Moisture content in steam increases with high TDS levels in the feedwater tank due to water carry over. Wet steam reduces the process efficiency thereby increasing fuel consumption.
As steam is generated, dissolved solids in the boiler feedwater become more and more concentrated. As a result, the steam bubbles formed reach the water surface but do not burst, eventually forming foam which is carried over into the steam mains. This also leads to wastage of fuel due to increased moisture content in steam.
Eg: The increase in fuel consumption due to high level of TDS in the boiler, is illustrated below.
The high level of dissolved and suspended solids in wet steam, can also cause damage to control valves, heat exchangers and steam traps.