Davron Technologies Inc., Chattanooga, Tenn., has designed and manufactured the DTI-1140, a natural gas-heated indexing conveyor oven system that heat treats engine components for a Tier 1 automotive supplier. The system includes an indexing conveyor oven, a quench tank, and a rinse tank. It also includes an automated pick-and-place system, which had to be precisely calibrated to streamline the heat treating process and meet demanding production requirements.
The heated chamber in the system includes four index positions that process 840 parts (530 pounds) in an eight-hour cycle. In the first zone, product ramps to temperature, and then soaks in the next three positions. For the heat-treat process to be successful, the product must never dip below the temperature reached in the first zone. Upon exiting the heated chamber, the product must be submersed in the quench tank within seconds. The DTI-1140’s sophisticated heating and air distribution system, along with its pick-and-place system, ensure that both of these critical requirements are met.
The system features two zones of temperature control in the heated chamber. Each zone is individually controlled to enable flexibility in the temperature profile, and utilizes its own natural gas burner and circulation fan. It also includes one exhaust fan to meet NFPA standards for gas-fired equipment. The maximum operating temperature is 1000°F. The indexing conveyor oven features PLC control, and all motion functions are controlled by servo for accuracy and speed. Both the quench and rinse tanks include electric heaters to ensure that the solutions are the required temperatures prior to the start of production. The quench tank also features a chiller to cool the solution after each cycle.
The furnace is 4 feet wide by 2 1/2 feet high and 29 2/3 feet long. The interior of the oven is made of 16-gauge aluminized steel, backed by 10 inches of eight-pound density mineral wool insulation. The exterior is constructed of 16-gauge carbon steel backed by a structural steel frame and finished with high-temperature paint. The oven features four access doors for explosion relief and access to the heated chamber. Pneumatically operated vertical doors cover both the entrance and exit of the oven chamber.
