The gas or oil fired tilting crucible furnaces of the KB series are characterized by their high melting performance. They are perfectly suited for the melting of aluminum and other nonferrous alloys. The use of high-quality insulation materials results in very low power requirements. The two-stage burner can be configured for either gas operation or oil operation.

• KB../12 with maximum furnace chamber temperature of 1200 °C for aluminum or zinc
• KB../14 with maximum furnace chamber temperature of 1400 °C suitable for bronze alloys or brass, with a maximum melt temperature of 1300 °C
• Fuel heating using gas or oil
• Two-stage power control: high load for melting operation, low load for holding mode, with automatic switching
• Positive pressure in the furnace chamber keeps air out for high-efficiency operation
• Gas system consisting of pressure regulator, gas filter, manometer, and solenoids
• Low NOx emissions
• Burner flame continuously monitored
• Burner technology with service-friendly construction, e.g. flame head easily removable when the burner is swung out
• Burner technology manufactured in compliance with EN/DIN 746 part 2
• High melting power due to powerful burner and high-quality insulation
• Insulation constructed in multiple layers with lightweight refractory bricks in the furnace chamber
• Crucible of clay-graphite up to KB 240, or isostatically pressed clay-graphite or SiC from KB 360 and up
• Electrohydraulic tilting system with nonflammable ultra-safe hydraulic fluid
• Safe, even, and precise pouring due to optimum pivot point in the furnace and manual throttling valve operation of the hydraulic system
• Emergency outlet for safe draining of the melt in case of crucible breakage
• Exhaust gas discharge over the crucible edge, resulting in about 20% higher melting performance than with side exhaust gas discharge. Swing lid as option
• Integrated safety system which continues to operate the furnace at reduced power in case of malfunction in the bath thermocouple, in order to prevent the freezing of the melt
• Over-temperature limit controller in furnace chamber for protection against overheating. The limiter switches the heating off when the set limit temperature is reached, and only switches it back on after the temperature has fallen again
• Furnace chamber control with temperature measurement behind the crucible, recommended for melting

Additional Equipment

• Crucible of isostatically pressed clay-graphite or SiC with higher thermal conductivity up to KB 240
• Side exhaust gas discharge with swing lid, with the following features:
  • high melt quality due to lower burnoff
  • lower hydrogen absorption in the melt
  • reduction of power consumption due to swing lid in holding mode
  • operator exposed to less heat in the area above the crucible
  • about 20% lower melting performance compared with exhaust gas discharge over the crucible edge
• Insulated connection piece for side exhaust gas discharge to connect exhaust ductwork
• Exhaust gas collection hood for furnaces with exhaust gas discharge over the crucible edge
• Work platform
• Crucible breakage monitor with visual and audible signal (only for models KB ../12)
• Modulating burner with precise temperature control for optimum quality of the melt in holding mode
• Bath control with thermocouples in the furnace chamber and in the melt. The furnace temperature is controlled through the melt. Temperature overshoots are reduced, thus the quality of the melt is improved

The electrically heated tilting crucible furnaces of the K and KF series are characterized by high melting performance with very uniform temperature distribution in the melt. Aluminum and brass can be melted in the 1200 °C version. The 1300 °C version can also be used to melt bronze alloys. For faster heating-up cycles in batch operation furnaces can be insulated with fiber resulting in lower heat storage (KF models).

