(2)Since AFE nozzle systems use a zero psig water pressure feed network, the water feed system and nozzles must be horizontal and at the same height as the water pressure reduction regulator (vacuum valve). Valleys or dips in altitude will adversely affect performance and in extreme cases will prevent the nozzles from producing any output. If obstructions prevent straight level piping, the water and air network delivery pipes must be routed under the obstruction. It is vital that the water pipes, downstream of the vacuum valve, never be elevated higher than the nozzles.
2.GENERAL AIRFOG TECHNICAL CONSIDERATIONS
A.ADIABATIC COOLING PHENOMENA
(1)There are no heating elements in any of NORTEC’s AIRFOG humidifiers. Water is injected directly into the air at the temperature it is supplied. As the droplets evaporate they extract the required latent heat of vaporization from the surrounding air, causing the temperature of the air to decrease. This could be a significant energy saving technique if mechanical cooling is required. Since humidification is most often required when the exterior atmospheric temperature is below room temperature, there is a necessity to warm the air either prior to addition of the water droplets or after absorption of the droplets into the air. It is recommended to add the moisture after the air is heated as this dramatically reduces the time and distance taken for the water droplets to evaporate.
B.HUMIDIFICATION ZONES (IN SPACE APPLICATIONS)
(1)The movement of humidity through a space is very rapid. In applications where accurate humidity control is essential, it is important that the structure be reasonably
(2)AFE systems are frequently used in large factory applications for dust and static suppression. Often these structures have large doors open for loading and unloading of goods. Keeping doors closed, except when needed for movement of goods, can improve the performance of the humidification system by containing humidity levels within the space.
C.ABSORPTION DISTANCE
(1)Water mist sprayed by the AFE nozzle requires a certain distance to be absorbed by the air. Absorption distance is affected by many factors including temperature, existing humidity levels and air pressure. However, in general increasing the air pressure (and hence the water flow) to the nozzle will increase the absorption distance since more water is being sprayed. It is important to follow the clearances in this guide to prevent the accidental wetting of structures or machinery.
D.COMPRESSED AIR
(1)NORTEC AIRFOG systems use compressed air as the control fluid. Compressed air is provided by a compressor (supplied by others) or series of compressors. The modular approach to the NORTEC AIRFOG systems permits the designer to consider the cost implications of using multiple smaller horsepower compressors rather than one very large compressor. By using a multiple compressor design
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