Optimization of radial airflow path of water vapor inside a scraped film evaporator

Optimizing the radial airflow path of the water vapor helps to improve the evaporation efficiency of the scraped-film evaporator, thus contributing to the overall yield. Establishing a three-dimensional steady-state numerical simulation model of the gas phase of water vapor in a scraped-film evaporator investigates the radial flow characteristics of water vapor. And the deflector was introduced to optimize the radial flow path, and the deflecting effect of the deflector was comprehensively evaluated based on three indexes: vortex intensity, flux ratio, and axial flux. Studies have shown that there is a vortex phenomenon during the radial flow of water vapor, and the vortex causes water vapor to collect on the evaporation surface, thus inhibiting the evaporation efficiency. The introduction of the deflector can effectively weaken the vortex strength, optimize the airflow distribution, and effectively guide the airflow to the axial flow area, thus increasing the airflow discharge velocity. By comparing and analyzing the structure of different deflectors and considering the vortex strength, flux ratio, and axial flux, the optimal deflector scheme is finally determined. The scheme significantly reduced the vortex area by 60.57% and increased the axial flux in the axial flow region by 15.6%. This study is not only important in optimizing the performance of the scraped film evaporator but also achieves the effect of accelerating gas discharge by not increasing the pumping power above, thus achieving energy saving and emission reduction.