• K, KF../12 with maximum furnace chamber temperature of 1200 °C for aluminum or brass. Maximum bath temperature, depending on the condition of the crucible, between 1050 °C and 1100 °C
• K, KF../13 with maximum furnace chamber temperature of 1300 °C also suitable for bronze alloys or brass, with a maximum melt temperature of 1200 °C
• Heating from three sides using electric heating elements, radiating freely on carrier tubes, simple exchange of individual heating elements
• Multi-step wiring of the heating elements for furnaces with more than 50 kW electrical rating
• Heating of furnaces up to 24 kW power rating controlled using long-lasting, noiseless solid-state-relays
• Heating of furnaces beyond 24 kW with contactors
• High melting performance with uniform temperature distribution in the melt
• Insulation constructed in multiple layers with lightweight refractory bricks on the hot face (K models)
• Insulation constructed in multiple layers with fiber material in the side walls and corner bricks to support heating elements (KF models)
• Crucible of clay-graphite up to K 240, isostatically pressed clay-graphite or SiC from K, KF 360 and up
• Electrohydraulic tilting system with nonflammable ultra-safe hydraulic fluid
• Safe, even, and precise pouring thanks to optimum pivot point in the furnace and manual throttling valve operation of the hydraulic system
• Emergency outlet for safe draining of the melt in case of crucible breakage
• No exhaust gas discharge needed
• Integrated safety system which continues to operate the furnace at reduced power in case of malfunction in the bath thermocouple, in order to prevent the freezing of the melt
• Over-temperature limit controller in furnace chamber for protection against overheating. The limiter switches the heating off when the set limit temperature is reached, and only switches it back on after the temperature has fallen again
• Furnace chamber control with temperature measurement behind the crucible, recommended for melting

Additional Equipment

• Crucible of isostatically pressed clay-graphite or SiC with higher thermal conductivity up to K, KF 240
• Work platform
• Crucible breakage monitor with visual and audible signal (only for models K, KF ../12)
• Bath control with thermocouples in the furnace chamber and in the melt. The furnace temperature is controlled through the melt. Temperature overshoots are reduced, thus the quality of the melt is improved
• Heating system operated through thyristors in phase-angle mode assures even power from heating elements
• Multi-step switching of the furnace heat (see page 21). In holding mode, a switch or the controller is used to turn off one heating section in order to reduce the electrical rating
• Higher electrical ratings to increase melting performance

The electrically heated tilting crucible and bale-out furnaces of the KC and TC series are characterized by a higher melting performance than achievable with wire heated melting furnaces. These furnaces are designed for permanent operation at working temperatures.

• Maximum furnace chamber temperature of 1450 °C, also suitable for bronze alloys with a maximum melt temperature of up to 1320 °C, subject to the condition of crucible
• Heating from two sides by generously dimensioned SiC rods, uniform temperature distribution
• Simple exchange of individual heating elements
• Heat operation by thyistors in phase-angle mode with performance control: The resistance of the SiC rods changes with temperature and age. Performance control ensures constant power of heating irrespective to the condition of the heating elements.
• High melting performance with uniform temperature distribution
• Insulation constructed in multiple layers with lightweight refractory bricks on the hot face
• SiC-Crucible
• Electrohydraulic tilting system with nonflammable ultra-safe hydraulic fluid for KC models
• Safe, even, and precise pouring thanks to optimum pivot point in the furnace and manual throttling valve operation of the hydraulic system
• Emergency outlet for safe draining of the melt in case of crucible breakage
• No exhaust gas discharge needed
• Integrated safety system which continues to operate the furnace at reduced power in case of malfunction in the bath thermocouple, in order to prevent the freezing of the melt
• Over-temperature limit controller in furnace chamber for protection against overheating. The limiter switches the heating off when the set limit temperature is reached, and only switches it back on after the temperature has fallen again
• Furnace chamber control with temperature measurement behind the crucible, recommended for melting

Additional Equipment

• Work platform for simplified loading

The gas or oil fired crucible furnaces of the TB series are characterized by their high melting performance. They are the work horse for melting operation but also for holding of aluminum and zinc. The use of high-quality insulation materials results in very low power consumption. The two-step burner can laid-out for either gas operation or oil operation.

