CHAMBER AND HOT ZONE
The vacuum chamber is double-walled, manufactured from stainless steel, and is electro-polished for a clean, shiny and durable finish with excellent vacuum characteristics. The access door or cover gives full access to the hot zone for loading and unloading. All chamber components are water cooled as needed to keep external surfaces below 50 °C (122 F).
Numerous other hot zone sizes are available, with a maximum hot zone size of 36″ dia x 24″ high (914mm dia. x 610mm high). The usable area has a temperature uniformity of +/-10 °C or better. Our metallic hot zones made from tungsten, molybdenum or tantalum are ideally suited for vacuum furnaces as they have low vapor pressures and can handle high temperatures. A heating element surrounds the work area, with multiple layers of heat shielding encapsulating the hot zone to minimize heat losses and increase temperature uniformity. The maximum temperature of 3000 °C can be reached in rough vacuum levels with our Tungsten hot zone. Tantalum hot zones have a maximum temperature of 2200 °C, and molybdenum hot zones have a maximum temperature of 1750 °C.
In our graphite hot zones, we utilize fibrous graphite insulation with excellent insulation value. A resistance-heated graphite heating element surrounds the work area. Power to this element is delivered through tapered graphite pins that requires no threaded connections. The elimination of graphite threads greatly simplifies the design and reduces maintenance time for element replacement. The maximum temperature for graphite in vacuum is 2200 °C.
The chamber has a pumping port to accommodate the high vacuum system. Other chamber ports house the power connections, gas port, temperature sensors, sight windows, and other auxiliary equipment. The furnace chamber and all related components are mounted on a structural frame.
VACUUM SYSTEM
The standard roughing pumping system offered evacuates the furnace easily to the 10-2 Torr (mbar) vacuum level range using a Rotary Vane Pump. An electro-pneumatic vacuum valve isolates the chamber from the vacuum system when vacuum is not needed.
A diffusion pumping system allows vacuum levels in the 10-6 Torr (mbar) range. This system adds a diffusion pump , high vacuum valve, foreline valve and high vacuum sensor to the basic roughing system. Our diffusion pumping systems also come with a refrigerated baffle, which greatly reduces back-streaming of diffusion pump oil vapors.
A turbo pumping system allows vacuum levels in the 10-7 Torr (mbar) range. This system adds a turbo pump , high vacuum valve, foreline valve and high vacuum sensor to the basic roughing system. Turbo pumping systems typically have a lower through-put but better ultimate vacuum than diffusion pumping systems, and also have no oil, making for a cleaner or “dry” pumping system.
Vacuum levels can be monitored by visually observing the Vacuum Gauge Controller or the optional HMI interface. The vacuum system is operated by means of a graphical panel or the computer HMI system.
PROCESS GAS SYSTEM
The vacuum furnace system also provides means to perform thermal cycles in a positive inert gas environment. The standard positive pressure used in this furnace is 2 P.S.I.G.
An adjustable relief valve and a compound gauge (30 P.S.I.G. x 30 in. Hg.) are located on the top of the furnace body. The inlet gas flow is regulated by means of an adjustable flow meter, and a solenoid gas inlet valve.
POWER SUPPLY
Hot zone power is supplied by a three-phase SCR-controlled transformer sized to match the power requirements for the hot zone. This power supply is designed to accommodate high ramp rates to the maximum operating temperature.
All required circuit breakers, contactors and furnace controls are housed in one enclosure. The system meets all applicable Electrical and safety codes. Certification is available when required.
CONTROL SYSTEM
The basic control package consists of discrete controllers, push buttons and lights. In this package, temperature control is established with a programmable temperature controller. Temperature sensing is done with reading a type “C” Thermocouple for temperatures up to 2000 °C. For temperatures exceeding 2000 °C, we add a two-Color Optical Pyrometer and a retractable TC . The TC and pyrometer automatically and seamlessly switch as temperatures climb or drop.
The vacuum and gas system are controlled through a graphical control panel, housing the vacuum controller, push buttons and switches. Cycling of the vacuum valves is automated and interlocked for safety based on system pressures. Chamber pressure is read using the vacuum controller.
The optional HMI system provides fully automated cycles requiring minimal operator interaction. Graphic overviews on an industrial touch panel PC provide intuitive overviews of process data. A recipe contains all process parameters needed to perform a process cycle. An operator selects a recipe, and starts a run; the rest happens automatically. The HMI systems provides trending, data collection, alarming, user security, recipe management, remote connectivity and more. The HMI system come pre-configured and fully tested.
WATER SYSTEM
The water cooling system is designed to adequately cool the various furnace components and keep all external components under 50°C (120 F). A water flow switch with visual indication interlocks hot zone power. If insufficient flow is present, power to the heating element is interrupted.
UTILITIES:
| Power: |
kVA based on size and maximum temperature, 400-480V/3/50-60 Hz (other voltages available) |
| Water: |
20°C (70°F) and 50 P.S.I.G. (3.4 bar), Flow requirements based on kVA |
| Process Gas: |
Ar, He, 30-60 lpm @ 50 P.S.I.G. (3.4 bar) |
| Compressed Air: |
60-90 P.S.I.G. (4.1 – 6.2 bar) filtered |
Open 8AM-5PM business days