Showing papers on "Desalination published in 1970"

Interface condensation desalination membranes

Abstract: A desalination membrane-substrate composite, effective to permit the effusion of pure water and the rejection of dissolved impurities, comprising a semipermeable membrane layer of polymeric material in contact with at least one side of a porous substrate is made by in-situ interfacial condensation of two fast reacting organic compounds in the presence of a porous substrate.

Desalination of sea water

Abstract: Desalination of sea water is accomplished by use of osmosis wherein there is a saline water chamber and a chamber having a concentrated solution of an intermediate or precipitable soluble salt, such as aluminum sulfate, the chambers being separated by a semipermeable membrane. Fresh water will pass from the saline or sea water to the salt solution without use of pressure. The excess concentrated salt solution in the second chamber passes to a third chamber or place where salt is removed by being brought into contact with a precipitant such as calcium hydroxide in the case of aluminum sulfate.

Liquid purification system

Abstract: OSMOIS MEMBRANE ARE EFFECTIVELY REJUVENATED FOR SUBSTANTIALLY CONTINUOUS UTILIZATION. LIQUID PURIFICATION IS ACCOMPLISHED USING THE SAME PRESSURE DIALYSIS OR REVERSE OSMOSIS MEMBRANE IN DESALINATION OR FLUID PROCESSING APPARATUS TO ACHIEBVE TWO OR MORE SUCCESSIVE STAGES OF PURIFICATION, BY OPERATION THE APPARATUS USING A PARTICULAR TIME SEQUENCE PRESSURES AND/OR SOLUTION HAVING DIFFERENT CONCENTRATION AND CHEMICAL COMPOSITIONS, THE APPARATUS AND PARTICULARLY THE REVERSE

Pleated membrane transfer device

Abstract: This disclosure relates to an exchange device employed in desalination, ultra filtration, in the transfer of heat, the transfer of gas from the gas phase to the liquid phase, or the transfer of gases from the gas phase to another gas phase or the opposite sides of a permeable or permselective membrane, or to the traNsfer of waste products from blood to a suitable rinsing fluid. The exchange device is formed of a plurality of flow sheets or plates which are disposed between intermediate portions of a continuous pleated membrane. The flow plates have flow facilitating means formed therein and are reusable while the membrane is disposable.

Crosslinked poly(hydroxyethyl methacrylate) membranes for desalination by reverse osmosis

Abstract: A series of crosslinked hydroxyethyl methacrylate (HEMA) membranes for reverse osmosis desalination has been prepared. The crosslinkers used were trimethylol propane trimethacrylate (TPT) or ethylene glycol dimethacrylate (EGD). Membranes were synthesized by polymerizing the monomers as a thin homogeneous film. In addition to reverse osmosis tests, the membranes were also characterized by osmosis experiments and sorption measurements. The reverse osmosis water flux (1500 psi applied pressure, 4% NaCl brine, pH = 5) for these membranes decreases from 0.6 gallonmil/ft2-day (GMFD) to 0.055 GMFD and salt rejection increase from 78% to a maximum of 94% as the amount of TPT is increased from 0 to 11 mole-%. Water contents decrease from 42% to 15% over the same range of crosslinker, but the preferential sorption of water to salt does not vary. Thus, rises in reverse-osmosis semipermeability were found to result from changes in water–salt diffusivity ratios. The mechanism of permselectivity has been interpreted in terms of parallel diffusive fluxes across the membrane of primary H-bonded water and secondary water plus salt ions.

Desalination of seawater

Abstract: The water particularly for agricultural purposes, is treated by pumping it through electrically non-conducting tubes so arranged that the direction of flow is perpendicular to a magnetic field, whereby, at positions normal to both the flow direction and the magnetic field, a flow of water of higher ionic concentration than the purified water in the central region of the pipe is separated from the central flow. The ion enriched water streams are caused to pass electrodes for current production in an external circuit, the energy recovered being used as part of that required for pumping the raw seawater, or the separate anion and cation-enriched streams are pumped through chambers separated by permeable membranes from a further chamber through which seawater is passed.

Method of making reverse osmosis membranes for desalination of water

Abstract: REVERSE OSMOSIS MEMBRANES ARE PRODUCED BY SPRAYING A FILM-FORMING SOLUTION ONTO A SUBSTRATE IN A ZONE INTO WHICH IS INJECTED, THROUGHOUT SPRAYING, AN INERT GAS SATURATED WITH POLYMER SOLVENT VAPOR. SOLVENT IS THEN EVAPORATED FROM THE FILM BY REDUCING THE DEGREE OF SOLVENT SATURATION OF THE INERT GAS IN THE EVAPORATION ZONE BY INTRODUCING GAS THAT IS LESS THAN SATURATED WITH SOLVENT, BY LOWERING THE ATMOSPHERIC PRESSURE IN THE ZONE OR BY HEATING THE ATMOSPHERE. THE FILM IS THEN CURED IN THE PRIOR ART MANNER BY QUENCHING AND ANNEALING. ELECTROSTATIC SPRAYING IS MOST EFFECTIVE.

Feedwater heater and strainer arrangement for multiple-effect thin film desalination plant

Abstract: A vertical double fluted tube evaporator for water desalination has multiple closely-coupled effects with individual feedwater heaters in each effect. Feedwater manifolds in each effect supply feedwater to double fluted tubes through individual porcelain spray nozzles providing thin films on the tubes. The feedwater heaters are fed in series through each effect, while parallel branch lines supply the manifolds via in-line strainers with provisions for blow-down during normal operation if strainer blockage occurs.

