Laboratorium

The RD tube furnaces convince with their unbeatable price-performance ratio, very compact outer dimensions and their low weight. These all-rounders are equipped with a working tube which also serves as support for the heating wires. Thus, the working tube is part of the furnace heating which has the advantage that the furnaces achieve very high heat-up rates. The tube furnaces can be supplied for 1100 °C or 1300 °C. Both models are designed for horizontal application. If the customer requires protective gas atmosphere, a separate working tube incl. gas supply system 1, e.g. made of quartz glass, must be inserted in the working tube.

• Tmax 1100 °C or 1300 °C
• Housing made of sheets of textured stainless steel
• Inner diameter of the tube: 30 mm, heated length: 200 mm
• Working tube made of C 530 material including two fiber plugs as standard
• Thermocouple type K (1100 °C) or type S (1300 °C)
• Solid state relays provide for low-noise operation of the heating
• Heating wires wound directly around the working tube resulting in very fast heat-up rates
• Defined application within the constraints of the operating instructions

Additional equipment

• Over-temperature limiter with adjustable cutout temperature for thermal protection class 2 in accordance with EN 60519-2 as temperature limiter to protect the furnace and load
• Gas supply system for non-flammable protective or reactive gas

These compact tube furnaces with integrated control systems can be used universally for many processes. Equipped with a standard working tube of C 530 ceramic and two fiber plugs, these tube furnaces have an unbeatable price/performance ratio.

• Tmax 1200 °C or 1300 °C
• Single-zoned design as standard
• Dual shell housing made of sheets of textured stainless steel
• Outer tube diameter of 50 to 170 mm, heated length from 250 to 1000 mm
• Working tube of C 530 ceramic including two fiber plugs as standard equipment
• Tmax 1200 °C: Type N thermocouple
• Tmax 1300 °C: Type S thermocouple
• Solid state relays provide for low­noise operation
• Defined application within the constraints of the operating instructions

Additional equipment

• Over-temperature limiter with adjustable cutout temperature for thermal protection class 2 in accordance with EN 60519-2 as temperature limiter to protect the furnace and load
• Charge control with temperature measurement in the working tube and in the furnace chamber outside the tube
• Three-zoned design (heated length from 500 mm)
• Gas supply systems for protective gas or vacuum operation
• Process control and documentation with Controltherm MV software package

These compact tube furnaces are used when laboratory experiments must be performed horizontally, vertically, or at specific angles. The ability to configure the angle of tilt and the working height, and their compact design, also make these tube furnaces suitable for integration into existing process systems.

• Tmax 1100 °C, 1300 °C, or 1500 °C
• Compact design
• Vertical or horizontal operation freely adjustable
• Working height freely adjustable
• Working tube made of C 530 ceramic
• Type S thermocouple
• Operation also possible separate from stand if safety guidelines are observed
• Control system integrated in furnace base
• Defined application within the constraints of the operating instructions

These compact tube furnaces with SiC rod heating and integrated switchgear and controller can be used universally for many processes. With an easy to replace working tube as well as additional standard equipment options, these furnaces are flexible and can be used for a wide range of applications. The high-quality fiber insulation ensures fast heating and cooling times. The SiC heating rods installed parallel to the working tube ensure excellent temperature uniformity. The price-performance ratio for this temperature range is unbeatable.

• Tmax 1500 °C
• Housing made of sheets of textured stainless steel
• High-quality fiber insulation
• Active cooling of housing for low surface temperatures
• Type S thermocouple
• Solid state relays provide for low-noise operation
• Prepared for assembly of working tubes with water-cooled flanges
• Ceramic tube, C 799 quality
• Defined application within the constraints of the operating instructions

Additional equipment

• Over-temperature limiter with adjustable cutout temperature for thermal protection class 2 in accordance with EN 60519-2 as temperature limiter to protect the furnace and load
• Charge control with temperature measurement in the working tube and in the furnace chamber outside the tube
• Fiber plugs
• Check valve at gas outlet avoids intrusion of false air
• Working tubes for operation with water-cooled flanges
• Display of inner tube temperature with additional thermocouple
• Alternative gas supply systems for protective gas or vacuum operation

The high-temperature tube furnaces are available in either horizontal (type RHTH) or vertical (type RHTV) designs. High-quality insulation materials made of vacuum-formed fiber plates enable energy-saving operation and a fast heating time due to low heat storage and heat conductivity. By using different gas supply systems, operations can be performed under non-flammable or flammable protective or reactive gases or under vacuum.

