The airflow distribution and heat transfer principle of lime vertical kiln calcination of lime
ransfer principle play a crucial role in the calcination process of lime in a vertical lime kiln. Lime vertical kilns usually operate based on the principle of countercurrent heat transfer, where the materials inside the kiln move from top to bottom, while the flue gas passes through the entire column from bottom to top.
In terms of airflow distribution, the airflow inside the lime vertical kiln needs to be kept uniform and stable to ensure that the limestone can be fully preheated, calcined, and cooled. In the preheating zone, the rising smoke provides the necessary heat for preheating limestone, causing its moisture to evaporate and the temperature to gradually increase. After entering the calcination zone, the high-temperature flue gas comes into full contact with limestone, promoting the decomposition reaction of limestone. In the cooling zone, cold air is introduced from the top of the kiln and exchanges heat with the calcined lime, gradually reducing its temperature.
In terms of heat transfer principle, lime vertical kilns mainly rely on convection and radiation for heat transfer. In the preheating and calcination zones, high-temperature flue gas transfers heat to limestone through convection, causing its temperature to rise and undergoing decomposition reactions. At the same time, the kiln wall and limestone surface also transfer heat to each other through radiation. In the cooling zone, cold air carries away the heat of lime through convection, causing its temperature to rapidly decrease.
In order to ensure uniform airflow distribution and efficient heat transfer, the shape, size, and ventilation system configuration of the lime vertical kiln should be fully considered in its design. A reasonable shape and size of the kiln body can reduce airflow resistance and make the airflow pass through the material column more smoothly. The optimized configuration of the ventilation system can ensure uniform distribution of flue gas in the kiln, improve heat transfer efficiency, and thus produce high-quality lime products.
The airflow distribution and heat transfer principle of lime vertical kiln calcination are complementary. By optimizing the airflow distribution and heat transfer conditions, the production efficiency and product quality of lime kilns can be improved, providing strong support for the stable development of related industries.
