Multiple Prime and Finishing Ovens with Air Handling System for Metal Coating Application

Project No 1930

The Challenge

An international coating line builder, contacted Epcon regarding a new plant they were going to supply to their subsidiary in Shandong, China for coating metal strips for the architectural and transportation industries. In addition to traditional architectural and automotive coatings systems, the new line would need to process a special rubber based high solvent coating.  This unique coating requires a relatively slow and tightly controlled ramp rate to ensure proper curing.

The completed system would need to support curing of solvent based coatings on metal strip up to 30” (762mm) in width at rates of between 80 and 300 Feet/Minute (91.4 meters/minute) and Peak Metal Temperatures (PMT) of 475F.

In addition to the technical and performance challenges of this international project the team was faced with a compressed timeline. Epcon had both the experience and resources needed to deliver an energy efficient high performance curing system for this project on time and within budget.

Epcon was selected to design, fabricate and supervise the installation and commissioning of the prime and finish cure system and the associated process air handling ductwork and controls. 

The Solution

To meet the demands of the specified coating systems and production rates, Epcon provided a two (2) zone prime oven and four (4) zone finish oven system complete with integrated and recirculated air handling and controls.  Each of the ovens, with a designed maximum zone temperature capability of 800F, incorporates a number of Epcon’s innovative and proprietary design features.

Central to achieving uniform temperature control across the strip and within each zone are Epcon’s proprietary “EEZ” Energy Efficient Zone Control temperature control modules.  Each of these modules is paired with our continuous internal exhaust plenums.  The “EEZ” Zone Control Modules incorporate dedicated recirculation fans as well as modulating trim burners to accurately control zone temperature.  The tandem dedicated recirculation fans, for top and bottom of the strip, ensure balanced delivery of high velocity air across the material delivering edge to edge temperature uniformity within +/- 3F.

Complementing the “EEZ” Energy Efficient Zone Control Modules are Epcon’s propriety adjustable supply nozzles.  The user-friendly design provides high velocity strip impingement, resulting in increased coefficient of heat transfer.  The higher coefficient of heat transfer allows the system to operate at lower zone temperature set points while maintaining the targeted PMTs.  In addition to the energy efficiency benefits of this approach, a lower zone temperature also translates to longer life expectancy of the overall system.

Given the excellent distribution of temperature throughout the ovens, the precise and control ramp of metal temperatures required by the specialty rubber coating was easily achieved through optimization of oven zone lengths.  Of course, managing the VOCs released from the curing process, especially with the expected high solvent loads, would require careful design.

In this case, Epcon selected an even chambered Regenerative Thermal Oxidizer (RTO), including Secondary Heat Recovery, to achieve both the targeted emissions compliance performance and recovery of energy from solvent emissions destruction.  The integrated secondary heat recovery allows for cascading process air collection and preheating prior to being directed to the ovens as preheated make up air.  Leveraging decades of experience, designing and optimizing process air collection and make-up, allowed Epcon to provide the most efficient and balanced overall air handling solution, maintaining coater room air quality, achieving energy efficiency and environmental compliance all without compromise.

Having delivered dozens of large and complex systems globally over their 40 year history, Epcon was well versed in the unique challenges of installation, start-up and commissioning of an overseas project.  For this project, Epcon provided the system in a modular build kit.  All major components provided by Epcon were fabricated at their 250,000 Sq. Ft operations in The Woodlands, Texas and shipped both bulk and in containers to China.  From the Ovens and Thermal Oxidizer through the Process Air Handling Ductwork, Dampers and Controls System everything was kitted up and shipped overseas.

The Results

Epcon, working together with the Company and local contractors, supervised the installation, start-up and commissioning of the oven systems and associated air handling equipment.  The Grand Opening of the new plant was less than 12 months from contract closure to line start-up. 

Customer satisfaction is a critical part of Epcon’s long running success.  In the words of First Americans’ Project Leader Rick B. “Our opening ceremony went off without a hitch and the line ran as part of the ceremony…I want to thank you for all your efforts and your cooperation in making this happen on time and within budget!”  

Approximately one year after start of production the feedback is great…”The system and support provided by Epcon met all of our expectations and continues to perform as we had hoped.  Delivering the system in China was a unique challenge.  Looking back, I am confident we made the right choice in selecting Epcon and would refer them to others in the future as well.”