How These Functions Are Achieved: The Process
To fulfill these functions, a cooling tower performs a specific process:
- Heat Transfer: Hot water from the industrial process or condenser is pumped to the top of the tower.
- Distribution: This water is distributed across the “fill” (a large internal surface area). This maximizes water-to-air contact.
- Evaporation: Air is drawn through the falling water by large fans. A small portion of the water evaporates.
- This is the key: The process of evaporation requires energy (the “latent heat of vaporization”). This energy is taken from the remaining water, thereby cooling it significantly.
- Collection & Recirculation: The now-cooled water collects in a basin at the bottom and is pumped back to the plant to absorb more heat.
- Heat Dissipation: The warm, moist air created by evaporation is exhausted to the atmosphere, carrying the waste heat with it.