Why is periodic blowdown necessary for cooling towers or evaporative condensers?

Periodic blowdown is essential in cooling towers or evaporative condensers primarily for the purpose of removing the concentration of minerals and other contaminants in the water. As water evaporates in these systems, it leaves behind minerals such as calcium, magnesium, and silica, which can accumulate over time. If not regularly removed through blowdown, these minerals can lead to scaling, which negatively impacts heat exchange efficiency and can cause damage to the system components.

By implementing periodic blowdown, the concentration of these dissolved minerals is kept within acceptable limits, thereby helping to maintain optimal operational efficiency and prolonging the lifespan of the cooling equipment. This practice ultimately ensures that the cooling system operates effectively, avoiding potential issues like fouling and scaling which can hinder performance.