Materials of Cooling Tower Parts
1. Casing and Structural Framework
This is the tower’s exterior shell and internal support structure.
- Galvanized Steel (G.S.): The most common material for industrial and large HVAC tower frameworks and casings. The zinc coating provides excellent corrosion resistance. It offers a great balance of strength, cost, and durability.
- Stainless Steel: Used in highly corrosive environments or where very high-quality water is required (e.g., pharmaceutical or food processing applications). Grades like 304 and 316L are common but more expensive.
- Fiberglass Reinforced Plastic (FRP): Used for casings on factory-assembled or “package” towers. It is completely immune to corrosion, lightweight, and can be molded into complex shapes. It’s a premium choice for long life with minimal maintenance.
- Concrete: Used almost exclusively for the large hyperbolic natural draft cooling towers at power plants. It is incredibly durable and provides the necessary mass for the massive structure.
2. Fill (or Packing)
This is the internal component that maximizes water-to-air contact. It is the heart of the heat transfer process.
- PVC (Polyvinyl Chloride) & PP (Polypropylene): The standard for modern towers. They are inexpensive, lightweight, highly corrosion-resistant, and provide an excellent surface for water film formation. They are typically configured in a “film” (flat or corrugated sheets) or “splash” (grids of bars) design.
- Wood (Typically Fir or Redwood): Used in older towers and some specific splash fill applications. It is naturally rot-resistant but requires more maintenance and has largely been replaced by more efficient and consistent plastics.
- Ceramic/Plastic Composite: Used in applications with very high temperatures (e.g., near the hot water inlet) where standard plastics might soften.
3. Cold Water Basin
This is the tank at the bottom of the tower that collects the cooled water.
- Reinforced Concrete: Standard for large field-erected towers. It is extremely durable and permanent.
- Galvanized Steel: Common in factory-assembled towers. The interior is often coated with a heavy-duty, corrosion-resistant epoxy or vinyl ester lining to protect it from stagnant water and treatment chemicals.
- FRP (Fiberglass): Used as a basin for smaller package towers. Seamless and highly corrosion-resistant.
4. Drift Eliminators
4. Drift Eliminators
These prevent water droplets from being carried out of the tower with the exhaust air (a loss called “drift”).
- PVC/PP: The universal choice. Their intricate, labyrinth-like shape is easily extruded from plastic, which provides excellent droplet capture with low air resistance.
5. Fans, Stacks, and Mechanical Components
- Fan Blades: Typically made from aluminum or FRP for their excellent strength-to-weight ratio, which reduces the load on the motor and drive shaft.
- Drive Shafts: Often hot-dipped galvanized steel or stainless steel for strength and corrosion resistance.
- Gears and Gearboxes: Housings are cast iron or aluminum, with internal gears made from hardened