Showing papers on "Forward osmosis published in 1991"

Reverse osmosis system

Abstract: A reverse osmosis system includes a sediment filter which cleans feed water from a source and from which that feed water is fed to a reverse osmosis membrane filter. Permeate from the latter is fed to a bladder within a storage tank. Concentrate from the membrane filter is fed to and used within the storage tank as squeeze water for the bladder. When a faucet that delivers permeate to the user is open, squeeze water is used to cause permeate to flow out of the storage tank through an impurity filter to supply the faucet. A valve unit is included to control the amount of squeeze water fed to the storage tank and to regulate permeate flow so that the water outletted from the faucet remains at a constant pressure and provides relief as against overpressure in the system. A proportioning valve within the valve unit serves to maintain at all times a constant ratio of concentrate to permeate flow through the membrane filter for adequate cleansing of the membrane. Also included are input-side and output-side flow monitors which provide signals to a processor that serves to indicate the status of filter conditions. There also is an advantageous faucet assembly for controlling the delivery of permeate to the user with flexibility and convenience.

Method and apparatus having reverse osmosis membrane for concentrating solution

Abstract: A method and an apparatus for treating salt water by a multiplicity of reverse osmosis membrane modules or a structure constituted by combining a multiplicity of reverse osmosis membrane modules and an evaporating device and thereby capable of efficiently treating it while preventing excessively large energy consumption. Salt water is passed through a plurality of reverse osmosis membrane modules so as to be separated into desalted water of a potable water level and high density concentrated water the salinity quality of which is 80,000 to 120,000 ppm.

Compact reverse osmosis system with cold water flush

Abstract: A reverse osmosis purification system is operated on a ratio of approximately 1 to 1 to 2 to 1 waste water to product water. The system uses the cold water outlet and a cold water path which extends through the RO membrane to remove non-migrating particles trapped on the outside of the reverse osmosis membrane to remove salts from the membrane and allow to prolong the life of the membrane despite low brine to pure water ratio.

Evaluation of surface force-pore flow and modified surface force-pore flow models for reverse osmosis transport

Abstract: The surface force-pore flow (SF-PF) model of reverse osmosis transport and the extended and modified form (the MD-SF-PF model) have been employed to predict the performance of four aromatic polyamide (FilmTec, FT30)reverse osmosis membranes. The evaluation is based on a comparison of model predictions with experimental data. Dilute sodium chloride-water solution experimental data were used to estimate model parameters. The models are then used to predict flux and separation at various operating pressures and concentrations. Membrane performance (i.e., separation and permeate flux) can be well predicted by the MD-SF-PF model while the SF-PF model predicts the performance for the sodium chloride system less satisfactorily.

Reverse osmosis treatment process

Abstract: This invention relates to a reverse osmosis treatment process, particularly a stable reverse osmosis treatment process which prevents a lowering in throughput capacity by carrying out treatment while keeping the permeate flux of a reverse osmosis membrane constant through the time of use of a module. The process of this invention can keep the throughput capacity constant, can prevent adhesion and pollution onto membrane surfaces and fouling thereon, and moreover can maintain stable operation in a continuous run.