1853 results about "Microfiltration" patented technology

A hollow fiber microfiltration (MF) membrane is provided. The casting solution used to make this membrane includes a fiber-forming polymer having a degree of polymerization greater than about 1000, a water-soluble polymer, an anhydride with about 2 to 12 carbon atoms, and a solvent. The membrane is formed by mixing and heating these components to form a viscous dope and then extruding the dope through an annular orifice to form a hollow fiber MF membrane. The hollow fiber membrane is then fed through a coagulation bath and two leaching baths. The membrane is especially useful for filtering liquids, such as wine and juice, so as to remove bacteria, gel, and solid particles from the liquids.

A micro/ultrafiltering element (10) and method for making a filter element are provided. The filtering element comprises a multi-level support (26) having a filtering membrane layer (12) formed thereon comprising sintered particles (14) of uniform diameter. The filtering membrane preferably has an average pore size of from about 0.005-10 micrometers. The filter element is capable of being formed in a variety of geometrical shapes based on the shape of the porous support,

A method of purifying impure water contaminated with a filterable impurity and a dissolved impurity, such as sea-water, comprising the steps of: providing impure water to a primary microfiltration or ultrafiltration unit to remove the filterable impurity and produce impure filtered water contaminated with a dissolved impurity; providing the impure filtered water contaminated with a dissolved impurity to a reverse osmosis unit to produce a potable water stream and a residual reverse osmosis stream; and treating the residual reverse osmosis stream prior to reuse. The treatment may be in the form of passing through a secondary filter (such as another microfiltration or ultrafiltration membrane or a cartridge filter, and the subsequently treated reverse osmosis reject may be used to backwash the microfiltration or ultrafiltration unit.

The invention relates to methods of improving protein production, e.g., large-scale commercial protein production, e.g., antibody production, utilizing a modified fed-batch cell culture method comprising a cell growth phase and a polypeptide production phase. The modified fed-batch cell culture method combines both cell culture perfusion and fed-batch methods to achieve higher titers of polypeptide products. Because the modified fed-batch cell culture method of the invention produces higher polypeptide product titers than fed-batch culture alone, it will substantially improve commercial-scale protein production. The invention also relates to a perfusion bioreactor apparatus comprising a fresh medium reservoir connected to a bioreactor by a feed pump, a recirculation loop connected to the bioreactor, wherein the recirculation loop comprises a filtration device, e.g., ultrafiltration or microfiltration, and a permeate pump connecting the filtration device to a permeate collection container.

A microfiltration apparatus and method for separating cells, such as circulating tumor cells, from a sample using a microfiltration device having a top porous membrane and a bottom porous membrane. The porous membranes are formed from parylene and assembled using microfabrication techniques. The porous membranes are arranged so that the pores in the top membrane are offset from the pores in the bottom membrane.

The invention relates to a combination of electrostatic spinning and electrostatic spraying for preparing a nanofibre base composite separation membrane, comprising: dissolving functional polymer film material in solvent; preparing into polymer spinning solution A for electrostatic spinning, and obtaining non-woven fabrics to serve as the support layer of a composite membrane; dissolving another functional polymer film material in the solvent; preparing into polymer spinning solution B, and spraying the polymer spinning solution B on the surface of the non-woven fabrics by electrostatic spraying to serve as the selecting layer of the composite membrane; carrying out heat treatment or chemical treatment on the above product; and preparing the nanofibre base composite separation membrane. The preparation method provided by the invention is simple and easy to realize, can conveniently and accurately control the thickness and the evenness of the surface selecting layer, and is easy to realize the operation of large-scale production; the prepared nanofibre base composite separation membrane can be widely applied in the fields of microfiltration, ultrafiltration, reverse osmosis and the like.

A membrane is provided including a coating layer having cellulose nanofibers produced from oxidized cellulose microfibers and an electrospun substrate upon which the coating layer is applied. The nanofibers of the electrospun substrate have a diameter greater than that of the cellulose nanofibers. The membrane also has non-woven support upon which the electrospun substrate is disposed. Microfibers of the non-woven support have a diameter greater than that of the nanofibers of the electrospun substrate. Application of electrospun membrane is in microfiltration area, while the cellulose nanofiber membrane serves in ultra-filtration, nanofiltration, and reverse osmosis after chemical modification.

The invention relates to a terpolymer of tetrafluoroethylene (TFE) monomer, polyvinylidene fluoride (PVDF) monomer and hexafluoropropylene (HFP) monomer for forming an ultrafiltration or microfiltration membrane, method of forming said membranes, and to the ultrafiltration or microfiltration membranes themselves. The invention also relates to a method of forming a polymeric ultrafiltration or microfiltration membrane including preparing a leachant resistant membrane dope which incorporates a leachable pore forming agent, casting a membrane from the dope and leaching the pore forming agent from the membrane. The invention also relates to a method of preparing a polymeric ultrafiltration or microfiltration membrane of improved structure including the step of adding a nucleating agent to the membrane dope before casting.

