As a common intermittent industrial kiln, the shuttle kiln is widely used in high-temperature firing processes in industries such as ceramics. It has a high firing temperature and a short firing cycle. Therefore, its refractory lining needs to meet the dual requirements of “both fire-resistant and energy-saving”. High alumina bricks are an indispensable key material.
1.High alumina bricks in kiln walls
The kiln wall is the main area of the shuttle kiln that bears high temperature and structural pressure. High-alumina bricks in this area typically contain at least 50% alumina. This ensures a refractoriness of at least 1750°C.
Specifically, its high load softening temperature and compressive strength at room temperature can effectively resist the extrusion of high-temperature materials in the kiln and creep deformation under long-term high temperature.
At the same time, the dense microstructure significantly reduces the high-temperature gas permeability. This can reduce unnecessary heat loss through the kiln wall and maintain temperature uniformity in the kiln.
2.Lightweight high alumina bricks are placed on the top
The top of the shuttle kiln not only needs to withstand high temperatures, but also needs to reduce the weight of the structure as much as possible. Lightweight high-alumina bricks are an ideal choice here.
It forms a uniform closed-pore structure by introducing special pore-forming agents or foaming technology. The bulk density is usually controlled at 1.0-1.5 g/cm³, which is only about half of that of heavy high alumina bricks. Therefore, lightweight high-alumina bricks significantly reduce the load on the kiln roof steel structure.
At the same time, its thermal conductivity is low, forming a highly efficient thermal insulation layer, which can significantly reduce heat loss from the kiln roof.
In addition, the brick still maintains sufficient refractoriness and compressive strength to meet the requirements for safe operation of the top.
3.Burner nozzle
The fire mouth (burner nozzle) area is the most severe part of the shuttle kiln working conditions. It is directly exposed to high-temperature flame erosion, severe temperature fluctuations and chemical erosion by combustion products.
The high alumina bricks here need to have excellent thermal shock resistance and erosion resistance. High-quality high-alumina bricks with higher alumina content (≥70%) are usually selected. Its mineral phases are mainly mullite and corundum, with a dense structure and low thermal expansion coefficient.
Specifically, the brick can withstand frequent rapid cooling and heating at the flame nozzle without cracking or peeling. Furthermore, it exhibits strong chemical inertness to aggressive media in the combustion gases. This ensures long-term structural stability of the burner.
In general, high alumina bricks play an important role in the key parts of shuttle kilns. Selecting a professional refractories supplier who can provide customized high-alumina brick solutions according to the working conditions of different parts of the shuttle kiln is an important basis for ensuring the long-term and reliable operation of the kiln.