LEWCO, Inc. recently manufactured a large conveyor oven for an industrial roofing manufacturer. The oven, which is rated for a maximum operating temperature of 350°F, is used to dry the water off a coated scrim at 200°F. The finished product is used for various commercial roofing applications.
The oven features a single, direct-fired, natural gas heater-box with a capacity of 400,000 BTU’s/HR. The oven is equipped with two 8,000 CFM circulation fans and a 1,000 CFM exhaust fan which include air proving circuits that are electrically interlocked with the heating circuit. Variable frequency drives are included on both circulation fans allowing the user to adjust the convection flow depending on the product they are running. High-efficiency circulation fans and integral plenums deliver uniform dual vertical airflow throughout the workspace.
Adjustable plate covers are installed on the entrance and exit openings to minimize air leakage into the rest of the plant. The oven is also supplied with insulated bolt-on access panels for easy access to the oven chamber for service and maintenance. A cooling zone is included after the oven and supplied with a general purpose fan to blow ambient air onto the parts. An integral cooling plenum ensures even cooling airflow across the width of the product.
Controls include a Eurotherm Nanodac temperature controller and redundant high-limit controller. A PLC is interfaced with a remotely mounted touchscreen HMI allowing the customer to easily control all oven and conveyor operations from one convenient interface. A variable speed drive is included and allows the conveyor speed to be adjusted from 2-20 feet per minute.