Dehumidification system

The air quality in preparation and aseptic areas can be one of the greatest sources of product contamination. However, this problem can be minimized by use of the equipment currently available to provide clean air essentially free from microorganisms and dirt particles. Depth-type filters, electrostatic filters, and dehumidification systems are used to remove the major... 

The indoor air quality control appliance consists of air handling, filtration, purification and dehumidification systems. Mr. Peter Chan of Chiaphua Industries Ltd. was closely consulted in completing the engineering specifications for the product. 

The utilities check is used to verify that the utility supplied fulfills the chamber requirements as specified by the manufacturer. During IQ, the as found parameters are verified against the as specified parameters on the checklist. If the as found results are significantly different from the as specified parameters, it will be necessary to determine the cause of this discrepancy and to implement corrective actions. The utilities check is a part of the site preparation for the installation of the chamber and should include verification of the power supply, such as the voltage, amperage, and wire size and the quality, pressure, and flow rate of the feed water supply. The quality of the feed water supply is a critical component of proper operation of the chamber. Experience has shown that if the quality of the feed water does not meet the manufacturer s specifications, this will lead to premature corrosion within the humidification and/or dehumidification system and subsequent problems with maintaining the humidity in the chamber within the specified limits. 

In conclusion, the demonstration runs have shown that the membrane contactor dehumidification system is effective when the total loads of the refrigerated cell do not require an evaporative temperature of the cooling coil below —10 °C. In these conditions it has been shown that energy, operating costs and C02 emissions can be decreased up to 20% when optimized systems are built. The optimization is related mostly to the selection of adequate pumps, fans, heat exchangers. 

Desiccant dehumidification systems remove moisture from the air by forcing the water vapor directly into a desiccant material. The moisture from the air is attracted to the desiccant because an area of low vapor pressure is created at the surface of the desiccant. The pressure exerted by the water in the air is higher, hence the water molecules move from the air to the desiccant and the air is dehumidified. 

Solid desiccant materials are arranged in a variety of ways in desiccant dehumidification systems. A large desiccant surface area in contact with the air stream is desirable, and a way to bring regeneration air to the desiccant material is necessary. 

The components of a generic solid desiccant dehumidification system are illustrated in Fig. 7. At a minimum, the system will include separated air streams of process and regeneration for the desiccant device and some kind of heat source to raise the temperature of the regeneration air. 

A wide variety of configurations of desiccant dehumidification system are available. The air inlet conditions and outlet requirements of process and regeneration call for different configurations depending the individual situations. For illustration purposes, two examples are presented in Figs. 9 and 10. 

Fig. 9 Ventilated desiccant dehumidification system configuration. (View this art in color at www.dekker.com.)...

Refrigeration and dehumidification system All the persons and equipment would release water and heat during refuge and operation to... 

Figure 5. Various components of a commercial size solid desiccant dehumidification system (photo courtesy ot Semco Inc.. Columbia. MO). 

Another system program has been developed by SEI Associates, Boulder, CO, incorporating a desiccant dehumidification system model into the Trane Company s energy and economic simulation program TRACE (Trane Air Conditioning Economics). This program has not been used widely by the researchers and other HVAC users. 

US Department of Energy, Two-Wheel Desiccant Dehumidification System, Federal Technology Alerts. 

Chung, T.W., Predictions of moisture removal efficiencies for packed-bed dehumidification systems. Gas Sep. Purif., 8(4), 265-268(1994). 

Chung, T.W., et al.. Efficiency of a liquid desiccant dehumidification system regenerated by using solar collectors/regenerators with photovoltaic fans, Sep. Sci. Technol., 30(6), 1039-1045 (1995). 

To date, only microwave hot-air dryers used principally in flnish drying processes to level-off the moisture content in pasta, crackers or chips, and microwave vacuum dryers custom-made to specific product requirements, are available commercially (Ratti, 2008). Good microwave-assisted drying equipment should have a uniform distribution of the microwave field, provide a movement of the material to be dried, keep the microwave field strength in the drying chamber lower than the dielectric breakdovm strength, and possess an economic dehumidification system. 

During the 1950s, parts of the Atchison Storage Facility were converted to warehouse space for specialized military hardware. An ammonia-to-brine dehumidification system was installed to reduce the humidity to 42% relative humidity and to maintain the temperature of the facility at a range of 18°C-22°C. Later, the facility was used for record storage. 

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