Heating Furnace
Energy-saving scheme in the furnace
Technical Principle：
The energy-saving scheme of the working layer in the furnace involves two technologies, as follows：
1- The surface and gaps (cracks, expansion joints, end joints, etc.) of the working layer in the furnace will be repaired by this repairing mixes, and the repairing thickness is no less than 20mm to improve the air tightness of the working layer in the furnace and also to improve the thermal efficiency of the furnace. 2 – After the repair is completed, the working layer is sprayed with a black glaze energy-saving coating, which can greatly improve the blackness coefficient of the surface of the working layer. At high temperature, the glaze material can not only form a protective layer on the working layer, but also improve the adhesion of the black glaze material, which is not easy to fall off, and the energy-saving effect is long-lasting.
Energy-saving Scheme – Repairing Mixes for working layer
It is a new type of inorganic refractory material, and its core principle lies in the use of its own unique chemical composition and microstructure to achieve good repair results.
Among them, the content of SiO2+MgO is more than 90%, which can form a stable high-temperature-resistant structure in a high-temperature environment and effectively resist high-temperature erosion. The content of impurities such as FeO is very low, which reduces the risk of deterioration of material properties due to oxidation and other factors.
This material is closely combined with the original refractory material of the furnace wall through spraying to repair cracks and shedding areas, so that it can improve the air tightness and thermal insulation properties of the furnace. Its low thermal conductivity slows down heat transfer and has a good thermal insulation effect, thereby reducing energy loss.
Technical Parameters of Repairing Mixes
| Item | Repairing Mixes for Working Layer |
| Chemical Composition
(after firing at 1300× 3h) |
SiO2 +MgO≥90%
FeO≤1% |
| Bulk Density after drying（g/cm3） | 1.6 ±0.05 |
| Bulk Density after firing（g/cm3） | 1.2 ±0.05 |
| Refractoriness (℃) | ≥ 1680 |
| Max Service Temp. (℃) | ≤ 1350 |
| Cold Crushing Strength（ MPa） | ≥ 15 |
| Modulus of Rapture（ MPa） | ≥4 |
| Permanent Linear Change（%） | ≤±0.5 (1350℃x3h) |
| Thermal Conductivity [W/(m·K)] | ≤0.45（400℃, hot face） |
The common repairing thickness is no less than 20mm. After repairing of the whole working layer, the temperature of the outer wall can be reduced by at least 20℃.
Construction Effect of the Repair Mixes
Application
Construction and post-construction effects of steel rolling heating furnace
Project Introduction： Shanxi Jianlong Iron and Steel, Shanxi Liheng Iron and Steel, Jiangsu Yonggang Group, totally 5 Heating Furnace, Spraying thickness 1-3mm; construction area: ≥5000m2; Energy saving ratio 3-5%.
