FURNACE IS BASED ON XLE SERIES
The heating system is a modified XLE Series electric furnace. See
XLE Bulletin for more information.
ALLOY RETORT FOR LOW DEW POINT
The XLC features an alloy retort to contain the atmosphere. This prevents oxygen infiltration, providing a very low dew point for cleaner processing and safer operation. Depending on the size and temperature, retorts are “D” shaped and/or corrugated for extra strength. The alloy normally used is 330 alloy, Inconel 600, or Inconel 601 but may be other alloys engineered for specific applications.
PLUG RETORT DOOR WITH “O” RING WATER COOLED SEAL IS EXTREMELY TIGHT
Retort door is a deep plug door (typically 12” deep). The plug is insulated with ceramic fiber inside the alloy plug. The door plug is made of the same alloy as the retort and is completely surrounded with the alloy rather than exposing the refractory to the atmosphere as in some competitive designs. This insures that no oxygen gets trapped in the insulation and later reenters the chamber at high temperatures. There is a silicone rubber “O” ring seal around the perimeter of the machined flange of the re tort. This is cooled by water which runs in an enclosed channel. A complete water cooling system with flow switch interrupts power to the furnace if there is no water flow. The door is closed with quick release turn down latches. This forms an extremely tight seal and allows very low dew point operation. These seals will withstand high pressures. Most doors (except the smallest ones) feature a cart that holds the retort door. On smaller doors handles on the door plug are included.
ATMOSPHERE SAMPLE PORT
A sample port is provided. There is a valve to close this off when not in use. This is used to sample the atmosphere for oxygen, hydrogen, dew point, etc.
ATMOSPHERE CONTROL
A variety of atmosphere control systems can be provided. See
Bulletin H2 which describes the hydrogen flow control system or
Bulletin MPH for information on a mixing panel for forming gas. In addition, simple regulators / flowmeters can be provided for inert gas use. Back pressure control, pressure relief and gauge are included.
DIGITAL PID CONTROL SYSTEM
The standard control is a Honeywell UDC 2300 digital PID 3 mode tuning control. All fuses, transformers, contactors, and controls are housed in a NEMA 1 panel. If hydrogen is used then a purged NEMA 12 control panel is standard. Quiet, long life mercury power contactors are standard, but the SCR power control option is recommended. The thermocouple is Type K. Thermocouple break protection is included. Limit switches shut off furnace power if the door is opened or the power panel back is removed. Control voltage is transformed to 120 volts. A NEMA 13 lighted On/Off switch is included. The control circuit and each power branch circuit are fully fused. Honeywell UDC 2300 digital high limit back up control with manual reset, back up contactors and separate thermocouple included. The thermocouple for the high limit control is located between the retort and elements. NEMA 1 panels must be connected to a fused power supply. NEMA 12 panels have a fused disconnect switch.
WARRANTY
The furnace is warranted for one year except for elements, retort and thermocouples (warranted for 6 months.)
