Analysis of damage to refractory lining of hazardous waste incinerator

The damage of the refractory lining of the rotary kiln is one of the common equipment accidents in the hazardous waste incineration system, which directly affects the stability and continuity of the production system. In the actual operation of the rotary kiln, the damage of the lining refractory material is affected by the deformation of the cylinder, the mechanical stress caused by the thermal expansion of the bricks, the thermal stress caused by the thermal shock, and the chemical erosion caused by the clinker, alkali salts, etc. Among them, thermal stress damage and chemical erosion are the most important.

1) Thermal stress damage. Since rotary kilns burn a variety of wastes, when the characteristics of the incinerated wastes are not uniform, the calorific value of the materials fluctuates greatly, which will cause local working conditions to be unstable and easily cause thermal stress damage to refractory bricks.

2) Chemical erosion. Slag, acidic and alkaline liquids, steam and other solid, liquid and gaseous substances come into contact with refractory materials in a high temperature environment and undergo complex chemical reactions with them, which will corrode and damage refractory materials. Among them, liquid slag has the greatest erosion effect. The number of refractory materials damaged by slag erosion accounts for more than 50% of the total damage.

refractory lining materials for hazardous waste incinerator

After analyzing the application of rotary kiln lining refractory materials, it is necessary to reduce the impact of hazardous waste incineration rotary kiln lining materials on production from the aspects of lining structure design, refractory quality selection, masonry quality control, operation, and maintenance.

1) Lining structure design. The refractory brick structure of the rotary kiln lining includes single-layer bricks, double-layer bricks, and composite bricks. Single-layer bricks have a large heat conduction system and the kiln shell temperature is high, which will lead to large heat loss and high energy consumption; the use of double-layer bricks and composite bricks can reduce the kiln shell temperature, but the rotation of the kiln body can easily cause the dislocation and loosening between the brick body and the insulation layer, or loosening and falling off due to inconsistent thermal deformation.

2) Refractory quality selection. Appropriate refractory brick quality and configuration are the primary key. Different refractory composition and ratio are suitable for different types of incineration waste. However, practice has shown that the application of good refractory materials in a certain project is not effective in another treatment plant; even in the same treatment plant project, if the type or source of waste changes greatly, the life of the refractory will fluctuate. Therefore, it is necessary to select refractory materials with appropriate performance according to the characteristics of the waste received by the project.

3) Masonry quality control. High-quality masonry is a reliable guarantee for extending the service life of refractory bricks.

4) Operation and maintenance. During operation, the characteristics of the incineration materials should be uniform, and the fluctuation of the material composition should be reduced. In particular, the slag that is prone to corrosiveness or waste with sharp impact and explosion should be evenly dispersed. This has a very good effect on extending the service life of refractory materials. The establishment of kiln lining and temperature monitoring are also the key to extending the service life of refractory materials. The kiln lining can protect the refractory bricks so that the refractory bricks will not be directly eroded by high temperature and chemicals, and can store heat energy, reduce the heat loss of the rotary kiln shell to the surroundings, and transfer heat to the raw materials to improve thermal efficiency. Temperature monitoring during operation can enable operators to better understand the thermal conditions in the kiln, the thickness of the kiln lining and refractory bricks.

The design, selection, installation and operation and maintenance of refractory materials are related to the stability and continuity of the operation of the hazardous waste incineration system. The cost of refractory materials is high, and the replacement of refractory materials requires shutdown and maintenance, which will also affect the economic benefits of the incineration production line. In order to reduce the impact of lining refractory damage on production, comprehensive consideration should be given to lining structure design, refractory quality selection, masonry quality control, operation and maintenance, etc., based on the hazardous waste composition of the project location. Special research should be carried out in accordance with the actual conditions of the project to ensure the stable operation of the project. Rongsheng refractory manufacturer can provide refractory lining design, construction, and material supply. Contact Rongsheng for free detailed information.