Blog

Material Selection

PVC (Polyvinyl Chloride)

• Most common – 90%+ of fills
• Temperature limit: ~140-150°F (60-65°C)
• Advantages: Low cost, lightweight, corrosion-resistant
• Types: Various fire ratings (Class 1, Class 2)

CPVC (Chlorinated PVC)

• Higher temperature resistance
• Limit: ~180-200°F (82-93°C)
• Used in: Higher temperature applications

Polypropylene (PP)

• Chemical resistance to certain organics
• Used in: Special applications with unique chemistry

Wood

• Traditional material, now limited to special applications
• Used in: Some splash fills, certain corrosive environments

Fouling and Maintenance Concerns

Common Problems:

1. Biological Growth (algae, bacteria, biofilm)
2. Scale Formation (calcium carbonate, silica)

1. Suspended Solids (silt, mud, debris)
2. Corrosion Products (iron oxide, etc.)

Prevention:

• Regular cleaning (manual, chemical, pressure washing)
• Water treatment (biocides, scale inhibitors, dispersants)
• Proper filtration (side-stream filters)
• Fill design selection (splash vs. film based on water quality)

Selection Criteria

When choosing fill type, consider:

1. Water Quality
   1. Clean water → Film fill
   1. Poor water → Splash fill
   1. Variable quality → Hybrid fill
2. Tower Type
   1. Counter flow  → Usually vertical film or splash
   1. Cross flow → Usually diagonal or horizontal fill
3. Space Constraints
   1. Limited space → High-efficiency film fill (compact)
   1. Ample space → Splash fill (lower maintenance)
4. Operating Conditions
   1. Temperature
   1. Airflow velocity
   1. Water loading rate
5. Maintenance Capability
   1. Easy access for cleaning?
   1. Available water treatment program?