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Analysis of thermal and wet stress of corn kernel based on microwave drying

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Abstract

In order to reveal the relationship between temperature, moisture content and stress during microwave drying, the paper establishes a mathematical model of heat and mass transfer as well as stress during microwave drying using corn kernels as the medium, and couples the two models to solve the electromagnetic equation, energy and momentum conservation and stress equation, and conducts experimental verification. The results show that the maximum errors between the simulated and experimental values of temperature and moisture content are 8.04 % and 9.21 %, respectively, and the theoretical model can be used to simulate the changes of temperature, moisture content and stress of corn kernels. Under the set drying conditions, the thermal stress increased with increasing temperature, and the stress maximum was obtained on the upper and lower surfaces of the seeds. The wet stress increased with increasing moisture gradient, and the stress and crack index were maximum at a moisture content (dry basis) of 16.13 %.

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Abbreviations

A :

Surface area, m2

c 0 :

Concentration of initial water, mol/m3

c g :

Concentration of steam, (mol/m3)

C P :

Specific heat capacity, J/(kg·K)

c w :

Concentration of water, (mol/m3)

D d :

Stiffness matrix, Pa

D w :

Capillary diffusivity, m2/s

E :

Electric field strength, V/m

E(t):

Elastic modulus, Pa

E 0 :

Elastic modulus of corn kernel, Pa

G :

Shear modulus, Pa

h t :

Heat transfer coefficient, W/(m2·K)

I :

Evaporation rate of liquid water, mol/(m3·s)

j :

Imaginary part

K:

Evaporation rate constant

K b :

Bulk modulus of elasticity, Pa

K eff :

Thermal conductivity, W/(m·K)

k in,i :

Internal permeability, m2/s

k r.i :

Relative permeability, m2/s

M :

Moisture content of dry basis, kg/kg

M w :

Molar mass of water, kg/mol

n g :

Fluxes of steam, mol/(m2·s)

n w :

Fluxes of water, mol/(m2·s)

p :

Saturated vapor pressure of water, kg/m3

p eq :

Equilibrium vapor pressure of water, Pa

p g :

Vapor pressure calculated for the ideal gas law, Pa

Q :

The volumetric heat generation, W/m3

R:

Ideal gas constant

S q :

Viscoelastic stress, Pa

t :

Time, s

T :

Temperature, K

T 0 :

Initial ambient temperature, K

u :

Relative magnetic permeability, N/m2

u g :

Flow rates of steam, m/s

u w :

Flow rates of liquid water, m/s

v :

Poisson’s ratio

V :

Volume, m3

w :

Angular frequency, rad/s

ε :

Total strain

ε :

Complex dielectric constant

ε′ :

Dielectric constant

ε″ :

Effective loss factor

ε 0 :

Dielectric constant of free space

ε d :

Shrinkage strain

ξ :

Total conversion time, s

ρ :

Density, kg/m3

ρ g :

Density of steam, kg/m3

ρ w :

Density of water, kg/m3

σ :

Total stress, Pa

τ :

Relaxation time, s

a M :

Variation factor caused by water

a T :

Variation factor caused by temperature

References

  1. S. Wei et al., Prediction of drying stress cracks in maize seeds based on three-dimensional moisture and heat transfer, Journal of Agricultural Engineering, 35(23) (2019) 296–304+319.

    Google Scholar 

  2. J. R. M. Marques da Silva et al., Relationship between distance to flow accumulation lines and spatial variability of irrigated maize grain yield and moisture content at harvest, Biosystems Engineering, 94(4) (2006) 525–533.

    Article  Google Scholar 

  3. R. Wang et al., Analysis of influencing factors on dehydration rate of Maize Kernel, Chinese Agricultural Science, 50(11) (2017) 2027–2035.

    Google Scholar 

  4. W. Gao et al., Study on the characteristics and potential of postpartum loss of main grain crops in China, Journal of Agricultural Engineering, 32(23) (2016) 1–11.

    Google Scholar 

  5. N. K. Kabtar and A. Isci, Effect of different drying methods on drying characteristics of eggplant slices and mathematical modeling of drying processes, Academic Food Journal, 14(1) (2016) 21–27.

    Google Scholar 

  6. R. Béttega et al., Comparison of carrot (daucus carota) drying in microwave and in vacuum microwave, Brazilian Journal of Chemical Engineering, 31(2) (2014) 403–412.

    Article  Google Scholar 

  7. S. Çelen, Effect of microwave drying on the drying characteristics, color, microstructure, and thermal properties of Trabzon persimmon, Foods, 8(2) (2019) 84.

    Article  Google Scholar 

  8. A. Chahbani et al., Microwave drying effects on drying kinetics, bioactive compounds and antioxidant activity of green peas (Pisum sativum L.), Food Bioscience, 25 (2018) 32–38.

