FBSeries

Ceramic Fiber Lined Large Box Furnaces Temperatures To 2200°F (1200°C)


Type Large Box
Power Source Electric
Loading Front
Uniformity AMS Class 4 (± 20ºF / 10ºC)
Atmosphere Air
Lining Ceramic Fiber

Applications

Description

The FB Series Electric Box Furnaces are a general purpose ceramic fiber lined electric box furnace. They achieve high precision by featuring highly accurate controls, solid state contactors for fast cycle times, two zone control (top and bottom), and even spacing of elements. They reach temperatures up to 2200°F with iron-aluminum-chrome elements, and up to 2000°F with the standard nickel-chrome elements. Insulation is all ceramic fiber except for hearth and hearth support.


Processes


Markets

Standard Model Sizes

Our most popular model sizes are listed below. Discuss a custom solution that fits your exact needs by contacting our sales team today.
> > > > > Swipe right-to-left for more
LOCKED BY MODEL
Model
#
Working Dimensions
W
H
D
Outside Dimensions
W
H
D
Std Power
(kW)
Max Load
(Lbs)
Ship Weight
(Lbs)
FB333
36
36
36
84
88
69
64 675 4200
FB334
36
36
48
84
88
81
76 900 4900
FB336
36
36
72
84
88
105
100 1350 6300
FB444
48
48
48
96
100
81
91 1200 5900
FB446
48
48
72
104
92
102
136 1800 7300
FB555
60
60
60
116
104
90
157 1875 7700
FB666
72
72
72
128
116
102
219 2700 10000
FB888
96
96
96
152
140
126
375 4800 15800

