Chamber and Hot Zone
The chamber is loaded from the front and contains a Hot Zone with a 3.0″ dia. x 6.0″ high usable zone and +/- 10°C temperature gradient. The heating element is a 1/2- 1/2 split design allowing the crucible with solute to be inserted straight into the zone onto the support plate. The furnace chamber is manufactured from double-walled stainless steel welded together and polished for a clean finish and good vacuum integrity.
The hot zone assembly can be one of three choices: a graphite band element and rigid fibrous graphite insulation pack, a Moly-D rod element and ceramic insulation pack, or a high temperature metal mesh heating element and layered metal shielding. The maximum operating temperature is 2000°C ( 1650°C with ceramic zone) with the crystal growing kit, and is capable of 2800°C in batch mode.
Power Supply & Controls
Power to the hot zone is supplied by a three-phase SCR-controlled power supply, including a circuit breaker, a contactor, an SCR with 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.
The furnace controls consist of buttons, switches, lights and controllers which are mounted in a control panel. They provide safe, simple and reliable operation of the furnace components. The optional HMI system replaces these components with a PLC, computer and software package which allows Data Acquisition, unlimited recipe storage, alarming, trending, security, automation, networking and an intuitive graphical user interface. All safeties and interlocks are programmed and tested to conform with NFPA 86.
A type “C” sheathed and coated thermocouple is supplied and can be used to measure the furnace temperature up to 2000°C. An optional Pyrometer can also be used for temperatures above 800°C.
Vacuum and Gas System
The evacuation system consists of a rotary vane mechanical pump, an electro-pneumatic vacuum valve, vacuum gauge controller and vacuum gauge. This vacuum system will allow for operation in a vacuum environment (10-2 Torr range) A 4″ or 6″ diffusion pumping system or a turbo pumping system can be provided as well and can achieve vacuum levels down to 10-6 ( diffusion pumping system) and 10-7 Torr range ( turbo pumping system). A manual valve is provided for leak checking or air releasing the roughing line.
The gas system is supplied to provide an inert environment for the work samples during heating and physical testing. The process Gas System (Argon): includes 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. Optionally flammable gases can be used with the hydrogen gas kit.
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, a water flow switch interlock to protect the furnace in the event of a water flow failure. Each part of the furnace is supplied with a separate cooling circuit that can be regulated by independent manual ball valves.
Utilities
| Power: |
kVA dependent on max temperature rating, 480V/3/50-60 Hz (other voltages available) |
| Water: |
70°F (20°C) and 50 P.S.I.G. (3.4 bar) Required flow dependent on kVA rating. |
| Process Gas: |
Argon or Nitrogen 30 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. |
