High Temperature Walk-In Ovens

For annealing, sintering, precipitation hardening, burn-off or any other high temperature processing of large or numerous parts.

Constructed with an isolated inner oven to eliminate heat transfer and leakage at seams commonly found in standard panel construction. Designed and constructed for long, hard, continuous use with the temperature uniformity required for consistent results at elevated temperatures.

* Outside Dimensions

• Control panel overhang 9″ right side
• Blower motor overhang on rear
• 19″ on 3 and 5 HP motors
• 26″ on 7-1/2 and 10 HP motors, 28″ on 15 HP
• Gas Models: Burner overhang 15″ right side

 Operating Characteristics

• Accuracy as percent of controller span.
• Uniformity at 100°F below maximum temperature.
• Rise Time in minutes to 100°F below maximum temperature.
• Tests run with empty oven and minimum exhaust.
• Performance will vary with load and application.

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)
• OSHA
• Caution:
• When processing combustible material fire protection should be considered
• Processing flammable solvents or vapors requires forced exhaust to provide safety ventilation. 

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. Inlet 1” NPT (1-¼ “ NPT above 350,000 BTU/hr input)
• 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
• 325 CFM (650 CFM at 800,000 BUT/hr input) 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
• Heat chamber temperature controller on 1250⁰F models to limit heating element temperature
• Motor control push buttons and on-off heat switch
• LED pilot lights
• 5 kA short circuit current rating (SCCR)

Construction

Choice of

• Recirculating air flow patterns – Combination or Horizontal air flow
• Electric or Gas heat
• 208 volt, 230 volt or 460 volt, 3-phase, 60 HZ – other input power available
• All welded construction
• Durable, electrically isolated, Incoloy tubular heating elements
• Heat source located in heat chamber to prevent radiant heating
• High pressure stainless steel recirculating blower
• Full coverage supply and return duct work with adjustable opposed louvers
• Adjustable fresh air intake and 6” diameter exhaust outlet damper
• Isolated inner oven surrounded by 10 lbs per cubic foot density rockwool insulation to eliminate heat transfer due to through metal and hot air leakage at panel seams
• 2” of refractory ceramic fiber covers heat chamber walls on 1050°F models; covers all inner oven walls on 1200°F models
• 16 gauge aluminized steel interior with steel structural members at 900°F, 16 gauge stainless steel heat chamber on 1050°F models, entire 16 gauge stainless steel interior on 1200°F models
• Insulated floor covered with steel plate (stainless steel on 1200°F models) – 4” thick on 900°F model, 6” thick on 1050°F and 7”thick on 1200°F models
• Exclusive construction is far superior to commonly used panel construction
• Aluminized steel exterior with Trilite Green enamel finish
• Brushed stainless steel control panel face
• Exceptionally heavy duty doors, hinges and door frame with explosion venting latches
• Dual fiberglass door gasket with stainless steel spring insert; one gasket seals to inside door surface and second seals to outer oven face
• Expansion joints on inner door surfaces to guarantee uniform sealing at all temperatures
• Slip flashing at doorway to allow inner oven to expand without affecting door sealing
• 3/8” thick steel front plate around doors to provide rigid sealing surface
• Fully assembled and factory tested for temperature uniformity

READ ON OUR BLOG:

Standard & custom-made Grieve ovens in action