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ELECTRIC OR GAS OPERATION
The oven section can be gas fired or electrically heated. Electric units feature incoloy heating elements. Gas fired units feature packaged burners with complete IRI or FM gas trains with all necessary safety devices.
INSULATION
Typical insulation is 6” of mineral wool board encased between the case and a stainless steel liner. Thickness can vary with the application. No asbestos is used.
CASE CONSTRUCTION
A reinforced 3/16” outer case is normally employed. This is designed to allow maintenance access to the interior of the furnace. The base is heavy duty. Unit is primed with 800F silicone paint and finished in machine enamel.
TEMPERATURE LIMITATIONS
The temperature limit is a function of design. The oven pictured in this brochure was designed for 500F (260C). Temperatures up to 1400F (760C).
SIZE RANGES
The oven pictured is designed for a basket size of 24” by 24” by 24”. Each basket is designed to hold 500 pounds. It has 11 stations. This is a good medium range. Larger or smaller sizes are possible.
FANS PROVIDE UNIFORMITY UP TO +/-10F
Uniformity is mainly dependent on fan circulation. Typically 40 volume changes per minute of air circulation are employed through a recirculation baffle. The pictured oven features a plug type fan for easy removal and replacement.
MULTIPLE OR SINGLE HEAT ZONES
CP ovens may feature more than one heating zone. This allows control of the process temperature profile. Also, it allows more heat to be input to the cold work as it enters the oven. The length of each heating zone needs to be worked out with the customer based on known time/temperature ratios. The oven pictured has one heating zone with three stations of heating (all at the same temperature.)
AUTOMATIC PUSHER SYSTEM MOVES LOAD BASKETS INDEPENDENTLY
The pusher device featured on the pictured oven is a reversing jack screw. This moves a car back and forth on a track. On the car are one set of “dogs” for each basket. Each basket is pushed independently of each other so that the system could be used to heat treat as few as one basket if necessary. This is important for JIT manufacturing. In addition to the forward and reverse limit switches, there are also fail safe overtravel limit switches in case of misadjustment or limit switch failure.
COOL DOWN SECTIONS
The oven pictured features two independent cool down sections. The first cool down section blows air over the load. The second section features a recirculating water/oil coolant which sprays the load baskets from the sides and top. This cooling water/oil mixture is sent through a heat exchanger and recirculated through the system. Two filters with bypass valves, pressure gauges, pressure regulator, shut off valves, and all necessary solenoids are included. When the doors open, the spray stops and bypasses the pump flow directly to the tank reservoir. A sonar type tank level detector determines when to automatically fill the reservoir and when to shut down the pump in case of low level. A temperature control determines when to cool the heat exchanger. On this oven there are three water/oil cooling stations and one air cool station. Parts come out of the oven cool enough to handle by hand.
PNEUMATIC DOORS
Pneumatic doors are standard. Limit switches determine both up and down position of each door and act as an interlock for the loader.
AUTOMATIC PLC OPERATION
The CP Series features PLC programmed operation of all or most functions. All timing devices, limit switches, doors and loading devices are controlled by the PLC. Preferred manufacturer of PLC is Allen Bradley.
PID DIGITAL CONTROL SYSTEM
The typical controls used are Honeywell UDC 3000 digital PID 3 mode tuning controls. There is one control per heating zone. All fuses, transformers, contactors, and controls are located in a floor mounted NEMA 12 panel with a fused disconnect switch. SCRs are used for power control on electric ovens. Proportional controls are used on gas fired ovens. Thermocouples are normally Type K. There is normally one overtemperature control per zone. Single point power connection. Meets National Electrical Code.
TESTING , INSTRUCTIONS AND START UP SERVICE
The oven is completely tested in the factory and run off prior to shipment. A complete instruction manual includes easy start up instructions, theory of operation, maintenance instructions, parts list, and a detailed trouble shooting guide. A ladder logic diagram, panel layout, pneumatic and process schematics, general dimension drawings, and general assembly and sub assembly drawings are provided. L&L will provide start up service and can also provide reassembly service.
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