Drying operation is one of the widely used unit operations in industrial sectors such as chemical, light industry, and food. The purpose of drying operation is to remove moisture or solvents from certain raw materials, semi-finished products, and finished products. For the light chemical food industry, the goal is to make materials easy to package, transport, store, process, and use. Therefore, the quality of the drying operation directly affects the quality and appearance of the product.

The characteristics of drying equipment include:

1. The adaptability of drying equipment to the material being dried. If it is possible to achieve the required dryness level of the material and the uniformity of the dried product. The ability to adapt to the appearance and technical specifications of the dried material is a basic requirement for drying equipment, and it is also the primary condition for selecting drying equipment. Because some products require maintaining a crystalline shape, some products require maintaining a certain color, aroma, taste, and nutritional content, while others require no deformation or cracking during drying. However, unless it is for drying small batches and multiple varieties of products, it is generally not required that one drying equipment can handle multiple materials. General equipment may not necessarily conform to the principles of economy and optimization.

2. The thermal efficiency of the drying device (generally speaking, if the heat utilization of the drying device is good, the thermal efficiency is high, and vice versa, the thermal efficiency is low) is the main technical and economic indicator of drying. Drying is a unit operation that consumes a lot of energy, and it is crucial to improve the thermal efficiency of the drying device.

3. The economic processing capacity of drying equipment, the production intensity or drying speed of drying equipment. The drying intensity is high, the equipment used is small, and the fixed investment is low, otherwise the opposite is true. The number of auxiliary equipment for drying equipment sometimes affects its application, because although the size of the drying equipment itself is not large, its application is also limited due to the bulky auxiliary equipment.