Cooling towers use a large amount of toxic chemicals in order to keep the cooling water clean, protecting the cooling towers. Blow down water is discharged to keep the cooling tower safe, and before each discharge the water needs to be treated and cleaned. Environmentalists are putting pressure on officials to make a change.
There has been a wide acceptance of the use of ozone technology around the globe, however, the use of ozone in India has been under question because of the lack of quantified studies and references. OTSIL and WEDECO have undergone some very extensive studies with the use of ozone in cooling towers over the past 5 years, and have quantified the benefits that go with it for the first time.
The use of ozone provides the following beneﬁts in a nutshell:
- Completely eliminates Biocides, making the discharge water cleaner.
- More than reduces 90% of Sulphuric acids and de-scalents for large towers.
- No hazardous chemical storage and Handling such as gas chlorine.
- Enables the CT (contact time) to be operated at Higher COC (cycle of concentration), eliminates controlled blow down.
- Prevents scaling, corrosion and reduces algal growth.
- Saves energy in operation of the Cooling tower.
- Finally Saves water, saves chemicals costs, allows the power plant comply with environmental needs and make them environmentally friendly.
The same quality of MUW allows the cooling tower to more than double the COC of chemically treated tower, while using ozone.
Studies have shown that there is a buildup (0.1 in) of calcium carbonate scale on the heat exchanger surface that reduces the heat transfer by as much as 40%. The energy savings happen because virtually limited scaling is noted with ozone treatment, and reduction in scale thickness also improves heat transfer efficiency of an ozonated cooling tower, saving power. The power savings is anticipated to be around or above 10%.
Make up water quality is the most important criteria that influences the performance of the cooling tower. If it is good quality, then ozone can be introduced directly into the CT tower basin. By using ozone, you can ensure that the tower water will be very good quality. Ozone is able to remove many dissolved organics in the water, including the ones responsible for odor and color. The presence of organic matter in cooling towers will contaminate the entire cooling tower loop including the condenser, and could be the main reason bio fouling that induces scaling and corrosion. The presence of other bacteria’s as well, including the SRB bacteria, would also increase anaerobic reactions within the tower. It is an accepted fact that ozone in MUW and side stream filtration in a cooling tower can solve more than 60% of problems that cooling tower operators face.