Hot Water Distribution System
Cooling Tower Spares
Hot Water Distribution System
The hot water distribution system gets water evenly across the fill. If distribution is bad, you get channeling, dry spots, and poor cooling.
1. Gravity Distribution - Crossflow Towers
- How it works: Hot water goes to open basins above the fill. Water falls through metering orifices/nozzles onto the fill.
- Components: Distribution basin + nozzles/orifices + splash plates
- Pros: Low head, easy to see and clean, no spray pressure needed
- Cons: Large footprint, algae grows in open basins, freezing risk
- Used in: WSF- WDF Induced draft crossflow towers.
2. Pressurized Spray - Counterflow Towers
- How it works: Water is pumped through headers and spray nozzles / Water Sprinklers under pressure. Nozzles/ Sprinkler Pipes spray downward over fill.
- Components: Main header + lateral branches + spray nozzles / Sprinklers and Sprinkler pipes
- Pros: Compact, enclosed system, no sunlight = less algae, better for tall towers
- Cons: Needs 10-30 kPa pump head, nozzles can clog, harder to inspect
- Used in: – WRT-WST Series Induced/forced draft counterflow towers
Key Components Compared
- Component Gravity / Crossflow Pressurized / Counterflow
- Water entry: Top basin, low pressure Header pipes, 10-30 kPa
- Distribution device: Target nozzles, orifices Spiral, square, or low-pressure nozzles
- Flow control: Orifice size + water level Nozzle type + header pressure
- Access: Open top, easy Requires internal access
- Clog risk: Low, big orifices Higher, small nozzle holes
- Evenness: Good if basin level Excellent if pressure balanced
Common Nozzle Types
- 1. Target/spray nozzles: For crossflow basins. Water hits a plate and fans out. Large 20-25mm openings resist clogging.
- 2. Spiral nozzles: For counterflow. Full-cone spray with no internal parts. Good for dirty water.
- 3. Square spray nozzles: For counterflow. Square pattern reduces overlap gaps. High efficiency.
- 4. Low-pressure nozzles: For counterflow with low head. Bigger orifices, less clogging.
Why Distribution Matters
- Bad distribution causes:
- 1. Overloaded zones: Some fill gets too much water, air can’t cool it, you lose efficiency
- 2. Dry zones: Some fill gets no water, air bypasses, wasted surface area
- 3. Scaling/fouling: Dry-wet cycles cause hard scale on fill
- A 10% flow imbalance can cost you 2-3°C in approach.
Design tips:
– Crossflow basins need to stay level within 3mm or flow misdistributes
– Counterflow headers use looped piping to balance pressure
– Nozzle spacing is usually 300-600mm, depending on spray pattern