Additional Options

AGITATED AND HEATED QUENCH TANKS
AGITATED HEATED QUENCH TANKS
CAST ALLOY HEARTH TRAY
Cast alloy grids. Grade depends on temperature, quench severity and loading service factors.
CAST ALLOY ROLLER RAIL HEARTH
Cast alloy roller hearths and cast trays with roller wheels mounted in bottom rails are commonly used for loading of heavy loads. External roller assemblies, either fixed or movable on casters, which match the roller trays are also made.
CONTROL, RECORDER AND ELECTRICAL OPTIONS
CONTROL, RECORDER AND ELECTRICAL OPTIONS
COUNTERBALANCED VERTICAL DOORS
Manual hand crank, pneumatic or electric operation. For dual chamber furnaces available only for the top chamber.
FAN WATER COOLING SYSTEM
This is used typically when a water cooled fan or fans are employed. A manual ball valve shut off, flowmeter and regulating valve, and low flow switch are included plus hook ups for the inlet and outlet. The adjustable low flow switch alarm turns off element power and sounds an audible alarm.
HEAT SHIELD
A perforated heat shield is attached to the outside of the furnace back, sides and door. This maintains a low external case temperature below 120F (50C).
HIGH TEMPERATURE FANS
Fans are the best way to increase the gradient uniformity inside the furnace. The maximum continuous temperature of the standard L&L fan system is 1875F. This system will normally provide a gradient uniformity within the furnace chamber of +/-15F or better with appropriate loading of the furnace. A machined aluminum heat dissipator removes heat from the shaft before the heat reaches the bearings. Two self centering pillow block bearings hold the shaft and a belt drives it from the motor. An OSHA shield is provided. The fan automatically turns off when the door is opened. Some fans have 6 pitched blades and blow down. The blade section is cast and then welded to a machined alloy shaft. Others have either 4 or 6 flat blades and pull the air up, discharging it to the sides. See quote for specifics.
HORIZONTAL DOOR
The door is a double pivoted horizontal door with thrust bearings for ease of operation. The double pivoting allows the hot face to be kept from the operator. There are four large manual turndown clamps for tight sealing. There are two overlapping gaskets for gas tightness. This door is typically used only because of overhead space limitations.
INERT GAS PANEL
The furnace case is tightly sealed for use with a protective inert atmosphere. Argon, nitrogen and gases enriched with up to 4% combustible gas (such as hydrogen or propane) can be used. No safety systems are required. A threaded alloy fitting introduces the gas into the furnace chamber. The element connection chamber is typically purged. The door seal is augmented with a woven ceramic fiber gasket. A properly sized flowmeter/regulator is included with the atmosphere system. A rule of thumb on atmosphere usage is to figure six to ten times the furnace volume times the number of hours the work will be in the furnace.
JIC CONTROL OPTION
This includes a NEMA 12 control cabinet, all oil tight switches and a panel mounted fused disconnect switch. Zone switches if included are percentage timers.
LOADER
A heavy duty loader will pick up the hearth tray by pivoting slightly in the back by means of a hydraulic cylinder actuated by a hand pump located on the loader. The loader can have two swivel wheels and two fixed wheels. Optionally, the wheel can be mounted on either inverted "V" tracks or railroad tracks embedded in the floor. All distances are engineered for precise and trouble free operation. The loader is typically designed to pick up the maximum rated load of the furnace. The loaders can be fitted with motorized drives.
MANUAL INLET WITH DAMPER
Various kinds of sliding manual dampers are offered, each sized and located according to specific requirements.
MANUAL OUTLET WITH DAMPER
A sliding stainless steel damper with a heat resistant handle allow a 4” vent hole to open and closed.
MOTOR DRIVEN VENTURI SYSTEM
A motor driven venturi vent system is available. This system exhausts air out of the furnace and pulls in fresh air. Air inlets are located per customer specifications. (NOTE: venturis work by blowing air past a tube that is inserted into the furnace. This creates a vacuum without blowing cold air into the furnace. It has the advantage of having a controlled exhaust and minimizing heat shock in the furnace.) A 1 H.P. motor, complete with motor starter, drives the system. Capacity is 300, 600 or 1250 CFM, depending on the size of unit ordered. A stack should be installed to exhaust the hot air. Normally, a hand operated stainless steel damper is provided with the venturi system to control the amount of air being exhausted from the furnace.
PROGRAMMABLE MOTORIZED VENTURI
The venturi motor is controlled with a magnetic motor starter and push-button, with a relay programmed by the programmable temperature controller for turning the motor on and off in order to follow a programmed cooling curve. A separate pneumatically controlled inlet damper is normally also added. The inlet and out dampers then open or close with the programmed switch.
RECIRCULATION MUFFLE
This system will insure a gradient uniformity within the furnace chamber of up to +/-5F. It is used in conjunction with a furnace fan. A reinforced, welded stainless steel recirculation muffle rests inside the furnace chamber. (This can be lifted out without damaging the refractory.) The muffle typically includes baffles along the sides. On recirculation muffles with top mounted fans the bottom is typically constructed of heavy reinforced perforated or expanded alloy which becomes the hearth of the furnace. These baffles direct the moving air around the elements and through the work space to the fan. They also shield the work from radiant hot spots. Where the fan is mounted horizontally in the back, the bottom is solid and the air is recirculated around through the open front. On top loading furnaces, the fan is normally mounted on the bottom and the air is pulled through the open top. A stainless steel 304 recirculation muffle can be used to 1400F while the 330 alloy muffles can be used to 1875F.
SEALED CASE FOR INERT ATMOSPHERE
Case is sealed and inert atmosphere is introduced into the furnace chamber and through the element connection area. A flowmeter/regulatoror inert gas flow panel is provided.
SINGLE ZONE SCR POWER CONTROLLER
A zero fired SCR power control with two-leg control is used instead of contactors. This is constructed with transient voltage protection, sub-cycle fuse protection, extra large heat sinks, and positive zero firing. Gain and bias adjustments are included for tuning.
TWO TO EIGHT ZONE SCR POWER CONTROL WITH MANUAL BIASING
Digital biasing control is included to adjust relative output of SCRs to adjust temperature uniformity. There are up to 8 separate Zero Fired SCR power controls, one for each zone of heating. This allows you to fine tune the furnace for different temperature points. The SCRs are microprocessor based. The biasing switches have 99 increments.
TWO ZONE SCR POWER CONTROL WITH MANUAL BIASING
Digital biasing control is included to adjust relative output of SCRs to adjust temperature uniformity. There are 2 separate Zero Fired SCR power controls, one for each zone of heating. This allows you to fine tune the furnace for different temperature points. The SCRs are microprocessor based. The biasing switches have 99 increments.
VIEWPORTS
The cast iron peephole assembly includes a viewing glass. This is made by Tate-Jones. Other types are also available.
WATER COOLED FAN FOR 2000F OR 2200F
Various water cooled fans made by Industrial Gas Engineering are available. These generally include a vertically mounted fan cartridge assembly for operation up to 2200F. The fan shaft and blade is statically and dynamically balanced. Typically these fans use about one gallon of water per minute for cooling.

Downloads

Brochure For FB
Capabilities Brochure