Nalco 7330 to be used as a broad-spectrum biocide

NALCO 7330 serves as Water Substituted Isothiazolinone based biocide manufactured by Nalco Company. It manifests as a broad spectrum, non oxidizing biocide that has been formulated specially to be used in recirculating cooling towers, closed loop cooling systems, air washer and brewery pasteurizers.

A cooling tower is regarded as a heat rejection device that involves the extraction of waste heat to the atmosphere through the cooling of a water stream to a lower temperature. The type of heat rejection in a cooling tower is termed evaporative because it allows a little portion of the water being cooled to evaporate into moving air stream to impart significant cooling to the rest of that water stream. A cooling tower may be of two types - open circuit or closed circuit cooling tower. Common applications for cooling tower include manufacturing and electric power generation and providing cooled water for air-conditioning.

Though the cooling tower exhibits many advantages, but this application is also not free from problems like many such other applications. Cooling towers, on the basis of its properties, become efficient air cleaners. This process allows the airborne contaminants and particles to get aggregated into the cooling water. This, along with the contaminants in the feed water, creates an environment for microorganism growth, solid deposits and scaling. Microorganisms show the tendency to bloom in the re-circulated water and on wet surfaces. Bacteria slime and algae tend to foul heat– exchanger surfaces and in most of the cases attack and bring about the destruction of system components.

In order to prevent the biological growth, industry people generally employ chemicals specially biocides to stop bio-growth. Nalco Company has specially formulated Nalco 7330 to be used as a broad-spectrum biocide for the prevention of microbiological growth in the cooling towers. Nalco 7330 is essentially composed of 5-Chloro-2-Methyl-4-1sothiazolin-3- of Cas No. 26172-55-4 at about 1.1 % and 2-Methyl-4-1sothiazolin-3-o of Cas No. 2682-20-4 at about 0.3%. It appears as a Light green liquid having a mild odor by nature and of specific gravity 1.08. The pH of the product is around 3-4 and is a completely water soluble chemical.