Electric Immersion Holding
and Melting/Holding Furnaces
Shell Construction
Carbon steel plate welded 100% inside and outside. The shell will be ruggedly
reinforced with vertical and horizontal
structural members located to give optimal strength. The furnace is supported
on I-beams welded to the shell floor plate.
Refractory Lining
Walls: The furnace side walls are lined with 6" of
high strength 2800ºF insulating castable, backed with
3" of insulating
block. The walls are securely anchored to the steel shell with alloy anchors.
Floor: The furnace floor is cast 9" thick with 2800ºF
insulating castable.
Heating Elements
The heating element assemblies are a specially designed, tubular-type. The
elements are mounted in a ceramic block
that floats on the surface of the bath. The element wiring is terminated in
a box with terminal blocks. High temperature pigtails run in steel flex tubing
and terminated in either a Twist Lock or Pin and Sleeve plug (depending on
KW) is supplied. A corresponding receptacle is provided in the furnace mounted
terminal box. This arrangement provides for quick disconnect for customer convenience.
Control Panel
The furnace controls are housed in a NEMA 12 enclosure. Components supplied
are: a control transformer, fused disconnect, SCR controller, power-on-and-off
indicating lights, low temperature audible alarm circuit, high temperature
shutdown circuit, alarm silence pushbutton, ammeter, current transformer,
control relays and fuses. All components were selected for simplicity and
reliability.
Automatic Restart
The furnace is equipped with a Honeywell DC 230 series controller with dual
operating parameters to allow for automatic restart after a prolonged power
outage. The controller would restart the furnace at 20% output and begin
a slow ramp-up to avoid super heating the zinc and burning out the elements.
Once the zinc is molten the controller will automatically switch back to
the original operating parameters for normal operation. No operator intervention
is required.
Automatic Temperature Controller
Mounted in the control cabinet is a Honeywell DC 230 series microprocessor
based temperature controller featuring digital set point, L.E.D. readout,
L.E.D. deviation indicator, and up-scale burnout protection. Supplied with
this unit is a type K thermocouple, supported in a stainless steel protection
tube and 50 feet of chromel alumel thermocouple lead wire.
High-Limit Temperature Control
Mounted in the control cabinet is a Honeywell DC 230 series microprocessor
based high-limit controller featuring manual reset digital set point, L.E.D.
readout, and up-scale burnout protection. Supplied with this unit is a type
K thermocouple, supported in a stainless steel protection tube and 50 feet
of chromel alumel thermocouple lead wire.
Splash Shield and Stainless Steel Weir
(For Melter/Holder Furnace)
Lindberg/MPH will provide a ¼" carbon steel splash plate and ¼" stainless
steel weir to protect the heating element unit
during charging of the furnace.
Tapout
The furnace is equipped with a drain tapout to allow the furnace to be completely
emptied. The tapout has a cast iron plug with a sealing cover held in place
by a steel clamp.
Cover
A lightweight manually removable cover is furnished to reduce surface losses
from the bath.
Paint
The furnace exterior is finished and painted with vista green, safety blue
or aluminum high temperature paint in a
workmanlike manner. If other color or type of paint is specified, it may be
necessary to have it (including primer and MSDS Specs.) furnished by the customer
at their expense.
Instruction Manuals
Two instruction manuals are furnished, complete with starting instructions,
maintenance instructions, equipment bulletins, combustion drawings and wiring
diagrams.
Assembly
The furnace is completely assembled in our plant. The electrical components
are tested prior to shipment. The element
assembly covers, and control panel are boxed separately to avoid damage in
transit.
Furnished By Customer
- Dry out of furnace and dry out equipment as per our instructions.
- Start up of furnace.
- Labor and material to wire from your power source to and
between the panel and furnace terminal box.
- Hooding as required.
- Leveling and shimming of the furnace.
- Re-assembly of component parts removed for shipment.
- Provide protected electrical service to the control panel
disconnect.
|
