The metallic hood furnaces (HBO) generate the lowest achievable operation pressures. The highest purity gas atmosphere is attained due to the vacuum capability.
The materials used in the construction are selected for the lowest vapour pressures at the highest temperatures. Heat treatment up to the highest temperatures can be achieved without harming the heating elements or insulation material. Radiation shields are used to provide thermal insulation, which are made from the same material as the heating elements, and no fibrous thermal insulation is used.
Two varieties of HBO furnaces are produced: those made using molybdenum heating elements and radiation shields are suitable for use up to 1600 °C; those made using tungsten heating elements and radiation shields are suitable for use up to 2200 °C.
Nitrogen, Argon, and Hydrogen gases are available for use in mixed or pure forms. Additional gases can be installed upon request. A slight overpressure or controlled partial pressure between 10 and 1000 mbar can be achieved. Partial pressure provides a defined gas flow through the furnace.
Due to the complete metallic design, the final vacuum level in the HBO can reach the high vacuum range and better than 5 x 10-6 mbar. Depending on the vacuum requirements, the vacuum is provided by different pumping stations. Ultrahigh vacuum options are available upon request. Gases are controlled by various dosing and controlling devices. The temperature in each of the three heating zones is individually controlled to maintain the best uniformity.
Application Examples
annealing, brazing, carbonization, ceramic injection moulding (CIM), debinding, degassing, drying, hardening, metal injection moulding (MIM), pyrolysis, quenching, rapid prototyping, siliconization, sintering, soldering, sublimation, synthesis, tempering
Standard features
- Precisely defined atmosphere with highest possible purity (6 N or better)
- Best possible vacuum
- Fast heat up and cool down upon request
- Hydrogen partial pressure operation upon request
- Precisely controlled vacuum pumping speeds appropriate for powders
- Certified safety management for flammable and toxic gases
- Fully automatic operation
- Data recording for quality management
Options (specify these at time of order)
- Vacuum system for pre-vacuum, fine vacuum or high vacuum operation
- Software for automated operation, data tracking and data export
- Reaction gas equipment for more than one inert gas, retorts, afterburners
- Water cooling system
Top hat furnace - HBO View inside of the HBO Hood Furnace
- gas inlet or outlet
- gas outlet or inlet
- pumping unit attached from below
- location of the thermocouple
- radiation shields
- heating elements
- water cooled vessel
- sample holder (built on request)
To insulate the heat in metallic furnaces, tungsten or molybdenum radiation shields are used. The HBO has a double walled, water cooled vessel. The sample holder is positioned as required.
Each of the three heating zones are individually controlled and protected by an additional over-temperature protection thermocouple; therefore, unattended operation is possible. An optional fast cooling system significantly reduces the cool down time.
View inside HBO
Top hat furnace - HBO Technical Data
| Insulation material | Dimensions: External H x W x D (mm) | Transport weight (kg) | Usable space | Volume (l) | Ø x H, usable space without retort (mm) | Ø x H, usable space with retort (mm) | Thermal values | Tmax vacuum (°C) | Tmax atmospheric pressure (°C) | -Delta-T, above 800°C (K) according to DIN 17052 | Max. heat-up rate (K/min) | Cooling time (h) | Connecting values | Power (kW) | Voltage (V) | Current (A) | Series fuse (A) | Vacuum (option) | Leakage rate - clean, cold and empty (mbar l/s) | Vacuum range depending on the pumping unit | Cooling water required | Flow (l/min) | Gas supply | Nitrogen or Argon flow, others on request (l/h) | Controller | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HBO 10 MO/16-1G | Molybdenum | 2500 x 2300 x 2000 | 1800 | |
10 | 200 x 300 | 180 x 280 | |
1600 | 1600 | ± 10 | 10 | 3 | |
50 | 400 (3P) | 3 x 125 | 3 x 160 | |
< 5x10-3 | rough, fine, high or ultra high vacuum | |
40 | |
500-2000 | Siemens |
| HBO 25 MO/16-1G | Molybdenum | 2500 x 2300 x 2000 | 2000 | |
25 | 300 x 400 | 280 x 380 | |
1600 | 1600 | ± 10 | 10 | 4 | |
65 | 400 (3P) | 3 x 100 | 3 x 125 | |
< 5x10-3 | rough, fine, high or ultra high vacuum | |
50 | |
500-2000 | Siemens |
| HBO 60 MO/16-1G | Molybdenum | 2800 x 2300 x 2500 | 3000 | |
60 | 400 x 500 | 380 x 480 | |
1600 | 1600 | ± 10 | 10 | 5 | |
80 | 400 (3P) | 3 x 120 | 3 x 160 | |
< 5x10-3 | rough, fine, high or ultra high vacuum | |
64 | |
500-2000 | Siemens |
| HBO 10 W/22-1G | Tungsten | 2500 x 2300 x 2000 | 1800 | |
10 | 200 x 300 | 180 x 280 | |
2200 | 2200 | ± 10 | 10 | 4 | |
125 | 400 (3P) | 3 x 180 | 3 x 250 | |
< 5x10-3 | rough, fine, high or ultra high vacuum | |
100 | |
500-2000 | Siemens |
| HBO 25 W/22-1G | Tungsten | 2500 x 2300 x 2000 | 2000 | |
25 | 300 x 400 | 280 x 380 | |
2200 | 2200 | ± 10 | 10 | 5 | |
150 | 400 (3P) | 3 x 220 | 3 x 315 | |
< 5x10-3 | rough, fine, high or ultra high vacuum | |
120 | |
500-2000 | Siemens |
| HBO 60 W/22-1G | Tungsten | 2800 x 2300 x 2500 | 3000 | |
60 | 400 x 500 | 380 x 480 | |
2200 | 2200 | ± 10 | 10 | 6 | |
250 | 400 (3P) | 3 x 380 | 3 x 500 | |
< 5x10-3 | rough, fine, high or ultra high vacuum | |
200 | |
500-2000 | Siemens |
Top hat furnace - HBO Downloads
High vacuum soldering and brazing with hood furnaces
Nowadays many electronic components, for example devices used in satellites or aircraft, have to withstand challenging environments such as vacuum or extremely high temperatures. To manufacture reliable electronic components like these a connection between dissimilar materials is required.