. 15, pp. 1730-1740, 2012.
- T. Oksanen, "Controlling air flow in recirculating mixed flow batch dryer with double bed mode," Computers and Electronics in Agriculture, pp. Volume 149, Pages 133-138, June 2018.
- S. Ergun ve A. A. Orning, Fluid Flow through Randomly Packed Columns and Fluidized Beds, Ind. Eng. Chem., American Chemical Society, vol. 1, no. 241, p. 1179–1184, 1949.
- L. Amiri, S. A. Ghoreishi-Madiseh, F. P. Hassani ve A. P. Sasmito, Estimating pressure drop and Ergun/Forchheimer parameters of flow through packed bed of spheres with large particle diameters, Powder Technology, cilt 356, pp. 310-324, 2019.
- A. Klinger, Artificial Patterns, IEEE Transactions on Software Engineering, vol. 4, pp. 301-306, 1977.
- S. Pabis, D. Jayas ve S. Cenkowski, Grain Drying: Theory and Practice, New York: John Wiley & Sons, 1998.
- S. Ergün, "Fluid flow through packed columns," Chemical Engineering Prog., Vol. 48, pp. 89-94, 1952.
- M. Helsen, J. Mayerhofer, N. Govaerts, H. Parmentier ve L. Jeanmart, Experimental investigation of pressure drop in packed beds of irregular shaped wood particles, Powder Technology, vol. 205, no. 1–3, pp. 30-35, 2011.
- Glover, P.W.J., Luo, M. The Porosity and Permeability of Binary Grain Mixtures. Transp Porous Med 132, 1–37 (2020). https://doi.org/10.1007/s11242-020-01378-0.
- N. H., Abou-El-Hana ve M. A.Younis, Pressure Drop Through Shelled Corn As Affected By Aırflow Rates, Moısture Content And Aır Temperature, Process Engıneerıng, vol. 25, no. 3, pp. 944-956, 2008.
Geleneksel Tahıl Kurutuculardaki Kanal Geometrisinin Kurutma Havası Akışına Etkisinin Gözenekli Ortam Yaklaşımıyla İncelenmesi
Abstract
Pek çok tarım ürünün kurutulduktan sonra depolanması geleneksel bir uygulamadır ve bu şekilde yıl boyu kullanılması sağlanır. Hasadı yapılan tahılın depolama ömrünün artırılması için nem içeriğinin kabul edilebilir seviyelere (genellikle <%15) indirilmesi gerekir. Yığın kurutma prosesinde karışan karşıt akışlı havayla kurutma, en yaygın ve geleneksel yöntemlerden biridir. Bu uygulamada, kurutucu yatağına yerleştirilen hava kanalları sayesinde üretilen hava akışı, tahılların içerisinden tahıl akışına ters yönde akmaya zorlanır. Tahılların içerdiği nem zorlanmış taşınım yoluyla kurutucudan dışarıya atılır. Ancak, kurutuculara yerleştirilen hava kanallarının hem tahıl akışını engellememesi hem de mümkün olan en iyi kurutma performansını sağlaması beklenir. Bu çalışmada, karşıt akışlı bir tahıl kurutucu için hesaplamalı akışkanlar dinamiği (HAD) modellemesi yapıldı ve kurutma kanalları geometrisinin prosese etkisi incelendi. Kurutucu içerisindeki 2-boyutlu akış modellemesi için Fluent 2020 R2 ticari yazılımı kullanıldı. Gözenekli ortam olarak modellenen tahıl bölgesindeki hava akışı, kurutucu hava kanallarının üç farklı geometrisi (dairesel, açısal ve düz) için hesaplamaya dâhil edildi. Tahıla karışmayan kurutma havasının havanın dolaştığı hava kanalları için sabit sıcaklık sınır koşulu (37 °C) uygulandı. Analiz sonucunda, farklı hava akış hızlarının kurutma prosesindeki davranışını belirlemek için 5 farklı giriş hızının (0,005-0,25 arası) kurutucu çıkış sıcaklığı ve akış boyunca fark basınç değişimi hesaplandı. Giriş hızındaki artış, tüm modeller için basınç farkını ve buna bağlı olarak akışın kararlılığını artırdı. Çıkış sıcaklığı ise hızın 5 kat artmasıyla yaklaşık 2,5 °C düşüşe sebep oldu. Elde edilen sonuçlar, nem atma için yeterli çıkış havasının gözenekli ortamın yapısına ve akış geometrisine bağlı olduğunu gösterdi. Bu analiz için en iyi akışın dairesel kesitli model için olduğu ve çıkış sıcaklığının kabul edilebilir seviyelerde olabileceğini ortaya koydu.
