How to control high chloride levels in boiler water and prevent too rapid an increase in chloride concentrations?

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The boiler water treatment process in our plant is briefly described as follows: raw water pretreatment system (activated carbon filter—multi-media filter—regulation tank—hydrogen ion exchanger—intermediate tank) ---- two sodium ion exchangers ---- soft water tank ---- two atmospheric thermal deaerators ---- underground water pump ------ 5 boilers of 20T each ---- distribution cylinder. Additionally, the recovered condensate water (which exchanges heat with the soft water in the soft water tank through piping connections rather than direct contact) passes through a manganese sand iron-removal filter before entering the deaerator directly. The recovered condensate flash steam------enters the deaerator directly. The raw water pretreatment system is used to reduce alkalinity, while sodium ion exchangers are employed to lower hardness. To meet the plant’s process standards, when the levels of chlorides in the boiler water exceed 120 mg/l and the alkalinity exceeds 23 mmol/l, manual bottom blowdown of the boiler is required; otherwise, conductivity is automatically monitored to control the timing of both surface and bottom blowdown in the boiler. However, when the steam flow load on the boiler is high, such that two boilers need to operate simultaneously or during winter, the chloride level rises rapidly. I have checked every stage of the process: the chloride content in the water fed to the sodium ion exchanger is between 12 mg/l and 15 mg/l (this excludes the possibility that the failure of the sodium ion exchanger could lead to an increase in chloride levels due to processes like bed loosening, replacement, regeneration, cleaning, and water production). A chemical dosing system is used in the deaerator, and the chloride level in the soft water at the detection point of the deaerator also remains between 12 mg/l and 15 mg/l, which indicates that the parameters of the soft water remain within acceptable limits before it enters the boiler. To ensure the accuracy of the tests, the boiler’s water is completely drained at the start of operation, and then soft water is added again. It can be observed that once the steam flow load on a single boiler increases but does not exceed the rated design value, the chloride level rises quickly; similarly, when the steam flow requires the use of two boilers, the chloride level also increases rapidly, often reaching levels between 160 mg/l and 175 mg/l. The alkalinity increases slowly and remains within the specified range. To this day, it is still not clear what the cause of this issue is and how to control the chloride levels Chemicals are also added to the boiler body, but not those containing chloride ions; they are mainly used for corrosion prevention. The second issue is that the moisture content in our boiler’s saturated steam is extremely high. According to regulations, the moisture content in saturated steam should be between 5% and 10%, yet the moisture level detected at the steam distribution cylinder already reaches 53%. Multiple drain valves have been installed along the pipes that lead from the distribution cylinder to various steam-consuming endpoints, but the moisture content in the steam at those endpoints remains very high. What could be the cause of this, and how can it be resolved? The water level in our boiler is maintained at around 45–50 throughout the year, with the operating pressure set at 10.2 MPA. Therefore, I would like to ask my colleagues for advice on how to deal with this problem Thank you all for the active discussions.