182 results about "Transmembrane pressure" patented technology

A machine (1) for extracorporeal blood treatment comprises a device (2) for ultrafiltration of a liquid through a semi-permeable membrane (3) of a blood treatment device (4), a first sensor (11) for ultrafiltration rate through the membrane, a second group of sensors (13) for measuring a trans-membrane pressure, and a programmed controller (14) for calculating a maximum ultrafiltration rate as a function of the transmembrane pressure. The machine is suitable for kidney failure treatments, such as hemofiltration and hemodiafiltration. In a relatively short time the machine enables a large quantity of corporeal blood to be removed from the patient.

A reactor has an aerobic tank, an anoxic tank and a sealed membrane tank with conduits for circulating mixed liquor between them. Permeation starts when the mixed liquor reaches a high level and stops when the mixed liquor reaches a low level. A sensor, for detecting the mixed liquor level, may stop and start permeation. Pressure builds in the membrane tank when membrane air is on. Transmembrane pressure is also provided by gravity flow or siphon. Membrane air generates an air lift which drives the mixed liquor circulation. The total amount of air provided by an air source is divided and varied in time between the membrane aerator and the process aerator. The process aerator acts as a screening inlet to the conduit to the membrane tank. Chemical maintenance cleaning is provided by gravity flow.

A method of cleaning a porous polymeric membrane having a feed side and a permeate side including the steps of introducing a fluid containing a cleaning agent to the permeate side of a membrane allowing the cleaning agent to contact the permeate side of the membrane for a predetermined time, and contact the pores of the membrane, or introducing a fluid containing a cleaning agent to the feed side of a membrane; applying a transmembrane pressure to force the fluid containing the cleaning agent from the feed side to the permeate side of the membrane; allowing the cleaning agent to contact the permeate side of the membrane for a predetermined time, and contact the pores of the membrane. Preferably a concentration gradient between the feed side fluid and the lumen side fluid containing the cleaning agent causes cleaning agent to diffuse into the feed side fluid. Pressure may be applied to the fluid containing a cleaning agent to dislodge, where present, dissolved and undissolved solid from the membrane pores. The pressure may be applied in a pulsed fashion, and can be by way of compressed air at a pressure not more than the membrane's bubble point. The methods of the present invention may be preceded by, or followed with a backwash.

The present invention relates to methods and systems for optimization of dilution of a viscous starting material to isolate and/or concentrate the product of interest from the starting source material such that the process minimizes the volume of diluent and the total volume of the waste stream generated during the process as well as maximizing the yield of desired product. The system employs cross-flow filtration modules with sub-channels that are equidistant to the inlet and outlet of said modules and such modules are characterized by optimal channel height, optimal transmembrane pressure, etc., which are selected in order to achieve the best combination of product quality and production yield.

Desalination is carried out by a hybrid ion exchange-nanofiltration process in which ion exchange is followed by pressure-driven nanofiltration. Monovalent ions of sodium and chloride of saline water are exchanged for equivalent concentrations of poly-valent ions (for example, sodium ions for magnesium ions or chloride ions for sulfate ions) when passed through ion exchangers in the form of those poly-valent ions. The resultant solution has a lower osmotic pressure than the initial solution containing monovalent sodium and chloride ions, and requires less transmembrane pressure for membrane desalination compared to traditional reverse osmosis. The concentrated reject stream from the membrane process is used as regenerant for the exhausted ion exchanger, which has been converted to monovalent anionic or cationic form.

Processes and apparati are provided for separating molecules of interest from a mixture containing them which comprises subjecting the mixture to an improved method of tangential flow filtration (TFF). The improved TFF was used to clarify, and process various feedstreams for the removal of a molecule of interest. According to a preferred embodiment, a transgenic milk feedstream is stabilized and particulate matter such as fat, casein miscelles and bacteria are removed. The method of TFF used in the current invention utilizes optimized process parameters that include temperature, transmembrane pressure, cross-flow velocity, and milk concentration. Cleaning and storage procedures were also developed to ensure long membrane life. An aseptic filtration step was also developed to remove any bacteria remaining in a clarified transgenic milk feedstream.

