Temperature control of the calcination zone in a lime shaft kiln
In the calcination process of a lime shaft kiln, temperature control in the calcination zone is the core factor determining the activity, output, and energy consumption of lime. The key to its control lies in maintaining a stable, uniform, and suitable high-temperature environment, typically keeping the temperature precisely within the range of 1050℃ to 1150℃. Too low a temperature can lead to incomplete decomposition of limestone, resulting in unburned material; too high a temperature can easily cause overburning, leading to a decrease in lime activity and increased wear and tear on the kiln lining.
Achieving precise temperature control is a systematic project, primarily relying on the coordinated management of fuel and airflow. By adjusting the air pressure and volume of the blower, the combustion rate and heat release intensity of the fuel can be controlled, thereby influencing the temperature distribution in the calcination zone. Modern shaft kilns commonly employ automated control systems that rely on thermocouples placed at different heights within the kiln body to monitor temperature curves in real time and feed the data back to the central controller. Based on this, the system dynamically adjusts the fuel feeding quantity and air supply parameters into the kiln, forming a closed-loop control to resist fluctuations in operating conditions.
In addition, the granularity and uniformity of raw limestone, as well as the stability of fuel calorific value, are also important factors affecting the uniformity of the temperature field. During operation, it is necessary to avoid significant and rapid temperature fluctuations and adhere to the principle of "balanced feeding and uniform calcination". Through refined temperature control, not only can high-quality and high-activity lime be produced, but also fuel consumption per unit product can be effectively reduced, achieving the comprehensive goals of energy conservation, high quality, and high yield.
