This is a membrane filtration operation for professionally gaining freshwater out of those waters where classical refining systems are insufficient (sea water, well waters with high conductivity etc.) by separating minerals from the water. 

The working principle bases on membranes located on the device. Water is forced to flow through membranes with pores of 2x10-6 mm diameter. Water molecules and some inorganic molecules pass these pores during this operation while many particles do not. The output is concentrated water. This method provides much better water quality in desired amounts compared with other filtration systems.