What are the causes of lime kiln down fire?
In lime kiln production, the phenomenon of low firing can seriously affect the quality and production efficiency of lime, usually caused by the following factors:
Abnormal air supply system
Insufficient air flow is a common reason. The combustion of fuel in a lime kiln relies on oxygen. If the air volume is insufficient, it will lead to insufficient oxygen supply in the kiln, resulting in incomplete combustion of the fuel. The temperature of the calcination zone will decrease and become unstable, which will cause the calcination zone to move downwards and cause the phenomenon of low flame. In addition, uneven distribution of air supply can also cause similar problems. On the section inside the kiln, if the local air volume is small, the fuel combustion in that area is insufficient, the heat transfer is uneven, which affects the overall calcination effect and promotes the downward movement of the calcination zone.
Raw materials and fuel factors
When the particle size of limestone is not reasonable, if the particle size is too small, there will be more soil after rain and snow, and the permeability of the kiln will decrease, which will affect the combustion and calcination process and cause the calcination zone to move downwards; If the particle size is too large, it is difficult for heat to enter the interior of the stone, which slows down the calcination speed and easily leads to sandwich burning, resulting in a change in the position of the calcination zone. In terms of fuel, if the proportion of fuel is small or the calorific value is low, it cannot provide enough heat to completely decompose limestone, the combustion temperature is not enough, and the calcination zone is difficult to maintain in the normal position, which will cause it to move downwards and result in lower combustion.
Improper ash removal operation
Excessive or rapid ash discharge can accelerate the downward movement of materials in the kiln, causing insufficient calcination of limestone and resulting in lower firing.
