Nucor Steel-Texas
Nucor Steel-Texas (NSTX) is a world-class producer of hot-rolled carbon steel products. As a member of the Nucor Bar Mill Group, NSTX offers an extensive range of carbon steel angles, channels, flat bars, rounds, squares, and UM plates, in addition to concrete reinforcing steel.
The Challenge
Nucor Steel Texas’ baghouse was built with five forward-curved, radial tipped centrifugal main air fans rated at 330,000 acfm and connected with 1,750-hp motors. It was originally designed with four operating fans, one in-line spare, and two LMS fans connected with 1,250-hp motors.
Additionally, a reverse air fan provided negative pressure to clean the baghouse bags. However, due to their design, the fans were prone to dust impact at steep angles, causing erosion of the blades. This constant erosion meant that NSTX was faced with the decision to either conduct major fan blade maintenance and repair or to completely replace the fan blades.
The Solution
Our first step was to carry out original fan performance assessments to establish a project baseline. Following our assessment, we conducted computer modeling using our proprietary iFlow technology.
Our assessment indicated that AirStream’s high-efficiency impellers would greatly reduce power use and increase wear life. In order to reduce waste and maximize return on investment, our solution also allowed for the original fan housing to be used, as well as, bearings, couplings, and motors.
The Results
Following project completion, NSTX switched operations to run only three fans rather than the original four. Using only three fans achieved the same airflow and used less electricity per fan than when four fans were required. The new fan blades increased the efficiency from 39 percent to 68 percent, and resulted in an energy demand savings of 2,000 kW during operation. This project was also the 2012 Energy Achievement Award winner for Best Energy Efficiency upgrade in the steel industry.
