Cooling Towers Continued…

Cooling towers also have pumps. In the large, power plant cooling towers, pumps can suction well over one hundred thousand gallons of water each minute. Smaller cooling towers have smaller pumps. These pumps will only suction a few gallons each minute. After the water is suctioned into the system through the pumps, it travels to the condenser. It is in the condenser that the water is actually heated.

The supply of water is cooled through an evaporative process. A small percentage of the water is allowed to evaporate during the cooling. This helps to cool the entire supply of water. The evaporative process is a very effective cooling process that can result in much lower temperatures much quicker than other cooling processes, such as air-cooling.

Types of Cooling Towers

There are three types of cooling towers. The first is a natural-draft cooling tower, which depends on the buoyancy of the waste air to provide a draft as it rises up the tower and out into the atmosphere. A mechanical-draft cooling tower uses fans to provide this draft. Finally, fan-assisted natural-draft cooling towers use fans to assist the buoyancy of the waste air.

Maintaining Water Levels

When the waste air leaves the tower, small drops of water are carried along with it. This water loss is called the drift. Because the amount of water traveling through the system must stay consistent, the water lost through the drift gets replaced. Water must also replace the blow-out, or the water lost due to wind or splashing.

Water, of course, carries along with it certain solids and minerals. This level, like the amount of water, needs to remain consistent within the tower. When water evaporates, it leaves behind its solids in the large water supply. So, the level of solids within the supply increases. In order to bring that level down again, some of the water is removed. This removed water is called the blow-down.

By Christy Patrick