- Time:Sep 26, 2023
refractory castables used for heating furnace linings are typically selected based on the specific requirements of the furnace and the operating conditions involved. Here are some common types of refractory castables used for heating furnace linings:
1. Dense Castables: Dense castables are composed of high-density refractory aggregates and binders, resulting in a dense and strong material. They are suitable for areas of the furnace exposed to high mechanical and thermal stresses. Dense castables provide excellent resistance to abrasion, erosion, and thermal shock, making them ideal for applications such as burner blocks, furnace doors, and high-temperature zones.
2. Insulating Castables: Insulating castables are formulated to have low thermal conductivity, providing effective insulation for heat containment within the furnace. These castables are lightweight and offer thermal energy savings. They are commonly used in furnace walls and roofs to reduce heat loss and improve energy efficiency.
3. Low Cement Castables: Low cement castables contain reduced amounts of calcium aluminate cement (CAC), resulting in improved refractoriness and mechanical properties. These castables exhibit good strength and resistance to spalling at high temperatures. They are often used in areas of the furnace that experience moderate to high temperatures, such as hearths, soaking pits, and tundishes.
4. Ultra-Low Cement Castables: Ultra-low cement castables have an even lower content of calcium aluminate cement compared to low cement castables. This composition enhances their high-temperature stability and resistance to chemical attack. Ultra-low cement castables are employed in critical parts of the furnace, including hot spots, burner blocks, and areas with severe thermal cycling and corrosion conditions.
5. Self-Flowing Castables: Self-flowing castables, also known as pumpable castables, have a higher fluidity, allowing them to be easily poured or pumped into complex shapes and areas. They offer excellent installation convenience and are often used in intricate furnace linings, such as in coil windings or thin-walled structures.
The selection of the appropriate refractory castable for a heating furnace lining depends on factors such as the temperature range, thermal cycling, chemical exposure, mechanical stress, and specific furnace design. Consulting with refractory experts or manufacturers can help determine the most suitable castable for a particular heating furnace application.
