Ultrafiltration device

(I) Functional Description The ultrafiltration unit employs hollow fiber membrane modules, featuring excellent effluent quality and high permeate flow. It can further remove suspended solids, colloidal silica, and other macromolecular substances (such as proteins, nucleic acids, polysaccharides) as well as bacteria, organic matter, and other impurities from water, effectively reducing the SDI value to ensure the effluent meets standards. The ultrafiltration unit is widely adaptable for separating solutes from dilute solutions; the ultrafiltration process involves no phase change, operates at room temperature, saving energy, and is particularly suitable for the separation of heat-sensitive substances; the ultrafiltration separation process is simple, with few auxiliary devices, easy operation, and low maintenance costs; the ultrafiltration membrane is resistant to chemical corrosion, with a wide pH adaptation range; hollow fiber ultrafiltration units have a large membrane area per unit volume, low investment costs, and simple cleaning characteristics. (II) Ultrafiltration Membrane System Compared to traditional filter media filtration processes, ultrafiltration is a water treatment technology with higher filtration precision, effectively removing bacteria, viruses, macromolecular organic matter, colloids, and particulate matter. It features anti-fouling properties, low chemical usage, high water recovery rate, and a small footprint. (1) Introduction Hollow fiber ultrafiltration is an internally pressurized membrane module, with hollow fibers made of hydrophilic polyethersulfone, and a nominal molecular weight cut-off of 150,000 Daltons. During use, raw water enters the inside of the hollow fibers, and the product water radially permeates through the membrane wall into the inner cavity, while externally it radially permeates through the membrane wall, resulting in a product water turbidity of no more than 0.1 NTU. The membrane modules can operate in full-flow filtration mode or cross-flow filtration mode. In full-flow filtration, all raw water is converted into product water, whereas in cross-flow mode, a portion of the raw water is discharged from the concentrate outlet as concentrate. During filtration, water flows inside the hollow membrane module from the inside out, meaning the feed water is distributed through the component end face, simultaneously entering the interior of each hollow fiber, flowing along the inside of the hollow fiber tube, permeating through the hollow fiber membrane wall along the way, and the product water permeating from the outer surface of each hollow fiber is collected into the central tube before exiting the membrane module. The membrane fibers are made of hydrophilic polyethersulfone, resistant to fouling, residual chlorine, and chemical cleaning. The ultrafiltration membrane has a molecular weight cut-off of 150,000 Daltons, with a membrane separation pore size of approximately 25 nm, effectively removing fine particles, colloids, bacteria, and viruses. The ultrafiltration membrane has a removal rate of 96% for particles >1μm, offering higher filtration precision than traditional filters and a smaller footprint. As membrane flux decays due to the accumulation of solid substances on the membrane, the modules employ periodic frequent backwashing to restore flux. The membrane's inherent excellent chemical stability allows it to meet the requirements for chemical cleaning and chemically enhanced backwashing.