Specialized COPV Curing Oven with Motorized Rotating Cart System

A leading aerospace manufacturer required a precision thermal processing solution for curing composite overwrapped pressure vessels (COPV). The application imposed demanding requirements across product rotation, pressurization, temperature uniformity, safety compliance, and site constraints.

APPLICATION & PRODUCT TYPE

• Product: composite overwrapped pressure vessels (COPV) — large cylindrical aerospace components with epoxy resin coatings applied over carbon fiber composite structures.
• Process: batch curing in a controlled thermal environment to polymerize epoxy resin coatings and cure the composite matrix.
• COPVs are cylindrical; rotation during curing is required to ensure uniform epoxy distribution across the full part surface.
• Internal vessel pressurization must be maintained throughout the cure cycle to preserve structural integrity of the composite overwrap.

LOAD REQUIREMENTS

• Product weight: 200 lb per batch.
• Two vessels per batch, mounted on dual spindle stations at 29.5-inch centers; each vessel is 23.5 inches in diameter with a 6-inch gap between vessels.
• Loading method: car-bottom cart rolls out of the oven on the internal floor-mounted track; components are loaded onto spindles outside the oven with pressurization fittings connected, then the cart drives back in.

THERMAL REQUIREMENTS

• Operating temperature range: 110°F to 350°F typical.
• Maximum temperature capability: 350°F.
• Temperature uniformity: ±10°F at operating setpoint across the full work area.
• Programmable ramp/soak profiles required to manage precise temperature ramp rates and soak periods critical to epoxy cure chemistry.

VOC / SAFETY COMPLIANCE REQUIREMENT

• VOC loading: 0.5 gallon per batch of standard solvent emitted during epoxy cure.
• Required: NFPA 86 Class-A oven compliance with appropriate exhaust, purge, and safety interlock systems.

SITE CONDITIONS

• Heating: electric (54 kW specified).
• Electrical service: 460V / 3-phase / 60 Hz.
• Site altitude: less than 1,000 feet above sea level.

ACCESSIBILITY CONSTRAINTS

• Equipment must enter facility through a 12’ × 16’ dock door.

These thermal process requirements were developed to meet the customer's curing process needs for composite overwrapped pressure vessels, based on the application conditions and operating parameters.

TEMPERATURE REQUIREMENTS

• Operating temperature range: 110°F to 350°F.
• Maximum temperature capability: 350°F.

LOAD / PRODUCT PARAMETERS

• Batch capacity: 200 lb per batch.
• Individual part geometry: cylindrical COPVs (23.5″ diameter); rotation throughout the cure cycle ensures all surfaces receive consistent thermal exposure.
• Vessels are pressurized during cure; PLC-integrated pressure regulators maintain internal vessel pressure throughout the cycle.

HEAT INPUT REQUIREMENT

• Required heat input: 54 kW electric.
• Incoloy sheathed heating elements arranged in multiple heater banks for precise zone-level control.

AIRFLOW DELIVERY

• Combination horizontal-vertical airflow through the 182 cubic foot oven chamber.
• Supply fan: 4,410 CFM at 2″ WC static pressure, 5 HP TEFC motor, belt-driven.
• Supply ductwork: 16-gauge aluminized steel with adjustable slot nozzles for airflow balancing around rotating cylindrical parts.

EXHAUST REQUIREMENTS (CLASS-A VOC REMOVAL)

• Class-A exhaust fan: 580 CFM at 1″ WC static pressure, 0.75 HP ODP motor.
• Exhaust type: gravity port with adjustable damper for VOC removal control.
• Exhaust discharge: per applicable code (customer to vent outside building).

TEMPERATURE UNIFORMITY

• ±10°F from setpoint at operating temperature across the full 182 cubic foot work area, ensuring consistent and complete epoxy cure across the full load.

To deliver the thermal process requirements (which deliver the customer process requirements), Precision Quincy settled on the following equipment concept and architecture for the COPV batch curing oven.

