Application of belt dryer in the drying of flowing granular materials

For those granular materials and extrusion granulation products which are easy to flow, the belt dryer is an ideal choice. Belt dryer is essentially a conveyor dryer. There are holes on the conveyor belt, and the dried materials are placed on the conveyor belt. The drying medium moves upward through the porous material at a relatively low speed.

For those granular materials and extrusion granulation products which are easy to flow, the belt dryer is an ideal choice because it is easy to cause mechanical damage in the dispersion process. Belt dryer is essentially a conveyor dryer. There are holes on the conveyor belt, and the dried materials are placed on the conveyor belt. The drying medium moves upward through the porous material at a relatively low speed. Obviously, this dryer is not suitable for very wet or very fine materials. If the material layer is too thick (more than 10-15cm), an obvious humidity field will be formed in the material layer, and the materials on the belt will be over dried and overheated. One solution is to alternately change the direction of air flow in the length direction of the belt dryer, which can make the moisture of the material on the cross-section uniform and increase the drying rate. Another solution is to mix materials in a certain space. In some commercial designs, there is a kind of multi-layer dryer, which is divided into several layers of mesh belt and layer by layer. The materials fall from the higher layer to the lower layer by gravity, causing random mixing of materials before the next cycle drying. If necessary, it is possible to take a certain temperature distribution along the length of the conveyor, which allows the drier material to come into contact with lower temperature air. The back can also be a simple cooler to make the product easy to pack or store. The residence time is between 10 min and 60 min, which is more economical and feasible. The dryer is also versatile and can handle relatively large and arbitrarily shaped particles, whether the material is heat sensitive or brittle. Because of the low gas flow rate, the requirement of tail gas purification is low. Due to the low pressure loss, the required fan power is also low. In the industrial design of large-scale belt dryer, it is very important to ensure the uniform distribution of the products on the mesh belt and the hot air distribution in the drying chamber of the dryer, so as to make the product moisture content uniform