Friday 26 December 2014

Fresh water generator – Invention of the century

The earth is seventy percent water and though it may seem that there is water everywhere, only three percent of this water is fresh water and drinkable and the rest is all salty water which is not fit for drinking. Years ago, old cargo ships were required to carry huge supplies of fresh water for their crew when departing upon a long voyage. If there were a ship that would run out of water for drinking, it would be carrying a very miserable crew indeed. However, this has changed thanks to technology as in today’s era; almost all commercial ships are equipped with a fresh water generator. A fresh water generator is basically a kind of evaporator that converts salty sea water into water that is drinkable and fresh.

The whole idea behind a fresh water generator is actually quite simple. It serves the purpose of evaporating sea water with the use of a source of heat in order to separate the pure water from the salt, sediment and other elements. A diesel engine is usually used by fresh water generators as the heat source. However steam can also be used to serve the same purpose. Since fresh water generators often make use of existing heat in order to run, the cost of operation of these machines is quite low.

The fresh water generator has two main elements which are the heat exchanger and the condenser respectively. The heat exchanger serves the purpose of evaporating the water and the condenser condenses the fresh water vapor, turning it into water that is drinkable. The condenser is the element that cools down the vapor which is simply done by using cold sea water to cool the outside of the machine.

Fresh water generators should include a feature that can be used to monitor or check the salinity of the water that is processed. If the salinity were to exceed a particular level, which is usually between one and ten parts per million (ppm), the unit would automatically take the water back to the feed line so as to run it through the complete cycle again.

Fresh water generators these days are increasingly being used in desalination plants. These are usually and typically located in coastal areas and serve the purpose of providing the local community with fresh drinking water. They have become quite common in some communities of California as well as in the Middle East. As a response to drought as well as the concern over the availability of water in the growing number of cities, more and more desalination plants are likely to be built in the near future. One drawback though is that the costs that are involved in these desalination plants are quite high and so they are considered by communities only in those situations where they are faced with shortages of water from the sources that are traditional. So this poses a problem when the construction of desalination plants is given a thought as people only build them when needed.


In passenger and merchant ships, the application of fresh water generator becomes even more important and crucial. The ship based fresh water generator uses heat from ship’s engine and salt water from the sea and makes it drinkable through either evaporation method mentioned above or through the reverse osmosis process that is more expensive but produces bulk amount of drinkable water essential for drinking, washing and consumption of masses. All in all, the fresh water generator may end up preventing a world war by providing drinkable water made from all the water in the world thus eliminating the scarcity of this precious life source.  

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