Multiple Heating Zone Atmospheric Oven

Application:

A large multiple heating zone atmospheric oven that is used to bake Polyimide on a stainless steel coils. The initial opportunity is for two ovens with more potential in the future.

Problem:

The thermal system needed to effectively control 32 zones of temperature. Each zone also required a limit and needed to communicate to a Programmable Logic Controller (PLC) and a Human Machine Interface (HMI). The controller needed to work with quartz glass panel heaters. The control scheme had to be capable of easily changing failed system components without altering or shutting down the other operating zones.

Solution:

The EZ-ZONE^® ST provided everything needed. The package included the controller, high limit, shutdown contactor, heat sink and solid state relay (SSR). Thirty-two of the EZ-ZONE STs were easily bussed together into the PLC. With the use of Modbus®, we were able to set the temperature to all the zones by using a PLC via Ethernet connected SERIES F4 controller. By having the set-point retransmit through Modbus® we could also individualize high limit problems and controller errors on our HMI from each of the EZ-ZONEs.The use of a multi-loop controller would not have solved the need of individuality amongst the zones in the event of a control failure. (Sort of the ?all the eggs in one basket? situation.) The EZ-ZONE ST breaks out each zone, which allows the user to isolate them or swap them out very quickly. Furthermore, multi-loop controllers do not give us the almost industry standalone high limit safety shutdown.