CBSeries

Heavy Duty 1850°F (1010°C) Electric Or Gas Fired Carburizing Box Furnaces


Type Medium Box
Power Source Electric
Loading Front
Uniformity AMS Class 3 (± 15ºF / 8ºC)
Atmosphere Special
Lining Brick w/ Fiber Roof

Applications

Description

The CB Series box furnaces are specifically designed for carburizing, neutral hardening and, optionally, carbonitriding. They are front loading box furnaces with vertical doors, very tight atmosphere seals, and complete atmosphere flow control systems. They have a normal maximum temperature of 1850ºF (1010ºC.)

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.
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LOCKED BY MODEL
Model
#
Working Dimensions
W
H
D
Outside Dimensions
W
H
D
Std Power
(kW)
Max Load
(Lbs)
Ship Weight
(Lbs)
CB222
24
24
24
60
108
66
51 400 5500
CB223
24
24
36
60
108
78
63 600 6000
CB224
24
24
48
60
108
90
74 800 6800
CB324
36
24
48
72
108
90
89 1200 7500
CB326
36
24
72
72
108
114
115 1800 9000

Additional Features

ELECTRIC VERTICAL DOOR WITH PNEUMATIC DOOR CLAMPS AND DOUBLE GASKETING
The door is counterbalanced and driven up and down by an electric gear motor with a torque limit safety. When the door is in the full down position, four pneumatic clamps automatically pull the door closed tightly against the two gasketed seals and into the heat interlock. This allows for an extremely tight interlocking door seal with double gasketing that won’t wear too rapidly. Because the presence of air leaks would decarburize and provide unpredictable results, this super tight door seal is critical.
VARIOUS HEARTHS AND LOADING SYSTEMS
The standard hearth is a series of piers for forklift or hydraulic loader loading. Cast or serpentine trays are common, as are loading baskets. Roller hearths are available on smaller models.
PROGRAM CONTROL SYSTEM WITH PLC LOGIC CONTROL AND SCR POWER CONTROL
The standard control is a Honeywell HC900 Hybrid Control with setpoint programming and all logic control integrated into a single instrument. A CS10 HMI is included for operator interface. The power control is a zero fired SCR. All fuses, transformers, contactors, and controls are located in a NEMA 12 floor standing panel with a fused disconnect switch. Thermocouples are heavy wall inconel sheathed Type K. The control voltage is 120 volts. A Honeywell UDC 1200 digital high limit back up control with manual reset is included with back up contactors and separate thermocouple. Includes door power cut off switch. Single point power connection. Meets National Electrical Code.
TESTING AND INSTRUCTIONS
The furnace is completely tested in our factory. A complete instruction manual includes easy start up instructions, theory of operation, maintenance instructions, parts list, and detailed trouble shooting guide. A ladder logic diagram, panel layout, general dimension and assembly drawings are prepared on CAD foir easy readability.
START UP SERVICE
An L&L factory technician will review and check out customer’s installation, start up and burn in furnace, and train the operators. Typically this takes one week.
WARRANTY
The furnace is warranted for one year except for elements and thermocouples which are warranted for six months. See warranty sheet Q12W.
FLAME CURTAIN
This helps prevent air inrush when door opens. Also ignites flammable gas when the door opens.
SAMPLE PORT
Combination atmosphere sample port and uniformity survey port includes a stainless steel shut off valve.
WATER COOLED ATMOSPHERE TIGHT FAN SYSTEM
A water cooled, atmosphere tight plug fan provides good temperature uniformity of +/-15 F (+/-8C) within the working dimensions and uniform atmosphere distribution. This insures consistent metallurgical results.
TWO TYPES OF ATMOSPHERE SYSTEMS AVAILABLE
Two types of atmosphere systems are offered, the NM Nitrogen/Methanol and the EN Endothermic Gas atmosphere control system. Both feature the addition of natural gas or propane as the carburizing agent in a carrier gas of approximately 40% nitrogen, 40% hydrogen and 20% carbon monoxide. Ammonia can be added for carbonitriding. See NM and EN Bulletins for details. The atmosphere systems are designed to NFPA 86 guidelines. L&L will submit certified drawings to customer’s insurance carrier such as FM or IRI.
AUTOMATIC CARBON CONTROL WITH BOOST/DIFFUSE PROGRAM
The carbon level is controlled by a carbon control with oxygen probe for automatic carbon control. Desired carbon level is set in percent of carbon desired. The standard carbon controller is a Honeywell UDC 3200. The standard oxygen probe is a Furnace Control Corp. AQ604-K-1 oxygen probe. This probe has a 12 month non prorated warranty which means that nothing is deducted for use if something goes wrong within 12 months. The boost/diffuse cycle is accomplished by changing a digital input on the carbon control automatically using an event switch on the program control. Details on EN and NM Bulletins.
EFFICIENT MULTILAYERED INSULATION
The standard insulation is 4-1/2” of 2300F (1260C) low iron firebrick backed up with 4” of mineral wool. The roof is made of 2300F Pyroblock ceramic fiber modules. All fiber insulation is an option. No asbestos is used.
ROD OVER/BEND HEATING ELEMENTS OR RADIANT TUBE GAS BURNERS
Heavy duty Kanthal APM (advanced powder metallurgy and ddispersion strengthened alloy) rod/overbend elements are standard. This alloy is highly resistant to carburizing. Elements are typically located on the sides, back and door for good uniformity. Gas fired radiant tubes with ignitors are also available.

Additional Options

AGITATED AND HEATED QUENCH TANKS
AGITATED HEATED QUENCH TANKS
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.
MISCELLANEOUS OPTIONS
MISC OPTIONS
VIEWPORTS
The cast iron peephole assembly includes a viewing glass. This is made by Tate-Jones. Other types are also available.

Downloads

Brochure For CB