Collagen membranes for reverse osmosis desalination

Abstract: A collagen membrane is employed as reverse osmosis membrane in desalination of water The process is particularly applicable to desalination of brackish waters containing substantial amounts of divalent ions

Polyacrylic desalination membranes. II. Reverse osmosis performance

Abstract: A new class of polyacrylic membranes has been tested under reverse osmosis conditions on dilute (1%–4%) salt solutions. Fluxes up to 0.2 gal-mil/ft2-day at greater than 98% rejection have been achieved. The effect of membrane composition on product flux and salt rejection is discussed. Increased fluxes at even higher rejection should be possible by proper selection of the type and concentration of hydrophilic, hydrophobic, and crosslinking monomers. It is concluded that improved membranes should have as high as possible a concentration of hydrophilic groups, distributed randomly through a lightly crosslinked, rubbery polymer matrix.

Reciprocating pump for desalination plant

Abstract: 1,212,917. Reciprocating pumps. PATERSON CANDY INTERNATIONAL Ltd. Jan. 31, 1969 [Feb. 1, 1968], No.5177/68. Heading F1A. [Also in Division B1] In a plant for the desalination of water operating by the process of reverse osmosis, a reciprocating pump 1 supplies saline water from an inlet pipe 10 to the plant 3 by means of a piston 7 which is assisted on its pumping stroke by rejected liquid which passes from the plant outlet 4 to chamber 9. Treated water passes from the plant through an outlet 5. The piston is reciprocated by a rod 19 connected to a rotating crank 18 which also operates a valve 15 controlling the plant outlet 14 and engine exhaust outlet 16. The pump inlet and outlet valves may be non-return valves 11, 12, or as in Fig.2 (not shown) may be combined as a single valve (11a connected by an extension to the valve 15. (For Figure see next page)

A process for producing semipermeable membranes

Abstract: Semipermeable membranes having improved reverse osmosis properties are prepared by crosslinking cellulose acetate methacrylate membranes in an aqueous persulfate-bisulfite redox system. The resulting membranes exhibit superior long-term reverse osmosis properties and find particular utility in desalination of water.

Fundamentals Of Desalination

Abstract: Reverse Osmosis By S. Sourirajan. Pp. xix + 580. (Logos, in association with Elek Books: London, August 1970.) 160s.

Quest For Water

Abstract: The frame of future development of water resources, as our needs and the respective strain on the environment increase, is outlined. Reference to available fresh water supply and to the respective demand, is followed by a brief account of environmental impact of exploitation of water resources. Then, alternative water resources, such as water conservation, wastewater reuse and desalination techniques are presented. Conflicts related to controversial water issues and the role of education in achieving a sustainable development of water resources are also discussed.

Low-Pressure Ultrafiltration Systems for Wastewater Contaminant Removal

Abstract: Low-pressure ultrafiltration is still in the preliminary stages of development as a unit process in municipal waste and wastewater treatment. Recently, the membrane process of reverse osmosis, developed initially for use in desalination, has attracted attention as a promising method for treatment of wastewaters. Data on the separation or removal of pure organic solutes is needed to evaluate the potential application of ultrafiltration systems in wastewater treatment. The organic solutes in wastewater streams cannot, in general, be economically recovered by chemical means. Ultrafiltration has the potential of making possible the economic treatment of at least some industrial wastewaters. A pertinent example is the pulp and paper industry, in particular, research efforts now being conducted by the Pulp Manufacturers Research League.(1,2,3) studies carried out on reverse-osmosis treatment of secondary-sewage plant effluent at Pomona, California(4), have demonstrated the feasibility of reverse osmosis for treatment of complex wastewaters containing relatively high concentrations of organic pollutants.

Centrifugal desalination plant

Abstract: Seawater or salt water is heated and supplied to a centrifugal zone followed by a condenser, as in 1,792,313. Centrifuge comprises a fixed cylindrical housing around the cylindrical rotation evaporator drum, axial water inlet and vapour outlet at opposite ends of drum, and perforations in drum wall for the concentrated residual water to drip into the housing. Used as intermittently or continuously operating plant.

Dual Plant for Producing Both Power and Process Heat for Distilling Liquid.

Abstract: 1,188,842. Evaporators, flash type, desalination of water; production of power. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. 20 May, 1968 [22 May, 1967], No. 23727/67. Heading B1B. [Also in Division F1] Salt water is desalinated and power is produced by burning fuel with compressed air in combustion chamber 11 to which distilled water is supplied through pipe 13, expanding the steam/gas effluent from chamber 11 in axial flow turbine 14 which drives alternator 15 and air-compressor 10, contacting the expanded steam/gas effluent from the turbine in packed bed 21 with salt water sprayed from pipe 23, and leading the heated salt water and condensate from well 17 to the first of a series of flash vaporization chambers a..h. Uncondensed vapours and gases leave the plant through stack 24. Salt water to be distilled flows through the condenser tubes 31 of the flash chambers. The condensate of the steam flashed in chambers a..h collects in trays 32 and runs into main 33. A metered quantity of the distilled water in main 33 is supplied to combustion chamber 11, and the remainder is withdrawn from the plant through pipe 34. About a third of the salt water which has passed through the condenser tubes of flash chambers h to e may be passed through pipe 23 to the packed bed 22. The remainder of the brine feed flows through the plant as shown.