• TB../12 with maximum furnace chamber temperature of 1200 °C for aluminum or zinc
• TB../14 with maximum furnace chamber temperature of 1400 °C suitable for bronze alloys or brass, with a maximum melt temperature of 1300 °C
• Fuel heating using gas or oil
• Two-step power regulation: high load for melting operation, low load for holding mode, with automatic switching
• Positive pressure in the furnace chamber keeps air out for high-efficiency operation
• Gas system consisting of pressure regulator, gas filter, manometer, and solenoids
• Burner flame continuously monitored
• Burner technology with service-friendly construction, e.g. flame head easily removable when the burner is swung out
• Burner technology manufactured in compliance with EN/DIN 746 part 2
• High melting power due to powerful burner and high-quality insulation
• Multi-layer insulation with lightweight refractory bricks on the hot face, 1400 °C models with additional wear and tear layer consisting of copper-resistant high-performance concrete
• Emergency outlet for safe draining of the melt in case of crucible breakage

• Exhaust gas discharge over the crucible edge, resulting in about 20% higher melting performance than with side exhaust gas discharge, swing lid as option
• Side exhaust gas discharge for TB ../12 models, see Additional Equipment below for features
• Integrated safety system which continues to operate the furnace at reduced power in case of malfunction in the bath thermocouple, in order to prevent the freezing of the melt
• Over-temperature limit controller in furnace chamber for protection against overheating. The limiter switches the heating off when the set limit temperature is reached, and only switches it back on after the temperature has fallen again
• Furnace chamber control with temperature measurement behind the crucible, recommended for melting

Additional Equipment

• Crucible of clay-graphite or SiC with high thermal conductivity
• Side exhaust gas discharge with swing or flap lid, with the following features:
  • high melt quality due to lower burnoff
  • lower hydrogen absorption in the melt
  • reduction of power consumption due to swing lid in holding mode
  • operator exposed to less heat in the area above the crucible
  • about 20% lower melting performance compared with exhaust gas discharge over the crucible edge
• Insulated connection piece for side exhaust gas discharge to connect exhaust ductwork
• Exhaust gas collection hood for furnaces with exhaust gas discharge over the crucible edge
• Work platform
• Crucible breakage monitor with visual and audible signal (only for models TB ../12)
• Modulating burner with precise temperature control for optimum quality of the melt in holding mode
• Bath control with thermocouples in the furnace chamber and in the melt. The furnace temperature is controlled through the melt. Temperature overshoots are reduced, thus the quality of the melt is improved
• Crucible pulling feature for models up to TB 40/14 with special swinging collar plate

Exhaust gas discharge over the crucible edge is a standard feature of our gas or oil fired crucible furnaces, with the exception of the TB models for 1200 °C furnace chamber temperature, because these furnaces are often also used for holding. Exhaust gas discharge over the crucible edge offers the following advantages:

• Very high melting performance
• Low power consumption, since the crucible is not only heated from outside, but also additionally from the top.

Side exhaust gas discharge is available for all gas and oil fired crucible furnaces as optional equipment. Although the melting performance is not as high as for exhaust gas discharge over the crucible edge, this alternative offers the following advantages:

• High melt quality due to lower burnoff
• Lower hydrogen absorption in the melt
• Reduction of power consumption due to swing lid in holding mode
• Operator exposed to less heat in the area above the crucible

Subject to the specific application, direct heating with immersion heaters can be a practical alternative to an electrically heated holding furnace with indirect heating outside the crucible. Heating takes place through a powerful immersion heater which is introduced from above directly into the open crucible. This system has the following features:

• Good energy utilization due to direct heating
• Very high melt quality due to precise temperature control
• Only a small gap is needed between the crucible and the furnace wall, thus the furnace can be smaller or crucible might be larger with same outer furnace dimensions
• Immersion heating element might turn-out as obstacle during bale-out
• High wear & tear of heating elements
• Substantial heat loss due to operation without lid

The gas or oil fired crucible furnaces of the TBR series are characterized by a high melting performance with the best possible energy utilization. They are perfectly suited for the melting of aluminum. Due to the use of a high-performance fan burner, which is feed with preheated air from a recuperator in the exhaust channel, energy consumption up to 25 % lower than conventional heating systems can be achieved.

