Optimizing Energy Use
Compressed air is used in many of our processes and in many plants we have a bank of compressors operating to provide sufficient air pressure.
In our Marion, North Carolina plant, we have 7 compressors that have historically run continuously with the air pressure varying between 100 and 110 psi depending on demand. During 2020 we developed a control system linked up to a demand expander which means that the compressors now start up in sequence to maintain a constant pressure of 95 psi, reacting to the fluctuations of demand at all times. About 90% of the time at least two compressors are now not required to run and sometimes we have 3 or 4 idle. This has allowed us to reduce the energy consumption in compressed air supply by 30% compared to the previous system. The modest cost in the demand expander and control system will be recovered in well under a year. We will be looking to extend this practice across other units in 2021.