Desalination Using Humidification Process

You can refer, TAS Engineering Pvt. Ltd, Wagle Induatrial Estate, Dist - Thane, India. who are manufacturers of Desalination plants for marine ships. They have both evaporation & membrane technology. Now a days, membrane technology is more popular due to it's compact design.

How is it that you are going to school for mechanical engineering and you already need help when you haven't done anything yet?

Oh, come on now! We all needed help when we were in engineering school and didn't have any experience yet. Much better to ask for help than to blindly forge ahead and get it wrong.

Man, you are supposed to study, research, and crack your head open for creative ideas and dont waste your time with already proven technology. An interesting subject for you should be to use such technology(ies) and seek the means on how to improve the evaporation or membrane processes to a much more eng efficient and cost effective operation! that should be your project dont you think?

Many different levels of technology may be applied to desalinization through "humidification" (I assume you mean "evaporation").

As a Boy Scout, I was taught that one could get potable (drinkable) fresh water from dirty water, salt water, or even moist vegetation, using any clear, clean, plastic film, like polyethylene. First dig a whole just slightly smaller in diameter than the film you will use. At the center of the whole place a clean collection container, cup, canteen, pot, etc. Pour your undrinkable water and/or vegetation into the hole, being caeful not to splash into the container. Then stretch your film out over the hole, weighting it down at the edge of the hole (with rocks, logs, or whatever is handy) so it will not sink in of its own weight. Next place a small weight, usually a stone, at the center of the film, directly over the container, being sure that the film is slightly lower at the center than at the rim.

Leave in hot sun all day and into evening. The heat of the sun will evaporate the water in the hole, which has a very large surface area. This water vapor will rise and condense on contact with the cooler film. Liquid water will collect on the film in drops, clinging to the film due to surface tension. Gravity will eventually pull the drops together as they flow down the slope to the lowest point where the center weight is. when the drop gets to big and heavy to cling to the film it will drip into the container, et voila, clean drinking water!

The next step up in technology could use mirrors to concentrate solar energy onto a glass container of dirty/salt water. As the water warms up, it will evaporate. If you are using a large mouth container you can repeate the film technique, placing a smaller container inside. The small container should be heavy enough or be fixed so it will not float or tip over inside the larger container. If small container(s) are used they can be capped with a ported top which is connected to a downward sloping hose or tube, preferably metal for good heat exchange. As the vapor makes contact with the wall of the tube it will condense and the liquid will rund down the slight slope to a clean water receptacle.

At the high end of evaporative technology, mirrors and/or lenses focuse high level solar energy on a tank containing the dirty or salt water, raising the temperature to or near the boiling point. Much higher energy vapor or steam will come off quickly. The "boiler" is also topped with a ported cap, but it is connected to a metal coil tube, preferably copper or stainless steel (brass or lead pipe should not be used, because the lead content could leach out and be a health hazard), which spirals down, allowing condensed liquid to flow out the end and not back into the "boiler". This is typical of a "distillation" process, similar to extracting alcohol from fermented liquids (wine, corn mash, fruit juices, etc.)

This is sufficient for personal or experimental use. Now, if you want to buy commercial equipment for large scale use, see the recommendations posted previously.

if i spray droplets of water at 70 degress and mass flow rate of water sprayed is 1kg/s. And the water mix with air stream which is 20 degrees and 40% relative humidity. how do i calculate the increase in moisture content of the air?