456 results about "Flat sheet membrane" patented technology

Advanced submerged membrane systems are provided. Said submerged membrane systems have multiple membrane modules comprising of strips of flat sheet membrane, bundles of self-support hollow fiber membranes braided together for reinforcement, tubular membranes, and braid supported hollow fiber membranes. Said submerged membrane systems have alternating relay, or two-way floating switch or computer to control filtration and back flush/pulse cleaning. Said submerged membrane systems have an oscillating motor, and aerator which can generate liquid vortex (whirlpool) flow around membrane to keep membrane from fouling. The present invention provides advanced submerge membrane systems at very low cost for drinking water production, wastewater treatment and membrane bioreactors for biotech, pharmaceutical and other industries.

A flat sheet membrane element for performing solid-liquid separation by immersion in a liquid to be treated which contains a suspended component includes sheet-shaped filtration membranes disposed opposite to each other with a space for a treated liquid flow path, a support portion for securing the space for the treated liquid flow path, and a peripheral sealing portion for sealing the peripheral edges of the filtration membranes arranged opposite to each other so as to form at least one treated liquid outlet, the filtration membranes including at least expanded PTFE (polytetrafluoroethylene) porous membranes.

The present invention discloses high performance cross-linked polyimide asymmetric flat sheet membranes and a process of using such membranes. The cross-linked polyimide asymmetric flat sheet membranes have shown CO₂ permeance higher than 80 GPU and CO₂/CH₄ selectivity higher than 20 at 50° C. under 6996 kPa of a feed gas with 10% CO₂ and 90% CH₄ for CO₂/CH₄ separation.

The invention discloses a method for preparing an asymmetric nanofiltration membrane by blending polyether sulfone and sulfonated polysulfone high polymers. A blending nanofiltration membrane with an asymmetric structure is prepared in one step by the nanofiltration membrane through a phase transformation method. The method comprises the following steps of: preparing casting membrane liquid, namely mixing the polyether sulfone, the sulfonated polysulfone high polymers, an additive and a solvent to prepare the casting membrane liquid; and forming a membrane by the phase transformation method, wherein the membrane comprises a flat membrane and a hollow fibrous membrane. The interception rate of the nanofiltration membrane to 0.5 to 1.5 g/L sodium chloride and 0.5 to 1.5 g/L sodium sulfate under the operating pressure of between 0.1 and 0.8 MPa is between 20 and 95 percent, the interception rate of the nanofiltration membrane to polyethylene glycol with the relative molecular mass of between 600 and 2,000 is between 40 and 99.9 percent, and the pure water flux of the membrane is between 10 and 250 L/(m2hbar). The asymmetric nanofiltration membrane of the invention has the advantages of high strength and toughness, high compactness resistance, chlorine resistance and high-temperature resistance, and can be applied to aspects of water treatment, wastewater treatment, material separation and the like.

The present invention discloses high performance UV cross-linked polymer functionalized molecular sieve/polymer mixed matrix membranes (MMMs) with either no macrovoids or voids of less than several angstroms at the interface of the polymer matrix and the molecular sieves. These UV cross-linked MMMs were prepared by incorporating polyethersulfone (PES) functionalized molecular sieves such as AlPO-14 and UZM-25 small pore microporous molecular sieves into a continuous UV cross-linkable polyimide polymer matrix followed by UV cross-linking. The UV cross-linked MMMs in the form of symmetric dense film, asymmetric flat sheet membrane, or asymmetric hollow fiber membranes have good flexibility, high mechanical strength, and exhibit significantly enhanced selectivity and permeability over polymer membranes made from corresponding continuous polyimide polymer matrices for carbon dioxide/methane and hydrogen/methane separations. The MMMs of the present invention are suitable for a variety of liquid, gas, and vapor separations.

The invention relates to a conductive filter membrane and its application. Based on manufacturing of a flat sheet membrane, a stainless steel screen is embedded to prepare a conductive membrane, and a conductive filter membrane is formed. The conductive filter membrane is directly used as a negative electrode, conductive corrosion-resistant materials such as graphite, stainless steel and the like are used as a positive electrode, and facilities such as a constant potential rectifier and the like are used along with a power supply so as to make the conductive filter membrane negatively charged. Electronegative pollutants in mixed liquor are obstructed by electrostatic repulsion so as to be deposited on the surface of the membrane. Meanwhile, the conductive filter membrane is directly used as a negative electrode, and a certain amount of H2O2 will be generated near the negative electrode (near the membrane) under the electrochemical action. By strong oxidizing ability, a certain amount of pollutants on the surface of the membrane can be removed by oxidation so as to enhance anti-pollution capacity. A routine filter membrane material determines practical applicability of the conductive filter membrane. The conductive filter membrane is directly used as the electrode to enhance fusion of an electrochemical system and an MBR system and strengthen effect of an electrical field.

