These air circulation chamber furnaces are available for maximum operating temperatures of 260 °C, 450 °C, 600 °C or 850 °C and are perfectly suited for demanding processes. Due to their robust and solid design even heavy loads can be heat treated. These furnaces are suited for use with baskets, pallets, and mobile furnace racks. The charging can be carried out with fork lift, pallet truck, or charging trolley. The basic furnace is standing on the shop floor without floor insulation. Charging can be simplified by roller conveyors, if necessary also motorized. All furnaces are available with electric or gas heating.

Standard version for models up to 600 °C

• Tmax 260  °C, 450  °C or 600  °C
• Electrically heated or gas-fired
• Electric heating by means of heater coils
• Direct gas heating or upon request with indirect gas heating with radiation tube, e.g. for heat treatment of aluminum
• Optimal air circulation for your charge by means of adjustable air outlets
• Horizontal air flow (type ../HA)
• High air exchange for perfect heat transfer
• Ground level charging without floor insulation for 260  °C models
• Temperature uniformity up to ∆T 8 K according to DIN 17052-1
• Furnace chamber lined with alloy 1.4301 (DIN)
• High quality mineral wool insulation provides for low outer temperatures
• Inside unlocking device for furnaces with walk-in chambers
• Furnace sizes suitable for common charging systems, such as pallets, baskets, etc.
• Double-wing door for furnaces N 1500 and larger
• Over-temperature limit controller with manual reset for thermal protection class 2 in accordance with EN 60519-2 as temperature limiter to protect the furnace and load

Additional equippment for models up to 600 °C

• Optional floor insulation provides for improved temperature uniformity for 260  °C models
• Entry ramps or track cutouts for floor-level charging of models with bottom insulation
• Furnace positioned on base frame provides for ergonomic charging height
• Electro-hydraulic lift door
• Fan system for faster cooling with manual or motor-driven control
• Motor-driven control of air inlet and exhaust air vents for better ventilation of the furnace chamber
• Observation window and/or furnace chamber lighting
• Optimization of the temperature uniformity up to ∆T 6 K according to DIN 17052-1
• Safety technology according to EN 1539 for charges containing solvents
• Charging systems or roller conveyors, also electrically driven provide for easy charging
• Catalytic or thermal exhaust gas cleaning systems
• Custom sizes up to 30,000 liters and charge weights up to 30 tons
• Process control and documentation with Controltherm MV software package

Standard version for models 850 °C

• Tmax 850  °C
• Electrically heated or gas-fired
• Electric heating with heating elements on supports tubes
• Direct gas heating into the outlet of the air circulation fan
• Optimal air circulation for your charge by means of adjustable air outlets
• Horizontal air-flow (type ../HA)
• High air exchange provides for perfect heat transfer
• Base frame with 900 mm charging height
• Temperature uniformity up to ∆T 10 K according to DIN 17052-1
• Air baffles made of 1.4828 (DIN)
• Multi-layered insulation with fiber plates (not classified according to EU directive 67/548) provides for low outer temperatures
• Furnaces sizes perfectly suited to accommodate common charging systems, e.g. like pallets or pallet boxes
• Over-temperature limit controller with manual reset for thermal protection class 2 in accordance with EN 60519-2 as temperature limiter to protect the furnace and load

Additional equipment for models 850 °C

• Electro-hydraulic lift door
• Fan system for faster cooling with manual or motor-driven control
• Motor-driven air inlet and control of exhaust air vents for better ventilation of the furnace chamber
• Optimization of the temperature uniformity up to ∆T 6 K according to DIN 17052-1
• Base frame for customized charging height
• Charging systems or roller conveyors, also electrically driven provide for easy charging
• Custom sizes up to 30,000 liters and charge weights up to 30 tons
• Designed for Tmax 950  °C, fan blade driven indirectly via a belt to protect the air recirculation motor against over-heating
• Process control and documentation with Controltherm MV software package

The very good temperature uniformity of these chamber furnaces with air circulation provides for ideal process conditiones for annealing, curing, solution annealing, artificial ageing, pre-heating, or soft annealing and brazing. The furnaces are equipped with a suitable annealing box for soft annealing of copper or tempering of titanium, and also for annealing of steel under protective gases. The modular furnace design allows for adaptation to specific process requirements with appropriate accessories.

