Variable Frequency Drives at Steel Mill
is the backbone of industrial and developing nations, but often its production
is more energy intensive than necessary. Bethlehem Steel Corporation (BSC), the
second largest producer of steel in the
An important part of the steel-making process involves blowing gaseous oxygen in the BOF, generating high temperatures and chemical reactions that oxidize impurities in the metal and convert iron into steel. The fans used to remove gas produced in this process operated at a continuous 1,200 RPM, though analysis showed that maximum was only needed during one-third of the BOF's 45-minute cycle. In addition, the fans only needed to run at a maximum rate of 1075 RPM. Controlling the flow by modulating the inlet dampers on the induced draft fans caused unnecessary pressure drop in the system. Therefore, a VFD was installed to modulate the flow.
The average monthly energy consumption of the BOF fell nearly 50% from 2,602 MWh a month to 1,310 MWh. Over a year, that translates to energy savings of about 15,500 MWh.
The project produced savings of $620,100 (USD) a year. Total project cost was $1,225,000 (USD), creating a simple payback of about two years.
The project reduction the production of 36,600,000 lbs (1,6601,000 kg) of CO2, 115,000 lbs (52,163 kg) of SO2, and 143,000 lbs (64,863 kg)of NOX.
Bethlehem Steel Corporation
Meade Industrial Services Inc.
1825 Summer Street
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