Cross Flow Evaporative Cooling Tower
In a cross-flow cooling tower, the flow of air is directed perpendicular (across) the downward flow of the water being cooled. This is in contrast to a counter flow design, where air moves directly upward against the downward flow of water.
This cross-flow arrangement defines the tower’s design and performance characteristics.
How a Cross Flow Cooling Tower Works
- Water Distribution: Hot water from the industrial process or HVAC system is pumped to the top of the tower and is distributed into open gravity-fed basins (or hot water basins). These basins have metering orifices or nozzles that allow the water to flow evenly by gravity down over the fill media.
- Air Intake: Meanwhile, ambient air is drawn into the tower horizontally through large, open intake louvers located on the sides of the tower.
- Heat and Mass Transfer (The “Cross Flow”): As the water cascades down through the fill media, it breaks into small droplets and thin films, massively increasing its surface area. The air moves horizontally across this falling water. This perpendicular contact allows for heat transfer and evaporation, cooling the water.
- Air Discharge: The now warm, moist air is drawn upward by one or more fans mounted at the top of the tower (induced draft) and is exhausted into the atmosphere.
- Collection: The cooled water collects in the cold-water basin at the bottom of the tower and is pumped back to the process to begin the cycle again.
Key Components of a Cross Flow Tower:
- Open Hot Water Basins: A defining feature. These are located at the very top and distribute water by gravity.
- Louvers: Large openings on the sides that allow air to enter. They are designed to minimize water splash-out (“drift”).
- Fill Media: Splash-type or film-type plastic packs located directly below the water basins. Their job is to maximize water-to-air contact.
- Drift Eliminators: Located above the fill and before the fan, they capture entrained water droplets from the air-stream to prevent water loss.
- Fan(s) & Motor: Typically axial fans mounted at the top for induced draft.
Cold Water Basin: The reservoir at the bottom that collects the cooled