Nabertherm GmbH

The RSRC rotary tube furnaces are particularly suitable for processes where continuously running batch material is heated for a short time. The rotary tube furnace is positioned slightly inclined heated-up to the target temperature. The material is then continuously supplied at the upper end of the tube. It passes through the heated area of the tube and falls on the lower end out of the tube. The time of heat treatment results from the inclination angle, the rotational speed and the length of the working tube, as well as from the flow properties of the batch material. Equipped with the optional closed loading system for 5 liter charge material incl. receptacle, the rotary tube furnace can also be used for processes under protective gas or vacuum. Depending on process, charge and required maximum temperature, different working tubes made of quartz glass, ceramics or metal are used. This rotary tube furnace is therefore highly adaptable for different processes.

These gas tight retort furnaces are equipped with direct or indirect heating depending on temperature. They are perfectly suited for various heat treatment processes requiring a defined protective or a reaction gas atmosphere. These compact models can also be laid out for heat treatment under vacuum up to 600 °C. The furnace chamber consists of a gas tight retort with water cooling around the door to protect the special sealing. With the corresponding safety technology, retort furnaces are also suitable for applications under reaction gases, such as hydrogen or, in combination with the IDB package, for inert debinding or for pyrolysis processes. Different model versions are available depending on the temperature range:

Models NRA ../06 with Tmax 650 °C
 

• Heating elements located inside the retort
• Temperature uniformity up to +/- 5 °C inside the work space
• Retort made of 1.4571
• Gas circulation fan in the back of the retort provides for optimal temperature uniformity
• Insulation made of mineral wool

Models NRA ../09 with Tmax 950 °C
Design like models NRA ../06 with following differences:
 

• Outside heating with heating elements around the retort
• Retort made of 1.4828
• Only fiber materials are used which are not classified as carcinogenic according to TRGS 905, class 1 or 2

Models NR ../11 with Tmax 1100 °C
Design like models NRA ../09 with following differences:
 

• Retort made of 1.4841
• Without gas-circulation

The compact retort furnaces of the VHT product line are available as electrically heated chamber furnaces with graphite, molybdenum, tungsten or MoSi2 heating. A wide variety of heating designs as well as a complete range of accessories provide for optimal retort furnace configurations even for sophisticated applications.
The vacuum-tight retort allows heat treatment processes either in protective and reaction gas atmospheres or in a vacuum, subject to the individual furnace specs to 10-5 mbar. The basic furnace is suited for operation with nonflammable protective or reactive gases or under vacuum. The H2 version provides for operation under hydrogen or other flammable gases. Key of the specification up is a certified safety package providing for a safe operation at all times and triggers an appropriate emergency program in case of failure.

Alternative Heating Specifications
In general the following variants are available wit respect to the process requirements:

VHT ../..-GR with Graphite Insulation and Heating

• Suitable for processes under protective and reaction gases or under vacuum
• Tmax 1800 °C , 2200 °C or 2400 °C (VHT 40/.. - VHT 100/..)
• Max. vacuum up to 10-4 mbar depending on pump type used
• Graphite felt insulation

VHT ../..-MO or VHT ../..-W with Molybdenum or Tungsten Heating

• Suitable for high-purity processes under protective and reaction gases or under high vacuum
• Tmax 1200 °C, 1600 °C or 1800 °C
• Max. vacuum up to 10-5 mbar depending on pump type used
• Insulation made of molybdenum rsp. tungsten radiation sheets

VHT ../..-KE with Fiber Insulation and Heating through Molybdenum Disilicide Heating Elements

• Suitable for processes under protective and reaction gases, in air or under vacuum
• Tmax 1800 °C
• Max. vacuum up to 10-2 mbar (up to 1300 °C) depending on pump type
• Insulation made of high purity aluminum oxide fiber
• Only fiber materials are used which are not classified as carcinogenic according to TRGS 905, class 1 or 2

The high­temperature furnaces HT 04/16 ­ HT 450/18 have proven reliability over many years in laboratory and production. Whether for quartz glass or glass ceramics, for sintering CIM components or for other processes up to a maximum temperature of 1800 °C, these furnaces afford the optimal solution for the sintering process.

High­temperature furnaces can either be insulated with fiber material or lightweight refractory bricks. Furnaces with fiber insulation achieve significantly shorter heating up times because of the low thermal mass. An insulation made of lightweight refractory bricks, on the other hand, has the advantage of better chemical stability.

These furnaces can also be tailored to specific processes by means of a wide range of additional equipment. The addition of a debinding package, for example, allows the use of these models as combi furnace for debinding and sintering in one process. Thermal or catalytic exhaust cleaning equipment rounds­off the system.