Water sprays, usage

The water source and the site where the water is used are frequently separated by some distance. Even if they aren t, having water at the usage site does not automatically guarantee water flow from faucets, spray from showers, or a full toilet bowl. If we want this capability, then the water must be processed into useful form. Processing water involves as many as four functions (Fig. 5 and Sidebar C). The standard utility-powered water system based around the submersible pump performs these functions simnl-taneously. While this is convenient, it is also wasteful and inappropriate. Each function is distinct. A good water system acknowledges the differences in functions and accommodates their virtues individually. The explo-... 

Figure 54.9 shows an installation in which wastewater is concentrated from 2% to 50% of solid content. By using MVR, the process has a high efficiency, giving an energy usage of about 134 kJ/kg water, which is 20 times better thau the typical adiabatic spray drying. 

Municipal water works may aerate water by spraying into the air to remove disagreeable tastes and odors. Also, well water can be improved by aeration, particularly if it contains carbon dioxide, hydrogen sulfide, or iron. The term aerated water is synonymous to mineral water in British usage. However, mineral water in Britain is water that has been aerated or charged with carbon dioxide—soda water, or soft drink. 

Whilst the presence of liquid water droplets from rain or marine spray cannot be avoided, the more serious situation with water drops comes in the provision and use of compressed air systems. If the intake air is close to saturation before compression it takes but a small increase in pressure for the water vapour to condense into drops. These drops can be a problem in the subsequent usage of the compressed air, and quite complex chains of filters and filter/dryers, together with intercoolers, are used to reduce the water content to an acceptable level. 

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