The deceleration stage of the rotary flash dryer is one of the most critical stages in the drying process. At this stage, the drying speed gradually decreases as the remaining moisture in the material has decreased. However, at this stage, the temperature of the material is still high and the specific heat capacity of the material is also large, so it is necessary to continue to supply heat to the material to dry it sufficiently.
In the deceleration drying stage, the humidity gradient and temperature gradient inside the material gradually decrease, and the drying speed becomes slower and slower. At this time, a dry shell has formed on the surface of the material, which can effectively prevent the diffusion of moisture from the inside of the material to the surface. As a result, the drying rate is gradually reduced until equilibrium is finally reached.
In the deceleration drying stage, it is necessary to pay attention to controlling the drying temperature and drying time. If the drying temperature is too high or the drying time is too long, it may cause the material to overheat or deteriorate. Therefore, it is necessary to choose the appropriate drying temperature and drying time according to the characteristics of the material and the drying requirements.
In addition, in the slowdown drying stage, it is also necessary to pay attention to factors such as the particle size and shape of the material. These factors may affect the drying speed and drying effect of the material. Therefore, it is necessary to select the appropriate particle size and shape according to the characteristics of the material and the drying requirements.
In short, the deceleration drying stage of the rotary flash dryer is one of the most critical stages in the entire drying process. Factors such as the appropriate operating parameters and material characteristics need to be selected to ensure that the material can be fully dried and achieve the expected drying effect.