Practice of Capacity Enhancement and Parameter Adjustment in Lime Vertical Kiln
As the core equipment of traditional lime production, the capacity improvement and parameter optimization of lime vertical kiln are the key to improving production efficiency and reducing energy consumption.
Raw material pretreatment and particle size control
The quality of raw materials directly affects the yield and activity of lime. A certain steel enterprise has strictly controlled the particle size of limestone within the range of 40-80mm by introducing a multi-stage crushing and vibration screening system, while cleaning and removing surface impurities, thereby increasing the purity of raw materials to CaCO3 content ≥ 90%. After the renovation, the limestone decomposition rate increased by 12%, the firing rate decreased to below 5%, and the daily output of a single kiln increased from 110 tons to 130 tons.
Optimization of Combustion System and Air Volume Control
Combustion efficiency is the core of capacity improvement. A certain 120m ³ vertical kiln upgraded the power of the air supply system motor from 75kW to 90kW, and increased the fan speed to 2900 revolutions per minute, increasing the inlet air volume from 11000m ³/h to 14500m ³/h. At the same time, the "micro negative pressure" control technology is adopted to stabilize the kiln top pressure at -80~0Pa, combined with multi-point air supply devices, which improves the temperature uniformity inside the kiln by 20%, shortens the calcination time to 8 hours, and increases production capacity by 18%.
Automated Control and Intelligent Monitoring
After introducing the DCS distributed control system, a certain enterprise has achieved real-time control of key parameters such as kiln temperature, material layer thickness, and ash discharge frequency. By linking thermocouples with infrared thermometers, the system automatically controls the temperature in the calcination zone within the range of 1050-1150 ℃. When the flame color deviates from bright yellow, the fuel ratio is immediately adjusted. After the transformation, the activity of lime remained stable at over 350mL, and the heat consumption per unit product decreased by 15%.
Process innovation and equipment upgrade
After adopting SR multi-channel low nitrogen burner in a project in Jiangsu, the flame length was increased by 30% and the temperature uniformity of the calcination zone was improved by 25% by optimizing the gas and air mixing path. Combined with a closed cooling system, the ash discharge temperature was reduced from 300 ℃ to 180 ℃, reducing heat loss while extending the service life of the kiln lining. After the renovation, the single line production capacity increased from 700 tons/day to 880 tons/day, and the NOx emission concentration decreased to 30mg/m ³, meeting the ultra-low emission standards.
Practical achievements and industry insights
The above case shows that through the four paths of raw material pretreatment, combustion system optimization, automation control, and process innovation, the production capacity of lime vertical kilns can be increased by 15% -30%, while reducing energy consumption by 10% -20%. In the future, with the popularization of technologies such as intelligent fabric distributors and waste heat recovery devices, lime vertical kilns will continue to evolve towards large-scale, intelligent, and green directions, providing more efficient raw material support for industries such as steel and building materials.
