Study Of Marine Reverse Osmosis Desalination Plant

The seawater desalination plant is a relatively important device in ships. At present, there are mostly two methods of seawater desalination for ship using, which are distillation and reverse osmosis. During the past years, with membrane technology progressing, the applied foreground of marine reverse osmosis seawater desalination plant will be more extensive.The marine power plants consume large amount of high purity water every day. On board, the way gaining high purity water is letting the fresh water produced by the distilling plant pass through the ion-exchange reactor. In actually using, the distilling plant has three problems such as high salt content of product water, scaling on evaporation surfaces easily, and building vacuum difficultly. For resolving these problems, this paper brings forward a new kind of seawater desalination plants. This seawater desalination plant is designed by the principles of reverse osmosis and plate heat exchangers. The product water which comes from the reverse osmosis seawater desalination system distils in plate heat exchangers to get high purity water as anticipated purpose.This paper mostly introduces the basic principles of the new seawater desalination tester, the design of reverse osmosis seawater desalination system, the experiments of desalination system, and the standardization method of the data. The working data of experiments show that, both the quality and yield of product water are steady comparatively; the reverse osmosis system can wipe off foreign substance and most ions of seawater, the salt rejection can reach 99.55%; the decrease of seawater's hardness is so huge that product water can evaporate in normal pressure instead of in vacuum, as it could be avoided that fouling on evaporating face at this hardness. The experiments confirm that this design of seawater desalination plant is feasible. The standardization data show that the reverse osmosis system should be chemical washed after working about 200 hours if using the offshore seawater for the raw water, so the new marine seawater desalination tester should be improved on pretreatment for the purpose of working offshore or in ports.