References
- H. Duan, H. Tong, A. Zhu, H. Zhang ve L. Liu, Effects of heat, drought and their combined effects on morphological structure and physicochemical properties of rice, Journal of Cereal Science, Vol. 95, no. 103059, 2020.
- E. Elert, Rice by the numbers: A good grain, Nature, Vol 514, no. 7524, p. S50+, 30 Oct. 2014.
- P. C. Coradi, C. H. P. Fernandes ve &. J. C. Helmich, Adjustment of mathematical models and quality of soybean grains in the drying with high temperatures, Revista Brasileira de Engenharia Agrícola e Ambiental, vol. 20, no. 4, pp. 385-392, 2016.
- Z. M. Shad ve G. Atungulu, Post-harvest kernel discoloration and fungi activity in long-grain hybrid, pureline and medium-grain rice cultivars as influenced by storage environment and antifungal treatment, Journal of Stored Products Research, Vol. 81, no. ISSN 0022-474X, pp. 91-99, 2019.
- B. J. Olorunfemi ve S. E. Kayode, Post-Harvest Loss and Grain Storage Technology- A Review, Turkish Journal of Agriculture-Food Science and Technology, Vol. 9, no. 1, p. 75–83, 2021.
- N. L. de Menezes, L. L. Pasqualli, A. P. Piccinin Barbieri, M. D. Vidal and G. M. Conceição, Drying temperatures on physical integrity, physiological quality and chemical composition of rice seeds, Pesquisa Agropecuária Tropical; Goiânia, Vol. 42, no. 4, pp. 430-436, 2012.
- N. Donla, Y. Matsushita and Y. Ogawa, Influence of postharvest drying conditions on resistant starch content and quality of non-waxy long-grain rice (Oryza sativa L.), Drying Technology, vol. 36, no. 8, pp. 952-964, 2018.
- L. P. Mussi, A. O. Guimarães, K. S. Ferreira ve N. R. Pereira, Spouted bed drying of jambolão (Syzygium cumini) residue: Drying kinetics and effect on the antioxidant activity, anthocyanins and nutrients contents, LWT - Food Science and Technology, cilt 61, no. 1, pp. 80-88, 2015.
- M. K. d. Guzman,S. Parween, V. M. Butardo, C. M. Alhambra, R. Anacleto, C. Seiler, A. R. Bird, C.-P. Chow ve N. Sreenivasulu, Investigating glycemic potential of rice by unraveling compositional variations in mature grain and starch mobilization patterns during seed germination, Nature Publishing Group UK-Scientific reports, vol. 7, no. 1, p. 5854, 2017.
- T. J. Siebenmorgen, R. C. Bautista ve P. A. Counce, Optimal harvest moisture contents for maximizing milling quality of long-and medium-grain rice cultivars, Applied Engineering in Agriculture, Vol.23, no. 4, pp. 517-527, 2007.
- G. H. Lang, B. A. Rockenbach, C. D. Ferreira ve M. & de Oliveira, Delayed drying interval of red rice: Effects on cooking properties, in vitro starch digestibility and phenolics content, Journal of stored products research, Vol. 87, no. 101613, 2020.
- S. Cenkowski, S. Pabis and D. S. Jayas, Grain Drying: Theory and Practice, New York: John Wiley & Sons, 1998.
- Mortaza Aghbashlo et al., Influence of drying conditions on the effective moisture diffusivity, energy, Energy Conversion and Management, p. 2865–2871, 2008.
