Humidity control & dehumidification for power plants & water treatment works

Water treatment plant dehumidification

Ground water and reservoir temperatures are often much lower than air dewpoints, which can result in condensation on the outside of the pipes, valves and controls in the water treatment plant. Lowering the humidity the plant prevents the condensation that leads to mold and fungus growth, as well as rusting the valves and controls.

The cost of the dehumidifier is very modest compared to the cost of painting pipes and periodical replacement of controls and valves. Additionally, the sanitary benefits of eliminating fungus and bacteria have increased in importance as consumers become more sensitive to water quality issues.

Power plant dehumidification

When power plants are idled for maintenance or because of excess generator capacity, dehumidifiers are installed to blow dry air through both the steam side and generator windings. This costs less and is safer  than blanketing with nitrogen, and is far more effective than either wet  layup with corrosion inhibitors or preservation in grease. Dry air layup is very simple, and the plant can go back on-line in a matter of hours rather than weeks.

  • The best type of dehumidifier for any specific application will depend on the environment it's being used in and the level of control needed. Very cold or close control drying applications will benefit from using desiccant dehumidifiers. Dehumidification at conditions above 15-20°C and for humidity control of 50%RH and above would largely benefit from condensing dehumidifier technology.

  • To prevent condensation on pipes, the air dew point temperature has to be below the pipe surface temperature to prevent moisture condensing on the cold surface. To calculate what relative humidity the air would need to be for the air dew point temperature not to be reached, you would need to know the surface temperature of the pipe and the ensure that the absolute moisture content in the air surrounding the pipe is less than the surface temperature at 100%RH.

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