The present invention discloses mixed matrix membranes (MMMs) containing polymer-functionalized low acidity, ultra low silica-to-alumina ratio, nano-sized SAPO-34 small pore molecular sieves and a continuous polymer matrix and methods for making and using these membranes. The surface functionalization of these molecular sieves provides a desired interfacial adhesion between SAPO-34 nano-particles and the continuous polymer matrix, which results in either no macrovoids or voids of less than 5 angstroms at the interface of the continuous polymer matrix and SAPO-34 in the MMMs. These MMMs, in the form of symmetric dense film, asymmetric flat sheet membrane, or asymmetric hollow fiber membranes, have good flexibility and high mechanical strength, and exhibit remarkably enhanced CO₂ permeability (or CO₂ permeance) and maintained CO₂/CH₄ selectivity over the continuous polymer matrices for CO₂/CH₄ separation. The MMMs of the present invention are suitable for a variety of liquid, gas, and vapor.

The present invention discloses a method of making high performance UV cross-linked polymer functionalized molecular sieve/polymer mixed matrix membranes (MMMs) with either no macrovoids or voids of less than several angstroms at the interface of the polymer matrix and the molecular sieves. These UV cross-linked MMMs were prepared by incorporating polyethersulfone (PES) functionalized molecular sieves such as AlPO-14 and UZM-25 small pore microporous molecular sieves into a continuous UV cross-linkable polyimide polymer matrix followed by UV cross-linking. The UV cross-linked MMMs in the form of symmetric dense film, asymmetric flat sheet membrane, or asymmetric hollow fiber membranes have good flexibility, high mechanical strength, and exhibit significantly enhanced selectivity and permeability over polymer membranes made from corresponding continuous polyimide polymer matrices for carbon dioxide/methane and hydrogen/methane separations. The MMMs of the present invention are suitable for a variety of liquid, gas, and vapor separations.

The present invention discloses methods of separating gases using high performance UV cross-linked polymer functionalized molecular sieve/polymer mixed matrix membranes (MMMs) with either no macrovoids or voids of less than several angstroms at the interface of the polymer matrix and the molecular sieves. These UV cross-linked MMMs were prepared by incorporating polyethersulfone (PES) functionalized molecular sieves such as AIPO-14 and UZM-25 small pore microporous molecular sieves into a continuous UV cross-linkable polyimide polymer matrix followed by UV cross-linking. The UV cross-linked MMMs in the form of symmetric dense film, asymmetric flat sheet membrane, or asymmetric hollow fiber membranes have good flexibility, high mechanical strength, and exhibit significantly enhanced selectivity and permeability over polymer membranes made from corresponding continuous polyimide polymer matrices for carbon dioxide/methane and hydrogen/methane separations. The MMMs of the present invention are suitable for a variety of liquid, gas, and vapor separations.

The invention discloses an inorganic filler and dopamine compound inorganic and organic hybrid membrane as well as a preparation method and application of the membrane. With linear or tubular nano particle as a carrier, L-dopamine is grafted on the surface of the carrier to obtain compound inorganic particle and membrane material polymer mixture and a flat sheet membrane is prepared through submersion phase conversion. By virtue of the L-dopamine, the hydrophilicity of the blend and hybrid flat sheet membrane is improved; the osmosis performance of the prepared inorganic filler and dopamine compound inorganic and organic hybrid membrane is remarkably improved; the pure water flux is increased; the filtering efficiency is high and the retention rate is increased.

Porous membrane contactors and/or their methods of manufacture and/or use are provided. In at least selected embodiments, the present invention is directed to flat panel hollow fiber or flat sheet membrane contactors and/or their methods of manufacture and/or use. In at least certain particular embodiments, the present invention is directed to hollow fiber array flat panel contactors, contactor systems, and/or their methods of manufacture and/or use. In at least particular possibly preferred embodiments, the contactor is adapted for placement in an air duct (such as an HVAC ductwork) and has a rectangular frame or housing enclosing at least one wound hollow fiber array or membrane bundle.

