In the construction and maintenance of industrial furnaces, refractory materials play a vital role. Among them, refractory castables and refractory plastics are two widely used materials. Although they are both refractory materials, they have their own unique characteristics and uses.
1. Different expansion design
Refractories castables must reserve expansion joints during construction, usually by burying PVC expansion joint plates. Although this approach can cope with the expansion of the material due to temperature changes, it may have a certain impact on the overall structural continuity of the furnace lining or furnace bottom.
The design concept of refractory plastics is more advanced, and it follows the "0" expansion design principle. This means that the material formula and structural design have been carefully adjusted so that at high temperatures, the material can be maintained at a very low level regardless of whether it is subjected to tensile or compressive stress. This design ensures that the furnace lining can maintain a high degree of stability in a high temperature environment and is almost unaffected by thermal expansion, thereby significantly improving the integrity and service life of the furnace lining.
2. Different thermal shock resistance
There are significant differences in thermal shock resistance between refractory castables and refractory plastics. Refractory plastics exhibit extraordinary thermal shock resistance and can calmly cope with the drastic temperature fluctuations in the furnace, and can even withstand the direct impact of flames without performance degradation or structural damage. The uniqueness of this material is that it can withstand frequent shutdowns and rapid heating processes without worrying about the lining peeling or cracking. In fact, its thermal shock resistance is 3 to 6 times that of ordinary castables, thanks to its advanced material formula and sophisticated production process.
Traditional refractory castables often seem to be unable to cope with rapid temperature changes, and their linings are prone to peeling, cracking and other problems, which seriously affect the normal operation and service life of the equipment.
3. Different furnace baking methods
After the construction of refractories castables, they must go through a relatively lengthy curing, curing and furnace baking process to ensure that the material achieves the ideal physical and chemical properties. In this process, the control of ambient temperature and humidity is crucial, especially in winter, strict antifreeze measures must be taken to prevent material damage, which increases the complexity and time cost of construction to a certain extent.
Refractory plastics are not restricted by seasons in terms of furnace drying methods, and construction can be carried out all year round, which greatly improves the freedom of project arrangement. After the construction of refractory plastics, no additional maintenance time is required, and the furnace can be heated and dried immediately, and the furnace heating rate can be as high as 50℃/hour. Under normal circumstances, it only takes 24 hours for the furnace temperature to reach the production operation requirements, thereby greatly shortening the furnace drying cycle and reducing related costs.
4. Different quality control of construction
When the construction personnel unpack and use it on site, the uniformity and quality of the plastic have been effectively guaranteed. In the ramming operation, due to the stability of the material itself and the standardization of the construction process, the influence of human factors on the quality of the final furnace lining is minimized, thereby greatly improving the controllability and reliability of the construction quality.
Since refractory castables need to carry out multiple key links such as precise control of additives, dry mixing, wet mixing, and vibration at the construction site, each step of these processes has a direct and far-reaching impact on the quality of the final furnace lining. This requires construction personnel to have deep professional knowledge and rich practical experience to ensure precise operation and strict quality control in every link.
5. Different construction processes
The construction process of refractory plastics includes out-of-box use, die drawing, ramming, demolding, grinding and direct furnace baking. The whole process is designed to be quite simple and efficient. In particular, the preload and die drawing construction technology adopted by it shows excellent advantages in furnace roof construction. This technology can ensure that the deformation of the furnace roof steel structure and the furnace lining is highly synchronized, so that the anchor bricks bear uniform force, effectively preventing potential safety risks such as fracture or collapse.
The construction process of castables covers multiple links such as precise water ratio, mold setting, strict control of mixing time, pouring operation, vibration treatment, curing period, demolding and furnace baking. Each step requires high-precision operation and extreme control of details, because negligence in any link may have an adverse effect on the final performance of the material. It is particularly noteworthy that even under such strict construction technology, the refractory castable is still prone to secondary deformation after the furnace wall and furnace roof are demolded, which will cause uneven force on the anchor bricks and thus affect the structural stability and service life of the entire furnace.
