Project Background and Core Process Requirements

WONDERY recently completed the delivery of an HRJ3-130-9 large-scale pit-type anaerobic annealing furnace. Primarily used for non-ferrous metal parts and pipes, the project required strict oxidation control. The client prioritized atmosphere integrity at the 850 ℃ operating temperature and high thermal consistency for the large-diameter (Ø1400mm) loading area.

Technical Solutions and Parameterized Evidence

1. Structural Sealing and 321 Stainless Steel Muffle

To achieve oxygen-free heating in a fully sealed state, WONDERY optimized the muffle and sealing interface:

• Muffle Material: Welded from 10mm thick 321 stainless steel with an elliptical head bottom to manage thermal expansion.

• Cooling and Sealing: The flange, machined from 30mm carbon steel, features a high-temperature silicone seal at the top and a water-cooling channel at the bottom. Secured by 10 manual compression screws, it ensures consistent atmosphere purity.

2. Dual-Zone Control and Thermal Stability (±10 ℃)

For the Ø1400 × 1500 mm chamber, the system utilizes zoned management to eliminate gradients:

• Heating Zones: The furnace is divided into 2 independent zones, each with a dedicated heating group, ensuring balanced thermal distribution across the large volume.

• Control Precision: Managed by a Japanese Shimaden PID controller and a 10.1-inch industrial touchscreen, maintaining temperature field uniformity within ±10 ℃.

• Energy Efficiency: With a rated power of 130kW (1-100% adjustable), the empty furnace power loss is restricted to 13kW, demonstrating superior thermal retention.

3. High-Temperature Heating Elements and Mounting

• Material Standards: Utilizes 0Cr25Al5 high-resistance alloy strips. Lead-out rods (φ16) are made of the same material with professional terminals to ensure reliable high-current transmission.

• Insulation Support: Elements are secured using specialized high-alumina ceramic screws and washers. The washers create a gap between the fiber lining and the elements, maximizing heat radiation while eliminating the risk of thermal short circuits to the shell.

4. All-Fiber Energy-Saving Lining

• Insulation System: The furnace employs a full silicate fiber lining sourced from Shandong Luyang.

• Advantages: The low thermal mass of the fiber lining allows for a rapid ramp-up. Non-load heating time is ≤1.5 hours, significantly enhancing production efficiency.

Delivery Specifications and Key Parameters

• Effective Working Dimensions: Ø 1400 × 1500 mm.

• Rated Temperature: 900 ℃.

• Normal Operating Temperature: 850 ℃.

• Safety Features: Includes over-temperature alarms and dedicated atmosphere ports for nitrogen protection to facilitate high-quality anaerobic annealing.