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Sea Water Evaporator


On ships there is a lot of drinking water needed. Of course it is used for the crew as water and for taking showers. Water in a good quality is as well needed for technical applications, for instance to produce steam. Depending on the route of the ship it will be sometimes for weeks away from a port, and therefore from fresh water supply. So it is pretty normal to produce the drinking water on board. Seawater cant be used for drinking, so the seawater has to be treated in order to get rid of the salt and other impurities. one of the most common ways of doing so is to use evaporators. As the name is telling, such machine evaporate seawater.
When this water becomes steam the salt and other particles stay in the seawater, so the condensate formed out of the steam has a good drinking water quality.
There are several techniques how to evaporate the water, but all have in common the solved salt from the seawater causes technical problems, and is responsible for heavy scaling. The inner surfaces of a evaporator which are used the transfer the heat in the water, start to scale a lot until if there is no adequate action taken lead to blocked systems.
The most common way to solve this problem is to have two evaporators on board, where one is producing water and the other is either cleaned or in standby. Depending on the part of the world the ship is cruising, the need for cleaning the evaporator arises every 2 to 3 weeks. The cleaning is done either with chemicals and/or manually, which is a very though task to do. Installing PursanovaTM ahead of the evaporator is lessening or even stopping the scaling. The salt and calcium is kept solved in the so called brine, which is dumped back into the sea. There are ships using PursanovaTM for almost 10 years, where the requirement for cleaning the system is either very little or there is no need at all.
Please see as well the case studies of our first evaporator at a ship of Thenamaris a Greek shipping company, or the case study from the "Waterway".