Cooling towers, also known as heat rejection devices, are systems that remove heat from fluids like water, in order to provide cool fluids to controlled environments. Cooling towers are typically used to cool down water or other fluids that have been heated during an industrial manufacturing process or some similar process.
Cooling towers find extensive applications across various industries due to their ability to efficiently dissipate heat and regulate temperatures. One of their key applications is in power plants, where they play a crucial role in cooling the hot water used in electricity generation processes. By providing a continuous flow of cooled water, cooling towers ensure optimal performance and efficiency of power generation systems.
In the realm of commercial and industrial buildings, meanwhile, cooling towers are integral components of HVAC systems. They help regulate indoor temperatures, ensuring comfortable working environments for occupants in large buildings, factories, and shopping malls. By removing excess heat from air conditioning units, cooling towers contribute to better indoor air quality and energy efficiency, reducing overall electricity consumption.
The manufacturing sector, in particular, heavily relies on cooling towers to maintain equipment and process temperatures within specific operational limits. Industries such as metal processing, plastic molding, and chemical production benefit from cooling towers’ ability to dissipate excess heat generated during manufacturing processes, safeguarding machinery and enhancing productivity.
Additionally, cooling towers are essential in the oil refining industry. They aid in the cooling of hydrocarbons during the refining process, ensuring product quality and efficiency in this critical sector.
Cooling towers also play a vital role in data centers, where they help regulate the temperature of computer systems and servers. By preventing overheating, cooling towers safeguard the continuous and reliable operation of data center facilities.
In summary, cooling towers have diverse applications, ranging from power generation to manufacturing, HVAC systems, oil refining, and data centers. Their versatility and efficiency in heat dissipation make them indispensable components in a wide array of industries, contributing to enhanced productivity, energy efficiency, and environmental sustainability.
People have been utilizing the concept behind tower cooling since antiquity. Ancient peoples of Rome, Greece, the Middle East and the Americas alike used water to evaporate heat and relieve them of discomfort caused by high temperatures. Some, for example, placed porous water jugs in their windows, where the water would capture the heat and let through cooled air.
So, the idea of air conditioning is quite old. However, people did not manipulate the concept mechanically until the Industrial Revolution, starting around 1819. That year, William Warrel and Robert Salmon received a British patent for their “evaporative cooler,” which was meant to generally cool air. In 1840, French physicist Jean Claude Eugène Péclet designed an extremely early version of a modern evaporative cooler. Early evaporative coolers like his were used as evaporative condensers for steam engines.
Despite the attempts of these inventors and others, cooling towers didn’t really become viable until the turn of the 20th century. American inventors began rapidly patenting versions of the cooling tower, which they described in a variety of different ways. Some names used in US patents at that time included drip coolers, wet boxes, swamp coolers, and desert coolers.
The first modern cooling towers used direct cooling with the assistance of tools like fans, sprayers, nozzles, and troughs. As the years went on, manufacturers replaced these apparati with motorized fans, circulating pumps and the like. Today, cooling towers are available in a number of different configurations.
How It Works
Cooling towers work on the fundamental principle of evaporative cooling, which exploits the thermodynamic properties of water to remove excess heat from industrial processes or HVAC systems. The process begins with hot water being pumped from the industrial equipment or air conditioning system into the cooling tower. Inside the tower, the hot water is evenly distributed over a series of fill materials, which are designed to increase the exposed surface area. This arrangement allows for better interaction between the water and the air flowing through the tower.
As ambient air is drawn in by large fans at the base or top of the cooling tower, it comes into direct contact with the water-saturated fill material. A small fraction of the hot water evaporates as a result of this contact, transitioning from liquid to vapor state. This phase change from liquid to vapor requires energy, which is absorbed from the remaining water. As a result, the water’s temperature decreases significantly, effectively cooling it down.
The cooled water then collects at the bottom basin of the cooling tower and is subsequently recirculated back to the industrial process or HVAC system, where it can absorb more heat, continuing the cooling cycle. This recirculation process allows cooling towers to maintain a continuous and efficient cooling operation.
To ensure the optimal performance of cooling towers and prevent mineral buildup in the system, a portion of the water, known as “blowdown,” is periodically purged and replaced with fresh makeup water. This helps maintain the water’s chemical balance and prevent excessive mineral concentration.
