Electric Heated Cabinet Oven for Overseas Electric Motor Paint Drying

This oven was developed for the customer to support an overseas deployment of thermal-processing equipment for an electric-motor paint-drying application.

APPLICATION REQUIREMENT

• The equipment was required for drying polyurethane paint on electric motors.
• The customer required a repeatable batch-process platform suitable for industrial finishing work rather than a one-off laboratory unit.
• The project also reflected the need to support an international deployment through the customer procurement and integration channel.

WORK CHAMBER / LOAD REQUIREMENT

• Required work chamber: 48 in W × 48 in D × 38 in H.
• The oven was supplied with two 100 lb evenly distributed capacity shelves.
• The application also required load flexibility for varying motor sizes and configurations, with shelf loading limited to 100 lb per shelf.
• Customer loading practices had to preserve open airflow passage through the chamber for proper thermal performance.

PROCESS REQUIREMENT

• The system had to support drying of thin polyurethane paint coatings on electric motors.
• Process basis: approximately 0.25 gal of paint per batch.
• Required operating temperature: 482°F (250°C).
• The customer required consistent airflow and temperature control for repeatable batch drying results.

SAFETY REQUIREMENT

• The oven was configured as an NFPA 86 Class A unit.
• The documented maximum VOC load basis was 0.22 gal/batch (o-xylene basis).
• The control enclosure basis was UL 508A Open Industrial Control Panel.

UTILITY / SHIPMENT / EXPORT REQUIREMENT

• Required electrical service: 480V / 3PH / 60Hz.
• Intended location of operation: Petroterminal de Panama, S.A., Panama.
• The project was quoted for overseas deployment through the customer.
• Special or export crating was not included in the quoted oven price and would be handled separately if required.

These thermal process requirements were established from the customer’s need to dry thin polyurethane paint coatings on electric motors in a controlled Class A batch oven platform quoted for the customer and intended for operation at Petroterminal de Panama, S.A., Panama.

TEMPERATURE CAPABILITY

• Operating temperature: 482°F (250°C)
• Maximum temperature: 550°F (288°C)
• Required work-area uniformity: ±10°F

PROCESS BASIS

• The thermal process basis was drying thin polyurethane paint on electric motors.
• Process basis: approximately 0.25 gal of paint per batch.
• The application required repeatable temperature exposure and airflow across varying motor sizes while maintaining proper open airflow paths through the load.
• Design elevation basis: <1,000 ft.

HEAT INPUT REQUIREMENT

• Heat source: electric resistance heat
• Heater bank: 24 elements × 1500 W
• Total installed heat: 36 kW

AIRFLOW DELIVERY REQUIREMENTS

• Airflow style: full horizontal airflow
• Recirculation airflow basis: 1,500 CFM
• Recirculation static pressure basis: 2 in. W.c.
• Recirculation fan motor: 1.5 HP

EXHAUST / VENTILATION BASIS

• Exhaust fan: PQ1 exhauster
• Exhaust airflow: 300 CFM
• Exhaust static pressure: 1 in. W.c.
• Exhaust fan motor: 0.75 HP

THERMAL INSTRUMENTATION / CONTROL BASIS

• Primary controller: SSI-804 temperature controller
• Work-area thermocouple: Type J
• Excess temperature controller: Gefran 650L high-limit arrangement

SAFETY / CLASSIFICATION BASIS

• Oven classification basis: NFPA 86 Class A
• Maximum VOC load basis: 0.22 gal/batch (o-xylene basis)
• Purge timer basis: 3 minutes minimum
• Airflow switches were used on both exhaust and recirculation fans as part of the safe-operating sequence

To deliver the customer and thermal process requirements for this oven, Precision Quincy developed the following equipment concept and architecture.

OVERALL CONCEPT

• One 40C-550 Class A electric cabinet oven
• Designed for drying thin polyurethane paint on electric motors
• Developed for the customer for an overseas deployment
• Configured as a full-horizontal-airflow batch oven for repeatable drying performance

HEATING ARCHITECTURE

• Heat source: electric resistance heat
• Heater bank output: 36 kW total
• Heater bank arranged as 24 × 1500 W heating elements
• Heat controlled through solid-state relay architecture with a back-up contactor

AIRFLOW / RECIRCULATION ARCHITECTURE

• Airflow pattern: full horizontal airflow
• Recirculation fan concept:
• 1,500 CFM
• 2 in. W.c.
• 1.5 HP motor
• Exhaust fan concept:
• PQ1 exhauster
• 300 CFM at 1 in. W.c.
• 0.75 HP motor
• The chamber and load concept required maintaining open airflow paths around the product for proper process performance

CHAMBER / CONSTRUCTION ARCHITECTURE

• Internal work chamber: 48 in W × 48 in D × 38 in H
• Wall thickness: 4 in
• Insulation: 4 in of 6 lb mineral wool
• Interior material: unpainted aluminized steel
• Exterior finish: PQ Blue
• Control panel finish: ANSI 61 gray
• Floor: 3/16 in plate floor

DOOR / ACCESS ARCHITECTURE

• Two swing doors
• Supplied with two 100 lb evenly distributed capacity shelves
• Shelf spacing shown at 3 in adjustable increments
• The shelf and chamber arrangement supported load flexibility for varying electric-motor sizes and configurations, with 100 lb maximum per shelf

CONTROLS ARCHITECTURE

• NEMA 1 control enclosure
• Primary temperature controller: SSI-804
• Excess temperature controller: Gefran 650L
• Work-area thermocouples: Type J
• Control enclosure listed to UL 508A Open Industrial Control Panel

SAFETY / COMPLIANCE ARCHITECTURE

• Oven classification basis: NFPA 86 Class A
• Applicable standards basis: NFPA 79, NFPA 86, UL 508A
• Included Class A exhaust, purge timer, airflow switches on exhaust and recirculation fans, and overtemperature protection
• Maximum VOC load basis: 0.22 gal/batch (o-xylene basis)
• Design elevation basis: <1,000 ft

SHIPPING / INSTALLATION ARCHITECTURE

• Intended location of operation: Petroterminal de Panama, S.A., Panama
• The project was quoted for overseas deployment through the customer
• Special or export crating was not included in the quoted oven price and would be handled separately if required