• Tmax 450  °C, 650  °C, or 850  °C
• Heating from bottom, sides and top
• Stainless steel air-baffle box in the furnace for optimum air circulation
• Swing door hinged on the right side
• Base frame included in the delivery, N 15/65 HA designed as table-top model
• Horizontal air circulation
• Temperature uniformity up to ∆T 8 K according to DIN 17052-1
• Optimum air distribution enabled by high flow speeds
• One removable tray and rails for two additional trays included in the scope of delivery (N 15/65 HA without removable tray)

Additional equipment (not for model N 15/65HA)

• Optimization of the temperature uniformity up to ∆T 6 K according to DIN 17052-1
• Fan cooling to accelerate the cooling process
• Motorized exhaust vents
• Manual lift door
• Pneumatic lift door
• Adjustable air circulation for sensitive components
• Additional removable trays
• Roller conveyor in furnace chamber for heavy charges
• Annealing boxes
• Feed and charging aids
• Designed for Tmax 950  °C, fan blade driven indirectly via a belt to protect the air recirculation motor against over-heating
• Process control and documentation with Controltherm MV software package

Certain processes release and vaporize solvents or other flammable vapors. The concentration of these vapors must be kept below a certain limit to prevent ignition. European Norm EN 1539 and NFPA 86 in the USA prescribe the required safety equipment for these processes.

For these applications and processes, all air circirculation furnaces of the KTR and air circulation chamber furnaces < 450 °C product lines are suited with safety technology for protection of a potentional ignition in the furnace chamber.

To avoid an ignition in the furnace, flammable vapors must be diluted with air. Special care must be taken so high concentrations of flammable materials do not accumulate in “dead” areas within the furnace. For this purpose, the furnaces are equipped with an exhaust gas fan providing for a defined suction flow. A measurement system monitors this flow, while fresh air is simultaneously resupplied. In parallel, the furnace atmosphere is diluted by the inflow of fresh air. The air circulation is also monitored by the measurement system.

• Furnace sizes between 120 and 10,000 liters
• Powerful exhaust fan capable of maintaining negative furnace pressure
• Defined and monitored air circulation flow and exhaust air
• Visual and audible emergency signals
• Over-temperature limit controller with manual reset for thermal protection class 2 in accordance with EN 60519-2 as temperature limiter to protect the furnace and load

Specific heat treatment processes require the reduction of particle contamination in the furnace chamber and on the work floor down to a minimum. For these applications the NAC air circulation chamber furnaces are recommended. The inner chamber is made of stainless steel and offers best possible protection against impurities from the insulation. These furnaces are especially recommended for processes which require a clean atmosphere at the charge and on the shop floor. Depending on design and required clean room class these furnaces can be upgraded for this application.

• Tmax 650  °C
• Standard sizes between 120 and 500 liters furnace volume
• Customized dimensions, also available as production-scale furnaces up to 10000 l (KTR models)
• Dual shell housing provides for low surface temperatures
• Insulation made of mineral wool with aluminum protection cover provides for low emissions to the outside
• Welded inner housing made of stainless steel 1.4301
• Door with silicone sealing
• Horizontal airflow incl. air-guiding box provides for optimum temperature uniformity
• Tubular heating elements positioned behind the air-guiding box
• One shelf included in the delivery

Additional equipment

• Silicone-free design with door sealing made of Viton
• Electro-polished inner box
• Electrically driven air inlet and air outlet flaps
• Cooling system for reduction of process times
• Observation window in the door
• Manual or automatic gas supply systems
• Speed control for air-circulation fan
• Additional shelves
• Process control and documentation with Controltherm MV software package

With their maximum working temperature of up to 300 °C and forced air circulation, the ovens achieve a perfect temperature uniformity which is much better than in ovens of most competitors. They can be used for various applications such as e.g. drying, sterilizing or warm storing. Ample warehousing of standard models provides for short delivery times.