The present invention discloses polymer functionalized molecular sieve/polymer mixed matrix membranes (MMMs) with either no macrovoids or voids of less than several Angstroms at the interface of the polymer matrix and the molecular sieves by incorporating polyethersulfone (PES) or cellulose triacetate (CTA) functionalized molecular sieves into a continuous polyimide or cellulose acetate (CA) polymer matrix. The MMMs, in the form of symmetric dense film, asymmetric flat sheet membrane, or asymmetric hollow fiber have good flexibility and high mechanical strength, and exhibit significantly enhanced selectivity and/or permeability over the polymer membranes made from the corresponding continuous polymer matrices for carbon dioxide/methane (CO₂/CH₄) and hydrogen/methane (H₂/CH₄) separations. The MMMs are suitable for a variety of liquid, gas, and vapor separations such as deep desulfurization of gasoline and diesel fuels, ethanol/water separations, pervaporation dehydration of aqueous/organic mixtures, CO₂/CH₄, CO₂/N₂, H₂/CH₄, O₂/N₂, olefin/paraffin, iso/normal paraffins separations, and other light gas mixture separations.

The present invention discloses a method of making, compositions and method of using high performance UV cross-linked polymer functionalized molecular sieve/polymer mixed matrix membranes (MMMs) with either no macrovoids or voids of less than several angstroms at the interface of the polymer matrix and the molecular sieves. These UV cross-linked MMMs are prepared by incorporating polymer functionalized molecular sieves into a continuous UV cross-linkable polyimide polymer matrix followed by UV cross-linking. The UV cross-linked MMMs in the form of symmetric dense film, asymmetric flat sheet membrane, or asymmetric hollow fiber membranes have good flexibility, high mechanical strength, and exhibit significantly enhanced selectivity and permeability over polymer membranes made from corresponding continuous polyimide polymer matrices for carbon dioxide/methane and hydrogen/methane separations. The MMMs are suitable for a variety of liquid, gas, and vapor separations.

The invention discloses an organic-inorganic composite lithium ion battery diaphragm and a preparation method thereof. The diaphragm is a composite membrane formed by reinforcing organic resin by inorganic particles, wherein the inorganic particles account for 0.1 percent by mass to 20 percent by mass and the organic resin accounts for 10 percent by mass to 70 percent by mass. Preparation of the diaphragm comprises the following steps of: firstly, stirring the organic resin, the inorganic particles and a diluent according to a certain proportion at a temperature of 150 to 280 DEG C to form homogeneous solution; then carrying out hot-pressing on the obtained homogeneous solution at a temperature of 150 to 220 DEG C to form a flat sheet membrane with a thickness of 20 to 1,000 micron; cooling the flat sheet membrane to the room temperature by adopting water bath with a temperature of 0-100 DEG C or at a cooling speed of 0-200 DEG C/min; finally, carrying out operation of firstly stretching and then extracting or firstly extracting and then stretching and drying processing on the cooled flat sheet membrane. The diaphragm provided by the invention has the advantages of easiness for controlling the porosity, adjustability for the aperture, micropore penetration, good high-temperature stability and the like.

The invention provides a pollution resistant membrane module which is a flat membrane module. The membrane module comprises a frame and two filter membranes, wherein the two filter membranes respectively cover the two sides of the frame; a liquid flow channel is formed between the two filter membranes; a water outlet is arranged at one end of the frame; at least a conducting coil pipe vertical to the filter membranes is arranged between the two filter membranes; magnetic chips are arranged in the positions corresponding to the coil bodies on the filter membranes; and the orientations of the south and north poles of the two magnetic chips in the same positions on the two filter membranes are identical. The pollution resistant membrane module has the following beneficial effects: when being electrified, the conducting coils in the pollution resistant membrane module generate south and north poles and generate attractive forces or repulsive forces towards the filter membranes or supporting filter plates which are provided with the magnetic chips with south and north poles; the directions of the south and north poles of the conducting coils are changed by changing the current directions, so that the filter membranes can be continuously shaken to shake off the pollutants, thus alleviating membrane pollution and prolonging the service lives of the membranes; and less electricity is used, so the aeration energy consumption can be reduced and the operation cost can be lowered.

The invention discloses the use of polymer functionalized molecular sieve/polymer mixed matrix membranes (MMMs) with either no macrovoids or voids of less than several Angstroms at the interface of the polymer matrix and the molecular sieves by incorporating polyethersulfone (PES) or cellulose triacetate (CTA) functionalized molecular sieves into a continuous polyimide or cellulose acetate (CA) polymer matrix. The MMMs, particularly PES functionalized AlPO-14/polyimide MMMs and CTA functionalized AlPO-14/CA MMMs, in the form of symmetric dense film, asymmetric flat sheet membrane, or asymmetric hollow fiber have good flexibility and high mechanical strength, and exhibit significantly enhanced selectivity and/or permeability over the polymer membranes made from the corresponding continuous polymer matrices for carbon dioxide/methane (CO₂/CH₄), hydrogen/methane (H₂/CH₄), propylene/propane separations and a variety of liquid, gas, and vapor separations.