The evaporative cooling process used by cooling towers is highly effective and energy-efficient, making them a preferred choice for cooling in various industrial applications. Their ability to efficiently dissipate heat into the atmosphere or recycle it for reuse makes cooling towers essential components in power plants, manufacturing processes, oil refineries, and large-scale HVAC systems, contributing to energy conservation and environmental sustainability.
The main types of cooling towers are open loop towers, closed loop towers, counter-flow systems, and cross flow systems. Other types include HVAC cooling towers, industrial cooling towers, evaporative cooling towers, water cooling towers, and chiller cooling towers.
Open loop towers, also known as open circuit cooling towers, distribute water internally, where it encounters cooling air directly. The air absorbs the heat from the water and exits into the atmosphere as the now cool air falls into a collection basin.
Closed loop tower systems are designed to prevent contact between the cooling agent and the liquid being cooled. This means the liquid can be recirculated without being contaminated. It also means that the coolant and the material don’t need to be compatible with each other since they never make contact.
Counter-flow tower systems work using opposing air flows and water flows. The air moves up, absorbing the water’s heat as the water moves down.
Cross flow cooling towers work using perpendicular air flows and water flows. This time, the air flows sideways as the water flows down.
HVAC cooling towers are mostly found in large buildings, where they are used to keep the interior temperature at a comfortable level.
Industrial cooling towers are much more durable than an HVAC unit because they have to operate year-round and cool much larger volumes of liquid.
Evaporative and water cooling towers rely on evaporation to release heat into the atmosphere. They also require a local water source to remain efficient. Rivers, wells, seas, and lakes are all acceptable sources of cool water for evaporation and water cooling towers.
Chiller cooling towers have added refrigerant parts to cool fluid to an even lower temperature.
In general, cooling towers contain a wet deck, an air inlet and an air outlet port, intake louvers, a cool water basin, a fill space, mechanical instrumentation, fans, drift eliminators, and a shell.
Wet decks, also known as water distribution decks, consist of a set of nozzles that spray water onto fill material as it is being cooled. The goal of this is to maximize heat transfer.
Air inlet ports and air outlet ports are areas of entry and exits for air used in the tower.
Intake louvers are used to equalize the air flowing into the fill and to keep water inside the tower.
Cool water basins are used to collect cooled water after it has been discharged from the tower. It is located at the base of the tower.
Fill space is a corrugated or honeycomb patterned area made from PP or PVC. This is the main area in which cool air pulls heat from hot water.
Mechanical instrumentation includes driveshafts, gearboxes, fans, sensors, pumps, connectors, cables, etc. Elements such as these help the system run properly and efficiently.
Fans are an important component of those cooling towers without a natural draft system. Fans provide not only increased cooling, but also a level of drying that keeps the system from developing bad bacteria, mildew or mold on perpetually wet surfaces. Fans may be axial or centrifugal. Fans may also hang overhead the system, work within it, or be installed below it.
Drift eliminators help cooling towers be more efficient and environmentally friendly by capturing air stream water droplets before they escape into the environment as vapor.
Shells, also known as cases, are enclosures that hold liquid as it waits to recirculate through the system. Made from galvanized steel, ceramic, chemically treated wood, reinforced plastic or aluminum, shells also provide structural support in the internal elements and fan system of the tower.
Cooling towers offer a range of significant benefits, making them crucial components in various industrial processes and climate control systems. One of their primary advantages is efficient heat dissipation, which prevents equipment overheating and ensures smooth and reliable operations in power plants, manufacturing facilities, and refineries. By effectively removing excess heat, cooling towers help maintain optimal temperatures, thereby extending the lifespan of equipment and reducing the risk of costly breakdowns.
In the realm of commercial and industrial buildings, cooling towers play a pivotal role in HVAC systems, contributing to comfortable indoor environments for occupants. They efficiently remove heat from air conditioning units, allowing the systems to provide pleasant temperatures and better indoor air quality, which in turn enhances productivity and well-being in work environments.
Another key benefit of cooling towers is their energy efficiency. By employing the principles of evaporative cooling, they consume significantly less energy compared to traditional air-cooled systems. The evaporation process requires relatively low energy inputs, leading to cost savings and reduced environmental impact, especially in power-hungry industries.
