Different types of cooling tower principles
A cooling tower design has a specific purpose. Not all will work for every industrial processes or applications.
To circulate air throughout the tower, this cooling tower system uses fans like centrifugal and propeller fans or other mechanics. Though they are more effective than natural draft, they can consume more power resulting in more cost to operate.
Mechanical draft cooling towers can be split into 2 main types:
This cooling tower system has the water flowing downward through its fill media while the air flows horizontally through the structure. Hence the name crossflow since the water and air flows or cross paths, which results in air not needing to go through the distribution system. Crossflow cooling tower designs normally are less high but larger in footprint as forced draft counter-flow cooling towers.
In the counter-flow cooling tower system, the air moves upward via the structure while water flows downward to cool the air. Since the air flows vertically, it uses a pressurized spray system as a substitute instead of the basin’s gravity-flow in order to spray the water on top of the distribution basin. These type of cooling tower system are usually more compact than crossflow towers with regards to footprint and can help save energy in the long run.
These cooling towers, as the name suggests, depend on natural convection to circulate air through the tower, which then cools the water. It works on the stack effect which causes the hot air in the cooling tower to rise. Most and warm air naturally rises because of the density differential compared to the cooler and dry outside air.