Preserving water is an increasingly strong priority for industries that use it because of a potential impending water shortage. Predictions show a shortage could occur in as soon as 15 years, according to the United Nations World Water Assessment Program.
In an August article in Water Technology, Nate Maguire of Xylem Inc. outlines how food and beverage businesses can reuse water to ultimately reduce their use of it.
Because food and beverage operations use so much water for cooling towers, boilers, washing equipment and producing goods, many options exist for water reuse and treatment instead of drawing exclusively freshwater from the natural water supply or municipal system. Doing so also reduces water use ratios, decreases supply disk, saves costs, improves sustainability, reduces source-water risk and better control water quality.
Pumps play an essential role in the water reuse process, transporting water and boosting pressure through processes such as reverse osmosis that remove contaminants and particulates. Maguire recommends selecting pumps to operate at their best efficiency point (BEP) and engineering plumbing to reduce friction in order to further decrease energy consumption. In fact, not having the correct size pump or pipe can increase energy consumption by up to 300 percent. Maguire also lists his specific steps to select a pump:
- Determine the flow rate, or the volume of fluid that must pass through the pump.
- For a transport application, determine the static head and friction loss for the piping system. For a boosting application, determine the pressure requirements and friction loss for the system.
- Determine the water makeup, including the density of the water, and chemical compatibility such as pH levels.
- Select the pump working with a water technology partner. Also consider these points:
- Find the flow curves and best efficiency point.
- Choose the net positive suction head (NPSH) of section head value at a flow point that will keep the pump from cavitation.
- Be sure to consider certifications, environmental conditions that will determine motor enclosure, voltage requirements, and variable speed options and controllers.