Reverse Osmosis referred to as RO, is a kind of reverse migration movement of osmosis, is a pressure driven, with the help of semi-permeable membrane selective interception of the solute in the solution and solvent separate separation method. Under certain pressure, water molecules can pass through the RO membrane, and the inorganic salts, heavy metal ions, organic matter, colloid, bacteria, viruses and other impurities in raw water can not pass through the RO membrane, so that the pure water can be passed through and can not be separated from the concentrated water strictly.

The pore size of RO membrane is as small as nanometer (1 nanometer =10-9 m), and the system salt removal rate is generally more than 98%. Reverse osmosis (RO) is an advanced desalination method, which is also energy saving and environmental protection. It has become the mainstream pre-desalination process. The 8040 (8 "diameter, 40" length) and 4040(4 "diameter, 40" length) reverse osmosis membrane elements are commonly used.

Ultrafiltration is one of the membrane separation technologies driven by pressure, for the purpose of separation of large and small molecules, that is, under a certain pressure, the small molecule solute and solvent through a certain pore size of the special film, and the large molecule solute can not pass through, stay on the side of the membrane, can purify, separate or concentrate the solution.

Application:

Ultrapure water technology of boiler replenishment water system can be roughly divided into the following types:

1. Ion exchange is adopted, and the process is as follows:

Raw water → raw water pressure pump → multi-medium filter → activated carbon filter → water softener → precision filter → positive resin filter bed → negative resin filter bed → Yin and Yang resin mixed bed → microporous filter → water point.

2. Two-stage reverse osmosis is adopted, and its process is as follows:

Raw water → raw water pressure pump → multi-medium filter → activated carbon filter → water softener → precision filter → first stage reverse osmosis →PH adjustment → intermediate water tank → second stage reverse osmosis (reverse osmosis membrane surface with positive charge)→ purified water tank → pure water pump → microporous filter → water point

3. EDI is adopted, and the process is as follows:

Raw water → raw water pressure pump → multi-medium filter → activated carbon filter → water softener → precision filter → first stage reverse osmosis machine → intermediate water tank → intermediate water pump →EDI system → microporous filter → water point.