Splash Fill: A Detailed Explanation
Splash fill is a type of cooling tower packing designed to maximize heat transfer by repeatedly breaking the falling water stream into smaller droplets, creating a large surface area for air-water contact.
How It Works: The Core Principle
Unlike film fill (which spreads water into a thin film), splash fill relies on impact and disruption. Water droplets fall onto staggered elements, splashing and breaking into finer droplets, which then fall onto the next layer, repeating the process.
The cooling occurs through:
- Evaporation from the large droplet surface area
- Sensible heat transfer as air contacts the droplets
Key Characteristics & Design
- Open Geometry: Features spaced bars, grids, or slats.
- Staggered Pattern: Elements are offset to ensure water never falls in a straight vertical line, forcing maximum disruption.
- Droplet-Centric: Performance depends on creating and maintaining a “droplet curtain.”
Common Configurations & Types
- Bar/Slat Grids:
- The simplest form—horizontal or vertical wooden or plastic bars.
- Classic in old wooden towers.
- Splash Grids:
- Multi-directional grids (often in a square or honeycomb pattern).
- Example: Tellerette rings, staggered vertical grids.
- Modern 3D Trickle Grids:
- A hybrid evolution. Three-dimensional PVC grids with textured surfaces.
- Promotes both droplet formation and some film formation on the grid surfaces.
- Example: Munters’ Trickle Grid, SPX’s FG Splash Grid.
Materials
- Historically: Redwood, Cedar (for natural rot resistance).
- Modern: PVC (most common), Polypropylene (PP), occasionally CPVC for higher temperatures.
Advantages of Splash Fill
| Advantage | Why It Matters |
| 1. Fouling & Scaling Resistance | #1 Benefit. The open design allows suspended solids (silt, algae, scale flakes) to pass through without clogging. Easy to clean mechanically or with high-pressure water. |
| 2. Low Air Pressure Drop | Air moves freely through the large openings, requiring less fan horsepower compared to dense film fills. |
| 3. Durability & Structural Integrity | Robust construction can handle heavy loads, ice formation, and physical abuse better than thin-film fill sheets. |
| 4. Tolerance for Poor Water Quality | Ideal for water with high turbidity, high calcium hardness (scale potential), or where treatment is minimal. |
| 5. Lower Maintenance Costs | Less frequent cleaning and longer service life in harsh conditions. |