ThyssenKrupp Nirosta has implemented a spraying robot fitted with state-of-the-art control technology capable of performing maintenance on the refractory walls of the EAF at its Bochum, Germany, facility.
The robot will help to perform critical refractory wall maintenance, which will help to extend the operating period between relines. Partially automated, it is capable of carrying out complex refractory material maintenance without manual control. The robot also features a newly developed spray nozzle technology that facilitates a higher spraying speed, even application at the desired thickness, and optimized wetting that helps to reduce the consumption of hot repair material.
The spraying robot has helped the Bochum double the period before the refractory bricks need to be renewed from its previous average of two-and-a-half weeks with the furnace running at full capacity and operating temperatures of up to 1650° Celsius. It is controlled via a digital operator interface that enables the operator to select precisely which wall areas are to be sprayed with the wetted magnesite. Binder components ensure that the material hardens on contact with the damaged areas and seals them.
“We have also realized a further advantage in terms of servicing the new spraying robot,” explained Helge Mees, head of the melting team at the Bochum steel mill. “ThyssenKrupp is looking to insourcing rather than outsourcing here.”
In the past, robot maintenance was carried out by the manufacturer, Minteq. As part of the new acquisition, the American company provided two ThyssenKrupp team technicians with comprehensive training on how to service and maintain the modern equipment. “This enables us to act flexibly and be independent of third parties,” added Mees.
Refractory wall maintenance with the new spraying robot takes between five and ten minutes. As it helps to reduce the frequency of costly, time-consuming relines, the new robot is helping the Bochum facility maintain the production reliability of its electric arc furnace while reducing consumption of refractory compounds.
