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What are the characteristics of drying technology? What is the history of modern drying technology and the reasons for its formation? Today, the Drying Equipment Industry Association will introduce it to you.

The process technology of drying equipment is a cross-industry and cross-disciplinary technology. There is a wide range of service areas. Faced with many real estate industries, physical and chemical properties of different materials, product quality and other aspects of vastly different requirements.

The concept of drying oven is widely used in electromechanical, chemical, plastic, light industry and other industries and scientific research units for baking, drying, curing, heat treatment and other convenient heating of various products and test products.

Usually, three aspects of knowledge and technology are needed in the development and application of drying technology. First, it is necessary to understand the physical and chemical properties of the dried material and the use characteristics of the product. The second is to be familiar with the principles of transfer engineering, that is, the principles of energy transfer such as mass transfer, heat transfer, fluid mechanics and aerodynamics. The third is to have the means of implementation, that is, to be able to carry out the engineering design of drying process, main equipment, electrical instrument control and so on. Obviously, these three aspects of knowledge and technology do not belong to the same subject field. In practice, these three aspects of knowledge and technology are indispensable. Therefore, drying technology is a cross-industry and interdisciplinary technology.

Although modern drying technology has a history of more than one hundred years, it still belongs to the category of experimental science. At present, most drying technologies lack scientific theories and design methods that can accurately guide practice. In practical application, it is still the main way to rely on experience and small-scale test data to guide. The reasons for this situation are as follows:

One of the reasons is that some basic disciplines on which drying technology relies, mainly those belonging to the category of transfer engineering, have the characteristics of experimental science. The research and development of aerodynamics has to be driven by "wind tunnel" tests, which shows that it has not yet deviated from the category of experimental science. The development level of these basic disciplines directly affects and determines the development level of drying technology.

The second reason is that many drying processes are the intersection of various disciplines and technologies, involving a wide range of areas, many variables, and complex mechanisms. For example, in the field of spray drying technology, the trajectory of atomized droplets in the drying tower is the key to engineering design. The trajectory of a droplet is related to its own volume, mass, initial velocity and direction, and the flow direction and velocity of other droplets and hot air around it. However, these parameters are changing all the time due to the process of mass transfer and heat transfer. Moreover, in the initial state, neither the size of droplets nor the distribution of hot air can be uniform. Obviously, it is unreliable to carry out engineering design for such complex and changeable process only by theoretical calculation.
The third reason is that the types of dried materials are various, and their physical and chemical properties are also different. Even under the same drying conditions, the mass and heat transfer rates of different materials may be quite different. If it is not treated differently, it may cause unsatisfactory consequences. For example, in the drying of some Chinese herbal medicines, although they belong to the same medicinal materials, the drying conditions must be changed only because of the differences in the origin or harvest period of the medicinal materials, otherwise the quality of the products will be unqualified.

The above three reasons determine that the development and application of drying technology should be based on experiments. However, these characteristics of drying technology are often ignored intentionally or unintentionally. Manufacturers often avoid drying experiments due to lack of testing equipment or incomplete types (which is a common phenomenon in our country), and users often give up the requirements for necessary tests because they do not understand the characteristics of drying technology. The result is that the device is not effective in use, and even scrapped. In our country, such cases are not uncommon. There has been a lesson that a set of industrial drying equipment worth 20 million yuan was left idle because it failed to meet the requirements for use. Therefore, sufficient and convincing tests must be carried out before the construction of industrial drying equipment, especially large ones, and the test results should be used as the basis for the construction of industrial equipment. This is a remarkable feature of the application of drying technology.

Drying Equipment Industry Association

Contact: Secretary Xiao Zhou

Contact: 13906113036