The invention relates to flat membrane elements and components for water treatment, which are characterized in that the front face and the back face of a supporting plate of membrane elements are respectively provided with a plurality of scattered face bosses higher than the supporting plate. The adjacent membrane elements are combined and are supported at intervals by means of the face bosses of the supporting plate. The supporting plate can not be tilted and deformed, the condition that the distance of each point between the planes of the adjacent membrane elements is unchanged is ensured, aerated scouring is uniform, and the membrane pollution is lowered. Moreover, the thickness of the supporting plate can also be obviously reduced, and the thickness is reduced from original 5.5 to 6.0mm to about 3.5mm, so that the weight and the cost of the supporting plate are lowered by about 30 percent, the bosses are arranged at intervals, the adjacent intervals of assembled membrane components can also be changed according to actual requirements, and the condition that the distance of the membrane elements can be regulated is realized. Furthermore, the method of assembling the components of the membrane elements is also changed, the function of side inserting assembly can be realized, the structure of a membrane bracket is simplified, and the versatility of a component frame is enhanced. The front face and the back face of the supporting plate are additionally provided with transverse flow passages with transverse penetration, so that the resistance of water collection and flow deflection is small, the transmembrane pressure difference of a system is small, the water output of gravitational pressure difference can be adopted for filtering, and the running energy consumption of the system can be greatly lowered.

Cross-flow filters having improved uniformity in transmembrane pressures and consequent much greater flux are provided by the installation of barriers in permeate channels.

The invention relates to an ionic liquid gel supporting film and a preparation method thereof, belonging to the field of membrane separation techniques. The film is formed by loading ionic liquid gel on a macromolecule microporous membrane, and the mass of the ionic liquid gel accounts for 30-80% of the total mass of the ionic liquid gel supporting film. The preparation method of the film comprises the following steps: firstly, injecting a gel precursor solution into the macromolecule microporous membrane by adopting an impregnation method, and gelatinizing the gel precursor solution through ultraviolet light initiation to prepare the ionic liquid gel supporting film. The ionic liquid gel supporting film prepared by the method provided by the invention has relatively high gas permeation flux and relatively large gas separating factor, and can avoid the liquid leakage of the film under relatively high transmembrane pressure, enhance the performance stability of the film, and prolong the service life of the film. The method is simple and easy to control, the prepared ionic liquid gel supporting film is mainly used in the fields such as trapping of acid gas in industrial discharge exhaust gas, and CO2 separating in spacecrafts, submarines and other confined spaces.

The present invention provides a hollow fiber membrane for treating liquids. When used for a hollow fiber membrane module for refining a fermented liquid such as beer or wine, the hollow fiber membrane exhibits a high filtration performance per unit area thereof, with reduced clogging of the membrane. The membrane performance is sufficiently recovered by washing.

The present invention is a hollow fiber membrane for treating liquids, wherein a ratio of Flux 120 to Flux 30 is 0.45 or higher when filtration is performed by supplying a solution having a turbidity of 20 NTU into a hollow fiber membrane having an internal diameter of 500 to 1500 μm and a membrane thickness of 100 to 500 μm with a transmembrane pressure of 1.5 bar, the Flux 30 being flux 30 minutes after the start of the filtration, the Flux 120 being flux 120 minutes after the start of the filtration.

A crossflow membrane device that receives a feedstock at a feed end face and separates the feedstock into permeate and retentate. The device has a membrane support containing at least one monolith of porous material defining a plurality of passageways extending longitudinally from the feed end face of the monolith to a retentate end face of the monolith through which the feedstock flows to pass retentate from the device. A permselective membrane coating of finer pore size than that of the porous material is applied to the passageway wall surfaces of the monolith. At least one permeate conduit is formed within the monolith, the conduit containing a plurality of longitudinal permeate chambers communicating with a means of permeate introduction at or near the feed end face and permeate withdrawal at or near the retentate end face. The permeate is separated from feed and retentate, and a portion of the permeate is circulated through the permeate conduit to create a decreasing permeate pressure within the permeate conduit from the feed end of the membrane device to the retentate end of the device to control transmembrane pressure along the length of the device.