• TBR../11 with maximum furnace chamber temperature of 1100 °C for aluminum or zinc
• Fuel-fired with gas
• Modulating burner control for optimum quality of the melt
• Positive pressure in the furnace chamber keeps air out for high-efficiency operation
• Low energy consumption due to use of air preheated up to 250 °C by a recuperator in the exhaust channel
• Gas system consisting of pressure regulator, gas filter, manometer, and solenoids
• Low NOx emissions
• Burner flame continuously monitored
• Burner technology with service-friendly construction, e.g. flame head easily removable when the burner is swung out
• Burner technology manufactured in compliance with EN/DIN 746 part 2
• High melting power due to powerful burner and high-quality insulation
• Side exhaust gas discharge with swing or flap lid, with the following features:
  • high melt quality due to lower burnoff
  • lower hydrogen absorption in the melt
  • reduction of power consumption due to swing lid in holding mode
  • Operator exposed to less heat in the area above the crucible

The electrically heated crucible furnaces of the T and TF series are characterized by a good melting performance with excellent temperature uniformity in the melt. In the 1100 °C version, aluminum can be melted, and in the 1200 °C version, brass can be melted. The 1300 °C version is designed for melting bronze alloys. For faster heat-up times in batch operation, furnaces can alternatively be fiber insuated with low heat storage (TF models).

• T, TF../11 with maximum furnace chamber temperature of 1100 °C for aluminum or zinc. Maximum melt temperatures, depending on the condition of the crucible, between 950 °C and 980 °C
• T, TF../12 with maximum furnace chamber temperature of 1200 °C also suitable for brass. Maximum melt temperatures, depending on the condition of the crucible, between 1050 °C and 1100 °C
• T, TF../13 with maximum furnace chamber temperature of 1300 °C, also suitable for bronze alloys. Maximum melt temperatures, depending on the condition of the crucible, between 1150 °C and 1200 °C
• Four-side heating using electric heating elements, freely radiating on carrier tubes
• Simple replacement of individual heating elements. In case of crucible breakage, only the defective heating elements on each level need to be replaced
• Heating of furnaces up to 24 kW power rating controlled using long-lasting, noiseless solid-state-relays
• Heating of furnaces beyond 24 kW with contactors
• High melting performance with uniform temperature distribution in the melt
• Insulation constructed in multiple layers with lightweight refractory bricks on the hot face (T models)
• Insulation constructed in multiple layers with fiber material in the side walls and corner bricks to support heating elements (TF models)
• Emergency outlet for safe draining of the melt in case of crucible breakage
• No exhaust gas discharge needed
• Integrated safety system which continues to operate the furnace at reduced power in case of malfunction in the bath thermocouple, in order to prevent the freezing of the melt
• Over-temperature limit controller in furnace chamber for protection against overheating. The limiter switches the heating off when the set limit temperature is reached, and only switches it back on after the temperature has fallen again
• Furnace chamber control with temperature measurement behind the crucible, recommended for melting
• Crucible not included in the standard version

Additional Equipment

• Crucible of clay-graphite or SiC with high thermal conductivity
• Work platform
• Crucible breakage monitor with visual and audible signal (only for models T, TF ../12)
• Bath control with thermocouples in the furnace chamber and in the melt. The furnace temperature is controlled through the melt. Temperature overshoots are reduced, thus the quality of the melt is improved
• Heating system operated through thyristors in phase-angle mode assures an even charging of heating elements
• Multi-step switching of the furnace heat (see page 21). In holding mode, a switch or the controller is used to turn off one heating section in order to reduce the electrical rating
• Transport function: Electrical plug connection on furnace and shock absorbers under the furnace for transport to pouring location (see page 22)
• Higher electrical ratings to increase melting performance

Due to the particularly good insulation and reduced electrical rating, the furnaces of the T../10 series are perfectly suited for holding operation due to their great energy efficiency. Due to the reduced power rating only limited melting operation is possible.

