Combined Flow Configuration
Combined flow is the use of both a heat exchange coil and fill for heat transfer in a closed circuit cooling tower. The addition of fill to the traditional closed circuit cooling tower design reduces evaporation in the coil section, reducing the potential for scaling and fouling. BAC’s combined flow closed circuit cooling towers utilize parallel flow of air and spray water over the coil, and crossflow air/water flow through the fill.
In parallel flow, air and water flow over the coil in the same direction. The process fluid travels from the bottom to the top of the coil, increasing efficiency by bringing the coldest spray water and air in contact with the process fluid at its coldest temperature.
In the fill air and water interact in a crossflow configuration: water flows vertically down the fill as air flows horizontally across it.