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 Ħ°DĦħ 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 Ħ°OĦħ RING WATER COOLED SEAL IS EXTREMELY
Retort door is a deep plug door (typically 12Ħħ 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 Ħ°OĦħ 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.
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 2000 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 2000 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.
- MOST OF THE XLE OPTIONS: See Bulletin XLE
and Options Bulletins. Fans are not available.
- CONTROL, RECORDER AND ELECTRICAL OPTIONS
- START UP SERVICE: A factory technician will start up furnace in
your factory, leak test the entire atmosphere system, make all adjustments on site and
train operator. This is required for hydrogen systems.
- REMOVABLE RETORT SYSTEM: Removable retorts allow faster cool
down under atmosphere. However, retort life is reduced because of heat shock. This option
is available only on the smaller retorts. Includes integrated cart and track.
- SHELVES: These can be built into the retort or can be a separate
structure that inserts into the retort.
- POWERED VENTURI VENT: A 300 or 600 CFH motor powered venturi
will shorten the cool down rate of the furnace, especially in the lower temperature
ranges. The venturi pulls cool air around the outside of the retort without disturbing the
SEE ALSO BELL RETORT FURNACES: JSC