Coester Solution for Steel Industry: Electric Actuators for High Temperature Operation

Problem Identification and Solution

After identifying that the highest incidence of failures occurred due to the burning of the electronic boards of the actuators, the Coester team developed a model with reduced internal electronics, replacing most of the semiconductors and capacitors of the network boards and power supply with components resistant to operations with a minimum temperature of 85º C.

As the main objective of the project was to minimize heat generation inside the actuator housing, an external motor was chosen, designed to dissipate all the heat generated during operation into the environment. This way, the motor is activated without overheating.

The user interface board was also removed, as Liquid Crystal Displays (LCDs) do not perform adequately when exposed to high temperatures. According to the R&D Manager, Carlos Hennig, reducing the number of boards and components was crucial to ensure an increase in the mean time between failures. In addition, capacitors were selected for operation at temperatures above 105°C.

"Additionally, we developed exclusive thermal jackets to extend the thermal barrier for the components. The jackets covered the aluminum housing shell of the actuator, protecting the integrity of the electronic circuit," highlights Henning.

Project Development

Field tests started with the first supply of six electric actuators for application in two furnaces, four lateral and two top. Together with the project, development and technical assistance team, field surveys, design, adaptation manufacturing, assembly monitoring, configuration, startup, commissioning, testing, adjustments, network commissioning, and after-sales services were performed. With the success of the pilot project, Coester supplied a second batch of 50 electric actuators.

Guaranteed Application

The customized solution developed by Coester fully met the customer's requirements. Since the original supplies, there has been no need to acquire spare parts, whether electrical, electronic, or mechanical, which demonstrates the robustness of the equipment and the effective positive impact on operational efficiency and maintenance costs.