The invention provides a method for controlling the aeration quantity of a membrane tank. The method comprises the following steps of: calculating the permeability of each water producing period, the permeability each day and the change rate of the current permeability according to the data of membrane flux and transmembrane pressure difference acquired in real time; setting the reference value of the permeability change rate and calculating the ratio of the current permeability change rate to the reference value of the permeability change rate; and determining the ratio of the current permeability change rate to the reference value of the permeability change rate so as to adjust the aeration quantity. The invention also provides a system for implementing the method; and the system comprises a pressure gauge, a flowmeter, an aeration flow control device, a transducer, a blast blower and an aerator pipe, wherein the pressure gauge and the flowmeter are both connected with the aeration flow control device; and the aeration flow control device is orderly connected with the transducer, the blast blower and the aerator pipe. According to the invention, the purpose of reducing the aeration energy consumption of the membrane tank is achieved by regulating and controlling the aeration quantity required by aeration of the membrane tank with the change trend of the permeability of the membrane as a control parameter.

The invention discloses an optimized membrane bioreactor (MBR) back washing method. An MBR is operated at constant flux. The method comprises the following steps: I. computing the transmembrane pressure (TMP) of membrane modules of the MBR in a certain period of time; II. computing the similarity S in the certain period of time: specifically, firstly determining the reference value Tref of the TMP and then computing the similarity S by utilizing the TMP according to a formula in the specification; III. comparing the value of S with a preset threshold, washing the membrane modules by an online cleaning mode at different cleaning time if the value of S is not less than the preset threshold, and washing the membrane modules by an online chemical cleaning or offline cleaning mode if the value of S is less than the preset threshold. According to the actual situation of membrane pollution, through low-strength more timely cleaning, pollution of the MBR membrane is eliminated at the initial stage of formation, thus preventing synergistic deterioration effects caused because membrane pollution is not timely recovered, saving energy and time and prolonging the service lives of the membrane modules.

The invention discloses a ceramic membrane aeration and micro-positive pressure ozone membrane regeneration water treatment method. Sewage after ozone micropore aeration treatment is conveyed into a membrane tank; when a membrane on a membrane module is blocked by microorganisms or organic matter, compressed air enters the membrane of the membrane module through a water outlet of the membrane module for high-pressure back flushing; contaminants attached to the surface of the membrane are separated from the surface of the membrane; after the back flushing of the compressed air, ozone is supplied to the membrane of the membrane module under critical micro-positive pressure; after a gel layer difficult to degrade on the surface of the membrane is decomposed and dissolved by using an ozone and air space, the compressed air is used for reverse purging of decomposed substances on the membrane to accomplish membrane flushing; a nano ceramic membrane with small pore size distribution, small transmembrane pressure and a very small pore size is used for aeration; the micro-positive pressure aeration is adopted to form many fine and uniform oxygen bubbles to make full use of an oxygen source; oxygen is better dissolved in water; a utilization rate of the oxygen is increased; a biochemical effect is enhanced; and the energy source waste is reduced.

The present invention relates to a method for separating a catalyst by using a ceramic membrane filter, and an apparatus thereof, wherein discharged clear liquid of two membrane assemblies connected in series separately enter corresponding discharged clear liquid collection tubes, and then separately enter reaction product intermediate tanks. According to the present invention, the traditional clear liquid discharging way of the two membrane assemblies connected in series is changed so as to achieve the same transmembrane pressure difference of the two membrane assemblies connected in series, and concurrently achieve the same production load (a mount of the discharged clear liquid) of the two membrane assemblies, such that operation periods of the two membrane assemblies connected in series are the same, a service life of the ceramic membrane tube is substantially improved, and the ceramic membrane tube is only required to be chemically cleaned after operating about 2-3 months so as to prolong an operation period of the device and substantially reduce the number and cost of chemical cleaning.