Gruenberg Conveyor Oven
TPS, a global manufacturer of thermal-processing equipment, has designed a new, custom industrial oven that cures a thin coating onto glass vials used in the pharmaceutical industry to produce a specialized, low-friction surface. The four-module, 400 °C oven contains three heating chambers and one for cooling. The clean room conveyor oven processes 120 vials-per-minute as they advance in trays along a conveyor belt of more than 30 feet. The cooling zone allows the product to exit the oven at a temperature of 80 °C or less.
To ensure uniform heat distribution and optimize efficiency, a high-volume, 1750-cfm, vertical-down, air-circulation system with HEPA filters is installed in each of the four chambers. Designed for a global innovator in materials science, the electrically heated Gruenberg NFPA 86 Class A Conveyor Oven is engineered for thermal processing that involves solvents or combustible materials, where a potential explosion may occur, and includes a 120-cfm, forced-exhaust, solvent-venting package to rid the chamber of solvents released during the heating process. Other safety features include a purge timer, which requires four complete changes of air throughout the work chamber following a shut down; shaft-rotation switches that de-energize the chamber in the event of an exhaust- or circulation-system failure; non-sparking air movers to prevent igniting of flammable solvents; and emergency-stop buttons positioned in key locations.
Featuring a structural-steel frame, the oven contains a fully welded, 304L-2B stainless-steel liner with vertically adjustable sliding gates at each end to restrict the intrusion of ambient air into the process chamber. The conveyor system is equipped with bio seals at each end, making the industrial oven a continuously welded, sealed vessel. Offering temperature uniformity of ±5°C, the oven’s air-heating system features seamless, tubular, incoloy-sheathed heaters. The cooling system employs a self-contained, direct-expansion refrigeration system featuring a 7.5 HP compressor and approved, non-CFC refrigerant.
The variable-speed, continuous-conveyor system includes 13 PowerFlex 525 variable frequency drives and 13 corresponding human interface modules that are located on the face of the control panel. A supervisory control and data acquisition system features an Allen Bradley 1768 CompactLogix programmable logic controller with onboard Ethernet communications and a personal computer with Factory Talk View SE-based PC application software.
