Natural Gas Heated Walk In Oven with Integral Thermal Oxidizer

The equipment was developed for a curing application requiring the batch processing of rubber gaskets in a controlled thermal environment, supporting a solvent-bearing process requiring controlled heating, compliant VOC handling, and repeatable work-area performance.

APPLICATION REQUIREMENT

• The equipment processes rubber gaskets through a batch curing process.
• The system supports a solvent-bearing gasket-curing application requiring controlled heating and compliant handling of process exhaust.

WORK CHAMBER / LOAD REQUIREMENT

• Required internal work area: 69 in W × 84 in D × 88 in H.
• Maximum product load basis: 861 kg per batch.
• The oven was designed around cart-based loading with guided travel through the insulated floor track system.

PROCESS REQUIREMENT

• The system supports repeatable batch curing of gasket loads with stable temperature control and uniform heat delivery across the work area.
• The process requires accommodation of solvent-bearing loads, with ventilation and oxidizer architecture matched to the application basis.

SAFETY REQUIREMENT

• The oven was required to be designed as an NFPA 86 Class A unit.
• The equipment required compliant combustion, purge, exhaust, and VOC-handling architecture appropriate for the process basis.

UTILITY / SITE REQUIREMENT

• Required electrical service: 380V / 3PH / 50Hz.
• Required fuel: natural gas. Natural gas inlet pressure: 2 PSI. Natural gas flow basis: 3,000 CFH.
• Design elevation basis: less than 1,000 ft above sea level.

INSTALLATION / SHIPMENT REQUIREMENT

• Approximate overall shipped oven dimensions: 110 in W × 180 in L × 182 in H.
• Installation access basis: 12 ft W × 16 ft H dock/door size.
• The equipment was designed to ship factory assembled.

These thermal process requirements were established from the need to cure rubber gaskets in a controlled Class A batch environment.

TEMPERATURE CAPABILITY

• Operating temperature: 351°F (177°C).
• Maximum operating temperature: 482°F (250°C).
• Required work-area temperature uniformity: ±10°F (±5.6°C).

PROCESS BASIS

• The thermal process basis is batch curing of rubber gaskets.
• The application involves a solvent-bearing VOC load and required compliant thermal processing and exhaust handling.

HEAT INPUT REQUIREMENT

• Heat source: natural gas. Oven burner: Eclipse RatioMatic RM0100. Oven burner heat input: 950,000 BTU/hr.
• Natural gas inlet pressure: 2 PSI. Natural gas flow basis: 3,000 CFH.

AIRFLOW DELIVERY REQUIREMENTS

• Required airflow style: full-height horizontal-vertical airflow.
• Recirculation airflow basis: 12,600 CFM. Recirculation static pressure basis: 2.5 in. w.c.
• Supply delivery basis includes high-velocity nozzle discharge with design airspeed targeted at 4,000 FPM.

EXHAUST / VENTILATION BASIS

• Exhaust fan: PQ25 exhauster. Exhaust airflow basis: 2,427 CFM at 1 in. w.c.
• Maximum VOC load basis: 1.73 gal/batch of o-xylene. Oven classification basis: NFPA 86 Class A.

THERMAL OXIDIZER BASIS

• Oxidizer operating temperature: 1,400°F to 1,550°F. Oxidizer maximum temperature: 1,550°F.
• Oxidizer burner: Eclipse RatioMatic RM0200. Oxidizer burner heat input: 2,000,000 BTU/hr.
• Oxidizer dwell time: 0.5 seconds. Oxidizer operating airflow basis: approximately 2,317 CFM.

THERMAL INSTRUMENTATION / CONTROL BASIS

• Primary oven temperature controller: WATLOW F4T ramp/soak controller with non-encrypted data acquisition and graphical trend chart.
• Oxidizer temperature controller: Super Systems SSI 804.
• The process temperature control architecture uses Type K process thermocouples with dedicated high-limit protection circuits.

SAFETY / CLASSIFICATION BASIS

• Oven classification basis: NFPA 86 Class A.
• The thermal process was delivered within a natural-gas-fired safety framework with dedicated combustion safeties, airflow proving, gas pressure monitoring, purge sequencing, and thermal protection.

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

OVERALL CONCEPT

• One natural-gas-heated Class A walk-in batch oven with integral thermal oxidizer designed for rubber gasket curing in a solvent-bearing batch process.
• The design uses a back-mounted heat chamber and a top-mounted thermal oxidizer.

HEATING ARCHITECTURE

• Oven heat source: natural gas. Oven burner: Eclipse RatioMatic RM0100 at 950,000 BTU/hr.
• Oxidizer burner: Eclipse RatioMatic RM0200 at 2,000,000 BTU/hr.
• Both gas trains are designed to NFPA 86 requirements and use FM-approved components.

AIRFLOW / RECIRCULATION ARCHITECTURE

• Airflow pattern: full-height horizontal-vertical airflow.
• Recirculation fan: NYB 248PLR plug fan — 12,600 CFM at 2.5 in. w.c.; 10 HP motor; plug fan diffuser.
• Exhaust fan: PQ25 exhauster — 2,427 CFM at 1 in. w.c.; 2 HP motor.
• Supply ductwork uses straight four-sided duct construction with high-velocity nozzles to drive even air distribution.
• Return ductwork is designed to provide additional airflow control within the work area.

CHAMBER / CONSTRUCTION ARCHITECTURE

• Internal work area: 69 in W × 84 in D × 88 in H.
• Construction style: tongue-and-groove interlocking insulated panel construction with structural steel reinforcement.
• Wall system thickness: 4 inches. Insulation: 4-inch, 6 lb density mineral wool.
• Interior and exterior wall material: 18 gauge aluminized steel. Exterior finish: Sherwin-Williams RAL-9010.
• Oven floor: 2½-inch insulated floor with two sets of continuous cart guide tracks.

DOOR / ACCESS ARCHITECTURE

• Door style: 4-inch-thick bi-parting doors on one end.
• Doors use double-wall reinforced construction.
• The door system includes gasketing, drag seals, roller-bearing hinges, and FM-approved pressure-release latches.

THERMAL OXIDIZER ARCHITECTURE

• The oxidizer is individually dedicated to the oven.
• Shop assembled, pre-wired, pre-tested, and mounted above the oven on a structural frame.
• Oxidizer construction: PQ octagonal design with 3/16-inch plate exterior and 7 inches of high-temperature insulation.

CONTROLS ARCHITECTURE

• Primary oven controller: WATLOW F4T ramp/soak controller with data acquisition and graphical trend chart.
• Oxidizer controller: Super Systems SSI 804.
• Control enclosure: NEMA 12, approximately 42 in × 30 in × 12 in; UL 508A Open Industrial Control Panel labeled.
• Control package includes: digital/manual-reset high-limit controllers; airflow switches; gas pressure switches; Dungs flame safeguards; Siemens SQM41.25 burner control valve actuators; panel-mounted USB connection for controller data access; three-tier stack light.

SAFETY / COMPLIANCE ARCHITECTURE

• Oven classification: NFPA 86 Class A. Applicable standards basis: NFPA 79, NFPA 86, UL 508A.
• The design includes dedicated purge logic, burner proving, proof-of-closure monitoring, combustion airflow proving, exhaust airflow proving, work-area and combustion-chamber high-limit protection, and visual fault indication.

SHIPPING / INSTALLATION ARCHITECTURE

• The oven was designed to ship assembled as a complete package including the oven body, heat chamber, mounted control enclosure, and integrated oxidizer structure.