Cooling towers, whether in the industrial or HVAC sector, have a simple purpose – removing heat from a facility. They achieve this by spraying water down through the tower as air is typically introduced from the sides of the tower and passes through falling water.

In short, in a HVAC context, cooling towers are heat exchangers that use water and air to transfer heat from air conditioning systems to the outdoor environment, disposing of (aka ‘rejecting’) unwanted heat from a chiller.

The simplicity of the basic operation of cooling towers, however, masks their sophistication in terms of types and functions.

There are many cooling tower variants designed for different applications, including evaporative condensers and adiabatic systems. For the purposes of this blog, however, we will focus on two kinds – open and closed-circuit cooling towers which employ evaporative cooling.

Evaporative cooling towers

Simply put, evaporative cooling is the loss of energy from a surface as a liquid on it changes phases to a gas, resulting in a lower temperature.

In open circuit cooling towers, warm water can be cooled by ambient air drawn past a flow of water. Some of this water will evaporate, and the energy required to evaporate that portion of the water is taken from the remaining mass of water, thus reducing its temperature.

A medium called ‘fill’ is used to increase the surface area and the time of contact between the air and water flows, thus improving the transfer of heat.

Open circuit cooling towers

Open circuit cooling towers offer several solid business benefits, including the ability to use different water flow rates, long life by using corrosion-proof materials such as fibreglass and plastics, easy inspection of internal parts thanks to large manholes, and automatic parameterisation and/or remote monitoring (on request).

Klima-Therm distributes the comprehensive open circuit cooling tower range from Italian process cooling specialist MITA Cooling Technologies. This covers plant of all sizes including small and medium installations, large industrial cooling towers, and for sectors such as oil & gas and cogeneration.

Cooling towers for small & medium plant

The compact PMS evaporative open circuit cooling tower, for example, is designed for small and medium-sized plants. Manufactured entirely from fiberglass with protective gel-coat layer, it features a light and non-corrodible structure.

This versatile tower offers simple maintenance, certified performance, fast payback, and the ability to harness the power of Industry 4.0 for control, monitoring, and data collection on the company management system.

Cooling towers for medium to large systems

Another tower – the lightweight, non-corrodible PME-E – for medium to large systems offers the same benefits for the process industry. All models are fully pre-assembled in the factory for tightly controlled and precisely measured build quality, safety, security, and sustainability.

For large industrial plants, Klima-Therm can supply MITA’s PMM modular cooling tower. This series, designed for power generation, steel and aluminium processing, cogeneration, and other large production sites, offers a powerful combination of high efficiency and exceptional performance as well as reduced installation and transport costs.

The PMM cooling tower consists of components pre-assembled in the factory and transportable by container: the aim is easy remote transport to minimise costs. The devices are assembled with different heat exchange fill packs selected according to the type of water to be cooled and specific customer needs.

The fill packs used by MITA, which are internally tested in its own test station, comprise self-extinguishing PVC sheets or thermoformed polypropylene available with different geometries depending on the characteristics of the water.

The PU series of field-erected industrial cooling towers, meanwhile, can serve very large plants, especially oil & gas, chemical, and power generation. Indeed, field-erected cooling towers are used in a wide range of cooling applications such as industrial processes, refineries, manufacturing, power plants, and HVAC.

MITA supplies these towers in different materials – including concrete, steel, fiberglass, and pultruded fibre-reinforced plastics – according to particular project needs.

PU towers offer the highest possible efficiency thanks to evaporative technology in combination with axial fans. Furthermore, a personal advisor can work alongside the customer for plant management needs.

Compact cooling towers

Finally, the compact MCT open circuit evaporative cooling tower benefits from centrifugal fans for special space configurations and is available as an option with electronically controlled fans (the MCT-EC model).

It consists of a self-supporting structure made of corrosion-proof fibreglass, including the water collection basin. This series is predominantly employed in air conditioning and refrigeration installations, but also industrial applications requiring low noise.

Closed circuit cooling towers

Closed circuit cooling towers offer the efficiency of evaporative cooling plus fluid ‘protected’ inside a closed circuit. Easy access and maintenance to the internal coils, fiberglass basin, and a possibility of free cooling mode.

Closed circuit devices use the same physical principle as the open circuit variations with one difference – the fluid to be cooled is introduced into a battery of pipes onto which water is sprayed.

The coolant can’t be polluted from the outside on closed towers. This is particularly useful in industries that need to keep the chemical-physical characteristics of the process fluids unchanged.

Typically, the cooling towers have removable side walls for an easy access to the internal parts to simplify inspection, cleaning, and maintenance operations.

The MITA closed circuit tower models offered by Klima-Therm include the MCC model. Able to work in free-cooling mode, this versatile tower offers the ability to operate with Industry 4.0 for control, monitoring and data collection on company management system.

This variation incorporates an axial motor-fan with direct coupling, low installed power, and low noise levels with an option with EC with electronically controlled plug fan (the MCC-EC version). Motors have IP56 protection, and the tower body is manufactured from 22mm thick fibreglass sandwich panels.

The MCC-T modular tower, meanwhile, is designed for large systems with fluids to be kept unchanged. Applications include oil & gas, food industries, and large paper mills. Components are preassembled to minimise installation time and cost, and modules can be transported over long distances at relatively low cost.

See MITA Cooling Technologies for more details.