UF technology is kind of membrane separation technology that can purify and separate the solution, it is a kind of solution separation device that via the UF membrane filtering medium and using the pressure difference of the both sides of the membrane. 

UF membrane only allow the solvent (hydrone), inorganic salt and low molecular organic matter go through, and will retain

the Macromolecular Substances like the Suspended solids, colloid, protein and microorganism.

for the UF filter port size usually consider from 0.001-0.1micro, and the MWCO is from 1,000 to 1000000 Dalton. if the filtering port size bigger than 0.01micro, or the MWCO higher than 300,000 DALTON , IT will be defined to be Microfiltration membrane or fine filtration membrane.  THE MWCO of the UF using for the water treatment is from 30,00 to 300,000 dalton. 

here for the UF membrane, which MWCO from 6000 to 30,000 dalton , is mostly using in the filed of material Separation, concentration,sterilization and depyrogenation .

there are two kinds of the UF membrane ,like the plate style or the tube style. the tube-type UF membrane, according to its tube dia, it can be called Hollow fiber , capillary tube or tubular.

the UF membrane for the water treatment basically using the capillary tube in the market, only some industry project is using the hollow fiber (with inner dia 0.1-0.5mm) PVC or propylene microporous membrane which is normally called MF.

and connect or combine the UF membranes which can be connected to the UF system , this is call the UF membrane module. 

UF module is devided into 3kinds,  inside-out, outside-in and submerged .

the submerged UF membrane is working with the pressure difference between the inner vacuo and the barometric pressure. so here for some high request with the  Filter Precision , this pressure pressure cannot easily reach the request for this filtering.  It is better suitable for some lower filter precision UF or MF membrane, 

the outside membrane ,due to it is different and uneven water flow when foward flush or back flush,it will effect the performance of the surface of the membrane flush. so here for the UF membrane when using, it is more advantage with the inside-out.

UF operating principle 

UF is kind of membrane separation process that with the screening principle and pressure using. it is filter precision is around 0.005-0.01um, which can filter the Particles, colloid, bacteria, heat source and the macromolecule organic matter in the water. it also widely using Separation, enrichment and purification of materials.  UF filter process is a No phase transformation, and it will be more suitable for the thermosensitive substance separation under the normal temperature. it also have a good Heat resistance, acid and alkali resistance and oxidation resistance. and can keep using long term under the ph 2-11 and temperature below 60℃

the classification  of UF

by structure : there will be plate UF, hollow fiber UF, Nano membrane table UF, tube and Spiral-wound UF membrane. 

here for the hollow fiber UF membrane is the most Mature and advanced technology. Hollow fiber outer 0.4-2.0mm , inner 0.3-1.4mm, and there are full of micropore on it is fiber tube, the port size is named as MWC (Molecular Weight Cut-Off) ,THE MWCO CAN BE THOUSANDS OR TENS OF THOUSANDS,,. 

the source water flowing inside or outside the membrane hollow fiber element, which be called outside-in or inside-out way , and this process is a dynamic process, in which the retain materials will be excluded with the concentrated solution, so it will not block the membrane. and keep running long term

the usage

in the early , the INDUSTRIAL UF is using in the waste water and the sewage watertreatment filed. but with the 30years more development, the UF membrane is widely using now, like The food industry, beverage industry, dairy industry, fermentation, biological medicine, medicine, chemical, biological agents, Chinese medicine preparation, clinical medicine, printing and dyeing wastewater, food industrial wastewater treatment, recycling and environmental engineering etc..