    Article  Google Scholar 

  9. H. Lv et al., Analysis of drying characteristics of apple slices under different microwave environments, Journal of Agricultural Machinery, 49(S1) (2018) 433–439.

    Google Scholar 

  10. J. Zhang et al., Effect of microwave inTermittent drying on protein and starch quality of Northern Japonica sorghum, Food Science, 43(7) (2021) 1–12.

    MathSciNet  Google Scholar 

  11. H. Liu et al., Microwave drying characteristics and drying quality analysis of corn in China, Processes, 9(9) (2021) 1511.

    Article  MathSciNet  Google Scholar 

  12. R. Q. De Faria et al., Optimization of the process of drying of corn seeds with the use of microwaves, Drying Technology, 38(5–6) (2020) 676–684.

    Article  Google Scholar 

  13. G. Song, R. Choudhary and D. G. Watson, Microwave drying kinetics and quality characteristics of corn, International Journal of Agricultural and Biological Engineering, 6(1) (2013) 90–99.

    Google Scholar 

  14. P. S. Takhar et al., Hybrid mixture theory based moisture transport and stress development in corn kernels during drying: validation and simulation results, Journal of Food Engineering, 106(4) (2011) 275–282.

    Article  Google Scholar 

  15. P. S. Takhar, Hybrid mixture theory based moisture transport and stress development in corn kernels during drying: Coupled fluid transport and stress equations, Journal of Food Engineering, 105(4) (2011) 663–670.

    Article  Google Scholar 

  16. S. Wei et al., Stress simulation and cracking prediction of corn kernels during hot-air drying, Food and Bioproducts Processing, 121 (2020) 202–212.

    Article  Google Scholar 

  17. A. K. Datta, Handbook of Microwave Technology for Food Application, CRC Press (2001).

  18. J. R. Arballo, L. A. Campañone and R. H. Mascheroni, Modeling of microwave drying of fruits, Drying Technology, 28(10) (2010) 1178–1184.

    Article  Google Scholar 

  19. T. Gulati, H. Zhu and A. K. Datta, Coupled electromagnetics, multiphase transport and large deformation model for microwave drying, Chemical Engineering Science, 156 (2016) 206–228.

    Article  Google Scholar 

  20. H. Liu et al., Analysis of mechanical properties of porous materials during hot air drying, Chemical Engineering, 43(3) (2015) 33–36.

    Google Scholar 

  21. W. A. Aregawi et al., Modeling of coupled water transport and large deformation during dehydration of apple tissue, Food and Bioprocess Technology, 6(8) (2013) 1963–1978.

    Article  Google Scholar 

  22. J. Liu et al., Analysis of internal stress in drying process of corn granules based on three-dimensional solid model, Journal of ShenYang University (Natural Science Edition), 27(3) (2015) 177–184.

    Google Scholar 

  23. D. Cheng et al., Heat and mass transfer and deformation parameter model of Antarctic krill minced meat during microwave drying, Journal of Agricultural Engineering, 36(3) (2020) 302–312.

    Google Scholar 

  24. A. Ghasemi, M. Sadeghi and S. A. Mireei, Multi-stage inTermittent drying of rough rice in Terms of tempering and stress cracking indices and moisture gradients interpretation, Drying Technology, 36(1) (2018) 109–117.

    Article  Google Scholar 

  25. J. Hundal and P. S. Takhar, Experimental study on the effect of glass transition on moisture profiles and stress-crack formation during continuous and time-varying drying of maize kernels, Biosystems Engineering, 106(2) (2010) 156–165.

    Article  Google Scholar 

  26. S. Wei et al., Stress simulation and cracking prediction of corn kernels during hot-air drying, Food and Bioproducts Processing, 121 (2020) 202–212.

    Article  Google Scholar 

  27. N. Srisang et al., Modeling heat and mass transfer-induced stresses in germinated brown rice kernels during fluidized bed drying, Drying Technology, 34(6) (2016) 619–634.

    Article  Google Scholar 

  28. J. Wu, H. Zhang and F. Li, A study on drying models and internal stresses of the rice kernel during infrared drying, Drying Technology, 35(6) (2017) 680–688.

    Article  Google Scholar 

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Acknowledgments

This work is supported by Anhui Provincial Natural Science Foundation (2208085ME140).

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Correspondence to Tongsheng Sun.

Additional information

Tongsheng Sun is a Professor of the School of Mechanical Engineering, Anhui Polytechnic University. He received his Ph.D in mechanical and electronic engineering from Southeast University of China. His research interests include drying technology and intelligent control equipment, microwave heating theory and electromagnetic system structure optimization.

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Sun, T., Cao, R. Analysis of thermal and wet stress of corn kernel based on microwave drying. J Mech Sci Technol 37, 1501–1508 (2023). https://doi.org/10.1007/s12206-023-0235-x

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  • DOI: https://doi.org/10.1007/s12206-023-0235-x

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