OVERALL CONCEPT

• Class-A, electrically heated, car-bottom batch curing oven with motorized rotating cart.
• Electric heating via 54 kW incoloy sheathed elements in multiple heater banks.
• Work area: 36″ W × 112″ L × 78″ H (182 cu ft interior volume).
• Overall equipment dimensions: 75″ W × 257″ L × 143″ H.
• Total equipment weight: approximately 9,500 lb.

DOOR SYSTEM

• Front-end bi-parting pneumatic doors: 4-inch thick insulated construction.
• Safety devices: manual safety latches; limit switches on access doors monitored by PLC.
• Seal: door gaskets around full perimeter for optimal chamber sealing during cure cycle.

PRODUCT ROTATION SYSTEM

• Two powered spindle stations on 29.5-inch centers.
• Drive side: three-jaw chucks. Driven side: V-rollers.
• Variable speed and acceleration control via PLC.
• Accommodates two 23.5-inch diameter cylindrical vessels with 6-inch gap between.
• Integrated pressurization: ¼-20 fittings for vessel pressurization; pressure regulators integrated with PLC for continuous monitoring and control throughout the cure cycle.

CAR-BOTTOM / LOADING ARCHITECTURE

• Motorized car-bottom cart rolls out of oven on floor-mounted internal track with V-groove wheels and 12-inch raised base incorporating cart bottom seal and tracking roller system.
• Cart bottom seal and tracking roller system maintain chamber sealing integrity during operation.
• Snap-together cable carrier system with mounting brackets protects all wiring and hoses during cart movement.
• Cart-mounted E-stop; limit switches on cart and access doors for full-cycle safety monitoring.

HEATING / AIRFLOW ARCHITECTURE

• 54 KW electric heating with incoloy sheathed elements arranged in multiple heater banks for efficient temperature control across the work area.
• Supply fan: belt-driven, 4,410 CFM at 2″ WC static pressure, 5 HP TEFC motor.
• Airflow pattern: combination horizontal-vertical via 16-gauge aluminized steel supply ductwork with adjustable slot nozzles for optimal distribution around rotating cylindrical parts.
• Class-A exhaust fan: 580 CFM, 0.75 HP ODP motor, gravity port with adjustable damper for VOC removal.

CONSTRUCTION / SHELL ARCHITECTURE

• Structural steel frame; an extremely robust and stable platform.
• 16-gauge aluminized steel interior and exterior walls.
• Wall thickness: 4 inches with 6-pound density mineral wool insulation.
• Finish: Precision Quincy Blue industrial epoxy enamel on body and door; ANSI 61 gray control panel.

CONTROLS ARCHITECTURE

• PLC: Allen-Bradley CompactLogix.
• HMI: Allen-Bradley PanelView Plus 10-inch color touchscreen.
• Temperature controller: Watlow F4T ramp/soak with 4.3-inch color touchscreen; up to 40 programmable cure profiles.
• Thermocouple type: Type J
• Rotation control: variable RPM and acceleration control via PLC.
• Pressure monitoring: integrated pressure regulator monitoring via PLC.
• Data collection framework included: battery backup.
• Panel rating: NEMA 1, UL 508A labeled.

SAFETY SYSTEMS

• NFPA 86 and OSHA compliant.
• Class-A exhaust system for continuous VOC removal during cure cycle.
• Work area hi-limit controller (digital/manual reset).
• Adjustable mechanical motor-driven purge timer.
• Airflow switches on supply fan and exhaust fan as safety interlocks.
• Cart-mounted E-stop and additional emergency stop locations.
• Manual safety latches and door limit switches; safety chain monitored by PLC for diagnostics.

OTHER NOTED ATTRIBUTES

• Utilities: 460V / 3-phase / 60 Hz; 100 FLA estimated.
• IEC-type motor starters; disconnect included.
• Equipment dimensions designed to pass through a 12’ × 16’ dock door for installation.