Tunnel Ovens

Tunnel ovens are designed for use with the customer’s conveyor system. 

Our experienced engineers will collect the features of your conveyor system and develop a tunnel oven to support your conveyor as well as meet your particular heat processing requirements.

Units can be provided in sections for easy installation and mating with existing conveyor system.

Certifications

• UL Listed Control Panel
• Meets the Requirements of the Following Standards:
• NFPA 86 (Standard for Ovens and Furnaces)
• NFPA 70 (National Electric Code)
• FM (Factory Mutual)
• OS

Caution

• Ovens processing combustible materials are required to have a fire suppression system per NFPA 86
• If flammable solvents or vapors are present in an oven, OSHA requires conformance with NFPA 86 Class A Oven requirements.  A powered forced exhauster and other non-standard safety equipment must be added. 

Safety Equipment

* Adjustable manual reset excess temperature interlock to turn off heat on malfunction of main temperature controller

* Recirculating blower air flow safety switch to turn off heat on loss of recirculated air flow

* Electrical interlock shuts off heat if power to recirculating blower is interrupted

Electric Heat Includes

• Separate heating element control contactors to turn off heat on malfunction of main control contactors

Gas heat includes

• Modulating burner for 1000 BTU per cubic foot natural gas at 6” water column pressure – propane available.
• Automatic pre-ignition purge period to clear accumulated gas or fumes
• Push button electric ignition
• Microprocessor based electronic flame safeguard protection to continuously monitor flame and close gas valves if flame is not present
• Powered forced exhauster to provide combustion venting
• Exhauster air flow safety switch to close gas valves on loss of venting
• Two pilot valves to guarantee gas flow to pilot can be stopped
• High and Low gas pressure switches to confirm safe operating pressure range
• Two main burner safety shut off valves with valve seat position indicator to assure gas flow to main burner can be stopped
• Proof of closure switch on one main valve to prevent igniting pilot unless main valve is closed
• Leak test station at each pilot and main burner valve to allow testing for leakage through valve

Controls

• Digital temperature controller
• Motor control push buttons and on-off heat switch
• LED pilot lights
• 5 kA short circuit current rating (SCCR)

Construction

Available construction features:

Oven design can include:

• multiple heat zones
• vertical or horizontal recirculated air flow
• cooling zone to reduce part temperature before handling
• unheated vestibules to reduce heat loss from ends of oven
• support points for existing conveyor system
• slide beds for conveyor belts
• tracks for monorail conveyors
• vertical lift doors tied to indexing
• Conveyor support can be designed to accommodate all conveyor types including:
• flat wire belts
• woven wire belts
• cross bar
• multi-strand roller chain
• monorails
• power or free roller conveyor

Choice of

* Maximum operating temperatures up to 1200°F

* Vertical or horizontal recirculated air flow

* Aluminized steel or stainless steel interior

Electric or Gas heat

• 208 volt, 230 volt or 460 volt, 3-phase, 60 HZ – other input power available

Design can include:

• Multiple heat zones
• Extended loading and unloading zones to accumulate parts
• Wire, cross bar, roller chain, and other belt options available
• Special belt construction or attachments
• Support points for existing conveyor system
• Slide beds for conveyor belts
• Tracks for monorail conveyors
• Cooling zone to reduce part temperature before handling
• Unheated vestibules to reduce heat loss from ends of oven
• Vertical lift doors tied to indexing
• All welded construction
• Structural steel base provides rigid assembly easily moved into position
• Conveyor supports held by cross angles welded to vertical wall members to transfer belt load to factory floor
• Heavy duty reducer, torque limiting device and variable frequency conveyor drive
• Durable, electrically isolated, Incoloy tubular heating elements
• Heat source located in heat chamber to prevent radiant heating
• High pressure recirculating blower
• Full coverage supply and return duct work with adjustable opposed louvers
• Adjustable fresh air intake and exhaust outlet damper
• Insulated with 10 lbs per cubic foot density rockwool insulation
• Aluminized steel exterior with Trilite Green enamel finish
• Includes 2” refractory ceramic fiber insulation on 16 gauge aluminized steel interior walls, 16 gauge 304 stainless steel heat chamber walls and stainless steel recirculating blower
• Brushed stainless steel control panel face
• Heavy duty access doors along oven length with explosion venting latches
• Adjustable dampers at ends of heat zone positioned near load to reduce heat loss
• Slip flashing at doorways allow inner oven to expand without affecting door sealing
• Fiberglass door gasket with stainless steel spring insert
• Fully assembled and factory tested for temperature uniformity