What is Meant by Coil Cooling Tower?
Coil Cooling Tower” is essentially another name for a Closed Circuit Cooling Tower.
The “Coil” is the Defining Feature
In a coil cooling tower, the hot process fluid that needs to be cooled is contained within a continuous, sealed coil of tubing, usually made of copper or stainless steel for good heat transfer. This coil is housed inside the tower structure.
The cooling process works like this:
- Hot process fluid (e.g., water, water-glycol mix) enters the coil.
- A water pump sprays cooling water from the tower’s basin directly over the outside of this coil.
- A fan forces or draws ambient air across the wet coil.
- A small portion of the spray water evaporates on the coil’s surface.
- The energy required for this evaporation (the latent heat of vaporization) is drawn from the coil.
- This removes heat from the coil, which in turn cools the process fluid flowing inside it.
- The now-cooled process fluid exits the coil and returns to the process it serves.
- The warmed spray water falls back into the basin to be cooled and recirculated.
Key Characteristics of a Coil Cooling Tower
- Two Separate Circuits: This is the most important concept.
- Primary Circuit (Closed): The process fluid inside the coil. It is a closed loop and never contacts the outside environment.
- Secondary Circuit (Open): The spray water and air. This is the “open” evaporative part that rejects the heat to the atmosphere.
- No Direct Contact: The process fluid and the cooling air/water never mix. They only exchange heat through the wall of the coil.
Why is it Called a “Coil Cooling Tower”?
The name is used to distinguish it from an open (direct contact) cooling tower and to highlight its main architectural feature.
- Open Tower: Cools water by having the hot water flow and mix directly with the cooling air.
- Coil (Closed Circuit) Tower: Cools fluid by having it flow inside a coil that is itself cooled by evaporating water and air.