Heat exchanger puts Corus at full steam

London – Corus has achieved saving of around £150,000 through the installation of a packaged plate heat exchange system at its Llanwern strip steel processing plant near Newport, Wales. The project was part of an on-going energy optimization programme at Corus, which has delivered £29 million in savings over the last five years.

The Corus site’s five reheating furnaces each take 20-tonne slabs of steel and heat them to 1250 degrees C for rolling into coils. The furnaces also drive five waste heat boilers, three of which produce high-pressure steam at 12 bar g for distribution around the site via the steam main.

However, as the other two boilers generate steam at 1.7 bar g, which is too low for most processes around the site, Corus was struggling to make full use of the steam. The company, therefore, decided to install a skid-mounted heat exchange system from Spirax Sarco to enable it to use the steam to preheat the feed to the site’s main boiler.

The company “could have scheduled a conventional build but we wanted to minimize the workload on Corus,” said Richard Charlton, process energy specialist at the steelmaker. “We wanted to have a main contractor who would oversee everything, including pipe and electrical work. In fact, Spirax Sarco handled it all and there was no problem.”

According to Charlton, the extra waste heat recovery was originally expected to save around £130,000 a year but is now recovering £150,000. This, he estimates, equates to a payback time of just 12 months.