• Maximum furnace chamber temperature of 1000 °C, ideally suited for the holding of aluminum
• Four-side heating using electric heating elements, freely radiating on carrier tubes
• Simple replacement of individual heating elements. In case of crucible breakage, only the defective heating elements on each level need to be replaced
• Heating of furnaces up to 24 kW power rating controlled using long-lasting, noiseless solid-state-relays
• Heating of furnaces beyond 24 kW with contactors
• Particularly good insulation constructed in multiple layers with lightweight refractory bricks on the hot face Emergency outlet for safe draining of the melt in case of crucible breakage
• No exhaust gas discharge needed
• Crucible not included in the standard version
• Integrated safety system which continues to operate the furnace at reduced power in case of malfunction in the bath thermocouple, in order to prevent the freezing of the melt
• Over-temperature limit controller in furnace chamber for protection against overheating. The limiter switches the heating off when the set limit temperature is reached, and only switches it back on after the temperature has fallen again.
• Furnace chamber control with temperature measurement behind the crucible, recommended for melting

The bath furnaces B 120 - B 500 have been especially designed for stationary holding in die-casting, with bale-out by robot. The bath chamber of the furnace is lined with long-lasting special bricks. The multi-layered back-up insulation allows very low electrical rating to keep the melt warm. The furnace chamber is divided into three interconnected sections. The center section is heated with elements mounted in the lid . The ladle openings are dimensioned for optimum access by robot for bale-out. Properly used in holding mode, it can provide for a higher energy efficiency than bale-out furnaces.

• Maximum furnace chamber temperature of 1000 °C, perfectly suited for holding of aluminum at about 720 °C
• Heating mounted in the lid, freely radiating from carrier tubes
• Particularly low energy consumption due to generously dimensioned, multi-layer insulation
• High melt quality due to very low corundum formation on the surface
• Heating switched by solid-state-relays
• No exhaust gas discharge needed
• Temperature control with measurement in the melt and in the furnace chamber
• Plug for connection with separate switchgear cabinet

Additional Equipment

• Customized furnace sizes
• Adaptation to dosing pump
• Automated lid opening for ladling operation
• Ladle opening adapted to size of ladle
• Alternative heating using immersion heaters for optimum melt quality

In standard version, Nabertherm crucible furnaces are built with a collar plate fixed to the furnace. The bale-out is done manually or by robot. As additional equipment, the smaller T .. models can be equipped with a swinging collar plate which allows crucible pulling. To pull the crucible, the collar plate is swung to the side, so that the operator has free access to the crucible from above.

The Crucible furnaces of the T.. Series can be equipped with an optional pneumatic lid opener. The pneumatic lid opener is activated by depressing a foot pedal. Optionally, the pneumatic lid opener can be controlled and triggered by an external signal to fully automate the ladling process. The furnace lid swings to the side and the operator has free access to the crucible. This practical feature increases energy efficiency because the furnace is only open during charging and bale-out. Over 50% energy savings can be realized with the pneumatic lid opener vs. an always open furnace (see tables for energy consumption for each model of melting furnace).

Especially for melting of ingots, the charging funnel, made of 1.4301 (304) stainless steel, is a handy tool for charging the furnace. Long ingots can also be loaded above the rim of the crucible taking a guided slide while sinking into the crucible. The charging funnel is suitable for all melting furnaces, whether electrically heated or gas-fired with a side exhaust gas discharge.

For crucible and tilting crucible furnaces, customized work platforms for charging and servicing can be provided as additional equipment. This feature is used to simplify access to the furnace, particularly for larger furnace models. The operator has access to the top of the furnace to charge ingots or clean the melt.

