CDI - Manufacturers of Mobile Desiccant Dehumidification Systems

LONG TERM STORAGE AND LAYUP

ARID-Dry mobile desiccant dehumidifiers provide corrosion protection, temperature, humidity and dew-point control for boilers, utiliy boilers and turbines in long term layup within power plant facilities. The use of dehumidified air systems to control corrosion in metals consists of removing atmospheric water vapor from the air to lower the ambient (Air) vapor pressure or % RH below the dew-point temperature of the surface. Maintaining an ambient vapor pressure lower than the corresponding surface vapor pressure will prevent moisture from collecting on the surface.

ARID-Dry brochure Print Version

ARID-Dry brochure HTML Version

Benefits of ARID-Dry desiccant dehumidifiers:

Corrosion protection for long term storage of turbine systems
Corrosion protection for long term storage of utility boilers and components
Monitor and data logging of environmental conditions
Control dewpoint differentials for corrosion protection
Extend the life of corrosion sensitive components
Long term storage of electrical components
Maintain electrical insulation and isolation values

Industrial Condensation Prevention
Metal Surfaces can oxidize when ambient dew point levels exceed the surface temperature. Microscopic moisture particles will collect on surfaces as the metal cools the ambient boundary layer in close contact with the cool metal. As more water molecules collect, visible moisture appears. This moisture can create rapid oxidation or flash rust. Other materials present from the combustion processes in the gas side of boilers and assorted auxiliaries can also interact with the moisture to form acids which can further accelerate the degradation of surfaces. Temporary or permanent desiccant dehumidifiers can eliminate the condensation.

Utility Boiler Long-Term Storage
If a utility or industrial boiler or generator is idled for long periods of time, corrosion can result. Corrosion is caused when elevated ambient dewpoint air contacts the metal surfaces. Temporary or permanent desiccant dehumidifiers can reduce the ambient dewpoint, which prevents corrosion. Large boiler/generators and ancillary components can be protected for long periods by providing dry air blankets to protect equipment without the expense or dangers of a nitrogen blanket.

		Deposits that contain chloride aggressively pit the turbine when it is allowed to sit in moist conditions. These pits become sites for corrosion fatigue. Courtesy: EPRI Below: Power plant turbine unit. Courtesy: TVA and EPRI.