The working principle of reverse osmosis membrane is to separate pure water and solute-containing solution with a semi-permeable membrane, and the semi-permeable membrane can only pass water. At this time, the water on the pure water side spontaneously enters the solution side through the semipermeable membrane, and the water surface on the solution side rises. This phenomenon is called osmosis. When the liquid level rises to a certain height, the pressure on both sides of the membrane reaches equilibrium, and the liquid level on one side of the solution no longer rises. At this time, there will be a pressure difference on both sides of the membrane, which is the osmotic pressure. If a pressure greater than the osmotic pressure is applied to the solution side, the water molecules in the solution will be squeezed to the pure water side. This process is the exact opposite of osmosis and is called reverse osmosis. From the reverse osmosis process, we can see that due to the action of pressure, water molecules in the solution enter pure water, the amount of pure water increases, and the solution itself is concentrated. The principle of reverse osmosis desalination is to apply a larger pressure than the natural osmotic pressure, so that the osmosis proceeds in the opposite direction, and the water molecules in the raw water are pressed to the other side of the membrane, so as to achieve the purpose of desalination. This is the principle of reverse osmosis membrane desalination.

1. Raw water— raw water pump —quartz sand filter — active carbon filter — soften filter — cartridge filter — sotten water tank
2. — one-stage high-pressure pump — RO membrane —two-stage high-pressure pump— RO membrane — pure water tank
3. —converter—water point.