Filter Membranes The Technical Definition
Filter Membranes Filtration membrane full name microporous membrane, used in bulk drugs. Pharmaceutical solvents. Injection water. Injection, including mixed fiber microporous membrane and other types.
1.1 Filter membrane technology definition
Membrane filtration is a solid-liquid separation technology, it is the membrane hole to filter the water, the water impurities trapped, and no chemical changes, simple processing technology, but the film hole is very small, the corresponding existence of some technical problems. Water is also useful in biofilm treatment of raw water, but it is different from the membrane separation technology. The membrane used for membrane separation is called film.
1.2 Filter Membranes Types and mechanisms of filtration membranes
(MF), ultrafiltration membrane (UF), nanofiltration membrane (NF) and reverse osmosis membrane (RO) were used to separate the size of raw water particles. MF membrane pore size of 0.05um or more, or more than 1000 molecular weight to remove colloids, macromolecules for the object. NF membrane pore size of 100 to 1000 molecular weight. It removes matter between UF and RO to remove trihalomethanes, odor, color, pesticide, soluble organic matter, Ca, Mg and so on. RO separation particle size of dozens of molecular weight, to remove salt and inorganic salts for the object. RO infiltration of water pressure than its osmotic pressure to 1 to 2 times. In addition to the above four, there are ion exchange membrane and gas permeable membrane. MF, UF, NF and RO are driven by pressure to separate the solid solution. Ion exchange membrane is driven by electricity to salt molecules separated, contributed to desalination and so on. Gas permeable membranes are recently developed by gas-based new films that allow ethanol to concentrate and desalinate.
1.3 film materials
There are three kinds of fiber, synthetic resin and ceramic. Some of the membrane material is weaker than salts and ozone and other oxidant materials and micro-material decomposition of the material. In addition, the RO used for desalination has a membrane that removes THM-producing bromine and a membrane that can not remove bromine, depending on the application.
1.4Filter Membranes Membrane type
The water flow through the membrane is not large, so the amount of water required by the membrane, the membrane unit of the monomer area to large, in a small space into a lot of root film tube. In addition, the film thickness of 100um or less due to high pressure, must also have the ability to withstand pressure, for which should try to manufacture a variety of high pressure resistant film. General membrane type of plate and frame, spiral, bridge, tube and hollow fiber type five. Plate-and-frame films should be made of porous materials, spiral and bridge-type membrane and the same frame. Spiral for the roll, the bridge in the folding into a small volume into a large area of the membrane. Tubular membrane also need to have a porous material, raw water from the inside of the tube through the infiltration of water out of the tube for the internal pressure of the membrane, this passenger is very common, but also the external pressure tube. The hollow system has a diameter of several hundred um, and the system has a large number of fibrous tubules, because the fiber tube is small and there is no need for a particularly high strength fiber tube, the membrane itself is sufficient to resist the pressure given, the hollow fiber system has raw water from the inside of the hollow system Through the internal pressure, and external pressure from the external pressure of two.