Pressure swing vacuum drying equipment is mainly composed of hot air distributor, screw feeder, agitator, classifier, rotary drying chamber, etc. The bottom of the drying chamber is a cone structure, and its outer ring is a hot air distributor, which is connected with the hot air inlet. The hot air is distributed in a circular ring here, and enters the fluidization section in a tangential direction from the slit at the bottom of the cylinder to form a rotating wind field. The annular gap size is the main parameter that directly affects the working condition of the dryer. The cone structure can continuously increase the hot air flow section from bottom to top, with relatively large gas velocity at the bottom and relatively small gas velocity at the upper part, so as to ensure that the large particles at the lower part are in the fluidization state and the small particles at the upper part are also in the fluidization state. In addition, the cone structure also reduces the length of the cantilever part of the mixing shaft, increases the reliability of operation, improves the working condition of the shaft in the high temperature area and prolongs the service life of the bearing.

In the face of severe energy and environmental challenges, China has recently formulated a medium - and long-term energy science and technology development strategy and development plan to 2020 under the guiding ideology of a comprehensive, coordinated and sustainable scientific outlook on development. The formulation of this energy and environmental development strategy also points out the direction for the development of China's drying technology, and it is imperative to explore a new development path of drying technology. Compared with other operation links in industrial and agricultural production, the task of energy saving and pollution prevention in the drying process is particularly urgent. Firstly, the drying operation involves a wide range of fields, and the proportion of drying energy consumption in China is almost half higher than that in the UK, reaching 12%. Secondly, the pollution of drying to the environment is also quite serious. Among the most widely used conventional drying equipment, more than three quarters are hot air drying. This kind of drying equipment pollutes the environment very seriously. The transformation of coal-fired furnace in drying system has become an important issue to be solved urgently.

The use of dry coal preparation equipment has achieved a historic breakthrough in the development of the company. It is a major measure to promote the strategy of revitalizing the company through science and technology and accelerate the pace of mechanized development. " According to the relevant person in charge of the company, the dry separation equipment was installed in only 24 days, nearly one month ahead of the original plan. The data results of 14 day load test show that the equipment can effectively improve the calorific value of commercial coal and reduce ash content. At the same time, it has multiple advantages such as protecting water resources, energy saving, environmental protection, comprehensive utilization of resources and developing clean coal technology, which can fully meet the requirements of the market for commercial coal quality. In case of air leakage of the system, it is easy to explode when there is an ignition source. But in fact, the leakage rate of the tank and pipeline in the gas-phase drying equipment for transformer has been accepted, and it is also checked and maintained at any time. At the same time, fire prevention measures are also taken for electrical equipment to reduce ignition sources. Therefore, there will be no risk of explosion.