Numerical Simulation for Infrared-Assisted Freeze Drying of Solution Products

This study numerically investigated the one-dimensional freeze drying of a solution product assisted with infrared radiation heating. In order to accurately consider the spectral radiative transfer inside the moisture-rich product, the two-flux radiation model was incorporated with our previous freeze drying analysis model based on the fixed grid method. Thus, this model fully takes into account the spectral absorption characteristics of ice and the spectral composition of light emitting from an infrared heater. The infrared-assisted freeze drying characteristics were investigated in detail, along with the spatial variation of radiation intensity inside the product. Then, the effects of infrared heater temperature on freeze drying behaviors were parametrically studied, and the results were discussed in relation with the spectral effects in the radiative transfer in the moisture-rich product.