The thermal insulation materials for the lime kiln body have been put into production and operation for about 5 years. Due to severe wear and tear, the inner refractory bricks in the impact area of the cutting material began to fall off frequently, which caused great damage to the working conditions of the lime kiln and the continuous and stable operation of subsequent equipment. Therefore, choosing suitable and durable thermal insulation materials and installing effective protective devices play a vital role in the stable operation of the lime kiln.
Cause Analysis and Technical Improvement of Shedding
1. Analysis of the cause of shedding
The shedding is mainly due to the premature damage of the inner layer bricks under the influence of various factors. After the inner layer is damaged to a certain extent, a large area will fall off.
1) The quality of the masonry is not up to standard, which leads to premature damage of the thermal insulation materials of the lime kiln, which seriously shortens the service life.
2) The kiln guard plate on the top of the lime kiln directly bears the impact of the material. Under the impact of the material, the kiln guard plate quickly wears out and fails, resulting in premature damage to this area.
3) Refractory bricks have low compressive strength at room temperature, small body density, and poor wear resistance, resulting in premature damage.
4) The inner layer of the calcination area is subjected to high temperature, and under the action of Ca2+, alkaline corrosion is likely to occur there, resulting in a decrease in the overall performance of the bricks and premature damage.
2. Technical improvement
During the lime kiln installation process, professional technicians are arranged to track and inspect the masonry quality throughout the process. At the same time, our company’s lime kiln thermal insulation materials are constantly improving and exploring in terms of structure and material.
2.1 Kiln guard board
Install the impact belt on the inner side of the original kiln guard plate to prolong the service life of the kiln guard plate and alleviate the direct impact to a certain extent.
2.2 Thermal insulation materials
The inner brick of the lime kiln is in direct contact with the material, and its various physical and chemical indicators have higher requirements than the outer brick. Our company has been seeking and exploring improvement schemes. In the initial stage, the content of Al2O3 in the inner layer of refractory bricks was increased from 65% to 70%, and its normal temperature compressive strength, body density and other physical and chemical indicators were also increased accordingly, so that the life of the calcination zone was extended to a certain extent. .
The refractory bricks in the material impact area are directly impacted by the material. The requirements for the wear resistance and impact resistance of the bricks in this area are relatively high. At the same time, this area is a preheating area, and the temperature is not high. The requirements can be kept unchanged, and the wear resistance and impact resistance of bricks can be improved by increasing the normal temperature compressive strength index and bulk density index of bricks. After combining with professional technical manufacturers and going out to investigate, corundum mullite bricks were selected for this area as the inner refractory bricks. Compared with ordinary high alumina bricks, corundum mullite bricks have higher compressive strength, better wear resistance and erosion resistance. Good and other excellent features.
