Continuous furnaces for preheating transformer molds and curing transformer potting compound
In the production of high-voltage transformers, it is necessary to first preheat the transformer mold and then harden the potting compound. The line for their production consists of a preheating and curing furnace. These are continuous furnaces with a chain conveyor divided into several heating zones. The furnaces have forced circulation of the internal atmosphere.
The line is fully automatic, controlled by a programmable Simatic controller, which communicates with another superior control system of the customer. A huge advantage of this line is the fully automatic operation of transformer production, because the batch does not have to be manipulated between individual operations. Even loading into the casting machine is ensured by robots, so when designing these furnaces we also addressed the connections to the handling mechanisms in the intermediate steps. Thanks to the automation of the line, we limited the number of manual interventions by the operator.
The customer primarily required an even temperature distribution in the oven due to the casting compound, which has manufacturer-specified conditions of use to achieve the required properties. At the same time, the curing oven needed to be able to achieve different temperatures in individual zones. However, the fundamental thing we had to solve was the automatic handling of parts between the preheating oven and the curing oven.
We achieved the required temperature distribution of +/-3 °C by powerful air circulation, and different temperatures by dividing the furnace into the required number of heating zones. To solve the last item of the assignment, we then used special manipulators for reliable and precise unloading and loading of parts. Precise positioning is important because the parts are handled by a robot. In addition, thanks to the automation of the line, we managed to increase the quality of production and, compared to the original solution, we also increased production capacity and shortened production times. We also adapted the line to the customer's requirements as much as possible in order to reduce space requirements as much as possible.