FURNACE DATA

Additional sizes are available upon request.

FEATURES

This specification is for a single zone, high temperature furnace that is capable of operation in dry inert, reducing, and vacuum atmospheres. The basic Model 1100 system includes the refractory metal furnace, support column and bracket, power supply, and water-cooled flexible power leads. The operational specifications for these systems are as follows.

HOT ZONE

Depending on the specific model either molybdenum or tungsten wire mesh (or weave), or molybdenum sheet, is used for the heating element.

THERMAL RADIATION SHIELDS

Radiation shields are molybdenum or tungsten-molybdenum sheet. Minimum shield thickness is 0.010” (0.024 mm).

WORK SUPPORT HEARTH

Molybdenum or tungsten work support hearth is attached to the furnace bottom door.

FURNACE CONSTRUCTION

Based on model, the furnace shell is heavy-wall, seamless extruded 6061 T6 aluminum with an anodized exterior or SST (water-jacketed). The bulkheads are hard-anodized aluminum and the doors are nickel-plated copper. The shell and bulkheads have integral water-cooling passages. External surface temperatures are maintained at 65°C or less. O-ring seals are Viton.

Radial and axial ports are provided to permit viewing and instrumentation access to the furnace hot zone. Two 1 1/8 inch-16 threaded ports are located at the middle of the hot zone. One port has a shuttered viewing window with anti-fog gas diffuser for atmosphere operation. The second port is blanked off but will accept a second window and shutter assembly for straight-through viewing access. A plugged thermocouple feedthrough is located 45° from the window. A plugged instrumentation port is provided through the center of each end door. A radial vacuum port with a water-cooled cover plate is also located at the furnace mid-point, 90° from the window.

MAXIMUM TEMPERATURE

Temperature to 3000°C in vacuum, inert, and reducing gas atmospheres.

TEMPERATURE UNIFORMITY

At 1700°C a 2-inch (50 mm) long uniform temperature zone with a uniformity tolerance of ± 3°C is possible in all models. A uniformity tolerance of ± 8°C is possible over 4 inches (100 mm). Uniformities will improve above 2000°C due to the high thermal radiation flux. Full length, very uniform hot zones can be provided for specific operating conditions upon special order.

CYCLE TIME

Heat-up time from ambient to maximum temperature is usually 30 minutes or less. Power-off cooling time from maximum to 100°C is 2 to 3 hours. More rapid cooling can be achieved by increasing gas flow into the furnace chamber or adding the optional cooling chamber accessory.

POWER SUPPLY

The power supply consists of an SCR power regulator and step-down load transformer.

Power is activated with an on/off switch that controls a furnace power contactor. A panel meter indicates secondary voltage and current. A safety interlock with warning lamp, audible alarm, and operate/reset switch monitors cooling water flow and optional alarm circuits.

Power is manually adjustable from 0-100% by means of a programmable controller (manual mode). Power supply components are housed in a floor console that shares a common 25” by 44” base with the furnace support column.

AVERAGE POWER CONSUMPTION

At maximum temperature, steady state power consumption is approximately 75% of rating in vacuum, 83% in argon and 87% in helium or hydrogen. Power supplies have ample reserves to compensate for the additional power required by increased heat losses due gas convection and to the eventual discoloration of the radiation shields.

FACILITY REQUIREMENTS

Electric: 208/230 volt, 60 hertz, single phase (or 220 volt, 50 hertz, single phase), for systems requiring 20 kVA or less. 440/480 volt, 60 Hz, 3 phase (or 380 volt, 50 Hz, 3 phase) for systems requiring 30 kVA or more.
 
Water: 2.0–8.0 gpm at 50 psig; 65-85°F (7.5 to 30.0 l/min. at 345 kPa; 18-30°C) depending upon the model. The water should be filtered if it contains sand or other solid matter.
 
Air: Regulated to 70 psi (required with lift elevator, pneumatic thermocouple retractor and high vacuum systems).
 
Space: Maximum floor area: 5’ x 5’ (1.3 m x 1.3 m) including access. Height: 7’ (2.1 m).
 
Installation: Systems are complete and require only connection to user supplied sources of power, cooling water, and operating gas/vacuum.

GROUP 1100 – ACCESSORIES AND OPTIONS

TEMPERATURE SENSORS

Standard temperature sensors are tungsten 5% vs. tungsten 26% rhenium thermocouples and radiation pyrometers. Thermocouples are usable at temperatures through 2000°C. Optical pyrometers are recommended for use at temperatures above the thermocouple range and are effective from room temperature to 3000°C with controlled atmosphere conditions.

AUTOMATIC TEMPERATURE CONTROL

Automatic temperature control may be achieved with a versatile, high stability, precision PID, setpoint programming controller. Different models with a variety of features are available. These features include self-tuning, multiple stored programs with multiple ramp/dwell segments, and event outputs. Digital serial communications via EIA 232/422/485 are available.

TEMPERATURE RECORDING

Recorders are available in single and multi-pen and single and multi-point models in several chart widths and speeds.

VACUUM PUMPING SYSTEMS

Diffusion pumped vacuum systems are recommended for use with this series of furnaces. The integrated, stainless steel pumping module consists of an oil diffusion pump, optically opaque water-cooled baffle, and manually operated high vacuum, roughing, and foreline valves. 

VACUUM PUMPING SYSTEMS

Other major components are: a 2-stage mechanical pump and an ionization gauge control with 2-station thermocouple gauge control. One cold cathode ionization gauge tube and 2 thermocouple gauge tubes are included.

A water-cooled, stainless steel elbow and all manifolding, vacuum lines, and water-cooling circuits required to connect the module to the furnace are also included.

Pumping systems with 2.5” (63 mm) 4” (100 mm) and 6” (160 mm) diffusion pumps are available for use in high outgassing applications. Standard system options are air-operated valves and automatic valve control.

Additional vacuum pumping systems are available upon request (mechanical purge pumping systems, turbo and cryo).

GAS CONTROL SYSTEMS

Inert gas controls, burnoff systems for combustible gases, and the Model GSS-99 hydrogen gas safety system are available for controlled atmosphere operation.

HEARTH ELEVATOR

A hearth elevator is available to facilitate bottom furnace loading. An elevator attached to the furnace permits smooth raising and lowering of the furnace bottom door and work support hearth.

QUENCH AND COOLING CHAMBERS

Liquid quench and gas-cooling chambers are optionally available for use with all Group 1100 models.

SPECIAL MODIFICATIONS

Additional radial view ports including dual opposed windows for optical extensometer work and long, slot-shaped, through-view access.

Stainless steel and nickel-plated copper vessel construction for corrosive gas use including hydrogen fluoride and chlorine.

High pressure construction to ASME standards for pressure vessels.

Special models are available with hot zone lengths to 36 inches (914 mm).