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Foundry

Rotary Hearth Furnaces up to 1300 °C with and without Air Circulation Electrically Heated or Gas-Fired

Electrically heated rotary hearth furnace with Tmax 1100 °C, movable on rails, for preheating of molds for two forges Directly gas-fired rotary hearth furnaces with Tmax 1300 °C

Gear rim drive under the rotary hearth furnace

Rotary table with fire-resistant concrete plates to protect the insulation

Electrically heated rotary hearth furnaces with Tmax 450 °C, prepared for automatice operation

The rotary hearth furnaces of the DH product line are optimally suited for continuous processes on a small floor space. They are designed for preheating processes such as the preheating of metal parts for forging or for preheating of moulds. Charging and discharging can, be done at one position – either by a person or fully automatic. The hearth rotates in pre-set segments individually reconciled with the workpart geometry. The rotational speed and rotational intervals can be defined by the control system or by manual switching. The rotary hearth furnaces are specifically designed for the required throughput and charge dimensions. They are heated electrically or alternativelly gas-fired by means of powerfull gas burners. Subject to the temperature range these rotary hearth furnaces are equipped with or without air circulation.

  • Tmax > 850 °C up to 1300 °C with radiation heating
  • Tmax up to 850 °C with powerful air-circulation for better heat transmission onto the charge and to optimize the temperature uniformity in the low-temperature range
  • Electrically heated:
    • Wire heating elements in the furnaces ceiling
    • Heating via SiC rods installed in the furnace ceiling for furnaces up to 1300 °C
  • Gas-fired:
    • Directly gas-fired: The burner fires directly in the furnace chamber
    • Indirectly gas-fired: The burner fires in a radiation tube to avoid a direct contact between the charge and the burner exhaust gases
  • Very compact design compared with continuous furnaces
  • Designed for continuous operation at one working temperature
  • Table diameter up to 6000 mm
  • Only fiber materials are used which are not classified as carcinogenic according to TRGS 905, class 1 or 2
  • Additional water sealing between the rotary table and the housing for forced convection furnaces and directly gas-fired furnaces
  • Table drive under the furnace provides for movement in defined segments or continuously
  • Low-vibration movement of the rotary hearth
  • Charging through a lift-door
  • Actuation of rotary drive via foot pedal or external contact in case of automatic operation
  • Additional Service door on request

Additional equipment

  • Exhaust hood above the door opening for discharge of the warm exhaust air when door is open
  • Charging aids for ease of loading and unloading
  • Multi-zone control for uniform thermal profile during the cycle
  • Protective gas connections
  • Process control and documentation via VCD software package or Nabertherm Control Center (NCC) for monitoring, documentation and control
  • Visualization of loaded positions on the human machine interface (HMI)
 

Continuous Furnaces Electrically Heated or Gas-Fired

Continuous furnace D 1500/3000/300/14 for thermal ageing with mesh belt transport system and subsequent cooling station Roller continuous furnace N 650/45 AS for heat treatment of heavy workparts

Continuous furnace for bulk materials in baskets

Heat treatment plant D 1600/6100/800/26AS according to EN 1539 with cooling station KS 1600/6100/800/AS for vulcanization processes of hoses

Mesh belt drive in a continuous furnace

Continuous furnace D 700/10000/300/45S with chain conveyor for 950 °C, gas-fired

Continuous furnace D 1100/5800/100/50 AS for annealing of springs incl. feeding system

Mesh belt drive in continuous furnace D 1100/3600/100/50 AS

Rotary hearth furnace for preheating

Continuous furnaces are the right choice for processes with fixed cycle times such as drying or preheating, curing, aging, vulcanisation or degassing. The furnaces are available for various temperatures up to a maximum of 1400 °C. The furnace design depends on the required throughput, the process requirements for heat treatment and the required cycle time. The conveyor technology is tailored to the required working temperature, geometry and weight of the charge and to the requirements regarding available space and integration into the process chain. The conveyor speed and the number of control zones are defined by the process specifications.

Conveyor concepts

  • Conveyor belt
  • Metal conveyor belt with adjusted mesh gauges
  • Drive chain
  • Roller conveyors
  • Paternoster
  • Pusher-type
  • Rotary hearth

Heating systems

  • Electric heating, radiation or convection
  • Direct or indirect gas-fired
  • Infrared heating
  • Heating with the use of external heat sources

Temperature cycles

  • Control of working temperature across the whole length of the furnace, such as for drying or preheating
  • Automatic control of a process curve applying defined heat-up, dwell and cooling time
  • Heat treatment including a final quenching of the charge

Process atmosphere

  • In air
  • For processes with organic outgassings incl. mandatory safety technology according to EN 1539 (NFPA 86)
  • In non-flammable protective or reactive gases such as nitrogen, argon or forming gas
  • In flammable protective or reactive gases such as hydrogen incl. the necessary safety technology

Basic configuration criteria

  • Conveyor speed
  • Temperature uniformity
  • Operating temperature
  • Process curve
  • Work space width
  • Charge weights
  • Cycle time or throughput
  • Length of charge and discharge zone
  • Generated exhaust gases
  • Specific industry standards such as AMS, CQI-9, FDA etc.
  • Other individual customer requirements