• Tmax 300  °C
• Working range: + 5 °C above room temperature up to 300  °C
• Models TR 60 - TR 240 designed as tabletop models
• Models TR 450 and TR 1050 designed as floor standing models
• Horizontal, forced air circulation results in temperature uniformity better than ∆T 8 K
• Stainless steel chamber, alloy 304 (AISI)/(DIN material no. 1.4301), rust-resistant and easy to clean
• Large handle to open and close the door
• Charging in multiple layers possible using removeable grids (number of removeable grids included, see table to the right)
• Large, wide-opening swing door, hinged on the right with quick release for models TR 60 - TR 450
• Double swing door with quick release for TR 1050
• TR 1050 equipped transport rollers
• Infinitely adjustable exhaust at the rear wall with operation from the front
• PID microprocessor control with self-diagnosis system
• Solid state relays provide for low­noise operation

Additional equipment

• Over-temperature limit controller with manual reset for thermal protection class 2 in accordance with EN 60519-2 as temperature limiter to protect the furnace and load
• Infinitely adjustable fan speed of the air circulation fan
• Window for charge observing
• Further removeable grids with rails
• Side inlet
• Stainless steel collecting pan to protect the furnace chamber
• Safety Technology accorging to EN 1539 wor charges containing liquid solvents up to model TR 240
• Transport costors for model TR 450
• Various modifications available for individual needs
• Upgrading available to meet the quality requirements of AMS 2750 D or FDA
• Process control and documentation with Controltherm MV software package

The air circulation bogie hearth furnaces W 1000/60A - W 1000/85A are used when heavy charges weighing up to more than 25 t have to be heat-treated. They are ideal for processes such as solution annealing, artificial ageing, annealing or soft annealing, for which a high degree of temperature uniformity is crucial. The high-performance air circulation assures that the temperature uniformity achieved throughout the usable space is outstanding. A broad selection of additional equipment enables these furnaces to be optimally adapted to suit specific processes.

• Tmax 600  °C or 850  °C
• Dual shell housing with rear ventilation provides for low shell temperatures for the 850  °C models
• Swing door hinged on the right side
• Heating from chrome steel heating elements in the intake area of the air circulation system for the 600  °C models
• Heating from three sides (both side walls and the trolley) for the 850  °C models
• High-performance air circulation fan with vertical circulation
• Temperature uniformity up to ∆T 10 K according to DIN 17052-1
• Bottom heating protected by SiC tiles on the bogie providing level stacking surface for the 850  °C models
• Furnace chamber fitted with inner sheets made of stainless steel 1.4301 for 600  °C models and of 1.4828 for 850  °C models
• Insulation structured with high-quality mineral wool for 600  °C models
• Insulation made of high-quality, non-classified fiber material for 850  °C models
• Bogies with flanged wheels running on rails for easy and precise movement of heavy loads
• Electric chain-driven bogie in combination with rail operation for smooth movement of heavy loads from model W 4800
• Over-temperature limit controller with manual reset for thermal protection class 2 in accordance with EN 60519-2 as temperature limiter to protect the furnace and load

