A cooling tower is a specific heat exchanger, where water and air are brought into direct contact with each other to reduce the temperature of the water. The water which has been heated previously is pumped to the cooling tower through pipes where the water is sprayed onto a kind of material known as fill which essentially slows down the flow of water through the cooling tower and at the same time exposes as much water as possible to the air for maximum air-water contact. The air is driven through the tower by an electric fan. When this happens some amount of water will evaporate thus, having a cooling effect the cold water will then be pumped back to the industrial process where it will be heated again afterward it will be pumped back to the cooling tower for the process to be repeated. Depending on the project there are several types of International Cooling Towers.
Induced draft vs forced draft cooling towers
In induced draft cooling towers the funds are normally placed on top of the unit and they then pull the air through the material based fill medium. On the other hand, concerning forced draft cooling towers the blowers are in place at the bottom of the air inlet base and from this position they push up the air towards the fill.
Crossflow cooling towers
In these towers, the water will flow vertically through the material-based fill while at the same time the air will be flowing horizontally against the falling water. This eliminates the need for a distribution system which is where the air would have passed through. The hot water used is distributed by the use of gravity. The hot water is placed in basins on top of the whole component which is essentially above the fill.
Counter-flow cooling towers
The design of counterflow towers ensures that the air is flowing vertically upwards in the opposite direction to the flow of the water that is falling into the fill. Due to the airflow which is vertical the use of gravity flow basins which are open is rendered impossible such as, those found in crossflow towers. Therefore the counterflow tower will use a pressurized spray system to spray water onto the top of the fill. The pipes and nozzles must be a further distance apart to enable the air to pass through the spraying system without any airflow restriction.
Factory assembled vs field-erected cooling towers
The factory-assembled power is shipped and rebuild using as few as possible sections as the type of transportation will allow. If a tower is fairly small then it can even be shipped as a whole unit. Larger multi-cell cooling towers are made as separate components at the factory and they are shipped ready to be assembled on site. These towers can either be counterflow or crossflow, forced draft or induced draft depending on how they are going to be used.
Field erected cooling towers are essentially constructed on the site where they will be eventually used. The large cooling towers and some of the smaller towers are prefabricated and shipped to the site where they can be finally all put together. These towers are either crossflow or counter-flow and mainly used for power generation or heavy industrial use.