Experimental and numerical study on the shrinkage-deformation of carrot slices during hot air drying

Abstract

In order to further understand the mechanism of material volume change in the drying process, numerical simulations (considering or neglecting shrinkage) of heat and mass transfer during convective drying of carrot slices under constant and controlled temperature and relative humidity were carried out. Simulated results were validated with experimental data. The results of the simulation show that the Quadratic model fitted well to the moisture ratio and the material temperature data trend with average relative errors of 5.9% and 8.1%, respectively. Additionally, the results of the simulation considering shrinkage show that the moisture and temperature distributions during drying are closer to the experimental data than the results of the simulation disregarding shrinkage. The material moisture content was significantly related to the shrinkage of dried tissue. Temperature and relative humidity significantly affected the volume shrinkage of carrot slices. The volume shrinkage increased with the rising of the constant temperature and the decline of relative humidity. This model can be used to provide more information on the dynamics of heat and mass transfer during drying and can also be adapted to other products and dryers devices.

Finite element modeling in heat and mass transfer of potato slice dehydration, nonisotropic shrinkage kinetics using arbitrary Lagrangian–Eulerian algorithm and artificial neural network

“…This crust makes the material rigid (stiff or hard), which prevents shrinkage. The results agreed with the previously reported articles (Jiang et al, 2023; Salehi, 2023; Seyedabadi et al, 2017).…”

“…In Equation 13, the symbol h ev signifies the latent heat of vaporization (J/kg) at the surface of the potato slice, which is described as a function of temperature (Gowwomsa Erko et al, 2016; Jiang et al, 2023): $$$$ {h}_{ev}=2.5\times {10}^6\times {\left(\frac{647.3-T}{374.15}\right)}^{0.3298} $$$$ …”

Design and Experiment of Combined Infrared and Hot-Air Dryer Based on Temperature and Humidity Control with Sea Buckthorn (Hippophae rhamnoides L.)

“…To increase the relative humidity in the drying chamber, existing drying equipment has frequently used wet curtain humidification. However, this method has drawbacks, including a long delay and slow response time [ 12 ]. To avoid the low temperature and high humidity of wet curtain humidification, the combined infrared and hot-air drying equipment based on temperature and humidity control used steam humidification.…”

“…A high relative humidity during the initial drying stage causes the internal temperature of a material to rapidly increase. Once the relative humidity in the environment has been reduced, the drying rate increases, and the problem of the surface developing a crust from rapid drying can be avoided [ 12 ].…”