Parts of Cooling Tower
Main Components of a Cooling Tower:
1. Frame and Casing
- Function: The structural skeleton and external shell that supports all other components and contains the internal environment. It provides shape, strength, and protection from the elements.
- Description: Typically made of corrosion-resistant materials like fiberglass, stainless steel, or coated wood. The casing is the outer wall that directs airflow and contains the water within the system.
2. Fill (or Packing)
- Function: This is the heart of the heat transfer surface. Its primary job is to maximize the surface area and contact time between the hot water and the air flowing through the tower.
- Description: A medium made of plastic, wood, or other materials arranged in a grid or honeycomb pattern. There are two main types:
- Splash Fill: Uses layers of bars or sheets to break falling water into smaller droplets.
- Film Fill: Uses closely spaced sheets that cause water to spread into thin films, providing a much larger surface area for evaporation. This is more efficient and modern.
3. Cold Water Basin
- Function: To collect the cooled water at the bottom of the tower after it has passed through the fill. It acts as a reservoir for the cooled water ready to be pumped back to the process system.
- Description: Located at the base of the tower, it often includes a sump for the suction connection to the return pump.
4. Drift Eliminators
- Function: To capture and remove tiny water droplets that are carried away in the air stream (called “drift”). This prevents water loss and potential chemical treatment loss to the environment.
- Description: A series of baffles, usually made of PVC, that force the air to make sharp turns. The water droplets, being heavier, impact the baffles, coalesce, and fall back into the tower.
5. Inlet Louvres
- Function: To evenly distribute incoming air into the tower and to prevent water from splashing out of the tower. They also help shield the internal components from sunlight and debris.
- Description: Located on the sides of the tower (in crossflow designs), they are angled slats that guide air inward while containing water.
6. Nozzles & Distribution System
- Function: To spray and evenly distribute the hot incoming water over the top of the fill material. Uniform distribution is critical for efficient heat transfer.
- Description: A network of pipes (called laterals) and spray nozzles, typically made of plastic or brass, located above the fill.
7. Fan and Drive Assembly
- Function: To move large volumes of air through the tower. The fan creates the necessary airflow for evaporation.
- Description: Consists of:
- Fan: A large, low-pressure axial fan (like a giant propeller) located at the top of the tower (induced draft) or at the bottom (forced draft).
- Motor: Provides the power to rotate the fan.
- Drive Shaft & Gearbox (if applicable): Transmits power from the motor to the fan. Some designs use belts or direct drives.
8. Intake (Fan Cylinder)
- Function: To direct the airflow efficiently into the fan and minimize energy loss due to turbulence.
Supporting & Auxiliary Parts:
- Float Valve / Make-up Valve: Automatically adds fresh water (make-up water) to the cold water basin to replace water lost through evaporation, drift, and blowdown.
- Blowdown (Bleed-off) Valve: Periodically drains a portion of the concentrated system water to control the buildup of dissolved solids (scale and corrosion). This is necessary because evaporation leaves minerals behind.
- Strainers: Filters installed in the pipework to catch debris and prevent clogging of the nozzles.