In recent years, my country’s mineral processing industry has continued to develop, and the application of dryers has become increasingly frequent. Consequently, problems related to the use of dryers have become more prominent. Based on years of observation, Xinshengrun has categorized and summarized these issues. Furthermore, to address these problems, our company has developed a new generation of dynamic vertical dryer equipment. This article mainly provides a brief introduction to the technical features and innovations of the dynamic vertical dryer.

Traditional dryers suffer from the following problems

1. They generally suffer from high heat loss, low thermal efficiency, high coal consumption, difficulty in controlling output moisture content, and relatively low output.

2. They are not suitable for using waste heat flue gas with temperatures below 350℃ as a heat source for drying materials.

3. They are not suitable for drying materials containing water of crystallization (e.g., drying dihydrate gypsum into hemihydrate gypsum) or materials with high moisture content.

4. They cannot resolve the phenomenon of material agglomeration and increased particle size during the drying process, which greatly affects the drying effect.

5. The drying system does not use an automatic microcomputer detection and control system, which cannot accurately detect and control the material, air, and coal online in a timely manner, resulting in the drying system not achieving optimal performance.

Dynamic Vertical Dryer Development

To address these issues, Xinshengrun has developed a new generation of dynamic vertical dryer equipment. Addressing the shortcomings of current domestic and international drying equipment and processes, it employs new processes, equipment, and computer software technology. A digital design parameter model for the drying system has been established, resulting in significantly improved energy efficiency and reduced consumption. Coal consumption is only 8 kg standard coal/t dry material, and electricity consumption is only 2–2.5 kWh/t dry material. This is a newer, more powerful, and more energy-efficient vertical dryer.

Technical features of the new generation dynamic vertical dryer: It allows materials to be dispersed as much as possible within the dryer, increasing the contact area between hot flue gas and materials. Simultaneously, it controls the flow rate and residence time of materials in different areas of the dryer, ensuring sufficient convection, radiation, and conduction heat exchange between the hot flue gas and materials. We will also use microcomputer software technology to optimize material drying parameters, and conduct online monitoring of material moisture and gas temperature in the three zones of the preheating zone, drying zone, and drying zone. We will also adjust system parameters such as heating capacity, induced draft volume, secondary hot air distribution and heating capacity, material interception volume and residence time online to achieve dynamic optimization and balance of the system and improve the system’s thermal energy utilization rate.

Technological Innovations of the Dynamic Vertical Dryer

1. Utilizing the drying principles and methods of high-efficiency vertical dryers, while employing material balance and heat balance principles, it retains the external static insulation structure. The internal heat exchange device is designed and installed to adapt to materials of different properties, resulting in a high-efficiency, high-heat-exchange system. It incorporates features of dynamic vertical dryers, such as an anti-clogging vibration feeding device, a vibration flow regulation device, a rotary material crushing device, and internal and external annular air inlets, completely solving the clogging problem.

2. Variable diameter structure: The dry process rotary kiln production line in the cement industry generates a large amount of waste heat flue gas with a temperature below 350℃. Utilizing this waste heat flue gas plays a crucial role in reducing energy consumption and lowering production costs. Previously, due to inherent limitations of rotary dryers, this waste heat could not be effectively utilized. However, the dynamic high-efficiency vertical dryer, through a variable-diameter structure, expands the diameter of the preheating and drying zones, reduces air velocity, and increases the evaporation space. Simultaneously, different types of grates and cones control the material residence time, maximizing waste heat utilization efficiency.

3. Monitoring System: The drying monitoring system performs online monitoring of material moisture and gas temperature in the preheating, drying, and drying zones. It automatically balances the material, air, and coal in the control system and adjusts system parameters online, such as heating capacity, induced draft volume, secondary hot air distribution and heating capacity, material interception flow rate, and residence time, to achieve dynamic optimization and balance of process parameters and improve the system’s thermal energy utilization rate.