In industrial production, the normal operation of kilns is inseparable from suitable refractory materials. The correct selection of refractory materials is of vital importance to improving the service life of kilns, ensuring product quality and reducing energy consumption. So, how to make appropriate choices according to the use conditions of kilns?
1. Understand the type and working temperature of kilns
First of all, it is necessary to clarify the type of kiln, such as tunnel kiln, rotary kiln, box kiln, etc. Different types of kilns differ in structure and working mode, and the requirements for refractory materials are also different.
Working temperature is one of the key factors in selecting refractory materials. For example, for kilns with an operating temperature below 1200℃, clay refractory materials may be selected to meet the requirements; while for kilns with an operating temperature exceeding 1600℃, high alumina, corundum or even silicon carbide refractory materials need to be selected.
2. Consider the atmosphere inside the kiln
The atmosphere inside the kiln is divided into oxidizing atmosphere, reducing atmosphere and neutral atmosphere. In an oxidizing atmosphere, refractory materials containing chromium oxide and magnesium oxide perform better; in a reducing atmosphere, carbon-containing refractory materials are more suitable.
For example, in the reduction zone of a copper smelting reverberatory furnace, since the atmosphere is a reducing atmosphere, carbon-containing refractory materials should be selected to prevent other materials from being damaged by reduction.
3. Evaluate the load and mechanical wear of the kiln
If the material in the kiln is heavy or there is strong mechanical stirring, it is necessary to select refractory materials with higher strength and wear resistance. For example, in the firing zone of a cement rotary kiln, due to the continuous tumbling and friction of the clinker, refractory bricks with excellent wear resistance are required.
4. Pay attention to thermal shock stability
For intermittent kilns, due to frequent temperature changes, the thermal shock stability of refractory materials is required to be higher. Refractory materials with good thermal shock stability, such as mullite and cordierite refractory materials, can reduce the risk of cracking and spalling when the temperature changes sharply.
5. Consider energy saving and environmental protection requirements
With the increase in energy costs and the improvement of environmental protection standards, it is becoming increasingly important to choose refractory materials with good thermal insulation performance and low energy consumption. Materials such as lightweight refractory bricks and refractory fibers can effectively reduce heat loss and reduce energy consumption.
For example, in the insulation layer of a glass melting furnace, the use of refractory fiber wool can significantly improve the insulation effect and reduce heat emissions.
6. Balance between economic cost and service life
When choosing refractory materials, we should not only focus on the initial purchase cost, but also consider its service life and maintenance cost. Sometimes, although some advanced refractory materials are more expensive, they may be more economical in the long run due to their long service life and low maintenance requirements.
In short, choosing refractory materials according to the use conditions of the kiln is a comprehensive consideration process. It is necessary to fully understand the working characteristics of the kiln, environmental requirements, economic budget and other factors in order to make a wise choice to ensure the efficient and stable operation of the kiln and extend its service life.
HOME