The present invention discloses new types of poly(amidoamine) (PAMAM) dendrimer-cross-linked polyimide membranes and methods for making and using these membranes. The membranes are prepared by cross-linking of asymmetric aromatic polyimide membranes using a PAMAM dendrimer as the cross-linking agent. The PAMAM-cross-linked polyimide membranes showed significantly improved selectivities for CO₂/CH₄ compared to a comparable uncrosslinked polyimide membrane. For example, PAMAM 0.0 dendrimer-cross-linked asymmetric flat sheet poly(3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride-3,3′,5,5′-tetramethyl-4,4′-methylene dianiline) (DSDA-TMMDA) polyimide membrane showed CO₂ permeance of 135.2 A.U. and CO₂/CH₄ selectivity of 20.3. However, the un-cross-linked DSDA-TMMDA asymmetric flat sheet membrane showed much lower CO₂/CH₄ selectivity (16.5) and higher CO₂ permeance (230.8 GPU).

The invention discloses a process and a device for recovering sodium sulphide wastewater in barium sulphate production, belonging to the technical field of wastewater recovery. The process comprises the following steps performed by the corresponding devices: adding sulphuric acid to neutralize dilute sodium sulphide waste solution; absorbing hydrogen sulphide by a sodium sulphide spray tower; adding hydrogen peroxide in the sodium sulphate solution, so as to oxidize hydrogen sulphide which is dissolved in sodium sulphate solution into sulphur; filtering the sodium sulphate solution; and finally charging the sodium sulphate dilute solution in a disc-tube type reverse osmosis membrane system or a high-pressure flat-sheet membrane system, then concentrating, reusing the concentrate in barium sulphate production, and directly draining clear solution, so as to achieve the effect of turning waste into wealth.

The invention relates to a high-flux ceramic flat sheet membrane and a preparation method thereof. The high-flux ceramic flat sheet membrane comprises a ceramic flat sheet membrane supporting body and a separation membrane layer wrapping the outer surface of the ceramic flat sheet membrane supporting body. The ceramic flat sheet membrane support body is prepared from the following raw materials in parts by mass: 40-57 parts of diatomite, 30-40 parts of alpha-alumina powder, 4-12 parts of a pore forming agent, 20-40 parts of a support body binding agent, 8-12 parts of a lubricant, 9-13 parts of a plasticizer and 12-18 parts of chopped fibers. The separation membrane layer is prepared from the following raw materials in parts by mass: 40-43 parts of ceramic powder particles, 4-6 parts of ethanol, 19-40 parts of a separation membrane layer binding agent and 9-12 parts of polyethylene glycol. The high-flux ceramic flat sheet membrane product is low in sintering temperature, low in production cost, high in product porosity, small in filtering resistance and high in water flux.

The invention relates to a recycling method of a waste polyvinylidene fluoride (PVDF) flat sheet membrane, which comprises the recycling of the PVDF and a non-woven supporting layer on the surface of the membrane. The method comprises the following steps: firstly, removing contaminants from the surface of the waste membrane in a cleaning manner; drying the waste membrane and then dissolving the waste membrane in an organic solvent in a soaking manner so as to recycle the PVDF on the surface of the membrane; performing solid-liquid separation on the PVDF so as to obtain a PVDF extracting solution and a non-woven fabric; filtering and removing impurities from the PVDF extracting solution in a high-speed centrifugation manner or by using a filter membrane; adding partially fresh PVDF resins, pore-foaming agents, additives and the like into the PVDF extracting solution so as to prepare a membrane casting solution; preparing a regenerated flat sheet membrane by using a nonsolvent induce phase separation (NIPS) method; washing, drying and smashing the non-woven polyethylene terephthalate (PET); and then processing the non-woven PET into PET granules by using an extrusion melting method.

The invention discloses a method for preventing split membrane bio-reactor (MBR) flat membrane pollution. The method for preventing split MBR flat membrane pollution is characterized in that a bottom screen and a top screen are arranged in a membrane assembly box; filling material particles are arranged between the bottom screen and the top screen; and diameters of the filling material particles are greater than diameters of meshes of the bottom screen and the top screen. The method provided by the invention has the advantages that the filling material particles are arranged in a membrane bioreactor and are subjected to circulation stirring in the membrane assembly box so that the problem of an insufficient shear force produced by conventional aeration on a membrane surface is solved and a cleaning effect on a membrane surface is improved; a risk of membrane pollution is reduced without increasing of aeration quantity, breaking of a membrane surface and an influence on product water quality; chemical cleaning frequency is effectively reduced; and a time interval of membrane cleaning is prolonged by about 30%. Therefore, the method provided by the invention is a low-cost and high-efficiency membrane pollution-resistance method.