How to efficiently repair cracks in lime kiln body
Lime kilns are exposed to high temperatures and acid-base erosion for a long time, and the kiln body is prone to cracks. If not repaired in a timely manner, it can lead to heat loss, increased energy consumption, and even safety accidents. Efficient repair requires following the process of "precise diagnosis material adaptation standardized construction post monitoring", with specific operations as follows:
1、 Crack diagnosis and pre-processing
Firstly, through visual inspection and ultrasonic testing, determine the crack width (≤ 3mm for micro cracks,>3mm for wide cracks), depth, and extension direction, and mark the areas of leakage or high-temperature gas breakthrough. During pre-treatment, use a high-pressure air gun to remove the accumulated dust and residue inside the cracks, then use an angle grinder to dig a "V" groove along the cracks (depth ≥ 1.5 times the crack depth, width 8-15mm), and finally use compressed air for secondary cleaning to ensure that the groove is dry and free of impurities, laying the foundation for repairing material bonding.
2、 Selection and construction of repair materials
Select materials based on crack type and kiln working conditions: high-temperature wear-resistant grout (capable of withstanding temperatures of 1200-1500 ℃) is used for micro cracks, and high-temperature resistant castables (with added corundum and silicon carbide aggregates to enhance strength) are used for wide cracks. During construction, low-pressure grouting method is used for micro joints. After mixing the grouting material evenly according to the ratio, it is slowly injected into the cracks through the grouting nozzle until the slurry overflows from the joint; First, lay heat-resistant steel wire mesh in the "V" - shaped groove to enhance crack resistance, and then pour the pouring material layer by layer. Each layer should be compacted by vibration, and the surface should be smoothed with a spatula to ensure it is flush with the original kiln surface.
3、 Maintenance and post monitoring
After repair, gradient curing is required: first naturally cure for 24 hours, then heat up to 200 ℃ for 6 hours, and finally heat up to 80% of the kiln working temperature (about 800-1000 ℃) for 12 hours to avoid material cracking due to temperature differences. In the later stage of operation, the temperature of the repair area is monitored by an infrared thermometer, and cracks are checked weekly to ensure that the repair effect is long-lasting and stable, thereby extending the service life of the kiln body.
