Dehumidification by cooling or dessication has a variety of applications, including:
Preventing moisture regain. Nearly all materials have some affinity for moisture based on surface characteristics and the amount of surface exposed to humid air. Moisture regain occurs when moist particles stick together.
Preventing condensation. Air holds water vapor in proportion to its temperature. Cold surfaces of pipes, vessels, valves and heat exchangers condense moisture unless the air around them is dried to a dewpoint below the temperature of the cold surface.
Preventing corrosion. The exposure of metal surfaces to atmospheric corrosion can be reduced by surrounding the surfaces with dry air. Dehumidifiers also keep humidity low in process control rooms, preventing the corrosion of electrical contacts and sensitive electrical components.
Drying heat-sensitive products. Typically, drying time is reduced by heating a product. If the product is susceptible to damage by heat, drying time can be reduced by using dehumidified air, which reduces the vapor pressure of air above the wet surface.
A common method for dehumidification is the use of air conditioning. Figure 1 shows a typical vapor-compression cooling-based dehumidification…