Additional equipment

• Direct gas heating or upon request with indirect gas heating with radiation tube
• Custom-built sizes
• Electric chain-driven bogie in combination with rail operation for smooth movement of heavy loads up to Model W 4000
• Optimization of the temperature uniformity up ∆T 6 K according to DIN 17052-1
• Bogie running on steel wheels with gear rack drive, no rails in front of the furnace necessary
• Different possibilities for an extension to a bogie hearth furnace system:
  • Additional bogies
  • Bogie transfer system with parking rails to exchange bogies running on rails or to connect multiples furnaces
  • Motor-driven bogies and cross-traversal system
  • Fully automatic control of the bogie exchange
• Electro-hydraulic lift door
• Motor-driven exhaust air vents, adjustable via the program
• Controlled cooling system with frequency-controlled cooling fan and motorized exhaust air vent
• Multi-zone control adapted to the particular furnace model provides for optimum temperature uniformity in the 850  °C models
• Commissioning of the furnace with test firing and temperature uniformity measurement (also with load) for the purpose of process optimization
• Designed for Tmax 950  °C, fan blade driven indirectly via a belt to protect the air recirculation motor against over-heating
• Process documentation and control with Controltherm MV software package and the Nabertherm NCC control center for monitoring, documentation and control

Ovens with bogie hearth from the WTR range are used to dry, temper, or vulcanize large quantities of material. The design of the oven corresponds basically to the bogie air circulation furnaces W 1000/60A ff. They can be individually adapted to suit the required process. These ovens can also be designed for heat treatment of combustible materials according to EN 1539.

• Tmax 260  °C
• Swing door hinged on the right side
• Heating from chrome steel heating elements in the intake area of the air circulation system
• High-performance air circulation fan with vertical circulation
• Temperature uniformity up to ∆T 8 K according to DIN 17052-1
• Oven chamber with inner shelves made of galvanized steel sheet
• Insulation structured with high-quality mineral wool
• Bogies with flanged wheels running on rails for easy and precise movement
• Over-temperature limit controller with adjustable cutout temperature for thermal protection class 2 in accordance with EN 60519-2 – as temperature limiter controller to protect the oven and load
• Manually adjustable air inlet and exhaust air vents
• High air exchange for fast drying processes
• Oven sizes suitable for common charging systems, such as pallets, baskets, etc.

Pit-type furnaces with air circulation offer the advantage of easy charging, for heat treatment of heavy parts or loads in charge baskets. With maximum application temperatures available from 450 °C to 850 °C, these compact furnaces are particularly useful for processes such as tempering, solution annealing, artificial ageing, and soft annealing.

• Tmax 450  °C, 650  °C, 850  °C
• Air circulation fans in the furnace bottom, high circulation rate
• Vertical air circulation with square air heating chamber
• Temperature uniformity up to ∆T 8 K according to DIN 17052-1
• Interior walls from stainless steel
• Switchgear with solid-state relays

Additional equipment

• Charging hoist with swivel arm and charge basket
• Optimization of the temperature uniformity up to ∆T 4 K according to DIN 17052-1
• Integrated fan for rapid cool down or separate cooling station for retort box cooling outside of the furnace
• Retort box with protective gas inlet and outlet for production in a defined atmosphere
• Manual or automatic gas supply systems

Due to their robust design, these pit-type furnaces with air circulation are particularly useful for a professional heat treatment demanding optimum temperature uniformity. Production processes such as tempering, solution annealing, artificial ageing, and soft annealing can be realized with these pit-type furnaces.

• Tmax 600  °C or 850  °C
• Useful for heavy charge weights
• Air circulation fans in the furnace lid, high circulation rate
• Heating chamber with air baffle cylinder
• Heating elements on all wall surfaces
• Distribution of air flow through grid at the furnace floor
• Pneumatic or hydraulic lid lifting
• Temperature uniformity up to ∆T 6 K according to DIN 17052-1

Additional equipment

• Integral fan for fast cooling
• Optimization of the temperature uniformity up to ∆T 4 K according to DIN 17052-1
• Variable rpm converter control of the air circulation velocity for sensitive parts
• Multiple zone control or special air circulation system for optimum temperature uniformity tailored to the charge
• Custom dimensions up to 10,000 liters
• Charge weights up to 7 tons
• Designed for Tmax 950  °C, fan blade driven indirectly via a belt to protect the air recirculation motor against over-heating
• Process control and documentation with Controltherm MV software package