The present invention relates to method of treating soybean processing waste water by using membrane filtration technique, the soybean processing waste water is pretreated through pH value regulation, centrifuge, prefiltration, microfiltration, and temp regulation etc; then the pretreated soybean processing waste water is passed through ultrafiltration membrane system under pressure to extract soybean lactoalbumin; then the filtrate from ultrafiltration membrane is passed through nm filtration membrane system under pressure to extract soybean oligosaccharide which is further decolorized; the filtrate from nm filtration membrane system is post treated to obtain water suitable for use in production or water conformed with state discharge standard. Advantages: low cost, high purity of soybean lactoalbumin and oligosaccharide.

The present invention is a method for optimizing operating conditions for yield, purity, or selectivity of target species, and/or processing time for crossflow membrane filtration of target species in feed suspensions. This involves providing as input parameters: size distribution and concentration of particles and solutes in the suspension; suspension pH and temperature; physical and operating properties of membranes, and number and volume of reservoirs. The method also involves determining effective membrane pore size distribution; suspension viscosity, hydrodynamics, and electrostatics; pressure-independent permeation flux of the suspension and cake composition; pressure-independent permeation flux for each particle and overall observed sieving coefficient of each target species through cake deposit and pores; solving mass balance equations for all solutes; and iterating the mass balance equation for each solute at all possible permeation fluxes, thereby optimizing operating conditions. The invention also provides a computer readable medium for carrying out the method of the present invention.

The invention relates to a preparation method of a gradient ceramic tube with continuous holes, which combines with the advantages of a centrifugal shaping method and gel-casting. Evenly distributed gel-casting suspension is poured into a pattern to carry out centrifugation and gelatinization occurs to the suspended slurry under the effect of centrifugal force and heating to realize solidification and shaping. A wet blank is demoulded, dried and sintered and the gradient ceramic tube with the continuous holes is prepared. The pore diameters of pattern tubes are distributed continuously along the radial direction of the pattern tubes, the pore diameter of an inner surface is the smallest while the bore diameter of an outer surface is the largest; besides, the inner surface is quite flat and smooth without defect, therefore, the ceramic tube can be used both in the process of microfiltration and ultrafiltration and as a good support to further paint film on the inner surface. The preparation method is simple, thus saving the vacuum degassing procedure in traditional gel-casting; the gradient ceramic tube with the continuous holes can be shaped by one step; the pattern tubes with different pore diameters can be prepared by controlling the initial grain sizes of ceramic powders; the blank has high strength and is easy to operate with high efficiency and the yield of pattern tubes is high.

The present invention deals with a process for treating a polyimide comprising exposing said polyimide to a compound selected from the group consisting of dendrimers, hyperbranched polymers and mixtures thereof. The polyimide may be in the form of a membrane and the membrane, after treatment according to the process of the invention, may be suitable for use in a membrane-based separation technique, for example gas separation, filtration, microfiltration, ultrafiltration, reverse osmosis or pervaporation. The membrane may for example be suitable for separation of gas and hydrocarbon mixtures including mixtures of H2/N2, H2/CO2, He/N2, CO2/CH4, and C2-C4 hydrocarbon mixtures.

Porous poly(aryl ether ketone) (PAEK) articles are prepared from PAEK/polyimide blends by selective chemical decomposition and subsequent removal of the polyimide phase. Porous PAEK articles exhibit highly interconnected pore structure and a narrow pore size distribution. The porous PAEK articles of the present invention can be utilized as a porous media for a broad range of applications, including membranes for fluid separations, such as microfiltration, ultrafiltration, nanofiltration, and as a sorption media.

Membranes suitable for microfiltration, ultrafiltration (UF) and nanofiltration (NF) filters are provided. Such membranes may include a nanofibrous scaffold, optionally in combination with a non-woven substrate and/or a coating of a polymer and a functionalized nanofiller. Suitable membranes may also include a coating of a polymer and a functionalized nanofiller on a substrate, which can include a non-woven membrane, a nanofibrous scaffold, or both.

A lateral displacement array that includes a conduit in which there is an array that includes a number of vertically asymmetrical posts that are positioned in an ordered fashion that is asymmetric with respect to the direction of liquid flow within the array such that particles of at least a critical size will be laterally displaced as they flow through the array is described. Methods for separating particles having at least a critical diameter from 16 a liquid using a lateral displacement array and a microfiltration system including a number of lateral displacement arrays are also described. Array subunits suitable for the assembly of the lateral displacement array are also described that include posts on either side of a floor that are arranged on each side with half the usual density so that when the subunits are combined a lateral displacement array with the desired array of posts is formed.

The invention relates to a polymer membrane composition having improved water flux and stable pore size. The water flux is improved by increasing the hydrophilicity of the membrane using a matrix polymer blended with controlled architecture amphiphilic block copolymers. Preferred membranes are those having a fluoropolymer matrix and acrylic amphiphilic block copolymers. The addition of the amphiphilic block copolymers are especially useful in microfiltration and ultra filtration membranes when used in water filtration.

