Cooling Towers & Evaporative Cooling Systems
Cooling towers and evaporative cooling systems are used extensively in many industrial, process and commercial applications where there is a need to remove excess heat from liquids, fluids, process materials and indoor environments.
Typical settings for cooling towers and evaporative water systems will include power stations, manufacturing plants, large computer data centres, office buildings, hospitals, hotels etc.
Different Types of Cooling Towers
There are several types of evaporative cooling systems and cooling towers currently commercially available, and they come in many different shapes, sizes and designs.
In the UK the most common types of cooling tower include:
Forced Draught Cooling Towers
Forced draught cooling towers use a mechanically forced air flow to create cooling.
They are often noisier as the fan often operates at ground level.
Induced Draught Cooling Towers
Induced draught cooling towers are often the largest towers used.
They also use a mechanically forced air flow to create cooling.
They are usually quieter because of the location of the fan which is fitted at high level, often on top of the tower itself.
Natural Draft Cooling Towers
Natural draft towers are the most recognisable of all cooling towers.
They are the large hyperbolic concrete structures often seen close to power stations.
These towers use a natural draught process and use no fans to circulate the air.
They rely entirely on convection with the internal movement of air resulting from the difference in density between the air entering the tower and the air already inside it.
Cooling Tower Elements
The two essential elements present in cooling towers are a heat exchanger and cooling water or airflow.
However not all cooling towers are the same.
The large curved designs seen at power stations (natural draught towers) use the natural flow of air to cool water.
Other towers are called forced draft or mechanical draft cooling towers because they use fans to force the flow of air.
A complete cooling system will typically include a cooling tower, an evaporative condenser or some cooling element, a re-circulating system, a heat exchanger, plus other equipment such as sumps, pumps, storage tanks and water treatment equipment and chemicals.
The Dangers of Legionella & Legionnaires’ Disease
It is important to note that under certain circumstances cooling towers may present a significant risk as they can create a suitable environment for the growth of many micro-organisms, including legionella bacteria, which can be spread widely by aerosol into the surrounding area by the cooling tower and cause Legionnaires’ disease.
Cooling Tower Notification & the HSE’s ACOP L8
In the UK any business that uses one or more cooling towers or evaporative condensers must ensure that they take appropriate precautions to control the risks associated with legionella bacteria and Legionnaires’ disease.
This can be achieved by following the Health & Safety Executive’s Approved Code of Practice (ACOP) L8, Legionnaires’ disease: The control of Legionella bacteria in water systems, otherwise, alternative precautions need to be put in place which must be as equally effective.
Such businesses must also notify their local council to let them know that they operate cooling towers within their local area.
The cooling towers must be registered and then well maintained.
This is primarily because cooling towers can, if poorly maintained of left un-managed be an excellent source of legionella bacteria, which can easily multiply in conditions presented by the average cooling tower.
Tower Maintenance
Thus every cooling tower needs to be checked and maintained on a regular basis.
While it is not uncommon for legionella bacteria to be present inside a cooling tower, it should not be left to proliferate and rise above specific prescribed levels (set out by the HSE).
Cooling towers need to be tested, chemically treated and cleaned regularly to make sure that they are in good clean condition, fully managed, under control and safe at all times during their operation.
World Class Cooling Tower Solutions
Water Treatment Services offer a full range of cooling tower management solutions including cleaning, disinfection, water treatment and tower maintenance services including:
- Cooling tower cleaning and disinfection to meet the HSE’s ACOP L8 and HSG274 Part 1.
- Cooling tower water treatment programmes.
- Tower packing inspection and cleaning.
- Cooling tower maintenance, repair and refurbishment.
- Water sampling and laboratory testing.
With offices in London serving the South and South East England, Manchester (North West), Birmingham (Midlands), Bristol (South East England and Wales), Leeds (North and North East) and Glasgow (Scotland), supported by regional teams of trained engineers, service specialists and technical experts we can offer professional, cost effective cooling tower management and maintenance services across the whole of the UK… management →
Contact us today to learn how our expert cooling tower management and engineering solutions can help optimise operational costs, reduce downtime, increase plant reliability, and improve safety and regulatory compliance…. contact us →
Further Reading…
More information about cooling towers and evaporative cooling systems… here →
