Water Treatment Solutions Blog

Scaling is one of the most common types of foulants to occur on heat exchanger surfaces. When we refer to scale, we most often mean mineral scale that develops most commonly as calcium or hardness based salts such as calcium carbonate. These salts are unique in that they exhibit reverse solubility e.g. they become less soluble in water as the temperature rises. While the relationship between temperature and the level of salts in the water will determine if scale will form on the heat exchanger, there are relatively easy ways to control this type of scale in most situations.

Cooling tower system operation requires that a close eye be kept on performance in order to maintain cost and efficiency across the life cycle of the equipment. Heat exchanger fouling is a serious problem and can have a major impact on the performance of the systems if left unchecked.

The warm weather is retreating and the days are getting shorter - fall is here. Here are a few things to consider at the end of the cooling season if your cooling system does not run throughout the year.

Back in June, QualiChem had a blog post on the approval of AHSRAE 188 which covered Legionella Risk Management Standards for the industry. With the recent legionella outbreaks in New York City and the fact that there generally are an increase in positive Legionella tests during the summer, we wanted to use this blog article to briefly discuss potential measures to take in response to a positive test in your cooling systems as well as share what the City of New York is doing in response to these outbreaks. 

This article is Part 3 of 3 of a series on nitrite closed loop treatment programs.

In Part 1, we introduced nitrite programs for closed loops, and in Part 2, we discussed the nitrogen cycle and how biological problems will show themselves with nitrite based programs by consuming any available nitrite in the system. In Part 3, we will discuss the consequences and ways to correct program deficiencies with nitrite treated systems.

Cooling towers concentrate water by evaporation and therefore concentrate dissolved solids in the water.  They also act as air scrubbers; collecting dirt, debris and microbiological material that gets sucked into the tower.  This material circulates throughout the water circuit and concentrates along with the dissolved solids as the water evaporates. As the concentration increases, the dissolved solids (mineral salts) reach the saturation point and precipitate to form a gritty sludge that accumulates and deposits on condenser tubes, heat exchanger surfaces and can harden into scale.

This article is Part 2 of 3 of a series on nitrite closed loop treatment programs.

In Part 1, we introduced nitrite programs closed loops, discussing how they perform and some of the issues to be aware of with these programs. In Part 2, we will take a deep dive into the nitrogen cycle and how that can impact nitrite based programs, or quite simply, what are the technical reasons behind why your nitrite residuals keep disappearing.

When treating a closed loop cooling system, you may encounter some of the same issues or problems that you have experienced when treating cooling towers.  Closed loops can experience problems that rob efficiency and destroy equipment through corrosion, scale, biological growth and fouling.  The initiation of these shared issues may be different between a closed loop and a cooling tower system, but the water related problems to be addressed are fundamentally the same.