Electric Cabinet Oven for Controlled Batch Curing of Serpentine Product

The project required a shelf-loaded batch oven for controlled curing of serpentine product in a technical operations environment. The customer needed a repeatable batch process that fit within a compact cabinet format while still allowing flexible product placement and multiple shelf elevations.

APPLICATION REQUIREMENT

• The project required controlled batch curing of serpentine product.
• The oven supported a technical operating environment handling government- and engineering-related program work.
• The process required repeatable thermal performance for batch-loaded product rather than continuous conveyorized flow.

WORK CHAMBER / LOADING REQUIREMENT

• Required internal work chamber: 55 in W × 30 in D × 60 in H.
• The customer required a chamber large enough for multi-shelf batch loading.
• The loading package included two 100 lb shelves and three 250 lb shelves.
• Total oven load basis was 750 lb maximum capacity.
• Product and fixture placement had to support open airflow passage through the work chamber.

OPERATOR / ACCESS REQUIREMENT

• The oven had to allow front loading and unloading through two swing doors.
• The loading arrangement had to support flexible shelf placement with 3-inch minimum shelf spacing, center to center.
• The installed layout had to allow clearance for door swing and control enclosure access.

QUALITY REQUIREMENT

• The process required repeatable batch-to-batch curing performance.
• The customer required controlled temperature operation within the stated work-zone uniformity.
• The curing process needed a batch timer and temperature-control system suited for repeatable cycle execution.

SITE / UTILITY REQUIREMENT

• Required electrical service: 230V / 3PH / 60Hz.
• Design elevation basis: less than 1,000 ft.
• Shipping and receiving access basis: 12 ft W × 16 ft H dock doors.

The project required a moderate-temperature batch curing process based on electric heat, full horizontal forced convection, and controlled cooldown protection.

TEMPERATURE REQUIREMENT

• Operating temperature basis: 400°F.
• Maximum temperature capability: 550°F.
• Required work-zone uniformity: ±10°F.

AIRFLOW / HEAT-TRANSFER REQUIREMENT

• Airflow direction basis: full horizontal airflow.
• The curing process required consistent horizontal forced-convection airflow across the shelf-loaded work chamber.
• The airflow pattern had to support even heat delivery across multiple shelf elevations within the chamber.

HEAT-INPUT REQUIREMENT

• Heat source: electric resistance heat.
• Installed heat basis: 24 kW total.
• Heating was divided into two 12 kW heater banks.
• The heat system had to provide controlled temperature rise and stable setpoint holding for the curing cycle.

VENTILATION / CHAMBER REQUIREMENT

• The process used a non-powered exhaust arrangement with a fresh-air inlet integrated into the oven body.
• The curing application was defined on a Class B, no-VOC load basis.

CONTROL / CYCLE REQUIREMENT

• The process required a work-area temperature controller, excess-temperature protection, and a heat cycle timer.
• The batch cycle had to turn heat off at the end of the timed cycle while preserving controlled cooldown behavior.

COOLDOWN REQUIREMENT

• The recirculation fan had to remain in operation during cooldown until oven temperature fell below 250°F.
• The control system included fan-shutdown logic tied to the oven temperature falling below that threshold.

To satisfy those requirements, Precision Quincy configured the project as a 40D-550 electric Class B cabinet oven with horizontal airflow, multi-shelf loading, side-mounted controls, and interlocked electric heat.

OVERALL CONCEPT

• One electric cabinet batch oven.
• Class B curing configuration.
• Front-loading, shelf-loaded chamber sized for flexible batch placement.

HEATING ARCHITECTURE

• Heat source: electric resistance heat.
• Total installed heat: 24 kW.
• Heating split into two 12 kW heater banks.
• Each heater bank used twelve 1000 W elements at 230V.
• Heater power was controlled through solid-state relays with backup contactors.

AIRFLOW ARCHITECTURE

• Airflow pattern: full horizontal airflow.
• Recirculation system used a Jan-Air 9.94 × 6 FC fan assembly.
• Recirculation performance was 1,500 CFM at 2 in. W.c. With a 1.5 HP motor.
• The oven used a roof-mounted fresh-air inlet and a 6 in × 6 in exhaust opening with non-powered exhaust.

CHAMBER / SHELL ARCHITECTURE

• Internal work chamber: 55 in W × 30 in D × 60 in H.
• Wall system: 4-inch-thick insulated construction.
• Insulation: 4 in of 6 lb mineral wool.
• Interior material: unpainted aluminized steel.
• Exterior finish: PQ Blue (RAL 5005).
• Control panel finish: gray (ANSI 61).
• The oven body included four floor anchors.

DOOR / LOADING ARCHITECTURE

• Two swing doors at the front of the oven.
• Shelf package included two 100 lb shelves and three 250 lb shelves.
• Shelf arrangement used 3-inch minimum spacing, center to center.
• Maximum oven load basis was 750 lb.

CONTROLS ARCHITECTURE

• Primary temperature controller: Super Systems SSI-804.
• Excess-temperature controller: Gefran 650L.
• Thermocouples: Type J work-area thermocouples.
• Control enclosure: NEMA 1 UL508A open industrial control panel.
• Enclosure size: 42 in × 36 in × 12 in.
• Operator controls included recirculation fan start/stop and independent heater-bank switches with status indication.
• The enclosure also included an enclosure cooling fan and internal power distribution, disconnect, motor protection, and relay hardware.

SAFETY ARCHITECTURE

• Applicable standards basis: NFPA 79, NFPA 86, UL508A.
• Safety logic included:
• Recirculation airflow proving
• Excess-temperature shutdown
• Heat shutdown if safe operating conditions were not met
• Controlled fan shutdown below 250°F

INSTALLATION / ACCESS ARCHITECTURE

• Controls were mounted on the side enclosure face.
• Required access included 36-inch door swing clearance and 36-inch control enclosure clearance.
• Shipping and receiving basis used 12 ft W × 16 ft H dock doors.