Cooling towers: components
Main cooling towers parts are found in both open and closed circuit cooling equipments.
Structure
Containment and support structure can be made of metal, glass fibre reinforced polyester GRP or both. In the case of large, field erected cooling towers, FECT or hyperbolic type, concrete is also used.
Fill
Filling is one of the open-circuit cooling towers components also called heat exchanger coils in the close-circuit cooling equipments. They are the “heart” of evaporative cooling equipment as are used for heat exchange between water and air. In the case of closed circuit towers, the heat exchange coil consists of a closed tube through which the cooling fluid or water circulates and remains clean, as is not in contact with air, during the cooling process. On the other hand, in open circuit towers, the cooling circuit water may become contaminated during the process. Depending on water quality the most suitable type of fill pack has to be considered. A wide range of fill packs can be adopted: from “film” fill packs to “splash” fill packs.
Water distribution system
Water distribution system are usually made of PVC pipes and nozzles or through open channels. These two systems allow the water distribution over the filling in open cooling equipments or heat exchange battery in closed cooling towers.
Drift eliminator
Drift eliminators are located immediately upstream of the fan. It has the function of keeping micro-drops of water that would otherwise be carried out by the air flow caused by the fan.
Fan
Axial or centrifugal type fans. It is the only moving mechanical part that “forces” the water evaporation necessary for cooling. The choice of axial or centrifugal type depends on design conditions. It will determine the best operation and the lowest system consumption.
Cooling towers: materials
The nature of the water to be cooled significantly affects both the choice of building materials to be used and the most suitable type of filler. In the presence of particularly aggressive or acid water, stainless materials or glass fibre is preferred as it is intrinsically insensitive to most chemical agents.