In recent years, the majority of cement workers have done a lot of work in improving the type of production kiln, process equipment and control technology, and improving operation technology, and have achieved gratifying results. The burning heat consumption of clinker has been declining year by year, and some are close to International advanced level. However, sufficient attention has not been paid to the selection of thermal insulation materials and refractory materials, and the reduction of heat dissipation losses of the kiln body. Especially for vertical kilns, it is believed that the heat dissipation loss of the kiln body is only about 3% of the total heat consumption, which can be ignored. The heat loss of the kiln body has a greater impact on the calcination process of the shaft kiln, because the vertical kiln generally has excessive side wind and insufficient stroke, and the heat loss from the side to the outside of the kiln body makes the temperature deviation of the side kiln even more obvious. It is low, and the firing of clinker is difficult. In order to improve this satin burning system, for most shaft kiln factories that use all black raw materials, they have to increase the coal bowl to meet the edges, which undoubtedly increases the burning heat consumption of the shaft kiln, and the central part The coal consumption is relatively high, resulting in poorer ventilation in the central part, and the appearance of a reducing atmosphere. Such a vicious circle affects the quality of clinker production. Therefore, the comprehensive heat loss may be several or more than ten times the apparent heat dissipation loss. Therefore, paying attention to the heat insulation of the kiln body and reducing the heat loss can greatly reduce the coal consumption and achieve the purpose of energy saving.
The role of heat insulation materials and refractory materials and the requirements for their materials
1. The role of heat insulation materials and refractory materials for the cement kiln
They are mainly kiln lining materials and thermal insulation fillers. They can reduce the temperature of the kiln shell, protect the kiln shell, reduce heat loss, reduce the heat consumption of clinker, reduce the temperature difference between the surrounding and central parts of the kiln, and promote the kiln. The stability of the internal thermal system.
2. Performance requirements of refractory materials and thermal insulation materials use for the cement kiln
The service life of kiln lining and thermal insulation materials directly affects the operation rate of rotary kiln or shaft kiln and the production quality of clinker. Therefore, the selection of kiln lining and thermal insulation materials is very important. When selecting, mainly consider the following properties of thermal insulation materials: mechanical strength, refractoriness, thermal shock stability, chemical resistance, thermal expansion or volume stability, thermal conductivity, wear resistance, porosity, etc.
3 performance and selection of kiln linings and thermal refractory insulation materials use for cement kiln
The cement kiln is not only a combustion equipment, but also a material conveying equipment. According to the material in the kiln during the satin burning process, it is divided into several reaction zones along the length or height of the kiln. Because of the reaction process of each zone and the different material temperature and state, the requirements for lining materials and thermal insulation materials are also different. Therefore, the types of linings and thermal insulation materials used in each belt of the rotary kiln or shaft kiln are also different.