The influence of upward movement of lime kiln calcination belt on lime quality
Lime kiln is a key equipment for producing lime, and its calcination process directly affects the quality of lime. During the actual operation of a lime kiln, the position of the calcination zone may shift upwards, which can have a series of impacts on the quality of lime.
1、 The reason for the upward movement of the lime kiln calcination belt
The reasons for the upward movement of the lime kiln calcination zone are complex and diverse, mainly including the following aspects:
Changes in raw material properties: Changes in the particle size, composition, or calorific value of limestone raw materials may result in uneven distribution of calcination speed and temperature, leading to an upward shift in the calcination zone.
Fuel supply issue: The supply and quality of fuel directly affect the temperature and position of the calcination zone. If there is insufficient fuel supply or insufficient combustion, it will cause a decrease in the temperature of the calcination zone, leading to an upward shift phenomenon.
Ventilation system issue: The operating status of the ventilation system has a significant impact on the stability of the calcination belt. If there is poor ventilation or uneven distribution of air volume, it will lead to uneven temperature distribution in the calcination zone, which will cause upward movement. Equipment malfunction: Some equipment malfunctions in the lime kiln vertical kiln may also cause the calcination belt to move upwards. For example, malfunctions in equipment such as feeders and ash discharge machines may affect the uniform distribution of raw materials and waste, thereby affecting the stability of the calcination belt.
2、 The specific impact of upward movement of calcination belt on the quality of lime
Reduced lime activity
The activity of lime is an important indicator for measuring its chemical reactivity. After the calcination zone is moved up, the heating time and uniformity of limestone in the kiln may change, thereby affecting the activity of lime. Specifically, the upward movement of the calcination zone may lead to a shortened residence time of limestone in high-temperature areas, incomplete decomposition of limestone, and a decrease in activity. In addition, the upward movement of the calcination zone may lead to uneven distribution of calcination temperature, resulting in significant differences in the activity of some limestone, further affecting the overall quality of the lime.
Lime purity decreases
The purity of lime refers to the content of effective calcium oxide in it. The upward movement of the calcination zone may affect the calcination process of limestone in the kiln, thereby affecting the purity of lime. Specifically, the upward movement of the calcination zone may lead to a shortened residence time of limestone in high-temperature areas, incomplete decomposition of limestone, and incomplete discharge of impurities, resulting in a decrease in lime purity. In addition, due to the upward movement of the calcination zone, the uneven distribution of calcination temperature may result in higher impurity content in some limestone, further affecting the overall purity of the lime. Uneven distribution of lime particle size
The particle size distribution of lime has a significant impact on its performance. The upward movement of the calcination zone may cause changes in the heating time and uniformity of limestone in the kiln, thereby affecting the particle size distribution of lime. Specifically, the upward movement of the calcination zone may lead to a shortened residence time of limestone in high-temperature areas, resulting in coarser particle size of some limestone; Meanwhile, due to uneven distribution of calcination temperature, some limestone may have finer particle size. This uneven particle size distribution not only affects the performance of lime, but may also increase the crushing and screening costs of lime.
Increase in lime calcination rate
Burning refers to the phenomenon where limestone fails to completely decompose during the calcination process. The upward movement of the calcination zone may lead to a shortened preheating zone, which prevents the limestone from being fully preheated before entering the calcination zone. This will lead to ineffective utilization of the heat energy rising from the calcination zone, resulting in an increase in the ratio and causing waste. Meanwhile, due to insufficient preheating, the decomposition rate of limestone in the calcination zone may be affected, resulting in an increase in the amount of raw material burned. Lime produced by calcination not only has low activity and poor purity, but also easily generates dust and harmful gases during use, causing adverse effects on the environment and human health.
3、 Measures to solve the problem of upward movement of calcination belt
Corresponding measures can be taken to address the impact of the upward movement of the lime kiln calcination belt on the quality of lime from the following aspects:
Strictly control the quality of raw materials: Strengthen the inspection and screening of limestone raw materials to ensure that the particle size, composition, and calorific value of the raw materials meet production requirements. At the same time, adjust the calcination process parameters in a timely manner according to the changes in the properties of the raw materials to ensure the quality of lime.
Optimize fuel supply system: Ensure stable fuel supply and quality, and improve combustion efficiency. Advanced combustion technologies and equipment, such as high-efficiency burners and automatic control systems, can be adopted to reduce fuel consumption and environmental pollution.
Strengthen ventilation system management: Ensure unobstructed ventilation system and even distribution of air volume. Advanced ventilation technologies and equipment, such as frequency converters and fans, can be adopted to improve ventilation efficiency and reduce energy consumption.
Regular inspection of equipment failures: Regular inspection and maintenance of the feeder, ash discharge machine, and other equipment of the lime kiln vertical kiln to ensure their normal operation. Once equipment malfunctions are discovered, they should be dealt with promptly to avoid affecting the stability of the calcination belt.
The upward movement of the calcination zone in the lime kiln has a significant impact on the quality of lime. It not only reduces the activity and purity of lime, but also leads to uneven particle size distribution and increased calcination, thereby affecting the performance and environmental protection of lime. Therefore, in actual production, it is necessary to closely monitor the stability of the calcination belt, and effectively prevent and control the upward movement of the calcination belt by optimizing the quality of raw materials, fuel supply, ventilation system, and equipment maintenance, to ensure the stability and improvement of lime quality.