Cast semi-permeable membranes made from synthetic polymer used in reverse osmosis, ultrafiltration and microfiltration are treated with a non-leaching antimicrobial agent to prevent its bio-fouling and bacterial breakthrough. The semi-permeable membranes include a polymeric material and a non-leaching antimicrobial agent that is incorporated into and homogeneously distributed throughout the polymeric material. The polymeric material, in the case of one membrane, may be cellulose acetate. In the case of thin film composite polyamide membranes, the antimicrobial agent is incorporated in a microporous polysulfone layer that is sandwiched between a reinforcing fabric and an ultrathin polyamide material. The invention also includes a treatment of flat and hollow fiber semipermeable membranes made with polysulfones and polyvinylidene fluoride.

High flow, low-pressure ultrafiltration or microfiltration spiral wound membrane cartridges are used in filtration of liquid feedstocks having high suspended solids. Applications may utilize either vacuum or pumping for transmembrane drive pressure (TMP), and gas may optionally be bubbled up through the cartridges with certain feedstocks. Water permeate flux rates as high as 90 gallons per square foot per day (gfd) can be obtained at TMPs below 5 pounds per square inch. By locating each spiral wound cartridge in its own casing and supplying liquid feedstock to an open lower end of the casing, as opposed to submerging such cartridges in a tank filled with feedstock, overall low pressure performance is greatly improved. High permeate flow can be maintained for long periods of time between shutdowns for intensive cleaning. TMP is gradually increased to maintain a substantially constant rate of permeate discharge until a target is reached, indicative of solids accumulation on the membrane surface to an undesirable extent; then backflushing is effected for a short time. Discarding the hold-up volume of feedstock in the cartridge, the backflushing fluid and dislodged solids, allows production to be promptly resumed with fresh feedstock at performance at near original levels.

The invention discloses a method for one-time separation and extraction of dendrobe polysaccharide, dendrobine and erianin from dendrobium candidum. The method for extraction of dendrobe polysaccharide, dendrobine and erianin from dendrobium candidum comprises the steps of crushing of dendrobe, enzymatic hydrolysis, ultrasonic extraction, microfiltration, ultrafiltration and nano-membrane concentration, solid-liquid separation, vacuum cryogenic distillation, solvent extraction, solvent recovery, recrystallization, vacuum low-temperature drying and purification in the carbon dioxide supercritical fluid, thereby obtaining the dendrobe polysaccharide, dendrobine and erianin. The prepared product has good color, good solubility and high active ingredients.

A method of treating a hollow fiber membrane microfiltration filter having an influent side and an effluent side to improve performance of the filter is disclosed. The method entails sealing imperfections in surfaces of the filter by flushing the filter with a liquid aqueous suspension of particulates. Filter cartridge devices also are disclosed. The devices may include a bactericidal chamber. A radial flow filter may be included in the devices. The filter cartridges may include a drain tube positioned within the filter for removing of effluent generated by the filter. A plurality of filter cartridges may be positioned on the drain tube.

The invention discloses a nanometre-sized fibre liquid separation composite film and a preparation method thereof. The preparation method comprises the steps of (1) performing electrostatic spinning for a macromolecular spinning solution A to obtain a non-woven fabric as a supporting layer of the composite film; (2) coating a macromolecular spinning solution B on the surface of the non-woven fabric obtained in the step (1) in a spray coating manner as a selection layer of the composite film; and (3) suffocating the surface of a second nanometre-sized fibre layer by solvent steam; and (4) thermally treating or chemically treating the product obtained in the step (3) to obtain the finished product. The method of the invention has a manufacturing process that is simple and easily controlled,is capable of conveniently and precisely controlling the thickness and uniformity of the surface selection layer, and easily realizes operations of mass production. The obtained nanometre-sized fibreliquid separation composite film can be widely applied to the fields such as microfiltration, ultrafiltration, nanofiltration and reverse osmosis, etc.

A system, processes, and milk-based food products made from the system and processes, in which cream is separated from milk to produce an ultra-low fat milk product. The milk product is microfiltered to produce a retentate that is ready to drink and is high in protein and has no or substantially no fat. The permeate from the microfiltration process is ultrafiltered to produce a retentate that is high in protein with few other solids. The permeate may be used to provide protein fortification to other food and beverage products, and is especially useful in its liquid form for such fortification.

Methods and systems are disclosed which provide for the purification of effluent from a septic system or natural water from rainwater or stormwater collection devices for the storage and reuse of water. The purified water may be supplied to water applications, such as a return conduit to a home for potable or graywater usage. The distillation unit may be powered by a local power independent of a municipal power grid and which may employ sustainable energy mechanisms. The distiller residue may undergo a volume reduction process, such as evaporation, coagulation, electrocoagulation or microfiltration. The purified water may be stored in a holding tank with sensors to monitor the water quality and water level within the tank. Alarms, release valves or relief valves may be activated in response to such monitoring.