First, the accident process:In April 2019, XX Company organized the annual kiln shutdown and overhaul, and resumed production on April 29. At 9:58 on December 4, 2019, it is planned to stop the kiln for regular inspection, replace the kiln head burner, overhaul the grate cooler, inspect and overhaul the kiln bucket lifting, process inspection and other items, and the kiln will be ignited at 20:18 on the 5th, and the feeding will be resumed at 8:58 on December 6. 50~21.0 meters covered by the old kiln skin, in the feeding process the kiln skin gradually fell off from the front to the back, the kiln skin fell off the part of the cylinder appeared local high temperature point, about 10:27 9At 5 meters, the temperature of the kiln skin fell instantly, the central control tube scan showed 530, and the area expanded rapidly, a large area of red kiln was found on the spot, the measured temperature was as high as 580, and the kiln was stopped at 10:32 for emergency repair. 
Red kiln partSecond, the repair process:On December 6th, the cold kiln was stopped after the material, and the team was urgently organized to repair it, and at 1:00 on the 7th, the kiln skin was entered to destroy the kiln skin, and the kiln lining was inspected after the kiln skin was cleaned: 88~10.There are two places in the 6 meters (a total of 9 ring bricks) ring direction that have no refractory bricks, with an area of about 30, one of which is dropped when the red kiln is dropped, and the cylinder has ablation marks, and the other is the kiln skin falling off after the kiln is stopped. The refractory bricks are all peeled off, the edge is the thinnest 20mm, the thickness of 10 bricks is about 145mm in the circumferential interval, and the thickness of 3 bricks in the longitudinal interval is about 150mm.
Note: The fired refractory bricks with mafic iron spinel bricks were replaced as a whole in April 2019. 
Red kiln part
Drop the brick red kiln part.
Measure the thickness of refractory bricks in other parts of the firing zone, and the data are as follows:
2.0~11.0 meters of refractory bricks are peeled off to varying degrees
11.After 0 meters, the refractory bricks are basically not peeled and burned
2.0~8.8 meters of refractory bricks at the thinnest point
The kiln skin and refractory bricks are melted together3. Cause analysis:1. The direct cause is not knowing the use of the burner, the risk assessment is not in place, the existing wear and tear is not paid enough attention, and the overall dismantling and inspection or return to the factory for maintenance are not in time, resulting in the serious burning of the head part of the coal wind and internal wind pipeline in the use of the burner, resulting in the deformation of the burner flame, insufficient rigidity, unstable temperature of the firing belt, frequent replacement of the kiln skin, and the refractory bricks are eroded, peeled and thinned layer by layer, and the refractory bricks of the weak parts are torn off by the large-scale collapse of the kiln skin in the process of heating up and feeding after the fixed inspection. 2. Indirect causes 21. The experience of calcining the kiln skin is still in the exploration stage, the risk control is not in place, and the kiln skin is not adjusted in time to reverse the planned shutdown of the kiln on the 4th, due to the firing with the kiln skin covering, the thickness of the fired refractory bricks was not detected in time according to the regulations5 meters of refractory bricks are weak and hidden. 
The burner head is badly worn4. Preventive measures1. Process equipment management: In the future, all burners must be dismantled and inspected or returned to the factory for maintenance when the service life reaches three years2. The daily process management of the kiln system The process management personnel pay attention to the operation status of the kiln and the temperature change of the cylinder every dayWhen calcining high-iron iron materials in the kiln, pay close attention to the falling situation of the kiln skin, and record the falling kiln skin in detail in each shift, and adjust the kiln skin in time to stabilize the kiln condition if there is frequent kiln skin dropping. 3. The heating curve must be formulated for each heating up of the kiln heating management, and the operator must strictly control the temperature in the kiln in accordance with the temperature rise curveWhen feeding, there must be process technology management personnel on duty at the site to observe the condition of refractory bricks in the kiln and the calcination of materials every hour, so as to avoid the occurrence of burning flow and burning refractory bricks. 4. The kiln cylinder must be monitored and managed to heat up and feed the material on site, especially in the area where the cylinder can not be scanned, and the daily inspection records the cylinder temperature twice per shift. 5. Refractory material inspection and management of large and medium repairs or temporary kiln shutdown, with the conditions for kiln inspection, must be checked for the thickness of all kiln bricks. 6. Quality management maintains the stability of coal quality, and the balance of coal blending and batching is stable.