Stage drying of drying equipment

How many stages can drying equipment be divided into? If we assume that the material is constant and there will be no chemical reaction, then the drying equipment will dry the material in four stages. The specific stages are as follows:

1. Speed up drying stage: it uses very high temperature to evaporate the water on the material surface in a relatively short period of time. The time required for this stage is relatively short, but it is also limited to the surface moisture, so the water output at this stage is not large.

2. Constant speed drying stage: at this stage, the material is heated to make the moisture inside the material slowly replenish to the surface. As the material surface is being heated by high temperature, the moisture on the surface of the material evaporates quickly. When the speed of water supplement from the material interior to the surface can not keep up with the evaporation rate of the moisture on the surface of the material, the material enters the stage of slow drying.

3. Slow down drying stage: at this stage, the moisture content of the material has been evaporated by more than half. In this stage, the material is dried slowly, and the moisture inside the material is forced to evaporate on the surface.

4. Balance drying stage: when the moisture inside the material is forced to dry, and there is no water to supplement to the surface, the balanced drying stage is entered. This stage is the stage when the material is dried to obtain the finished product.