Outdoor Steam-Heated Batch Curing Oven for Defense-Industry Confidential Materials

This project was developed for a defense-industry application requiring the batch curing of confidential materials associated with steel components used in downstream operations. Because portions of the customer's process details are proprietary or sensitive, this case study summarizes the requirement at a high level while focusing on the equipment performance, safety approach, and architecture delivered by Precision Quincy.

APPLICATION REQUIREMENT

• The equipment had to process confidential materials used in a defense-industry application.
• The thermal process is described at a generalized level as a batch curing operation.
• The system description is intentionally generalized to avoid disclosing customer-sensitive manufacturing details.
• The equipment had to provide consistent, repeatable low-temperature curing performance in a high-safety-duty environment.

SYSTEM CONFIGURATION REQUIREMENT

• The project required one large outdoor batch oven installed beneath a lean-to structure.
• The system operates as a single-zone batch unit suitable for field assembly, field conduit installation, and final on-site testing.

WORK CHAMBER / LOAD REQUIREMENT

• Required internal work chamber: 240 in W × 312 in D × 192 in H.
• Exterior oven size: 190 in W × 343 in D × 267.5 in H. Product entry opening: 120 in W × 192 in H.
• The work chamber is wider than the primary product opening, allowing product loading and positioning within a larger process envelope while limiting open access width.

THERMAL / OPERATING REQUIREMENT

• Intended operating temperature: approximately 140°F. Maximum operating temperature: 170°F.
• Required workroom temperature uniformity: ±15°F.

SAFETY REQUIREMENT

• Critical hardware at the oven required explosion-proof-rated components including recirculation fan motors, exhaust fan hardware, steam control valves, and pull-cord E-stop switch assemblies.
• The oven includes two interior pull-cord emergency stop stations, one at each end of the process chamber.
• Work chamber and shell construction must remain compatible with annual internal sprinkler testing.

UTILITY / CUSTOMER-LIMITATION REQUIREMENT

• Required electrical service: 460V / 3PH / 60Hz; 56.4 A FLA.
• Customer-limited steam inlet: 15 PSI max pressure / 250°F max temperature. Design elevation basis: less than 1,000 ft above sea level.

INSTALLATION / MAINTENANCE REQUIREMENT

• Oven designed to ship flat-packed for on-site assembly. Field wiring conduit and final testing completed on site.
• All steam heating equipment is roof mounted. Seams sealed with exterior-grade sealants for weather resistance and sprinkler test compatibility.

These thermal process requirements were established from the customer's need to cure confidential defense-industry materials in a tightly controlled, low-temperature, safety-focused outdoor batch environment.

TEMPERATURE CAPABILITY

• Normal operating temperature: approximately 140°F.
• Maximum operating temperature: 170°F.
• Required workroom temperature uniformity: ±15°F.

PROCESS BASIS

• The thermal process basis is batch curing of confidential materials used in a defense-industry application.
• The application requires repeatable low-temperature curing rather than high-temperature thermal processing.

HEAT INPUT REQUIREMENT

• Heat source: steam. Total installed heat input: 1,000,000 BTU/hr (two ST58 steam coils at 500,000 BTU/hr each).
• Steam supply limited to 15 PSI maximum inlet pressure and 250°F maximum inlet temperature.

AIRFLOW DELIVERY REQUIREMENTS

• Full horizontal recirculation airflow across the work area.
• Required total recirculation airflow: 50,000 CFM.

EXHAUST / VENTILATION BASIS

• Required exhaust airflow: 300 CFM via PQ1 exhauster with explosion-proof-rated hardware.

SAFETY / PROCESSING BASIS

• Design approach minimizes potential ignition sources within the process environment.
• Control package is located outside the immediate explosion-risk area.
• Annual sprinkler testing compatibility is a construction and sealing requirement built into the design.

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

OVERALL CONCEPT

• One outdoor steam-heated single-zone batch curing oven, installed beneath a lean-to structure.
• Designed for flat-pack shipment, on-site assembly, on-site conduit installation, and on-site testing.

HEATING ARCHITECTURE

• Heat source: steam — two ST58 steam coils at 500,000 BTU/hr each; 1,000,000 BTU/hr total.
• Steam inlet limited to 15 PSI max / 250°F max (customer-site constraints). All steam heating equipment is roof mounted.
• Steam control uses explosion-proof-rated steam control valves.

AIRFLOW / RECIRCULATION ARCHITECTURE

• Airflow pattern: full horizontal recirculation.
• Two New York Blower tube-backward inclined seal FP36 fans — 25,000 CFM each / 50,000 CFM total at 2,500 RPM; 20 HP explosion-proof-rated motor each (40 HP total).
• PQ1 exhaust fan — 300 CFM; explosion-proof-rated hardware.

CHAMBER / CONSTRUCTION ARCHITECTURE

• Internal work chamber: 240 in W × 312 in D × 192 in H. Exterior: 190 in W × 343 in D × 267.5 in H. Product entry opening: 120 in W × 192 in H.
• Shell style: structural steel tubing with interior panel cladding. Wall thickness: 6 inches, 6 lb density mineral wool insulation.
• Interior and exterior seams sealed with exterior-grade sealants — supports annual sprinkler testing and outdoor installation weathering.

CONTROLS ARCHITECTURE

• Primary process controller: Watlow F4T ramp/soak controller with encrypted data acquisition.
• NEMA 4 control enclosure, remote mounted away from the oven in a non-explosion-risk area.

SAFETY / COMPLIANCE ARCHITECTURE

• Explosion-proof-rated: recirculation fan motors, exhaust fan hardware, steam control valves, and pull-cord E-stop switch assemblies.
• Two pull-cord emergency stop stations — one at each end of the process chamber.

SHIPPING / INSTALLATION ARCHITECTURE

• Ships flat-packed due to overall size. Final assembly, wiring conduit installation, and testing completed on site.