What is the maximum recommended concentration of calcium chloride in a boiler when the feedwater averages 6 ppm?

In a boiler system where the feedwater has an average of 6 parts per million (ppm) of dissolved solids, the recommended maximum concentration of calcium chloride would be set to ensure proper operation and prevent scaling and corrosion. The concentration of boiler water is typically maintained within specific limits to prevent issues that can arise from high levels of dissolved solids.

Choosing 60 ppm as the maximum concentration is based on careful consideration of the balance needed in the boiler system. Excessive concentrations of calcium chloride can lead to boiler water corrosion, as well as increased risk of scale formation, which can negatively impact the efficiency and lifespan of the boiler. Thus, maintaining a maximum of 60 ppm helps to ensure that the boiler operates safely and effectively while adequately managing the risks associated with water quality.

In contrast, lower concentrations of calcium chloride, such as those suggested in other options, do not meet the operational needs of a system that runs with a feedwater concentration of 6 ppm, as they may not provide sufficient mineral balance for efficient steam production. However, significantly higher levels could lead to the aforementioned problems with corrosion and scaling. Therefore, 60 ppm is a reasonable upper limit that supports operational efficiency while safeguarding the boiler from water chemistry-related distress.