How does a desalination plant work?
Seawater is often used in various ships, offshore platforms and islands and other fields of fresh water acquisition, the main use of distillation method and method of two, then it is through what principle to make seawater into fresh water.
Principle of distillation:
Distillation method is a method to simulate the natural water cycle, seawater by the heat of the sun in which the water evaporates to form clouds, clouds in the high air to freeze into rain, falling rain is fresh water. Using this main principle, a variety of distillation desalination technologies have been developed, but they are all through the conversion of electrical energy into heat or the use of waste heat to evaporate water molecules in seawater into water vapor, to achieve brine separation, and then cooling into fresh water process. This method is a traditional desalination method, but after continuous improvement, it still occupies an important position.
Principle of reverse osmosis:
Reverse osmosis membrane is a semi-permeable membrane with selective permeability that allows water molecules to pass through. When the same volume of fresh water and seawater are placed on both sides of the membrane, the water molecules in the fresh water will naturally pass through the semi-permeable membrane and spontaneously flow to the seawater side, a natural phenomenon called osmosis.
When the flow stops, the liquid level of the seawater side will be higher than that of the fresh water, that is, a pressure difference is formed, and this pressure difference is called osmotic pressure.
If a pressure greater than the osmotic pressure is applied to one side of the seawater, the flow direction of the water molecules will be opposite to the original direction of penetration, and begin to flow from the seawater side to the fresh water side, a process called reverse osmosis.
Using this principle, the seawater is pressurized by using a high-pressure pump to make the water molecules in the seawater pass through the reverse osmosis membrane, so as to achieve the separation of water and salt.
The above is the desalination principle of two commonly used desalination desalination, with the progress of technology, desalination costs continue to reduce, desalination will be more widely used.
