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Cooling Towers
- Introduction to Cooling Towers
- How Cooling Towers Work
- Types of Cooling Towers
- Components of Cooling Towers
- Limitations of Cooling Towers
- Maintenance Schedule for Cooling Towers
- Location of Cooling Towers
What is a Cooling Tower?
A cooling tower extracts heat from water by evaporation. In an evaporative cooling tower, a small portion of the water being cooled is allowed to evaporate into a moving air stream to provide significant cooling to the rest of that water stream. Evaporative Cooling towers are relatively inexpensive and very dependable means of removing low grade heat from your process.
Cooling Towers are commonly used to provide lower than ambient water temperatures and are more cost effective and energy efficient than most other alternatives. The smallest cooling towers are structured for only a few gallons of water per minute while the largest cooling towers may handle upwards of thousands of gallons per minute. The pipes are obviously much larger to accommodate this much water in the larger towers and can range up to 12 inches in diameter.
How Cooling Towers Work
When water is reused in the process, it is pumped to the top of the cooling tower and will then flow down through plastic or wood shells, much like a honeycomb found in a bee’s nest. The water will emit heat as it is downward flowing which mixes with the above air flow, which in turn cools the water. Part of this water will also evaporate, causing it to lose even more heat.
Types of Cooling Towers
One way to distinguish between cooling towers is how the air and water interact, open cooling towers or closed cooling towers. Open cooling towers, also called direct cooling towers, allow the water to come into contact with outside air. If cooled water is returned from the cooling tower to be used again, some water must be added to replace the water that has been lost. Pollutants are able to enter into the water used in these processes and must be filtered out. Cooling Technology, Inc provides all open water cooling towers with sand and gravel filters to help combat this issue. Another method of combating the excess minerals and pollutants is some means of a dissolved solid control, such as a blow down. With this, you drain off a small percentage of the flow to aid in the removal of these contaminants. This is fairly effective, but not as efficient as filtration.
Closed loop (or closed circuit) cooling tower systems, also called indirect cooling tower systems, do not allow the water to come into contact with any outside substance, therefore keeping the water more pure due to the lack of foreign particles introduced. Contact Cooling Technology and one of our technical engineers will help you design one to meet your custom needs.
Another classification of cooling towers is made between field assembled towers and factory assembled towers. Field assembled towers are shipped in pieces and assembled on site by a highly qualified and certified installation team. Factory assembled towers typically only require the fan motor to be mounted. Please contact your Cooling Technology Sales Representative for more information on installation opportunities.
Components of a Cooling Tower
Since Cooling Technology, Inc uses only the highest quality Marley Cooling Towers©, those are the towers we will discuss. If you would like to be directed to the Marley Cooling Tower© website, please click here.
Cooling Tower Hot Water Basin: This basin receives the hot water that is piped into each cell in the tower and has removable covers to restrict the influx of debris. Water enters through a removable wave suppressor splash box.
Cooling Tower Fan: Fans are individually adjustable propeller type and driven through v-belts and protected with a belt guard, or with drive shafts and gear boxes.
Cooling Tower Fill, Louvers, and Drift Eliminators: Each fill sheet has louvers and drift eliminators formed by thermoformed PVC. The fills are suspended by hot dip galvanized structural tubing and are elevated above the floor of the cold water basin.
Cooling Tower Cold Water Basin: In a cooling tower, water is supplied from the discharge of the circulating water system to a distribution basin, from which the cooling tower pump takes suction. Accessories include both a side suction connection OR a hole and bolt circle in the basin floor suitable for gravity flow, which have debris screens and anti-cavitation devices.
Cooling Tower Pump: Pumps of a variety of sizes may be used, depending upon the size of cooling tower and the demands of your process. The technical engineers at Cooling Technology, Inc understand that each project is unique and will work diligently to make sure your site’s requirements will be matched to the best cooling tower and pump.
Limitations of Cooling Towers
There are some limitations to using cooling towers. Their ability to cool is based on how much water is lost due to evaporation. The evaporation from a cooling tower is based on the quality of air in the surrounding area. If an area has high humidity, less water will evaporate than in a dry climate. In the winter, cooling towers are usually able to cool more efficiently as the air is drier. If the water is needed to be cooled to higher than 75°F, a cooling tower is recommended, dependent upon wet bulb temperature for the region. If water is needed to be cooler, a chiller may be better suited to your cooling needs than a cooling tower.
Maintenance of a Cooling Tower
At Cooling Technology, Inc., we recommend your cooling tower be cleaned at least once every two years. Please contact a cooling technology representative to learn more about our maintenance packages for your cooling tower needs.
Location of a Cooling Tower
Due to the size impediments of cooling towers, most are stored outside with ample room for air flow. To prevent freezing in the winter in the northern colder climates, indoor reservoirs are highly recommended. However, some customers have chosen to immersion heaters as another way to prevent freezing in their cooling tower. A Cooling Technology representative will be happy to work with you to determine which will best fit your requirements and where your cooling tower should be housed.