Do You Know What are The Special Requirements for The Chamber Design of a High Temperature Graphitization Furnace?
Release time:
2025-08-11
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Abstract
In the manufacture of high temperature graphitization furnace, the chamber design directly determines the performance and service life of the equipment. Unlike conventional heating equipment, graphitization furnace needs to withstand the extreme environment of 2000-3000 ℃, its cavity design must meet a series of special requirements.
Ⅰ. Selection of High Temperature Resistant Materials
1. Core Material Requirements
Graphite material: use high purity isostatically pressed graphite (purity >99.99%)
Metal parts: use high melting point metals such as tungsten and molybdenum (melting point >3000℃)
Insulation material: use pyrolytic boron nitride or zirconia ceramics
2. Key Parameter Indicators
Long-term working temperature ≥3000°C
High-temperature strength retention rate >80%
Thermal expansion coefficient <5×10-⁶/°C
Ⅱ. Multi-layer composite structure design
Modern high temperature graphitization furnace commonly used "sandwich" type composite structure:
Lining layer: direct contact with the high temperature zone, using high-purity graphite
Insulation layer: multi-layer carbon felt/graphite felt (thickness 50-100mm)
Reflective layer: molybdenum or tungsten metal foils
Shell layer: stainless steel water-cooled jacket
Ⅲ. Special sealing and atmosphere control
1. Vacuum sealing system
Double metal sealing (copper gasket + stainless steel flange)
Vacuum up to 10-³Pa
Leakage rate <1×10-⁹Pa-m³/s
2. Atmosphere control system
Inert gas (Ar/N₂) purity ≥99.999%
Flow rate control accuracy ±1%
Pressure range: 10-³Pa-0.1MPa adjustable
Ⅳ. the design of heat field uniformity
1. Heating element layout
adopts three-dimensional three-dimensional arrangement
Multi-zone independent temperature control (usually 4-8 zones)
Power density gradient design
2. Temperature uniformity guarantee
Temperature difference inside the furnace <±15℃ (at 2000℃)
Special design graphite heat equalization plate
Rotating sample holder design (optional)
Ⅴ. Special application scenario design
1. Continuous graphitization furnace
Segmented chamber design
Air curtain isolation device
Material transfer system
2. Ultra High Temperature Furnace (>3000℃)
Composite Heating System (Graphite + Induction Heating)
Multi-layer heat radiation shielding
Special observation window design (sapphire glass)
Ⅵ. Maintenance points
Regular inspection: monthly detection of cavity deformation (should be <0.5mm)
Cleaning specification: use special graphite cleaner
Parts replacement: heating element life is usually 200-500 hours
Performance verification: quarterly thermal field uniformity test
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