At our Indiana Harbor site in Indiana, energy management efforts have already paid off in quick-wins worth hundreds of thousands of dollars.
These energy management efforts began with the Indiana Harbor energy conservation team, formed in February 2014. “At first, it was just a few engineers and we just started brainstorming,” recalls Katelyn Scheck, project engineer at the 12-inch bar mill. “Now it has grown to this really big group that we have here. We have involved the electric furnace and the 12-inch bar mill and we are working together to make a bigger difference.”
“One of the main motivations we had is that most plants are not running on a 24/7 basis,” added Marcelo Murta, engineer at the ArcelorMittal Americas – Long Carbon Chief Technology Office (CTO). “So, we started shutting off equipment in the same way that you would do at your home when you leave the house and you want to be sure that all the lights are off.”
The group quickly identified one big problem. “The biggest consumption of energy at the plant is air compressors because it is very expensive to make,” explained Larry Kandalec, senior mechanical engineer at the site’s steelmaking department. “First, you have to fix the ‘leaks’ and then you want to manage the usage.”
They started by shutting off air compressors whenever there was a delay or the furnace was down, saving a considerable amount of electricity.
Next, they worked on the usage of pumps – air and water alike. Three-hundred horsepower water pumps are used at Indiana Harbor and often four would be working at the same time. Upon examining this, the energy conservation team realised that four water pumps were not needed and brought the number down to one when they discovered it was enough to keep the water circulating.
The 700 horsepower baghouse fans were similarly audited and managed to switch off when the furnace goes down.
“After that, we started going after small hydraulic pumps, small water pumps and just about everything else,” Larry explains.
Measurement is a critical component of any energy programme and the Indiana Harbor long carbon team utilises a sophisticated computer system that tabulates data from meters throughout the area.
“If you cannot measure, you cannot improve,” says Murali Collur, manager of the continuous improvement programme, quoting the old adage. “Once we started installing meters, we could get visibility on a daily basis on how much energy we were consuming. Then, we could identify opportunities to save and cut.”
The team reviews the data each week and discusses it, always looking for new ways to save on energy costs. “The value of this is that it is tracking electricity use throughout the plant and telling us if something has been left on when it didn’t need to be,” said Cliff Barnett, environmental manager.
The measures taken have brought a dramatic turnaround and results of a larger scale than would be expected.
The savings with the energy programme will easily exceed US$300,000 in the first year alone. “If we continue this during the course of the next several years it will add up, leading to millions of dollars in savings,” concludes Murali.
Going forward, the team is looking at ways to make pumps run more efficiently, to install more energy-efficient motors and to assess the feasibility of using smaller units to run the air compressors.