4. Core Working Principle

Workpieces are sent into the hearth by the inlet roller table. Synchronously rotating transverse heat-resistant furnace rollers push the workpieces forward continuously. The workpieces go through the whole procedures of preheating, high-temperature soaking and cooling, while the temperature of each zone and conveying speed are precisely matched to the process cycle.

Process flow for atmosphere-protected furnaces:

Automatic loading → Nitrogen purging for oxygen replacement in vacuum airlock chamber → Constant temperature soaking in heating zone → Cooling in quenching or slow cooling section → Atmosphere replacement in outlet airlock chamber → Finished product unloading.

Workpieces enter and exit continuously without stopping for loading and unloading, supporting three-shift non-stop mass production all day long.

5. Reference of General Industrial Technical Parameters

5.1 Temperature Indexes

• Normal working temperature range: 200~1150℃

• Temperature difference along effective heating length: ≤±3~±5℃; cross-section temperature difference ≤±8℃

• Temperature control precision: ±1~±3℃, supporting programmable temperature control with more than 30 segments

5.2 Conveying & Production Capacity

• Furnace roller conveying speed: Stepless variable frequency adjustment from 0.1~2.0 m/s

• Hourly output of single line: 500~12000 kg/h

• Applicable workpiece dimensions: Pipe outer diameter Φ40~180mm, plate thickness 3~120mm, single piece length 1~12.5m

5.3 Atmosphere Parameters (Nitrogen-hydrogen Atmosphere Furnace)

• Controlled oxygen content inside furnace: ＜10~50ppm

• Hydrogen purity: ≥99.99% (all-hydrogen type)

• Slight positive furnace pressure: 10~300Pa to prevent backflow of ambient air

5.4 Energy Consumption Reference

• Gas radiant tube type: Natural gas consumption 55~105 Nm³/t, saving over 25% fuel via waste heat recovery

• All-electric roller hearth furnace: Power consumption 130~200 kWh/t, fluctuating with process temperature and soaking holding time