Electric Heated Cabinet Ovens for Paint Sample Curing and Test Processing

The equipment was developed for a coatings application requiring the batch curing of solvent-based liquid paint samples in a compact cabinet oven platform. The summary below focuses on the delivered equipment architecture and performance basis.

APPLICATION REQUIREMENT

• The equipment was used for curing solvent-based liquid paint samples.
• Two identical ovens were required to support repeatable testing or parallel batch processing with matched process conditions.

WORK CHAMBER / LOAD REQUIREMENT

• Required work chamber: 20 in W × 20 in D × 20 in H.
• Each oven included a 12 in diameter mild-steel rotating table suspended from the top of the work area, rated for 20 lb evenly distributed capacity at 5 RPM rotation.
• Each oven also shipped with four shelves rated at 100 lb evenly distributed capacity each for alternate loading arrangements.

PROCESS REQUIREMENT

• The process required elevated-temperature curing of paint samples with the rotating stand turning samples continuously during the curing cycle.
• Because the product was solvent-based, the oven had to support safe processing of volatile-bearing loads.
• The thermal architecture had to support matching process conditions across both ovens.

SAFETY REQUIREMENT

• The ovens were configured as NFPA 86 Class A units.
• The documented maximum VOC load basis was 0.12 gal/batch of o-xylene.
• The process required powered exhaust, purge sequencing, and airflow proving as part of the operating sequence.

UTILITY / SITE REQUIREMENT

• Required electrical service: 460V / 3PH / 60Hz. Full load amperage: 34.4 A.
• Design elevation basis: 1,955 ft.

MATERIAL / CONSTRUCTION REQUIREMENT

• Exterior finish: PQ Blue. Control panel finish: PQ White. Interior finish: unpainted aluminized steel.
• The unit was designed as a compact insulated cabinet oven with 5 in thick walls.

These thermal process requirements were established from the need to cure solvent-based paint samples in a compact cabinet platform with repeatable thermal exposure and safe Class A ventilation.

TEMPERATURE CAPABILITY

• Operating temperature: 850°F.
• Maximum temperature: 850°F.
• Required work-area uniformity: ±10°F.

PROCESS BASIS

• The thermal process basis is curing solvent-based liquid paint samples.
• The process required controlled elevated-temperature exposure while the internal rotating stand continuously turned the product during the curing cycle.
• The thermal architecture also had to support matching process conditions across both identical ovens.

HEAT INPUT REQUIREMENT

• Heat source: electric resistance heat. Heater basis: 1 kW elements. Total installed heat: 24 kW.
• Heat control basis: solid-state relay control for the electric heat bank.

AIRFLOW DELIVERY REQUIREMENTS

• Airflow style: full horizontal airflow.
• Recirculation airflow basis: 720 CFM at 2 in. w.c. Recirculation fan motor: 0.75 HP.

EXHAUST / VENTILATION BASIS

• Exhaust fan: PQ1 exhauster. Exhaust airflow: 225 CFM at 1 in. w.c. Exhaust fan motor: 0.75 HP.
• Powered exhaust and purge sequence included as part of the Class A operating logic.
• Airflow switches used on exhaust and recirculation fans as part of the safety sequence.

THERMAL INSTRUMENTATION / CONTROL BASIS

• Primary controller: WATLOW F4T ramp/soak controller.
• Work-area high limit: Gefran 650L.
• Classification basis: NFPA 86 Class A. Maximum VOC load basis: 0.12 gal/batch of o-xylene.

To deliver the customer and thermal process requirements for this paint-sample curing application, the following equipment concept and architecture was developed.

OVERALL CONCEPT

• Two identical electric-heated X2-8-202020 horizontal-airflow cabinet ovens configured for solvent-based paint-sample curing.
• Designed as Class A full-horizontal-airflow ovens in a compact cabinet platform sized for test and sample work rather than large-scale production loads.

HEATING ARCHITECTURE

• Heat source: electric resistance. Heater bank output: 24 kW total from 1 kW elements.
• Heat control basis: solid-state relay control.

AIRFLOW / RECIRCULATION ARCHITECTURE

• Airflow pattern: full horizontal airflow.
• Recirculation fan: Jan-Air 12.19 × 4.0 RBSS fan wheel — 720 CFM at 2 in. w.c.; 0.75 HP motor.
• Exhaust fan: PQ1 exhauster — 225 CFM at 1 in. w.c.; 0.75 HP motor.

CHAMBER / CONSTRUCTION ARCHITECTURE

• Internal work chamber: 20 in W × 20 in D × 20 in H.
• Wall thickness: 5 in. Insulation: 4 in of 6 lb mineral wool plus 1 in of 8 lb Superwool.
• Interior material: unpainted aluminized steel. Exterior finish: PQ Blue. Control panel finish: PQ White.
• Door style: single swing door.

PRODUCT HANDLING / PROCESS-FIXTURING ARCHITECTURE

• One 12 in diameter mild-steel rotating table per oven, supported from the top of the work area.
• Rotating table rated for 20 lb evenly distributed capacity at 5 RPM. Rotating stand control located on the control-cabinet face.
• Four 100 lb shelves included per oven for alternate loading arrangements.

CONTROLS ARCHITECTURE

• Oven-mounted NEMA 1 control enclosure, 42 in × 30 in × 12 in, listed to UL 508A Open Industrial Control Panel.
• WATLOW F4T ramp/soak controller. Work-area high limit: Gefran 650L.
• Applicable standards basis: NFPA 79, NFPA 86, UL 508A.

SHIPPING / INSTALLATION ARCHITECTURE

• Each oven shipped assembled. Approximate shipping weight: 1,100 lb per oven.

• Compact cabinet platform supported shipment of two matching units for the order.