The vacuum drying equipment by pressure swing mainly consists of a hot air distributor, a screw feeder, a stirrer, a classifier, a rotary drying chamber, etc. The bottom of the drying chamber is a conical structure. The outer ring is a hot air distributor, which is connected to the hot air inlet. The hot air is distributed in a circular ring here and enters the fluidization section tangentially from the slit at the bottom of the cylinder to form a rotating air field. The annular gap size is the main parameter that directly affects the working condition of the dryer.
The conical structure enables the cross-section of hot air flow to continuously increase from bottom to top. The air velocity at the bottom is relatively large, while that at the top is relatively small. This ensures that while the large particles at the bottom are in a fluidized state, the small particles at the top are also in a fluidized state. In addition, the conical structure also reduces the length of the cantilever part of the stirring shaft, enhances the reliability of operation, improves the working condition of the shaft in the high-temperature zone, and extends the service life of the bearings.
Facing severe energy and environmental challenges, China has recently formulated a medium - and long-term energy science and technology development strategy and plan up to 2020 under the guidance of the scientific outlook on development featuring comprehensive, coordinated and sustainable development. The formulation of this energy and environmental development strategy has also pointed out the direction for the development of drying technology in China. It is imperative to explore a new development path for drying technology. Compared with other operational links in industrial and agricultural production, the tasks of energy conservation and pollution prevention in the drying process are particularly urgent.
Firstly, the drying operation covers an extremely wide range of fields. In China, the proportion of drying energy consumption in the total industrial energy consumption is almost half higher than that in the UK, reaching 12%. Secondly, drying also causes quite serious pollution to the environment. Among the most widely used conventional drying equipment, more than three quarters are hot air drying. This type of drying equipment causes very serious pollution to the environment. The transformation of coal-fired furnaces in the drying system has become an important issue that needs to be urgently addressed.
The commissioning of dry coal preparation equipment has achieved a historic breakthrough in the company's development and is a major measure to promote the strategy of invigorating the company through science and technology and accelerate the pace of mechanization. The relevant person in charge of the company introduced that the dry selection equipment was installed in just 24 days, nearly one month ahead of the original plan. The data results of the 14-day load test show that this equipment can effectively increase the calorific value of commercial coal, reduce ash content, and at the same time has multiple advantages such as protecting water resources, energy conservation, environmental protection, comprehensive utilization of resources and development of clean coal technology. It can fully meet the market's requirements for the quality of commercial coal.
When a gas leak occurs in the system, it is prone to explosion in the presence of a fire source. In fact, the leakage rate of the tanks and pipelines in the gas-phase drying equipment for transformers has been inspected and accepted, and they are also inspected and maintained at any time. At the same time, fire prevention measures have also been taken for electrical equipment to reduce ignition sources. Therefore, there is no risk of explosion.