What are the characteristics of the downward movement of the lime kiln calcining zone?
Lime vertical kiln is a key equipment in the limestone calcining process. Its internal temperature distribution and combustion state directly affect the quality and output of lime. In the calcining process of lime shaft kiln, the position of the calcining zone is crucial, which determines the degree and efficiency of limestone decomposition. However, in actual production, the position of the calcined zone is not static and sometimes moves downward.
The downward movement of the calcining zone is one of the common problems in the operation of lime shaft kilns. Its characteristics are mainly reflected in the following aspects:
The increase in ash temperature is a significant sign that the calcining zone moves downward. When the calcining zone moves downward, the high-temperature area originally located in the middle of the kiln body will move downward, causing the temperature near the ash outlet to rise significantly. This will not only affect the cooling effect of the lime, but may also cause damage to the ash removal equipment.
The decrease in kiln gas temperature is also an important feature of the downward movement of the calcining zone. Due to the change in the position of the calcining zone, the temperature distribution in the kiln changes, and the temperature in the original high-temperature area decreases, causing the kiln gas temperature to also decrease. This phenomenon will affect the calcining effect and yield of lime.
The discharged lime contains unburned fuel blocks or red fire, which is also an obvious manifestation of the downward movement of the calcination zone. When the calcining zone moves downward, the residence time of the fuel in the kiln is shortened and the combustion is insufficient, resulting in part of the fuel block or red fire being discharged along with the lime. This not only wastes fuel resources, but may also affect the quality and stability of the lime.
The decrease in CO content in the kiln gas is also a characteristic of the downward movement of the calcining zone. Due to the change in the position of the calcining zone and the adjustment of the combustion state, the CO content in the kiln gas will change. When the calcination zone moves downward, insufficient combustion leads to a reduction in CO content, which may have an adverse effect on production processes that require high concentrations of CO.
In response to the problem of the downward movement of the calcination zone, relevant practitioners can take a series of measures to adjust and optimize. For example, by adjusting parameters such as fuel particle size, discharge volume, and air supply volume, the position and temperature distribution of the calcining zone can be changed; at the same time, strengthening the maintenance and management of ventilation and cooling equipment in the kiln can also effectively prevent the calcining zone from moving downward. occur.
The characteristics of the downward movement of the lime shaft kiln calcining zone are mainly reflected in the increase in ash temperature, the decrease in kiln gas temperature, the presence of unburned fuel blocks or red fire in the discharged lime, and the decrease in CO content in the kiln gas. Understanding these characteristics will help relevant practitioners promptly discover and solve the problem of downward movement of the calcining zone and ensure the efficient and stable operation of the lime vertical kiln.
