All Issue

2025 Vol.57, Issue 4 Preview Page

Original Paper

Numerical Modeling of Continuous Microwave Drying of Molded Pulp Product
Lingbo Kong1†
,
Ziliang Zhang2
,
Jie Li2
,
Juanjuan Xu3
,
Jiahao Li4
,
Huawei Zuo4
1College of Mechanical and Electrical Engineering, Shaanxi University of Science and Technology, Professor
2College of Mechanical and Electrical Engineering, Shaanxi University of Science and Technology, Student
3College of Mechanical and Electrical Engineering, Shaanxi University of Science and Technology, Lecturer
4Wing Fat Molded Fiber R&D Center, Engineer
†Corresponding Author: E-mail: lbkong@sust.edu.cn (Address: College of Mechanical and Electrical Engineering, Shaanxi University of Science and Technology, Xi’an, 710021, People’s Republic of China)
30 August 2025. pp. 54-65
PDF XML Citation
Abstract

This study investigates the variations in temperature and moisture content during the continuous microwave drying of molded pulp products (MPPs), using an electromagnetic-heat and mass coupling model. Numerical simulations were performed with the discrete-combined method and validated against experimental data. The results showed that, during the initial drying phase, fluctuations in electric field intensity led to an uneven surface temperature distribution, with faster heating occurring at the edges compared to the center. As drying progressed, the temperature increased and became more uniform across the MPP. The moisture content gradually decreased along the conveyor belt, eventually reaching a relatively uniform distribution. This indicates that the dynamic interaction between the continuous movement of the material and the microwave field effectively reduced drying non-uniformity. Additionally, the effects of microwave power were systematically analyzed, revealing final temperatures of 323.7, 343.9, and 363.9 K, and corresponding drying rates of 0.085, 0.120, and 0.145 g/(g·min) at microwave powers of 300, 500, and 700 W, respectively. The model offers valuable theoretical insights into the heat and mass transfer mechanisms during continuous microwave drying of MPPs and provides guidance for enhancing drying uniformity and optimizing process design.

Keywords
Molded pulp product
continuous microwave drying
heat and mass transport
mathematical model
numerical simulation
References
1

Debnath, M., Sarder, R., Pal, L., and Hubbe, M. A., Molded pulp products for sustainable packaging: Production rate challenges and product opportunities, BioResources 17(2):3810-3870 (2022).

10.15376/biores.17.2.Debnath
2

Didone, M., Mohanty, S., Hattel, J. H., Sonne, M. R., Fiordaliso, E. M., Checchi, A., and Tosello, G., On the drying process of molded pulp products: Experiments and numerical modelling, Drying Technology 38(12):1644-1662 (2020).

10.1080/07373937.2019.1653905
3

Li, B., Feng, S., He, Q., Zhu, Y., Wu, J., Yang, J., Hu, Z., and Ma, M., Numerical simulation of continuous microwave drying of rice grains, Journal of Food Process Engineering 47(7):e14678 (2024).

10.1111/jfpe.14678
4

Li, F., Sun, D., Zha, Z., Yang, K., Ge, Z., and Zhang, H., Numerical simulation of the coupled multiphysics fields and reactions during the microwave pyrolysis of wood particles, Energy 283:128493 (2023).

10.1016/j.energy.2023.128493
5

Huang, J., Xu, G., Hu, G., Kizil, M., and Chen, Z., A coupled electromagnetic irradiation, heat and mass transfer model for microwave heating and its numerical simulation on coal, Fuel Processing Technology 177:237-245 (2018).

10.1016/j.fuproc.2018.04.034
6

Fia, A. Z. and Amorim, J., Heating of biomass in microwave household oven - A numerical study, Energy 218:119472 (2021).

10.1016/j.energy.2020.119472
7

Thuto, W. and Banjong, K., Investigation of heat and moisture transport in bananas during microwave heating process, Processes 7(8):545 (2019).

10.3390/pr7080545
8

Vongpradubchai, S. and Rattanadecho, P., The microwave processing of wood using a continuous microwave belt drier, Chemical Engineering and Processing: Process Intensification 48(5):997-1003 (2009).

10.1016/j.cep.2009.01.008
9

Bedane, T. F., Chen, L., Marra, F., and Wang, S., Experimental study of radio frequency (RF) thawing of foods with movement on conveyor belt, Journal of Food Engineering 201:17-25 (2017).

10.1016/j.jfoodeng.2017.01.010
10

Palazoğlu, T. K. and Miran, W., Experimental investigation of the combined translational and rotational movement on an inclined conveyor on radio frequency heating uniformity, Innovative Food Science & Emerging Technologies 47:16-23 (2018).

10.1016/j.ifset.2018.01.003
11

Kumar, C., Karim, M. A., and Joardder, M. U. H., Intermittent drying of food products: A critical review, Journal of Food Engineering 121:48-57 (2014).

10.1016/j.jfoodeng.2013.08.014
12

Buttress, A. J., Binner, E., Yi, C., Palade, P., Robinson, J. P., and Kingman, S. W., Development and evaluation of a continuous microwave processing system for hydrocarbon removal from solids, Chemical Engineering Journal 283:215-222 (2016).

10.1016/j.cej.2015.07.030
13

Chen, J., Lau, S. K., Boreddy, S. R., and Subbiah, J., Modeling of radio frequency heating of egg white powder continuously moving on a conveyor belt, Journal of Food Engineering 262:109-120 (2019).

10.1016/j.jfoodeng.2019.05.029
14

Pitchai, K., Chen, J., Birla, S., Gonzalez, R., Jones, D., and Subbiah, J., A microwave heat transfer model for a rotating multi-component meal in a domestic oven: Development and validation, Journal of Food Engineering 128:60-71 (2014).