• Tmax 1600 °C, 1700 °C, or 1800 °C
• MoSi2 heating elements, mounted vertically for easy replacement
• Insulation with vacuum-formed ceramic fiber plates
• Rectangular outer housing with slots for convection cooling
• Models RHTV with hinges for wall mounting
• Housing made of sheets of textured stainless steel
• Ceramic working tube made of material C 799 incl. fiber plugs operation under air
• Type B thermocouple
• Power unit with low-voltage transformer and thyristor
• Over-temperature limiter with adjustable cutout temperature for thermal protection class 2 in accordance with EN 60519-2 as temperature limiter to protect the furnace and load and with selectable maximum temperature gradient as tube protection
• Switchgear and control unit separate from furnace in separate floor standing cabinet
• Defined application within the constraints of the operating instructions

Additional equipment

• Charge control with temperature measurement in the working tube and in the furnace chamber outside the tube
• Display of inner tube temperature with additional thermocouple
• Gas tight flanges for protective gas and vacuum operation
• Manual or automatic gas supply system
• Three-zone control for optimization of temperature uniformity (only RHTH)
• Check valve at gas outlet avoids intrusion of false air
• Stand for vertical operation

The tube furnaces of the product line RS can be used for horizontal as well as for vertical operation. The split-type design makes it easy to change the working tube. It allows for a comfortable exchange of various working tubes (e.g. working tubes made of different materials).

Using the wide range of accessories these professional tube furnaces can be optimally tailored to your process. By upgrading the furnaces with different gas supply systems the operation in a protective gas atmosphere, under vacuum or under flammable protective or reactive gases is possible. Besides convenient standard controllers for process control modern PLC control systems are also available.

• Tmax 1100 °C or 1300 °C
• Housing made of sheets of textured stainless steel
• Tmax 1100 °C: Type K thermocouple
• Tmax 1300 °C: Type S thermocouple
• Frame for vertical operation, which can also be retrofitted as additional equipment
• Split-type design for simple insertion of the working tube
• Working tube made of ceramic C 530 for operation in air included in scope of delivery
• Switchgear and control unit separate from furnace in own wall or standing cabinet
• Defined application within the constraints of the operating instructions

Additional equipment

• Charge control with temperature measurement in the working tube and in the furnace chamber outside the tube
• Display of inner tube temperature with additional thermocouple
• Different gas supply systems (page 44) for non-flammable or flammable protective or reactive gases and vacuum operation
• Three-zone control for optimization of temperature uniformity
• Check valve at gas outlet avoids intrusion of false air
• Ceramic half pipe for heating elements and/or as support surface for the load
• Optical temperature measurement for the use as lab strand annealing furnace
• Stand for vertical operation
• Base frame with integrated switchgear and controller

The rotary tube furnaces of the RSRB series are ideally suited for batch operation. The permanent rotation of the working tube ensures that the charge is constantly in motion. Due to the special shape of the quartz reactor with the tapered pipe ends the batch is kept in the rotary tube furnace and can be heat-treated an arbitrarily long time period time; a controlled heating to the temperature profiles is also possible.

• Tmax 1100 °C
• Thermocouple type K
• Housing made of sheets of textured stainless steel
• Furnace designed as table-top model with quartz glass reactor which opens on both sides, tapered ends
• Reactor is removed for emptying out of the rotary tube furnace. Beltless drive and hinged furnace housing (opening temperature < 180 °C) provide for very easy removal through
• Adjustable drive of approx. 2-45 rpm
• Switchgear and control unit separate from furnace in own wall or standing cabinet
• Defined application within the constraints of the operating instructions

Additional equipment

• Three-zone control for the optimization of temperature uniformity
• Temperature display unit in the working tube with measurement by means of an additional thermocouple
• Charge control by means of an additional thermocouple in the working tube
• Different gassing ensures good flushing of the charge with process gas through inlet on one side and outlet on other side of tube
• Gas-tight rotary feedthrough for connection of the rotating reactor to a gas supply system
• Check valve at gas outlet avoids intrusion of false air
• Vacuum design, up to 10-2 mbar depending on the applied pump
• Open on both sides reactor made of quartz glass with knobs for better mixing of the charge in the tube
• Package for improved charging and discharging of the working tube in the following design: 
  • Mixing reactor made of quartz glass with integrated blade for better mixing of the batch, closed on one side, large opening on the other side
  • Tilting mechanism to the left/to the right. For charging and heat treatment, the furnace is tilted towards the right side until the stop so that the load is charged into the furnace. For discharge, the furnace is tilted towards the other side to discharge the powder from the reactor. It is no longer necessary to remove the reactor.
  • Furnace assembled on base with integrated switchgear and controller, incl. transport casters

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 furnace can also be used for processes under protective gas or vacuum.

