What is Membrane Filtration?
Membrane filtration is a screening process related to membrane aperture size, driven by the pressure difference on both sides of the membrane, membrane as the filter medium, under certain pressure, when the original fluid flow through the membrane surface, the membrane surface with many tiny pores allow only water and small molecules through and become the liquid, and the substancesin the original fluidare greater than the membrane surface micro aperture, so they were trapped in the beginning side of the membrane, thus achieve the purpose of separation and enrichment of original fluid.
Membrane filtration technology is starting to be used frequently in all kinds of devices, especially in devices such as gas-liquid filters.
The classification of membrane filtration technology in practical application.
Ultrafiltration: So-called ultrafiltration is refers to under certain pressure, after a solution containing the small molecules are supported membrane surface, the solvent and a small molecule solute through the membrane, and macromolecules were intercepted, as concentrate are recycled. Head can ultrafiltration membrane filter particle size between 5–10 nm, operating pressure between 0.1–0.25MPa.
Nanofiltration: Nanofiltration is a membrane separation technology developed on the basis of a reverse osmosis, the interception of nanofiltration membrane size generally between 0.1 ~ 1 nm, operating pressure in 0.5 ~ 1 mpa, intercept molecular weight is 200 ~ 1000, the molecular weight of the water for hundreds of small organic molecules has good separation performance.
Reverse osmosis: Reverse osmosis can also be called high filter, is a kind of inverse penetration process, by in the liquid side of the filter with higher pressure than the osmotic pressure, makes the solution of the solvent to the other side of the membrane. The filter diameter of reverse osmosis membrane is between 0.2 and 1.0 nm, and the operating pressure is between 1~10MPa.
Microfiltration: Microfiltration is one of the membrane technologies that are used to filter the separation by the screening of the membrane. The characteristics of the microfiltration membrane are the neat and uniform porous structure design. The particles smaller than the membrane holes under the action of static pressure will pass through the filter membrane, and the particles larger than the membrane hole are intercepted at the surface of the filter membrane to achieve effective separation. In addition, the microfiltration membrane is a uniform porous membrane, and the thickness is between 90 and 150 mu m. The filtering particle size is between 0.025~10 mu m and the operating pressure is between 0.01~ 0.2mpa.