A cooling tower is a heat exchanger which, through evaporation, removes heat from the water and that rejected heat is transferred to the atmosphere. The cooling process occurs when the hot water contacts the air drawn through the cooling tower, this reduces the temperature of the hot water. To improve upon the efficiency of the cooling process, the effective surface area of the water running through the cooling tower is often increased by spraying, splashing or filming of the water to expose more of the water surface area to the air. Evaporative cooling is commonly seen when one steps out of the shower, the water drops still on your body evaporate quickly, leaving one with a cooling sensation. When a person sweats on a hot summer day, it is to help the body cool down. Sweat glands release sweat onto the skin, which then evaporates and helps reduce the body’s internal temperature.
How Do Cooling Towers Work?
Cooling towers hot water intakes spray hot water, usually pumped through FRP or PVC pipe headers, over PVC fill media. The fill acts as a heat transfer enhancer by providing the maximum amount of water surface area to transfer heat. The water and the air passing through come together, creating evaporative cooling. There is a small amount of water loss through evaporation, which is the result of cooling down the water. The remaining water falls into a water basin to be reused or pumped back into the cooling system. The cooling towers ICS builds are custom heat exchangers to meet industrial customer needs.
Where Are Cooling Towers Used?
Cooling towers are often used in commercial and industrial applications, but in this section, we will focus on industrial applications.
Power plants like biomass, gas – fired, nuclear, and geothermal power all use industrial cooling towers to cool-down processes. Additionally, petrochemicals, oil refineries, pulp and paper plants also use cooling towers to cool process water.
What Are The Different Types of Cooling Towers?
Natural Drafts or Atmospheric Cooling Towers: This type of cooling tower does not require mechanical components to operate, instead, the hot water is sprayed and the airflow through the tower is produced by the density difference between the less dense air inside the cooling tower stack and the more dense air outside the tower.
The natural draft cooling tower can be designed and erected as counterflow or crossflow as well.
Mechanical Draft: Mechanical draft cooling towers are categorized into an induced or forced draft type. These types of towers are usually driven by motors coupled to gear reducers connected to axial fans. It is common to see the cooling towers with a single fan but there are cases where the need of two fans per cell is required to meet the airflow volume.
Induced Draft: These types of cooling towers have axial fans on top of the cell. The fans move the air by suction instead of forcing (pushing) the airflow through the cooling tower. These types of cooling towers have air discharge velocity higher than the entrance velocity. Because of the high discharge velocity, the induced draft cooling towers are less probable to experience recirculation.
Forced Draft: These types are characterized by high airspeed at the air inlet (entrance) and low exit velocities. This makes them susceptible to recirculation and therefore are considered less efficient. Additionally, due to the location of the fans, these types are subject to developing severe icing during the winter months.
Induced and forced draft cooling towers can be built in counterflow or crossflow configurations.
Counterflow Cooling Towers: Air moves vertically upward, entering the cooling tower through the air inlets, then passing through the fill and counter to the down spray of the hot water. Due to the enclosed nature of these types of cooling towers, water is not exposed to the environment; thereby retarding the growth of algae.
Crossflow Cooling Towers: On this type of cooling towers, air moves through the fill positioned horizontally across the downward fall of water. The hot water is poured into hot water basins located at the top of the fill and it is distributed by gravity through nozzles on the floor of the hot water basins.
Whether you need to repair, upgrade or rebuild your tower, we customize solutions to restore your tower to its optimal condition and operational performance. Our innovative designs will increase tower efficiency, boost profitability, and ensure safety and longevity. Contact us today to request a quote!