• Tmax 1100 °C 
  • Working tube made of quartz glass open at both sides
  • Thermocouple type K
• Tmax 1300 °C 
  • Open tube made of ceramics C 530
  • Thermocouple type S
• Housing made of sheets of textured stainless steel
• Adjustable drive of approx. 2-45 rpm
• Digital display unit for the tilting angle of the furnace
• Beltless drive and split-type furnace housing (opening temperature < 180 °C) provide for very easy tube removal
• Compact system, rotary tube furnace positioned on a base frame with 
  • manual spindle drive with crank to preset the tilting angle
  • switchgear and controls integrated
  • castors
• Defined application within the constraints of the operating instructions

Additional equipment

• Three-zone control for the optimization of temperature uniformity
• Temperature display unit in the working tube with measurement by means of an additional thermocouple
• Charge control by means of an additional thermocouple in the working tube
• Different gassing systems with good flushing of the charge with process gas in counterflow (only in combination with feeding system below)
• Check valve at gas outlet avoids intrusion of false air
• Vacuum design, up to 10-2 mbar depending on the applied pump
• Charging system for continuous material transport, consisting of: 
  • Stainless steel funnel incl. electric vibration generator to optimize the material feeding into the working tube
  • Electrically driven screw-conveyor at the inlet of the working tube with 10, 20 or 40 mm pitch and adjustable speed between 0.28 and 6 revolutions per minute, different gear transmissions for other speeds on request
  • Collecting bottle made of laboratory glass at the outlet of the working tube
  • Suitable for operation in gas atmosphere or vacuum
• Working tubes made of differents materials
• Quartz glass batch reactors, Tmax 1100 °C
• Higher temperatures up to 1600  °C available on request
• Digital display unit for the tilting angle of the furnace
• Electric linear drive for the adjustment of the tilting angle
• PLC controls for temperature control and the control of connected aggregates such as gearshift and speed of the screw-conveyor, speed of the working tube, switching of the vibration generator, etc.

When equipped with various equipment packages, the tube furnace product lines can be adapted for operation with nonflammable or flammable gasses or for vacuum operation.

This package represents a basic version sufficient for many applications, for operation with non-flammable protective or reactive gasses. The standard working tube made of ceramic C 530 delivered with the furnace can still be used.

• Available for tube furnaces RD, R, RT and RS
• Standard working tube can be used
• 2 plugs made of porous, non-classified ceramic fiber incl. protective gas connections
• Gas supply system for nonflammable protective gas (Ar, N2, forming gas, others on request) with shutoff valve and flow meter with control valve (volume 50-500 l/hr), piped and ready to connect. One gas intake pressure at 300 mbar to be provided by customer.

Additional equipment

• Extension of gas supply system with a second or third nonflammable type of gas
• Bottle pressure regulator for use with bottled gas
• Automatic switching on/off by means of the program segments of the controller, only possible with control systems which include programmable extra functions

For increased atmospheric purity requirements in the working tube, we recommend this gas supply system. The system can also be equipped for vacuum operation.

• Available for tube furnaces R, RS, RSRB, RSRC, RHTC, RHTH, RHTV
• Gas supply system for nonflammable protective gas (Ar, N2, forming gas, others on request) with shutoff valve and flow meter with control valve (volume 50-500 l/hr), piped and ready to connect. One gas intake pressure at 300 mbar to be provided by customer.
• Additional equipment for static tube furnaces: 
  • Longer, gas tight working tube of ceramic C 610 for furnaces to 1300 C or of C 799 for temperatures above 1300  C
  • 2 vacuum-tight, water-cooled stainless steel flanges with fittings on the outlet side (cooling water supply with NW9 hose connector to be provided by the customer)
  • Mounting system on furnace for the flanges
• Additional equipment for RSRC models (continuous operation): charging system
• Additional Equipment for RSRB models: gas-tight rotarylead-outs on gas inlet and outlet, gas cooler and gas outlet valve

