Sodium measurement should be the preferred option to minimize risk. Just as water quality is critical, early signs of excursions are also critical. This is 100 times more sensitive than a conductivity measurement. A Hach NA5600 sodium analyzer can accurately measure below 0.1 ppb. In everyday conditions (with possible temperature, pressure and flow upset or high conductivity background levels), the minimum meaningful variation will be 0.02 mS/cm. Extracting the maximum benefit from condensate polishing systems continues to be a top priority among many electric utility plants.Īlthough cation and specific conductivity are used frequently to detect excursions in the water/steam loop, it is no longer sufficiently sensitive to measure the very small condenser leaks which have assumed greater importance in modern plant designs. Attainment of the high degree of feedwater purity necessary for chemical programs, such as oxygenated treatment for drum and once-through boilersĬareful management of condensate polishing systems is essential otherwise polishing plants can become a source of ongoing feed system pollution.Virtual elimination of chemically influenced boiler tube failures.Improved steam purity resulting in less turbine deposition and phase transition zone corrosion.Reduced impurities fed to steam generators, thereby minimizing the frequency of chemical cleaning.Protection of the steam generator during impurity ingress, such as with condenser in-leakage.Reduced delays to commissioning and start-up as a result of chemistry transients.The benefits of condensate polishing are: Sodium measurement should be the preferred option for early warnings of excursions on condensates to minimize associated risks.Ĭondensate polishing plays a vital role in power plant cycle chemistry, providing the means to reduce the transport of metal oxide and ionic impurities to the steam generator during all modes of operation, mostly during start-up and upset conditions. a mixture of sodium phosphate tribasic and sodium phosphate di-basic), the measurement of sodium in the steam is an excellent indication of mechanical carryover from the drum into the steam. Since non-volatile boiler treatments are typically sodium based (i.e. Specifically, for plants with low boiler pressure (40-80 bars). Chlorides and hydroxides are corrosive, but not the sodium. It should be noted that corrosion will occur only if sodium is present with chlorides or hydroxide anions and not, for instance, with sulfates. The measurement of sodium directly in steam immediately before entering the superheater is now recognized as a strong indicator of possible stress corrosion in the superheater. sodium chloride (NaCl) and sodium hydroxide (NaOH), because of the possibility of stress corrosion cracking in the superheating section. Of significance is the steam solubility (in addition to carry-over) of sodium compounds, e.g. Under the conditions of high pressure and temperature of today’s power plant, the problem of steam solubility of inorganic compounds is increasingly important. Presence of sodium in concentration as low as micrograms or even nanograms per liter in steam before the superheater, may cause its stress corrosion. Therefore, sodium levels in drinking water must be monitored to safeguard human health.Īt Hach ®, find the testing equipment, resources, training and software you need to successfully monitor and manage sodium levels in your specific process application. However, in excess, sodium can pose health risks for individuals with certain health conditions. It is possible to identify hazards or contamination with sodium measurement.Ĭommonly occurring in sodium chloride or table salt, sodium is a key element in bodily fluids. Though sodium naturally occurs in groundwater, high concentrations may indicate pollution or saltwater intrusion. Sodium monitoring is critical to the efficiency and performance of a steam generation plant and to the longevity of its associated equipment. Today, trace sodium concentration monitoring has become one of the most important live indexes for water quality throughout the steam and water cycle in power plants, as well as in any steam-based industry. Pure and ultra-pure water / Steam processes Sodium, part of highly soluble, conductive and corrosive compounds is a crucial parameter in water quality testing. Sodium and chloride ions are the most common dissolved elements by weight in the oceans. All salts of sodium are highly water-soluble. Sodium exists in numerous minerals such as feldspars, sodalite, rock salt (NaCl), etc., and it is the sixth most abundant element in the Earth's crust. With just a single electron in its outer shell, sodium is highly reactive. A soft, silvery-white, alkali metal, sodium is a chemical element with the symbol Na, atomic number 11, and atomic mass of 23.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |