CSP PlantBig River Steel
A new, consumption-optimized CSP® furnace and a plant wider than ever before: The CSP® plant of Big River Steel is setting new standards worldwide and is characterized by lower energy losses and very low emission levels.
With a finished strip width of 1,930 millimeters the CSP® plant of Big River Steel is the world’s widest of all CSP® plants. And not only that: SMS group implemented also a number of technological innovations in the 29th CSP® plant and attained optimum performances which impressively demonstrate the efficiency of CSP® technology. The CSP® plant consists of a CSP® continuous casting plant of the VSB (Vertical Solid Bending) type, the CSP® tunnel furnace, the six-stand CSP® rolling mill, the laminar cooling system and a downcoiler.
The first strip was produced on the CSP® plant on December 10, 2016. In January 2017, the first full production month, 57,000 metric tons (approx. 63,000 American short tons) left the plant – world record for all CSP® plants. At the beginning of November 2017, Big River Steel broke the mark of one million tons produced on the CSP® plant. Another outstanding achievement is also an extremely low cobble rate. Here, the figure for example in July and August 2017 was below 0.06 percent.
A complete novelty is the CSP® furnace by SMS group. Every effort has been made to ensure that the energy consumption of the CSP® furnace is reduced and ideal thin slab heating is achieved at the same time. In the entire roller hearth furnace environmentally-friendly ultra-low NOx burners are used. With an average NOx emission of 85 mg/Nm³ measured, the furnace at Big River Steel sets a new standard in its environmental performance. The legally required limit value is thus considerably fallen short of. To save energy, the combustion air is moreover pre-heated with waste heat from the furnace recovered by recuperators.
For slab transport through the furnace special water- cooled rollers are applied with an insulation made of aluminum-silicate wool. Compared to conventional concrete rollers, these rollers ensure a lower energy removal by more than 30 percent. By using these rollers, the energy efficiency of the furnace is significantly increased which results in low gas consumption values and therefore saves operating costs. The use of burners and special transport rollers results in a total reduction of energy consumption in the furnace by 25 percent.
For controlling the furnace a special DFC (Dynamic Furnace Control) furnace model is applied. The Level-2 process automation system ensures slab heating to the desired goal with high temperature uniformity and low energy consumption. The model also allows the application of different strategies for heating and acceleration of the slab and it simulates among others the temperature development inside the slab in a three-dimensional manner. It calculates from it the set temperatures for various furnace zones. A tracking module synchronizes the slab position in the furnace and calculates the control parameters of logistics.