Typically, the structural material of a rotary flash dryer depends primarily on the product to be dried. The advantage of this device is its ability to operate at high temperatures in non-sensitive products. In a rotary flash dryer, the heat exchange is mainly based on airflow and particles, and the heat exchange between the wall and the particles. The drying process can be seen as a diffusion process of moisture.
That is to say, when the material is dried by the rotary flash dryer, it is mainly carried out by external diffusion and internal diffusion. The so-called out-diffusion refers to the process in which the surface moisture of the particles diffuses from the surface to the surrounding medium in the form of steam. Internal diffusion is the process by which moisture moves inside the particles. The entire drying process is relatively simple, the equipment is mainly used to dry filter cake, paste and high viscosity liquid.
During the operation of the rotary flash dryer, it mainly uses the high-speed hot air flow to enter the cylinder in the tangential direction. Due to the spiral motion of the airflow in the cylinder, the temperature of the medium around the particles is lowered, and the flow rate and temperature of the medium can also be increased. . In this way, the speed of out-diffusion can be significantly improved. The high-temperature airflow impacts the particles or small wet materials located in the lower part of the cylinder at a high speed, and the stirring effect of the stirring blades in the cylinder causes the particles to be broken, the particle size is reduced, and the length of the internal capillary is also reduced, thereby enhancing the effect of internal diffusion. , reducing the resistance to internal diffusion.
Moreover, during the feeding process, the rotary flash dryer will make the material a powder which is viscous or gelatinous in nature, a paste or a filter cake. The two steps include decomposing the feed and drying the decomposed feed. Depending on the nature of the feed material, the arms are typically designed to be used in crystalline non-stick materials, or specially designed rotary pulverizers for treating viscous and gel-like materials.
During the drying of the material by means of a rotary flash dryer, the product clarifying agent ensures the required size and the dried granules can only leave the drying chamber. The high solids content makes the rotary flash dryer a very economical and practical drying equipment.