At the 3M plant in Brookings, South Dakota, nearly 1,000 employees manufacture 3M medical dressings, tapes, surgical drapes, biological indicators, and food safety products. The company’s engineers devised a system that cut water consumption for the plant vacuum pump system.
Historically, the plant utilized a vacuum pump system that required the continuous flow of water through the pumps to run production equipment and maintain equipment temperatures. City supplied water cooled the system and maintained a water ring seal to create the vacuum. Water was supplied for a single pass and sewered or supplemented water lost in facility cooling towers. The continuous water usage averaged over 20 million gallons annually.
Engineers modified the vacuum pump system by designing a closed loop system that could leverage recirculated water. The system uses a small heat exchanger to cool the water for the equipment and purges every 15 minutes to keep clean chlorinated water in the pumps to eliminate corrosion or fouling.
The new closed loop system was installed and water use tracked for several months. With the new system, 3M Brookings decreased annual water consumption for the vacuum system by over 18 million gallons annually, which reduced the facility water consumption in gallons per square foot by 32%. This water savings is enough to supply about 164 homes each year, according to 3M.