Industrial plants generate a lot of heat, which is typically removed by water that evaporates in cooling towers. As cooling towers transfer heat from evaporating water to ambient air, dissolved solids like calcium and magnesium remain in the cooling tower. Over time, an accumulation of solids will diminish thermal efficiency and cause corrosion. To prevent this, water is removed (during the blowdown phase) from the tower and new make-up water is added from the plant’s original water source.
The frequency of water replenishment in cooling towers is measured by “cycles-of-concentration.” This term compares the level of solids in cooling tower water to the level of solids in the original/raw make up water. If the circulating water contains four times as many solids as the source/make up water, then the cycles are four. Most cooling towers can operate within a range of two to seven concentration cycles, before eliminating water via blowdown. The ability to increase cycles in cooling towers increases plant efficiency and also helps to save water. But the key to increasing cycles-of-concentrations is to treat water effectively.
Although a variety of water treatment applications exist (membrane bioreactor technology, reverse osmosis, ultraviolet purification, etc.), the best practices for industrial water treatment in refineries, power plants and chemical plants involve the use of metering pumps to deliver highly accurate doses of chemicals for:
For refineries and petrochemical plants, API 675 diaphragm metering pumps are the preferred choice for cooling tower water treatment applications.
The use of these water treatment best-practices, administered by highly accurate metering pumps enable cooling towers to run at higher cycles of concentration, which enables plants to limit blowdown activities and save water.
For more information on how Pulsafeeder’s pumps are used in cooling tower applications, see the following story: