Square Brick with Round Hole (Perforated Mullite Brick)
Lightweight Mullite SeriesLightweight mullite square bricks with precision round boreholes are specialized insulating refractory blocks engineered for high-temperature furnace walls. Ideal for thermocouple insertion, burner nozzle sleeves, heating rod lead-throughs, and sight ports.
| Parameter | Specification |
|---|---|
| Material | Lightweight Mullite (JM26 / JM28 / JM30) |
| Max Service Temp | 1350°C ~ 1600°C |
| Bulk Density | 0.8 ~ 1.1 g/cm³ |
| Cold Crushing Strength | ≥ 2.5 ~ 3.5 MPa |
| Thermal Conductivity (600℃) | ≤ 0.35 W/(m·K) |
| Hole Machining Tolerance | Precision CNC Machining / Molded ±0.5mm |
Material Overview
Lightweight mullite square perforated bricks are manufactured from high-purity synthetic mullite raw materials, formed under high pressure or precision slip casting, and fired at elevated temperatures in tunnel kilns. Boreholes are machined with CNC tooling to ensure tight tolerances.
In industrial kilns (roller hearth kilns, heat treatment furnaces, metallurgical soaking pits, glass annealing furnaces), creating penetration openings on-site often leads to stress cracking and heat leakage. Our pre-formed perforated bricks provide structurally sound, energy-efficient solutions that minimize heat loss and simplify installation.
Key Features
- High Dimensional & Bore Precision: Smooth hole walls ensure easy insertion, accurate positioning, and airtight sealing for instrumentation and heating elements.
- High-Temperature Resistance & Low Thermal Conductivity: Withstands temperatures up to 1600°C while minimizing furnace wall heat transmission.
- Excellent Thermal Shock Stability: Resistant to cracking and spalling under rapid temperature cycling.
- Structural Integrity: Uniform density and high crushing strength ensure durability when mortared into standard brickwork.
- Comprehensive Customization: Available with single hole, multi-hole, eccentric, or angled bores customized to client blueprints.
Technical Specifications
| Property | JM26 | JM28 | JM30 |
|---|---|---|---|
| Max Service Temp (°C) | 1450 | 1550 | 1600 |
| Bulk Density (g/cm³) | 0.80 | 0.90 | 1.05 |
| Cold Crushing Strength (MPa) | ≥ 2.2 | ≥ 3.0 | ≥ 3.6 |
| Al₂O₃ (%) | ≥ 56 | ≥ 68 | ≥ 73 |
| Fe₂O₃ (%) | ≤ 0.8 | ≤ 0.6 | ≤ 0.5 |
| Thermal Conductivity @ 600°C (W/m·K) | 0.29 | 0.34 | 0.42 |
| Reheat Linear Change (%) | 1400°C×12h: ≤ -0.4 | 1500°C×12h: ≤ -0.4 | 1550°C×12h: ≤ -0.5 |
