Murray Hill & New Providence, N.J., U.S., May 1, 2013 -- At AISTech 2013, MST (South Lyon, Michigan) will report a 63 percent reduction in specific fuel consumption in its rotary hearth billet-reheating furnace operation after retrofitting the furnace with “flameless” REBOX® oxyfuel technology from Linde North America. The REBOX technical solution also greatly improved reheating capacity and eliminated the need for a walking beam furnace previously needed to preheat larger diameter billets.
Results will be co-presented with Linde at 3 p.m. May 8th in the Pipe and Tube Committee session titled “Seamless Pipe.”Full results will be published in the AISTech Conference Proceedings. In the presentation, MST Hot Mill Manager Tom Sleder describes project objectives, details of the implementation, as well as results and performance goals.
“Even though the burners for our furnace were relatively new, we saw the opportunity to improve our process with REBOX oxyfuel technology,” Sleder said.
The MST mill produces approximately 39,000 tons of cold-drawn seamless carbon and alloy tubing and pipe per year. First, solid steel round billets are reheated in a rotary hearth furnace, then the billets are rotary pierced in a Mannesmann style piercing mill. The rotary furnace, originally built in the late 1940s, was equipped with a traditional air-fuel heating system, and most recently updated in 2007. As MST increased the size of billets over the years, currently ranging from 2 7/8” to 4 ¾” in diameter, it installed a walking beam furnace for pre-heating large diameter material prior to charging in the rotary hearth furnace.
The REBOX® oxyfuel solution proposed by Linde included a revised heating profile (see Figure 1). The faster and optimized heating rate of the actual solution reduced heating time of the 4 ¾” billets by 50 percent compared to the previous air-fuel heating system including a walking beam furnace. It also reduced power consumption by 63 percent. The MST conversion included replacement of the air-fuel burners in the rotary hearth furnace with REBOX® flameless oxyfuel burners, modification of the flue gas system and a new stack as well as installation of new baffles at the charge and discharge doors.
“With the implementation of REBOX technology, we maintained our quality standards while increasing overall throughput, all while reducing our natural gas usage by 63 percent. Process control also took a major step forward with the Linde technology. The Linde REBOX technical solution enables us to monitor and control the entire heating process to ensure billet quality – and that quality is critical to our success at MST. The process improvement also eliminates the need to use the walking beam furnace for preheating, which made our operation more efficient and improved the working environment,” Sleder said.
Linde has been a pioneer in oxyfuel solutions since the 1990’s and has performed more than 130 installations around the globe. Over the past few years, the Linde REBOX® technology has become the premiere method for reducing specific fuel consumption in steel reheat furnaces. In addition to more efficient energy input and increased heating rate, the precision oxyfuel technology offers significant environmental and maintenance advantages, including reduced scaling, and minimizing NOx formation and total flue gas emissions.
The REBOX® portfolio includes equipment and control systems for oxygen-enrichment, oxygen-lancing, oxyfuel-boosting and 100 percent oxyfuel operation in reheat furnaces and annealing lines. Linde develops and produces powerful, compact and rugged oxyfuel burners needed to retrofit existing furnaces.
Linde, a leading global industrial gases company, provides industry-leading portfolio solutions for the ferrous and non-ferrous metallurgy industries, ranging from gases and equipment to process consulting and services. These solutions enable our customers to increase productivity, reduce fuel consumption and emissions and improve quality for every step in the metals process chain.
For more information, visit Linde at AISTech booth 1446, or contact Linde North America (www.lindemetallurgy.com),
MST (www.mstube.com) is a global manufacturing force, providing cold-drawn carbon, alloy and high chrome mechanical and pressure tubing and piping for many industries. The company’s seamless tube and pipe manufacturing facility has operated continuously since 1927, and now spans 320,000 sq. ft.
About Linde in North America
Linde North America is a member of The Linde Group, a world-leading gases and engineering company with around 62,000 employees in more than 100 countries worldwide. In the 2012 financial year, Linde generated revenue of EUR 15. 280 bn (USD 19.9 bn). The strategy of the Group is geared towards long-term profitable growth and focuses on the expansion of its international business with forward-looking products and services. Linde acts responsibly towards its shareholders, business partners, employees, society and the environment – in every one of its business areas, regions and locations across the globe. The Group is committed to technologies and products that unite the goals of customer value and sustainable development.
For more information, visit Linde North America online at http://www.lindeus.com.
908-771-1491, Fax 908-771-1460