Additional equipment

• Extension of gas supply system with a second or third nonflammable type of gas
• Bottle pressure regulator for use with bottled gas
• Automatic switching on/off by means of the program segments of the controller, only possible with control systems which include programmable extra functions
• Gas-supply programmable via mass-flow controllers (only in combination with PLC-controls)
• Process tubes made of different materials
• Quick-locks for watercooled flanges
• Cooling unit for closed loop water circuit
• Window for charge observation in combination with gas tight flanges

Vacuum Operation

• Vacuum package for evacuation of the working tube, consisting of connector for the gas outlet, ball valve, manometer, manually operated rotary vane vacuum pump with corrugated stainless steel hose connected to the gas outlet, max. attainable end pressure in working tube depending on pump type
• Pumps for max. final pressure of up to 10-5 mbar (models RSRB/RSRC up to 10‑2 mbar) on request
• The decrease in strength of the working tube at high temperatures limits the maximum operating temperature under vacuum

Adding gas supply system 4 to the tube furnace allows operation under a hydrogen atmosphere. During hydrogen operation, a safety pressure of approx. 30 mbar is ensured in the working tube. Surplus hydrogen is burnt off in an exhaust gas torch. With extended safety logic and an integrated nitrogen purge container, the system can be used for fully-automatic, unattended operation. Equipped with a Safety-PLC control system, pre-purging, hydrogen inlet, operation, fault monitoring and purging at the end of the process are carried out automatically. In case of default, the tube is immediately purged with nitrogen and the system is automatically switched to a safe status.

• Available for tube furnaces RS, RSRC, RHTH and RHTV
• Safety system for operation with flammable gases including monitoring of torch function and overpressure
• Extended safety control system with emergency tube purging in case of default
• Emergency purge container
• Safety-PLC control system with touchpanel for data input
• Exhaust gas torch
• Pressure switch for monitoring the safety pressure
• Gas supply system for H2 and N2. Volume adjustment is carried out by hand (the customer provides an H2 supply at 1 bar, an N2 supply at 10 bar, an O2 supply at 6-8 bar and a propan supply at 300 mbar)

Additional equipment

• Gas supply system extension for additional nonflammable gas types
• Operation with other flammable gases on request
• Bottle pressure reducer for use with bottled gas
• Cooling unit for closed loop water circuit
• Vacuum packages (with hydrogen operation, this package can only be used for pre-evacuation)
• Gas supply via program-dependent, controllable mass flow controllers

With respect to the final pressure different pumps are available

• Single-step rotary piston pump for a max. final pressure of approx. 20 mbar.
• Two-step rotary piston pump for a max. final pressure of approx. 10-2 mbar.
• Turbomolecular pump stand (rotary vane pump with following turbomolecular pump for a max. final pressure of 10-5 mbar.
• Independent pressure gauge for a pressure range of 10-3 mbar or 10-9 mbar as additional equipment

For protection of the vacuum pump only cold stage evacuation is allowed. 

The temperature is measured by thermocouples positioned outside of the working tube, one in the middle and two on the sides. The outer zones are controlled with a setpoint-offset in relation to the middle zone. This allows the heat loss at the ends of the tube to be compensated to ensure an extended zone of constant temperature (+/- 5 K). 

Furnace Chamber Control 
with temperature measurement in furnace chamber outside the working tube.

• Advantages: Thermocouple protected against damage and aggressive load, very even control, attractive price
• Disadvantage: Temperature difference between displayed temperature on the controller and inside the tube

Extension Package for Furnace Chamber Control 

• with additional temperature measurement in the working tube and display of the measured temperature

Charge Control 
with temperature measurement both in the furnace chamber outside the working tube as well as in the working tube.

• Advantages: Very precise and rapid control adjustment
• Disadvantage: Costs

Only the furnace chamber temperature is measured and controlled. Regulation is carried out slowly to avoid out-of-range values. As the charge temperature is not measured and controlled, it may vary a few degrees from the chamber temperature.

If the charge control is switched on, both the charge temperature and furnace chamber temperature are measured. By setting different parameters the heat-up and cooling processes can be individually adapted. This results in a more precise temperature control at the charge.