In the basic version, the bale-out and tilting crucible furnaces of the T.. and K.. series are equipped with with a thermocouple in the furnace chamber behind the crucible. To achieve fast heat-up times the temperature is set significantly higher than the desired bath temperature. Therefore, this control allows very fast heating-up times, but results in considerable temperature overshoots in the melt due to the indirect temperature measurement. As an option these furnaces can be equipped with a bath control system, which is particularly well-suited for holding operations. A second thermocouple in the bath is used in addition to the furnace chamber thermocouple to measure the bath temperature. Both temperatures are reconciled by the controller. The bath temperature is the target parameter and the chamber temperature is the working tool. This control system significantly improves the melt quality because overshoots can be effectively prevented. As an alternative to the thermocouple in the melt, a thermocouple in a special pocket in the crucible wall can be used (a special crucible with pocket is required) which measures the temperature of the crucible wall. Of course, this type of control is not as precise as with measurement in the melt. However, the thermocouple is positioned in a protected location. Information about temperature controllers, see pages 20/21.

Nabertherm melting furnaces are equipped with emergency outlet. In case of crucible breakage or leaking melt the crucible breakage alarm device will provide for a warning as soon as fluid metal emerges from the emergency outlet. The warning signal of the alarm is both optical, with an signal lamp, and acoustic, using a horn.

When crucible furnaces are used in continuous operation, it can be necessary to monitor the filling level of the crucible and provide for a signal when defined levels are reached. The signal can be either optical, acoustic, or a signal for automatic filling of the crucible. When the minimum level is reached, a signal to fill a crucible is given. On reaching the maximum level this process is stopped. The measurement of fill level can either be done by using a scale under the furnace or by using a measurement probe to detect the fill level and which records the data very precisely independent from external influences.

For melting furnaces with only furnace chamber temperature control, a separate bath temperature measurement device can be used to check the bath temperature. The measurement device is suitable for a temperature range from 0 to 1300 °C, and can be delivered with different dip pipe lengths (200, 380, 610 mm). Temperature measurement is carried out using a NiCr-Ni thermocouple. The submersion length of the pipe whould be 2/3 of the element length to achieve the most ideal reaction time. The average reaction time is 40 seconds. The thermocouple is suitable for all nonferrous metals except phosphor bronze.

Depending on the material flow and space requirements in a foundry, the charging height and pouring height may need to be different for a tilting crucible furnace. For instance, if loading is performed at ground level and the metal is poured into a machine at a higher level, then an optional electro-hydraulic lifting platform can adjust for the difference. The operation of the lifting platform is by means of a 2 hand operation with a manual throttling valve. It can also be interlocked with other machinery and be automatically operated.

Especially in smaller foundries or in foundries with narrow space availability, our TRP 240/S combi transport pan is available. It combines a melting furnace and a transport ladle in one unit. Its electrical connected rating allows the furnace to be used for melting.

• Furnace chamber temperature 900 °C for melting and holding of aluminum
• Electrically heated
• Connection between switchgear and furnace pluggable
• Customer must provide plant crane
• Comfortable planetary gearbox
• Simple handling and precise pouring
• Optimally arranged heating modules resulting in very long crucible standing times

The melting furnaces of the T and TF series can be equipped with a device for transport with a forklift. For this application, the furnaces are equipped with a pluggable connection and shock absorbers under the furnace. By using several switchgears, the same furnace can be transported to and used at different pouring locations.

For continuous processes, multiple crucible furnaces can be combined on a rotary table system. For example, when using three furnaces with a rotation in 120° steps, loading takes place at the first space, de-gassing at the second space, and bale-out at the third. This ensures a continuous supply of liquid metal at the pouring location. The rotary table is designed with an emergency drain below in case of crucible breakage.

Our melting furnaces in the K, KF, T, and TF series can be upgraded with adapted electrical heating for melting of heavy metals like lead and zinc. The furnace is equipped with a special crucible, in most cases a steel crucible. The melting power is tailored to the type of metal to ensure optimum utilization of the furnace.

In a variety of projects, Nabertherm has supplied melting furnaces upgraded by the customer for the melting of magnesium. Nabertherm supplied the furnace with all necessary control systems and the steel crucible. The furnaces were completed by the customer with the safety devices, pump systems for bale-out, and protective-gas systems. We are capable of implementing furnace systems to provide for a crucible volume of 1500 liters of magnesium.