Cooling towers also promote water conservation. Through the recirculation of cooled water, they minimize overall water usage, which is particularly critical in regions facing water scarcity. This recycling process not only reduces water consumption but also lessens the discharge of heated water into natural water bodies, thus mitigating thermal pollution and protecting aquatic ecosystems.
Moreover, cooling towers contribute to sustainable practices by aiding in the reduction of carbon emissions. As energy-efficient cooling solutions, they help industries lower their carbon footprint and move towards more environmentally friendly operations.
In summary, the multifaceted benefits of cooling towers encompass improved equipment performance, energy efficiency, water conservation, reduced environmental impact, and support for sustainable practices. These advantages underline the indispensability of cooling towers in modern industrial processes, power generation, and climate control systems, playing a crucial role in meeting the challenges of a rapidly evolving and environmentally conscious world.
Design and Customization
When designing cooling towers, manufacturers consider several important factors. These include available space, available water sources, electrical supply, materials and structural capacity. They also consider budget, as the design of a cooling tower plays an important part in its cost and efficiency during operation.
Based on your specifications, suppliers can offer you standard or custom cooling towers. Custom cooling towers are an excellent option if you are looking to meet specific volume specifications and/or account for the environment in which the tower will be used. For example, manufacturers often create custom tooling towers to compensate for elements that could hamper performance such as piping, electrical sources, capacity, etc.
To make cooling towers fit your application, manufacturers offer cooling towers made using a number of different materials in a wide range of sizes. Manufacturers build cooling towers using materials such as reinforced glass like fiberglass, stainless steel, ceramic, plastic, and aluminum. For outdoor applications, fiberglass is ideal because of its durability in harsh weather, and it’s lightweight and resistant to corrosion. Depending on the application, cool towers can be as small as a rooftop unit to as large as a 400-foot structure. If your cooling tower is to work in a moist, high temperature environment, manufacturers will certainly include a fan (or several fans) in the design. Fans are important in environments such as these as they make the environment less desirable for microorganisms that would otherwise settle down there. Fans move not only through the water, but also the air in the system.
Safety and Compliance Standards
The best quality assurance for your cooling tower is the knowledge that it has been certified or approved per the standards of a few important standards organizations. One of them is ASME (The American Society of Mechanical Engineers) and the other is CTI (Cooling Technology Institute). Both of these associations offer standards and advice on the performance and safety testing of cooling towers. In addition, in the United States, your cooling towers must meet the standards of the EPA (Environmental Protection Agency). Per the Clean Air Act Amendments of 1990, the EPA enforces rules designed to reduce the emissions produced by industrial cooling towers.
In addition to certifications and testing recommendations from ASME, CTI and the EPA, you should make sure that your cooling tower meets all the standard requirements of your industry, whether that be FDA standards, Mil-Specs or something else. If your cooling tower is using combustible materials or is in any danger of catching or causing a fire, it must meet the standard requirements of NFPA (National Fire Protection Association) 214.
It is important that you regularly check your cooling tower for performance, efficiency and general safety. For example, if your system works using evaporation cooling, both ASME and CTI recommend you measure your tower effectiveness using wet bulb temperatures. Wet bulb temperature is the lowest temperature to which water in your system can be cooled. It is measured with a psychrometer. You can tell how efficiently your system is running by using the wet bulb temperature of air moving into the intake port. You use it to help calculate how long it takes water evaporation in your system (the rate of heat transfer). Learn more about how to perform these measurements using guidelines provided by ASME or CTI.
Things to Consider
For the best results possible, you need to work with an experienced, trustworthy and intuitive cooling tower manufacturer. To jumpstart the process of finding that manufacturer, we have put together a list of industry-leading, vetted custom cooling tower manufacturers. You will find their information, complete with interaction profiles, interspersed with these information paragraphs.
The best way to figure out which manufacturer is best for you is to start by putting a list together of your specifications, questions and concerns. Do not forget to include your timeline, your budget, your standard requirements, your delivery preferences, if you require installation support, and the level of post-installation/delivery support you require. Once you’ve got your list together, you can begin your search for a supplier in earnest. Browse those we have listed on this page. Cross reference your specifications list frequently and pick out three or four who appear to offer the services you’re looking for. Then, reach out to each of them to discuss your needs. As you correspond with them, make sure to note their general demeanor. Remember, customer service is important. After you have done that, compare and contrast your conversations, and select the cooling tower manufacturer you believe is best for you.
Cooling Tower Informational Video