Drift Eliminators in Crossflow Cooling Towers

Low-maintenance drift eliminators have been developed as an advanced solution. These components effectively capture and redirect water droplets before they escape, minimizing water wastage while requiring minimal upkeep.
100tr Square Cooling Tower

Introduction

Drift eliminators may be small in size, but they play a huge role in the overall performance and sustainability of crossflow cooling towers. While fill media and fans help reduce the temperature of circulating water, drift eliminators protect the environment — and your operating budget — by capturing water droplets that would otherwise escape into the atmosphere.

In industrial and commercial cooling towers, uncontrolled drift can cause:

  • Excess water loss
  • Damage to nearby equipment
  • Chemical exposure to personnel
  • Violation of air quality and environmental standards

In this post, we’ll break down:

  • What drift eliminators are
  • How they function inside a crossflow cooling tower
  • Types and materials used
  • Performance benefits and efficiency impact
  • Maintenance practices
  • And why they’re essential for compliance and cost-saving

What Is Drift in Cooling Towers?

Drift refers to tiny water droplets that get carried away with the exhaust air leaving the cooling tower. These droplets often contain treatment chemicals, salts, or biological agents, and they don’t contribute to cooling — they’re just loss.

Drift eliminators are mechanical barriers that trap and redirect these droplets back into the tower, minimizing water loss and ensuring cleaner air emissions.

What Are Drift Eliminators?

Drift eliminators are structured assemblies of angled blades, slats, or corrugated profiles, typically installed above the fill media and below the fan deck. As the upward air passes through these baffles, it changes direction multiple times, causing heavier water droplets to separate from the air and fall back into the tower.

How Drift Eliminators Work

  • Air carrying water droplets flows vertically upward after crossing the fill media.
  • It enters the drift eliminator section, which forces the air to change direction sharply multiple times.
  • The inertia of the water droplets prevents them from following the air path, causing them to collide with the eliminator surfaces.
  • Water droplets coalesce and drain downward back into the fill or basin.
  • Clean, moist air exits through the fan stack with minimal water content.

This process can reduce drift loss by 0.005% of circulating flow — or even lower, depending on design.

Types of Drift Eliminators

Blade-Type Eliminators

  • Made of FRP, PVC, or stainless steel
  • Designed with angled fins or plates that redirect airflow
  • Common in open, large-scale towers

Cellular Drift Eliminators

  • Honeycomb or layered plastic profiles
  • High-efficiency models used in HVAC and process cooling
  • Often made from PVC or PP and modular in structure

Wave-Type or Chevron Eliminators

  • Corrugated plastic waveforms that form multiple turns
  • Compact and space-efficient
  • Offer high droplet capture rates with low pressure loss

Selection Tip:

  • Use cellular type for compact towers or high-efficiency demand
  • Use blade type in environments with larger airflow and fewer spatial constraints

Performance Benefits of Drift Eliminators

Water Conservation

  • Captures water droplets and returns them to the system
  • Saves thousands of liters annually, especially in large towers
  • Reduces water bills and make-up water demand

Environmental Compliance

  • Ensures drift rate stays within permissible limits (e.g., 0.005% of circulating flow)
  • Helps meet EPA, OSHA, and local environmental regulations
  • Reduces public complaints in urban areas

Protects Surrounding Infrastructure

  • Prevents corrosion or staining of nearby equipment, ducts, and structures
  • Reduces exposure to chemical-treated drift (e.g., biocides or anti-scalants)

Efficiency Metrics to Monitor

  • Drift Loss Rate: Should be ≤ 0.005% of total flow
  • Air Pressure Drop Across Eliminators: Should remain < 10 mm H₂O for optimal airflow
  • Visible Mist from Fan Outlet: Indicates failure or fouling of drift eliminators

In crossflow cooling towers, drift eliminators are non-negotiable for anyone serious about operational efficiency, environmental compliance, and cost control. Though often overlooked, these components:

  • Reduce wastewater discharge and chemical loss
  • Improve air quality and employee safety
  • Protect surrounding structures from moisture damage
  • Help your system maintain green certifications and industry standards

🧠 A smart cooling system doesn’t just cool efficiently — it also preserves resources, minimizes emissions, and runs sustainably. Drift eliminators help you do all three.

Whether you’re building a new tower or retrofitting an old one, always choose high-efficiency, low-pressure-drop drift eliminators — they protect your investment, the environment, and your bottom line.