Chamber and Hot Zone
The chamber is loaded from the front and contains a Hot Zone with a 12″ x 12″ x 12″ usable zone and a +/- 10°C temperature gradient. The heating element is comprised of four identical tungsten rod panels, providing four-sided heating. Six-sided heating also available. The elements are rugged and feature excellent uniformity and longevity at a low cost. Mesh heaters are also available for higher ramp rates and uniformity. The furnace chamber is manufactured from doubled-walled stainless steel welded together and polished for a clean finish and good vacuum integrity.
Numerous ports are incorporated for auxiliary equipment and sensors. The hot zone shields are mounted in a chamber frame, allowing for the thermal growth of the zone during the heat cycling. The optional gas heat exchanger allows for quick-cooling down to room temperature.
The furnace load is placed on the load support rails. The load supports are engineered to feature a high load capacity and a low thermal conductivity loss to the chamber walls.
Power Supply & Controls
Power to the hot zone is supplied by a three-phase SCR-controlled power supply which includes all necessary circuit breakers, a contactor, an SCR to modulate the power to the hot zone, a main step-down transformer matched to meet the heating element resistance, volt and amp meters, and a set of water-cooled power cables to supply power to the furnace.
Two control options are available, a control panel with switches, lights, temperature controller and vacuum instrument, or a Computer Interface package with HMI software and Industrial touch-panel PC. Both offer full control of the furnace and are easy to operate. The Computer package adds data acquisition, alarms, recipe storage, security and networking.
A type “C” sheathed thermocouple is supplied and can be used to measure the furnace temperature up to 2000°C. For maximum temperatures above 2000°C, a two-color pyrometer optically measures load temperatures. The TC is automatically retracted from the hot zone once the pyrometer has taken over temperature control. A safety over-temperature controller will shut off power to the hot zone if the maximum temperature is exceeded.
Vacuum System
- The basic system, an evacuation system, consists of a Rotary Vane mechanical pump, an electro-pneumatic vacuum valve, and a vacuum gauge. This vacuum system will allow for operation in a vacuum environment (10-2 to 10-3 Torr range).
- A 4″, 6″ or 10″ diffusion pumping system can be provided to achieve vacuum levels down to 10-6 Torr. All our diffusion pump systems include a refrigerated cold trap to prevent oil backstreaming and to obtain a lower ultimate vacuum.
- A turbo pumping system or cryogenic pumping system with a “dry” roughing pump provides an oil-less vacuum system for ultra clean environments and obtains a vacuum level of 10-7 to 10-8 Torr range.
Gas System
An inert or Hydrogen gas system provides an inert or reducing environment for the work samples during the heat testing. Partial pressure and custom gas systems are available.
The basic Inert gas system (Argon) includes a solenoid-operated inlet valve, a Compound Gauge (30 P.S.I.G. x 30 in. Hg.), a gas flow meter, and a 2 P.S.I.G. outlet relief valve to maintain a positive pressure. There is also a 5 P.S.I.G. over-pressure safety relief valve.
For operation in dry or wet Hydrogen, additional solenoids and sensors are supplied to provide safe and reliable operation. A burn-off kit will ignite and monitor any flammable gas exiting the furnace, a safety blow-off port is provided to relieve any excessive chamber pressure.
For a quick cool down to atmosphere in gas, a water-cooled gas heat exchanger can be provided.
Water Cooling System
The furnace water-cooling manifold consists of multiple circuits to adequately cool all the furnace parts and includes a strainer, pressure regulator, pressure gauge, water inlet and outlet manifold, and a water flow switch. The water flow switch serves as a visual water flow indicator and a flow interlock to protect the furnace in the event of a water flow failure. This switch turns off power to the hot zone contactor if water flow is below recommended minimum for a certain amount of time. Each part of the furnace is supplied with a separate cooling circuit that can be regulated by independent manual ball valves. All external surfaces remain below 50°C (120°F)
Utilities
| Power: |
kVA dependent on maximum temperature, 380-480-575 V/3/50-60 Hz. |
| Water: |
kVA dependent, 10-15 G.P.M.(39 – 58 lpm) @ 70°F and 50 P.S.I.G. (3.4 bar) |
| Process Gas: |
Argon or Nitrogen, Hydrogen 40 L.P.M. @ 50 P.S.I.G. (3.4 bar) |
| Compressed Air: |
60-90 P.S.I.G. (4.1 – 6.2 bar) filtered. |
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