Treated Water Chemistry
Maintaining proper water treatment chemistry is essential for controlling corrosion and maintaining a low scale-forming potential in treated water systems. Corrosion inhibitors, dispersants and polymers must be present at the proper levels and in the appropriate ratios in order for the water treatment program to be effective.
The dynamic conditions found in cooling towers present a special challenge to monitoring water chemistry due to the variable ambient conditions and make-up water quality.
AWTC has the analytical equipment to test the parameters that truly define whether a system is troubled or trouble-free. AWTC has the experience to interpret these results in the context of the operating parameters of the system and the treatment products in use.
Water-formed Deposit Analysis
All treated water systems have the potential to develop scale and other water-formed deposits. Even the condenser and chiller tubes in the cleanest systems require periodic brushing to remove bio-film and scale.
Water-formed deposits can be a complex amalgam of organic material, entrained dirt and debris, corrosion products and scale-forming minerals. The concentrations within the matrix and the ratio of the component concentrations provide insight into whether the water treatment program is successfully controlling fouling and the formation of bio-films.
Deposit samples obtained from different locations within a system each tell part of the story. “Brushwater” and debris samples obtained when chiller tubes are punched will indicate whether the treatment program is successfully controlling scale and, more importantly, controlling the formation of bio-film. Cooling towers present a wide variety of conditions, including the wet deck, the basin and the fill. Deposits from these different locations will have different compositions, but, together, they can pinpoint problems with water treatment chemistry.
AWTC has an in-depth knowledge of the deposit-forming potential of the various parts of treated water systems. With this knowledge, AWTC will obtain those deposit samples most likely to reveal useful information. AWTC has the experience to choose the appropriate analytical techniques (e.g., TEM, SEM, XRD, XRF and wet chemistry) and to interpret the results based on the existing water treatment program and the system operating parameters.
BIOLOGICAL ANALYSIS
Biological control is an important part of a successful water treatment program. If biological activity is not controlled, critical plant equipment and piping will experience under-deposit and microbially-influenced corrosion (MIC). MIC can produce pipe failures in a relatively short period. Inadequate bacteria control can contribute to potential health hazards such as Legionella. Even minimal biofilm on heat transfer surfaces can effect the efficiency of the equipment and result in higher operating costs. Maintaining proper control requires appropriate testing and monitoring.
Heterotrophic plate counts (HPC), bioassay slides, SRB tests, etc., are part of AWTC’s periodic monitoring program and help ensure that bio-activity remains in control, resulting in optimal heat transfer efficiency and increased equipment life.
PARTICLE ANALYSIS AND FILTER PERFORMANCE
How clean is the water in your system? . Is your filter operating at maximum efficiency? Is filtration needed? These questions can best be answered through laser particle count analyses of the system water. AWTC uses particle count analyses to determine the cleanliness of the system. Particle count data helps to determine the need for filtration or whether an existing filter is effective.
Common sense dictates that the cleaner the water, the better the corrosion and deposit control. Water that appears clean may be loaded with particles that are too small to see but can still contribute to fouling. Solid contaminants can deposit on heat transfer surfaces and promote under-deposit corrosion and biological growth. Fouled heat exchangers result in a significant loss of efficiency. Dirt, foreign matter and scale can clog or damage pumps and reduce the life of pump seals, spray nozzles, condensers and similar equipment.
