What is the reason for the abnormal downward movement of the flame position in the environmentally friendly lime kiln
The phenomenon of "low firing" in environmentally friendly lime kilns refers to the abnormal downward movement of the flame position inside the kiln, resulting in a high temperature at the bottom of the kiln and insufficient temperature at the top of the kiln. This abnormal phenomenon not only affects the quality of lime, but also increases energy consumption, and its causes need to be comprehensively analyzed from the perspectives of process and environmental protection transformation.
From the perspective of combustion dynamics, ignition is mainly caused by an imbalance in the mixing ratio of fuel and air. When environmental protection renovation adds desulfurization and denitrification devices, the airflow path inside the kiln changes. If the blower system is not optimized synchronously, it is easy to form a local oxygen deficient zone. At this time, the fuel can only be fully burned in the high-temperature zone at the bottom of the kiln, and the flame naturally descends. After the sealing modification of some kiln bodies, improper control of negative pressure inside the kiln may also cause flames to be dragged to the bottom by the flue gas.
At the operational level, excessive fuel particle size or high water content will prolong the combustion time, and unburned fuel particles will settle with gravity and undergo secondary combustion at the bottom of the kiln. If the feeding speed does not match the blowing volume, a thick material layer will hinder the normal rise of the flame, resulting in a "smoldering" phenomenon. When environmental protection equipment malfunctions and smoke emissions are obstructed, pressure fluctuations inside the kiln can also exacerbate flame deviation.
Cracking the fire requires multiple measures: establishing a dynamic monitoring system for fuel calorific value to ensure that the particle size of the fuel entering the kiln is less than 3mm and the moisture content is less than 2%; Add a secondary air inlet in the middle of the kiln body to optimize the airflow distribution; Adopting an intelligent combustion control system to adjust air distribution parameters in real-time based on kiln temperature; Regularly use an infrared thermal imager to inspect the kiln body and promptly repair sealing defects. Through the coordinated regulation of process parameters and environmental protection equipment, flame stability and stratification can be achieved while meeting emission standards, achieving a win-win situation for environmental protection and efficient production.
