The solution to the upward movement of the calcination belt in the lime kiln shaft kiln
In the production process of lime kiln shaft kiln, the upward movement of calcination belt will have a negative impact on the quality and production efficiency of lime. It is crucial to understand and adopt effective solutions to correct the upward movement of the calcination belt. This article will explore various solutions to this problem.
1、 In terms of raw material management
（1） Optimize the particle size of limestone
Strictly control the crushing process
Ensure the stable operation of limestone crushing equipment and avoid producing excessive fine powder. Regularly inspect and maintain the crusher, adjust its parameters to maintain the particle size of limestone within a reasonable range, such as 40-80mm.
A combination of multi-stage crushing and sieving can be used to precisely control the particle size of limestone and reduce uneven particle size.
Remove unqualified particle size raw materials
Before feeding, set up a screening device to screen out limestone particles that are too small (less than 30mm) or too large (greater than 100mm). For batches with excessive fine powder content, they can be re crushed or treated separately.
（2） Stable limestone composition
Strengthen raw material testing
Increase the frequency of detecting the chemical composition of limestone, especially the impurity content. Establish strict quality standards for raw materials, and reject limestone with excessive impurity content from entering the kiln or undergo pre-treatment.
Through chemical analysis, grasp the content of impurities such as silica and alumina in limestone, and adjust the production process according to the impurity situation.
Mixing different batches of raw materials
When there are significant fluctuations in the composition of limestone from different batches, they can be mixed and used. By reasonable combination, the composition of limestone entering the kiln is relatively stable, reducing the upward movement of the calcination zone caused by changes in impurity content.
2、 Regarding fuel adjustment
（1） Control fuel particle size
Adjust fuel crushing equipment
Adjust the fuel crushing equipment to ensure that the fuel particle size meets production requirements. For example, for coal fuel, its particle size should be controlled at around 20-50mm.
Regularly check the distribution of fuel particle size to avoid a high proportion of fine powder in the fuel.
Optimize fuel storage and transportation
During fuel storage and transportation, efforts should be made to minimize fuel breakage and refinement. Suitable storage containers and transportation equipment can be used to avoid excessive friction between fuel particles.
（2） Improve fuel distribution
Inspect and maintain fabric equipment
Regularly inspect and maintain fabric equipment to ensure its normal operation. For example, check whether the rotation speed and angle of the rotating fabric dispenser are uniform, and whether the pipes of the multi tube fabric dispenser are blocked.
Timely clean up the accumulated materials and debris on the fabric equipment to ensure that the fuel can be evenly distributed in the kiln.
Optimize fabric handling
Train operators to master correct fabric techniques. According to the actual situation inside the kiln, adjust the feeding speed and amount reasonably to avoid fuel accumulation in the upper part of the kiln body.
3、 Ventilation control aspect
（1） Adjust ventilation volume
Optimize the operating parameters of the fan
Adjust the power and speed of the fan reasonably according to the calcination situation inside the kiln. On the premise of ensuring sufficient combustion of fuel, avoid excessive ventilation.
Variable frequency fans can be installed to adjust the ventilation volume in real-time according to the actual needs of the production process, ensuring stable airflow inside the kiln.
Check the ventilation duct
Regularly inspect the ventilation ducts for any air leaks, blockages, or deformations. Timely repair air leaks, clean blockages, and ensure smooth and sealed ventilation ducts.
Optimize the layout of ventilation ducts, reduce unnecessary bends and resistance, and improve ventilation efficiency.
（2） Improve local ventilation
Install local ventilation control device
Install adjustable ventilation devices such as ventilation valves in different parts of the kiln body. According to the temperature distribution inside the kiln, fine tune the local ventilation volume to make the ventilation in the upper and lower parts of the kiln more uniform.
By adjusting local ventilation, the distribution of heat can be effectively controlled, avoiding the upward movement of the calcination zone due to uneven local ventilation.
4、 Optimization of process parameters
（1） Reasonably control the calcination temperature
Calibrate temperature detection equipment
Regularly calibrate the temperature detection equipment (such as thermocouples) inside the kiln to ensure the accuracy of temperature measurement. Adjust the calcination temperature reasonably based on accurate temperature data.
Avoid setting the temperature too high or too low due to temperature detection errors, which may affect the position of the calcination zone.
Develop a scientific temperature control curve
Develop a reasonable temperature control curve based on the characteristics of limestone, the properties of fuel, and the structure of the kiln body. On the premise of ensuring the quality of calcination, control the calcination temperature within the optimal range, such as 900-1200 ° C.
（2） Optimize calcination time
Establish a time calcination effect model
Establish a relationship model between calcination time and calcination effect through experiments and production practices. Determine the optimal calcination time under different conditions based on the model.
To avoid excessive calcination of the lower limestone due to prolonged calcination time, heat is transferred upwards, causing the calcination zone to move upward.
5、 Improvement of kiln structure
（1） Strengthen the insulation of the kiln body
Inspect and repair the insulation layer
Regularly inspect the condition of the insulation layer on the kiln body, especially the insulation material on the upper part of the kiln body. Timely repair or replace insulation materials that are aging, damaged, or have fallen off.
High performance insulation materials such as aluminum silicate fibers can be used to improve the insulation performance of the kiln body and reduce heat loss.
Optimize the structure of the insulation layer
Optimize the structure of the insulation layer by increasing its thickness or adopting a multi-layer insulation structure. Strengthen insulation measures at the interfaces, doors, and other parts of the kiln body to ensure its sealing and insulation properties.
The problem of the upward movement of the calcination belt in the lime kiln shaft kiln needs to be comprehensively solved from multiple aspects. By optimizing raw material management, adjusting fuel, controlling ventilation, optimizing process parameters, and improving kiln structure, the calcination zone can be effectively restored to its normal position, improving lime quality and production efficiency. In the actual production process, it is necessary to closely monitor the changes in each link and adjust relevant measures in a timely manner to ensure the stable operation of production.
