Continuous improvement legacy continues with new technology
8 September 2023
The Whyalla Steelworks coke ovens have been at the forefront of industry innovation during their 55-year history.
While the LIBERTY Primary Steel decommissioning of the coke ovens on September 15* signals a revolutionary change to the way steel is made, it is significant that the ovens themselves were always evolving with new technology of the day and refined processes to maintain efficiency.
One of these continual improvements includes the current method of quenching.
After the hot coke comes out of the ovens, at temperatures of around 1200 degrees, it needs to be cooled. The hot coke is taken to what is called the Quench Tower by rail on a ‘hot car’ with freshwater then dumped on top of the coal to bring it down to a temperature that it can then be transported via rubber conveyor without burning the conveyor.
Previously the water was sprayed onto the hot coke via fine jets but these were prone to clogging which required many hours of work to keep the sprays maintained and open.
One day, while dealing with spray problems, a group of employees decided to take the sprays off and let the water just dump onto the coke direct from the pipes.
The result was beyond anyone’s wildest dreams.
Not only did the rapid quench reduce the quench time required, thereby decreasing cycle times significantly, but the water remained in the bottom of the hot car long enough to cool the coke to the perfect temperature to be transported to the blast furnace without burning the rubber conveyors.
This in turn reduced the amount of coke needed for the blast furnace because there wasn’t as much energy required to remove all the moisture that remained inside the coke when the spray method had been in operation.
This is just one example of innovation over the years at the coke ovens that leaves a legacy of continual improvement now being embraced with the new electric arc furnace (EAF) technology announced in April by GFG Alliance Executive Chairman Sanjeev Gupta.
The coke ovens closure and installation of an EAF, to replace the coke-fed blast furnace, is another step in the GFG Alliance CN30 (Carbon Neutral by 2030) strategy for Whyalla.
Main picture: Coke Ovens Production Operator Chelsea McSeveney during a coke push. Picture: Hugh Brown
*Note: Scheduled closure date may change due to operational schedules.