What is meant by Evaporative Fluid Cooler?
An Evaporative Fluid Cooler is essentially another name for a Closed-Circuit Cooling Tower (CCT). The term describes the same piece of equipment but emphasizes its core function: cooling a fluid (liquid) by using the evaporative cooling process.
Let’s break down the name to understand exactly what it means:
“Fluid Cooler”
This part of the name highlights that its primary job is to cool a process fluid (a liquid) that is circulating within a closed loop. This fluid could be:
- Water
- A water-glycol mixture (for freeze protection)
- Oil
- A hydraulic fluid
- Other specialized industrial fluids
The key point is that this fluid is contained within a coil and never directly exposed to the atmosphere; it is “closed.” This distinguishes it from an open cooling tower, which cools water by directly exposing it to the air.
2. “Evaporative”
This specifies how the cooling is achieved. It uses the natural process of evaporation, which is highly energy-efficient.
- A separate spray pump continuously showers water (called “spray water” or “make-up water”) over the coil containing the hot process fluid.
- A fan simultaneously draws air through the tower.
- As the air moves past the falling spray water, a small portion of this water evaporates.
- The energy (heat) required for this evaporation is drawn from the remaining spray water, dramatically cooling it.
- This now-chilled spray water then absorbs heat from the hot process fluid inside the coil through the metal wall of the coil.
How It Works in a Nutshell:
Think of it as a hybrid between a dry cooler (air-cooled) and an open cooling tower (evaporative):
- Hot Process Fluid enters the coil.
- Spray Water is pumped and distributed over the outside of the coil.
- Air is forced or drawn across the wetted coil.
- Evaporation of a portion of the spray water cools the remaining spray water.
- Heat Transfer: The cooled spray water, in turn, draws heat from the hot process fluid inside the coil through the coil wall.
- Cooled Process Fluid exits the coil and returns to the process (e.g., a laser, chiller, or engine).
- Warm, Moist Air is exhausted from the top of the unit.