Cooling Tower Water Distribution System

A cooling tower water distribution system is the part of the tower that evenly spreads hot circulating water over the fill, ensuring maximum air–water contact and efficient heat rejection. Poor distribution = dry spots, scaling, and reduced capacity.

Below is a clear, practical explanation focused on industrial cooling towers.

1. Function of the Cooling Tower Water Distribution System

The cooling tower water distribution system must:

* Deliver uniform water flow across the entire fill area

* Maintain correct droplet size for evaporation

* Operate with low pressure loss

* Prevent clogging and scaling

2. Main Types of Cooling Tower Water Distribution System

2.1 Gravity (Open Basin) Distribution

Most common in crossflow cooling towers

Components

* Hot water basin

* Metering orifices

* Flow-control dams

Characteristics

✔ No spray pressure required

✔ Low pumping head

✔ Easy inspection

✘ Sensitive to uneven flow

✘ Not suitable for very high heat loads

Typical brands: Marley, EVAPCO crossflow towers

 2.2 Spray Header Distribution System

Most common in counterflow cooling towers

Components

* Spray headers (PVC / HDG / SS)

* Spray nozzles

* Riser pipe

* Flanges and supports

Characteristics

✔ Uniform distribution

✔ Compact design

✔ Handles high heat load

✘ Requires spray pressure (typically 0.7–1.5 bar)

2.3 Pressurized (Closed Pipe) Distribution

Used in high-capacity or industrial towers

Characteristics

✔ Very uniform spray

✔ Suitable for large flow rates

✘ Higher pump power

✘ More complex piping

3. Cooling Tower Water Distribution System Spray Nozzle Types

Nozzle Type	Application	Feature
Fixed cone (full cone)	Counterflow	Uniform spray pattern
Spiral nozzle	High solids water	Anti-clog
Variable flow nozzle	Varying load	Self-adjusting
ABS / PP nozzle	HVAC towers	Corrosion resistant
Stainless steel nozzle	Process cooling	High temperature

➡ Nozzle spacing typically 300–600 mm.

4. Cooling Tower Water Distribution System Design Parameters to Consider

4.1 Water Flow Rate

* Typical loading: 1.5–3.0 m³/m²·h over fill area

* Must match fill type and tower rating

4.2 Spray Pressure

* Gravity basin: ~0 bar

* Spray nozzles: 0.7–1.5 bar

* Excess pressure → misting & drift

4.3 Distribution Uniformity

Target:

* ±10% flow variation across fill

5. Cooling Tower Water Distribution System Materials Used

Component	Common Material
Spray headers	PVC / FRP / HDG / SS
Nozzles	ABS / PP / PVC / SS
Basin	FRP / concrete / galvanized steel

➡ Choose materials based on water chemistry and corrosion risk.

6. Common Problems & Solutions Of Cooling Tower Water Distribution System

Problem	Cause	Solution
Dry spots on fill	Blocked nozzles	Clean or replace nozzles
Uneven cooling	Poor header layout	Rebalance system
High drift loss	Excess spray pressure	Reduce pump head
Scaling	Hard water	Water treatment

7. Maintenance Best Practices Of Cooling Tower Water Distribution System

* Inspect nozzles every 3–6 months

* Clean headers during shutdown

* Check spray pattern visually

* Replace cracked or worn nozzles

* Ensure equal header elevation

8. Typical Layout (Counterflow Tower)

Hot Water Riser

     │

Spray Header

 │    │    │

Nozzle Nozzle Nozzle

     ↓

    Fill

     ↓

Cold Water Basin

9. Selection Tips

✔ Match distribution type to tower design

✔ Ensure nozzle anti-clog capability

✔ Avoid undersized headers

✔ Allow easy access for maintenance