- M. Danismaz and C. Demirtaş, Investigation of the Relationship Between the Core Temperature of Hazelnuts, International Journal of Computational and Experimental Science and Engineering, pp. Vol. 7-No.1, pp. 29-34, 2021.
- P. C. Coradi, Â. F. C. Lemes, S. J. Ibagé, A. Müller ve C. Z. Alves, Mathematical Modeling of Drying in a New Concept of Silo-Dryer-Aerator and the Quality of Soybean Seeds, 2018.
- P. Coradi ve Â. F. Lemes, Experimental prototype of silo-dryer-aerator of grains using Computational Fluid Dynamics (CFD) system, Acta Scientiarum - Technology, vol. 41, no. e36949, 2019.
- P. Przystupab, W. Wojciech and J. Nowaka, Methods for asssessıng energy effıcıency, Agricultural Engineering, vol. 23, no. 2, pp. 39-47, 2019.
- H. Scaar, G. Franke, F. Weigler, M. Delele and E. T. &. J. Mellmann, Experimental and numerical study of the airflow distribution in mixed-flow grain dryers, Drying Technology, vol. 34, no. 5, pp. pp. 595-607, 2016.
- H. Silva, C. Schepke, C. da Cruz Cristaldo, D. de Oliveira and N. Lucca, "An Efficient Parallel Model for Coupled Open-Porous Medium Problem Applied to Grain Drying Processing," Latin American High Performance Computing Conference, High Performance Computing, vol. 1540, p. pp 250–264, 2021.
- C. W. Cao, D. Y. Yang ve Q. Liu, Research on modeling and simulation of mixed flow grain dryer, Drying Technology, vol. 24, no. 4, pp. 681-687, 2007.
- F. Weigler, H. Scaar ve J. Mellmann, Investigation of particle and air flows in a mixed-flow dryer, Drying Technology, cilt 30, no. 15, pp. 1730-1740, 2012.
- T. Oksanen, "Controlling air flow in recirculating mixed flow batch dryer with double bed mode," Computers and Electronics in Agriculture, pp. Volume 149, Pages 133-138, June 2018.
- S. Ergun ve A. A. Orning, Fluid Flow through Randomly Packed Columns and Fluidized Beds, Ind. Eng. Chem., American Chemical Society, vol. 1, no. 241, p. 1179–1184, 1949.
- L. Amiri, S. A. Ghoreishi-Madiseh, F. P. Hassani ve A. P. Sasmito, Estimating pressure drop and Ergun/Forchheimer parameters of flow through packed bed of spheres with large particle diameters, Powder Technology, cilt 356, pp. 310-324, 2019.
- A. Klinger, Artificial Patterns, IEEE Transactions on Software Engineering, vol. 4, pp. 301-306, 1977.
- S. Pabis, D. Jayas ve S. Cenkowski, Grain Drying: Theory and Practice, New York: John Wiley & Sons, 1998.
- S. Ergün, "Fluid flow through packed columns," Chemical Engineering Prog., Vol. 48, pp. 89-94, 1952.
- M. Helsen, J. Mayerhofer, N. Govaerts, H. Parmentier ve L. Jeanmart, Experimental investigation of pressure drop in packed beds of irregular shaped wood particles, Powder Technology, vol. 205, no. 1–3, pp. 30-35, 2011.
- Glover, P.W.J., Luo, M. The Porosity and Permeability of Binary Grain Mixtures. Transp Porous Med 132, 1–37 (2020). https://doi.org/10.1007/s11242-020-01378-0.
- N. H., Abou-El-Hana ve M. A.Younis, Pressure Drop Through Shelled Corn As Affected By Aırflow Rates, Moısture Content And Aır Temperature, Process Engıneerıng, vol. 25, no. 3, pp. 944-956, 2008.
Details
| Primary Language | English |
|---|---|
| Subjects | Fluid Mechanics and Thermal Engineering (Other), Numerical Methods in Mechanical Engineering |
| Journal Section | MBD |
| Authors | |
| Publication Date | March 28, 2024 |
| Submission Date | August 4, 2023 |
| Published in Issue | Year 2024 Volume: 36 Issue: 1 |
