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Vertical Drier Development Of
- Jul 11, 2017 -

Since ancient times, Vertical Drier humans are accustomed to using natural heat and natural ventilation to dry materials, completely subject to natural conditions, low production capacity. With the development of production, they are gradually replaced by artificial controlled heat sources and air dehumidifiers. Vertical Drier The modern air dryer started using a fixed-bed air dryer with intermittent operation. Vertical Drier The mid-19th century, Vertical Drier the use of tunnel-type air dryer, marking the air dryer from the intermittent operation to the direction of continuous development. Rotary cylinder air dryer is better to achieve the agglomeration of granular materials, drying capacity and strength can be improved.

Some industries have developed a continuous operation of the industry to adapt to the requirements of the air dryer, such as textile, paper industry, drum air dryer. In the early 20th century, Vertical Drier dairy production began to use spray air dryer, for large-scale dry liquid material provides a powerful tool. From the beginning of the 1940s, with the development of fluidized technology, high-intensity, Vertical Drier high-productivity ebullated beds and airflow air dryers have emerged. While the frozen sublimation, Vertical Drier radiation and dielectric air dryer to meet the special requirements to provide a new means. 60 years began to develop far infrared and microwave air dryer.

Drying process requires a lot of heat, in order to save energy, Vertical Drier some high moisture content of materials, containing solid substances in the suspension or solution generally first mechanical dehydration or heating evaporation, and then dry in the air dryer to get dry solids.

The purpose of drying is for the purpose of material use or further processing. Such as wood in the production of wood mold, wood before the drying can prevent the deformation of the product, Vertical Drier ceramic billet in the calcination before drying can prevent the finished product cracking. In addition, the dry material is also easy to transport and storage, such as the harvest of food to a certain moisture content below, Vertical Drier to prevent mildew. As the natural drying can not meet the needs of the development of production, a variety of mechanized air dryer more and more widely applied.

In the process of drying, Vertical Drier it is necessary to complete the transfer of heat and mass (moisture) at the same time to ensure that the moisture partial pressure (concentration) of the wet surface is higher than that in the external space. The temperature of the heat source is higher than the material temperature.

The heat is transferred from the high temperature heat source to the wet material in various ways, Vertical Drier so that the surface of the material is wet and vaporized and escaped into the external space, resulting in a difference in moisture content between the surface and the inside of the material. The internal wet to the surface diffusion and vaporization, Vertical Drier so that the material wet content continues to decrease, Vertical Drier and gradually complete the dry material as a whole.

The drying rate of the material depends on the rate of surface vaporization and the diffusion rate of internal moisture. The drying rate and the surface temperature of the material are kept stable as long as the dry external conditions are constant. This stage is called constant speed drying stage; Vertical Drier when the wet content of the material is reduced to a certain The rate of diffusion of the internal moisture to the surface decreases and is smaller than the rate of surface vaporization. The drying rate is mainly determined by the internal diffusion rate and decreases with the decrease of the wet content. Vertical Drier This stage is called the deceleration drying stage.