1. Chamber and Hot Zone
The furnace chamber is round and is supplied with a hinged top lid to facilitate loading and unloading. The chamber is double-walled, manufactured from 304L grade stainless steel and is welded together by the heli-arc method. The chamber is electro-polished for a clean, shiny and durable finish.
In our graphite type hot zones, we utilize fibrous graphite insulation. A resistance-heated graphite element surrounds the work area. Power to this element is delivered through a set of graphite pins that require no threaded connections. This reduces down time for element replacement. The element zone area measures 4″ x 8″ with a usable zone 3.5″ diameter x 6″ high (89 mm x 152 mm). The usable area has a temperature uniformity of +/-10 °C. A 5/8″ diameter rotatable gas ported quartz sight window is located on the side of the chamber. Other hot zone sizes are available, refer to our Top Loading Furnaces.
The chamber has a 4″ pumping port on the back side to accommodate an optional high vacuum system. The bottom of the chamber houses ports for the adjustable power feed throughs. The furnace chamber is mounted on a structural, mild steel angle frame which houses the evacuation system and associated electrical components. The water and gas manifolds are also mounted to this frame. The control console is located to the left side of the furnace.
2. Evacuation System
The rough vacuum system offered includes a mechanical roughing pump able to evacuate the furnace to a 10-2 torr (mbar) vacuum level. An electro-pneumatic vacuum valve is provided to isolate the chamber for operation in gas. A manual valve is provided for leak checking the system. Vacuum levels can be monitored by visually observing the Vacuum Gauge Controller or optional HMI Interface. The 4″ port on the chamber will accommodate an optional high vacuum system.
3. Power Supply
Hot zone power is supplied by a three phase SCR Controlled transformer. This Power Supply is designed to accommodate a ramp rate of 100 °C/minute, and operating temperature of 3000°C. All circuit breakers, contactors and power controls are housed in one cabinet together with the instrumentation.
4. Process Gas System
This furnace system was designed to provide a positive pressure inert gas environment for your work samples. The standard positive pressure used in this furnace is 2 P.S.I.G. A 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 a valve mounted on a flow meter and a solenoid gas inlet valve. Partial pressure control systems, operation in hydrogen, gas purification, or oxygen monitoring are all available gas system options.
5. Control System
Furnace control is established with either graphical panel with push-buttons, selector switches and discrete controllers, or via an HMI computer interface. Temperature is read with a two-color Optical Pyrometer and a type “C” Thermocouple. An automatic TC remover retracts the TC out of the heated area to protect it from melting once the pyrometer is in control. This retractable TC is sealed with metal, vacuum-tight bellows, eliminating the need for sliding seals. The TC will control the zone temperature from room to 1500°C. The pyrometer will then read temperature from 1500°C to 3000°C. The vacuum gauge and controller with a pneumatic vacuum valve and control panel instruments allow monitoring and operation of the vacuum system.
The operation of the furnace is made simple and requires only minimal operator interaction, but still allows supervisors or technical personnel to re-configure and further customize the furnace operation.
6. Optional DAQ/ HMI System
As with any of our furnace systems, our HMI control system with a user-friendly operator interface is available as an option. This package has the added advantage of furnace stored data which is displayed in trends, alarms which are displayed/recorded, no limit to the number of temperature recipes, added security to keep operators from entering unauthorized parameters, and the furnace PC can be networked. Fully automated runs are programmable as well. This HMI system replaces the classic temperature and vacuum controllers containing push-buttons and switches.
7. Furnace Water Cooling Manifold
The water manifold provided with this system is designed to adequately cool the furnace and power cables. A water flow switch is installed with a light for visual indication and interlocking the hot zone power. The water manifold has several circuits supplying water to the various parts of the furnace. Each one of these can be manually adjusted to allow each circuit just the proper amount of flow to save water and allow a drain temperature of approximately 100 F.
||35 kVA, 480 V/3Ph/50-60-Hz (other voltages available)
||7 G.P.M.(27 LPM) @ 70F (20°C) and 50 P.S.I.G. (3.4 bar)
||Argon or Nitrogen 30 L.P.M. @ 50 P.S.I.G. (3.4 bar)
||60 – 90 P.S.I.G. (4.1 – 6.2 bar) filtered.