10.1016/j.jfoodeng.2013.12.015
15

Chen, L., Huang, Z., Wang, K., Li, W., and Wang, S., Simulation and validation of radio frequency heating with conveyor movement, Journal of Electromagnetic Waves and Applications 30:1-19. (2016).

10.1080/09205071.2015.1121841
16

Zhang, Y., Liu, C., Zheng, X., Zhao, X., Shen, L., and Gao, M., Analysis of microwave heating uniformity in berry puree: From electromagnetic-wave dissipation to heat and mass transfer, Innovative Food Science & Emerging Technologies 90:103509 (2023).

10.1016/j.ifset.2023.103509
17

Liu, C., Xue, H., Shen, L., Liu, C., Zheng, X., Shi, J., and Xue, S., Improvement of anthocyanins rate of blueberry powder under variable power of microwave extraction, Separation and Purification Technology 226:286 (2019).

10.1016/j.seppur.2019.05.096
18

Shen, L., Zhu, Y., Liu, C., Wang, L., Liu, H., Kamruzzaman, M., Liu, C., Zhang, Y., and Zheng, X., Modelling of moving drying process and analysis of drying characteristics for germinated brown rice under continuous microwave drying, Biosystems Engineering 195:64-88 (2020).

10.1016/j.biosystemseng.2020.05.002
19

Law, M. C., Liew, E. L., Chang, S. L., Chan, Y. S., and Leo, C. P., Modelling microwave heating of discrete samples of oil palm kernels, Applied Thermal Engineering 98:702-726 (2016).

10.1016/j.applthermaleng.2016.01.009
20

Zhao, H., Turner, I., and Torgovnikov, G., An experimental, and numerical investigation of the microwave heating of wood, Journal of Microwave Power and Electromagnetic Energy 33(2):121-133 (1998).

10.1080/08327823.1998.11688368
21

Ciacci, T., Galgano, A., and Di Blasi, C., Numerical simulation of the electromagnetic field and the heat and mass transfer processes during microwave-induced pyrolysis of a wood block, Chemical Engineering Science 65(14):4117-4133 (2010).

10.1016/j.ces.2010.04.039
22

Perre, P., Moser, M., and Martin, M., Advances in transport phenomena during convective drying with superheated steam and moist air, International Journal of Heat and Mass Transfer 36(11):2725-2746 (1993).

10.1016/0017-9310(93)90093-L
23

Law, M. C., Chang, J. S. L., Chan, Y. S., Pui, D. Y., and You, K. Y., Experimental characterization and modeling of microwave heating of oil palm kernels, mesocarps, and empty fruit bunches, Drying Technology 37(1):69-91 (2019).

10.1080/07373937.2018.1439057
24

Ni, H., Datta, A. K., and Torrance, K. E., Moisture transport in intensive microwave heating of biomaterials: A multiphase porous media model, International Journal of Heat and Mass Transfer 42(8):1501-1512 (1999).

10.1016/S0017-9310(98)00123-9
25

Chen, J., Lau, S. K., Chen, L., Wang, S., and Subbiah, J., Modeling radio frequency heating of food moving on a conveyor belt, Food and Bioproducts Processing 102:307-319 (2017).

10.1016/j.fbp.2017.01.009
26

Laskar, A. A., Ahmed, M., Vo, D.-V. N., Abdullah, A., Shahadat, M., Mahmoud, M. H., Khan, W., and Yusuf, M., Mathematical modeling and regression analysis using MATLAB for optimization of microwave drying efficiency of banana, Thermal Science and Engineering Progress 46:102157 (2023).

10.1016/j.tsep.2023.102157
27

Funawatashi, Y. and Suzuki, T., Numerical analysis of microwave heating of a dielectric, Heat Transfer—Asian Research 32(3):227-236 (2003).

10.1002/htj.10087
28

Venkatesh, M. S. and Raghavan, G. S. V., An overview of microwave processing and dielectric properties of agri-food materials, Biosystems Engineering 88(1): 1-18 (2004).

10.1016/j.biosystemseng.2004.01.007
29

Zhang, H. and Datta, A. K., Heating concentrations of microwaves in spherical and cylindrical foods: Part one: in planes waves, Food and Bioproducts Processing 83(1): 6-13 (2005).

10.1205/fbp.04046
30

Zhu, H., He, J., Hong, T., Yang, Q., Wu, Y., Yang, Y., and Huang, K., A rotary radiation structure for microwave heating uniformity improvement, Applied Thermal Engineering 141:648-658 (2018).

10.1016/j.applthermaleng.2018.05.122
31

Huang, Z., Datta, A. K., and Wang, S., Modeling radio frequency heating of granular foods: Individual particle vs. effective property approach, Journal of Food Engineering 234:24-40 (2018).

10.1016/j.jfoodeng.2018.04.008
32

Kumar, C. and Karim, A., Microwave-convective dying of food materials: A critical review, Critical Reviews in Food Science and Nutrition 59(3):379-394 (2019).

10.1080/10408398.2017.1373269
Information
  • Publisher :Korea Technical Association of The Pulp and Paper Industry
  • Publisher(Ko) :한국펄프종이공학회
  • Journal Title :Journal of Korea TAPPI
  • Journal Title(Ko) :펄프종이기술
  • Volume : 57
  • No :4
  • Pages :54-65
  • Received Date : 2025-06-23
  • Revised Date : 2025-08-11
  • Accepted Date : 2025-08-11
  • DOI :https://doi.org/10.7584/JKTAPPI.2025.8.57.4.54
Journal Informaiton Journal of Korea TAPPI Journal of Korea TAPPI
Online Submission
  • scopus
  • NRF
  • KOFST
  • crossref crossmark
  • crossref cited-by
  • crosscheck
  • orcid
Journal Informaiton Journal Informaiton - close