A process for treating water in which pressurized feed water is passed through at least one semipermeable membrane to produce a product water and brine wherein sparingly soluble salts present in the brine are removed by passing it through a salt removal unit, the brine being subject to a series of re-circulation steps including (i) returning the brine to the input chamber in a recirculation step to pass the brine through the membrane for re-concentration of the brine; and (ii) carrying out step by step recirculation steps (i) for continued re-concentration of the brine and crystallization of low soluble salts, wherein the saturation indexes of low soluble salts during these steps are maintained within predefined ranges within a controlled crystallization zone. The process also includes de-activation of anti-scalant prior to passing the brine through the salt removal unit.
C02F 1/52 - Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
C02F 5/08 - Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
C02F 103/10 - Nature of the water, waste water, sewage or sludge to be treated from quarries or from mining activities
C02F 1/68 - Treatment of water, waste water, or sewage by addition of specified substances, e.g. trace elements, for ameliorating potable water
C02F 5/14 - Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances containing phosphorus
A method and system for cleaning a semi-permeable membrane (3) in a pressure vessel (2) of a desalination plant, said membrane having a feed side (FS) and an opposite permeate side (PS) and extending between a front end and a rear end of the vessel, a front end feed port (12) and a rear-end brine port (14) in communication with the feed side of the membrane, at least one permeate port (16, 17) in communication with said permeate side of the membrane, each module having a normal separation mode and a cleaning mode wherein in the normal separation mode feed water passes from the feed side to the permeate side to provide residual brine water (BS) from the rear-end brine port and a permeate water from said permeate port, and in the cleaning mode a washing water is delivered from an external source to the permeate side under higher pressure than the permeate pressure during normal separation process so that a net driving differential is directed to the feed side to suck water from the permeate side to the feed side of the membrane thereby separating foulant from the membrane and withdrawing the solution together with the foulant from the feed side of the membrane, wherein each vessel is provided with at least one internal valve (50, 60) selectively operable to at least partially assist in changing the direction of flow of fluid across the membrane (3) during switching to or from the separation mode from or to the cleaning mode. Both the front and the rear end of the vessel may have internal valves (50, 60) for effecting a change in the direction of flow of fluid across the membrane.
A water intake and pretreatment system (4) for a desalination plant comprising at least one intake pipe (10) for delivering filtrated feed water from a water source, such as the sea, to a desalination plant (6) provided on land. A region of the intake pipe includes integrated ultrafiltration or microfiltration membranes to provide pretreatment (4) of the feed water as it enters the intake pipe (10) prior to its delivery to land for desalination of the feed water.
i) to the reverse osmosis or nanofiltration (8) to create a concentrated feed stream and a product water stream (PW); return pipes (2R, 4R) for selectively returning the concentrated feed stream to one or other of the at least two feed chambers (2, 4); a product water outlet for removal of the product water (PW); and means for switching the delivery of the concentrated feed stream between the selectable return pipes (2R, 4R) upon detection of a predetermined reduction in the efficiency of the RO or NF process within one or other of the feed chambers (2, 4). The pressure of the concentrated feed stream is reduced to atmospheric pressure prior to its delivery back to the chamber and the feed stream passes through a desaturation unit (20).
A water treatment system comprising a mechanical vapour compression apparatus (11), the mechanical vapour apparatus having a evaporation/condensation vessel (11a) and a recirculation circuit (20) whereby recirculated water is pumped from an outlet (18a) of the evaporation/condensation vessel (11A) to an inlet (18B) of the evaporation/condensation vessel (11A), wherein the recirculation circuit (20) comprises a fluidized bed crystallizer (22), and at least part of the recirculated brine is passed through the fluidized bed crystallizer (22) to remove dissolved minerals therefrom.
A thermal desalination system, comprising a multi-effect evaporator comprising a plurality of effects, configured to produce product water and brine and a fluidized bed crystallizer, configured to remove dissolved minerals and/or solids from the water, wherein the fluidized bed crystallizer is disposed between at least two effects of the multi-effect evaporator.
A reverse osmosis desalination system for treating feed water, the feed water containing minerals, the system comprising a reverse osmosis unit comprising a first reverse osmosis stage (21) and a second reverse osmosis stage (22), each of the reverse osmosis stages (21, 22) having a feed water input, a product water outlet and a brine outlet, and a fluidized bed crystallizer (30), configured to remove minerals from the water, wherein the fluidized bed crystallizer (30) receives brine from the first reverse osmosis stage (21) and passes treated water to the feed water input of the second reverse osmosis stage (22).
A water intake and pretreatment system (10) comprising an inlet for delivering water from a natural source to a reservoir (12); said inlet to reservoir having a net screen (16) to prevent entry of organisms above a predetermined size and including a one- way gate (30) to allow organisms to exit the reservoir; said reservoir further comprising a granular filter media for water and algae filtration; and a drainage layer for removal of filtered water from the granular filter media to a drainage outlet. A local backwashing apparatus (40) is included for localized backwashing of the granular filter media.
Locally backwashing portions of filter media allows a simple and effective design of intake and pretreatment units, as well as their integration. An enclosure is used to limit portions of filter media and backwash them locally by suction, utilizing filtered water from adjacent filter media as the back wash water. Wastewater is produced at small amounts that allows efficient sludge treatment. This design enables water pretreatment at the intake unit, simplifying overall plant design and preventing damage to organisms living outside the intake unit.
A method and system for cleaning a multistage evaporator, the evaporator having a normal operational mode and a cleaning mode and having at least two groups of effects (2, 4), each group having one or more effects. In a normal operational mode, input vapor is introduced to a first group of effects (2), the first group comprising the hottest effects, and then vapor is delivered from the first group to a second group of effects (4), and optionally, from the second group of effects to a third group of effects (6) and so on depending on the total number of effects. Upon detection of a predetermined level of scale formation in the first group of effects, the evaporator is switched to a cleaning mode wherein the first group of effects (2) is physically separated from the other groups of effects and the input vapor is re-directed into the second group of effects (4). A cleaning agent is introduced into the physically separated first group of effects (2) until a predetermined level of cleanliness is achieved.
A system for cleaning feed water of variable quality, the system comprising an inlet for selectively delivering feed water (FW) to one or other of at least two feed chambers (2,4), each feed chamber having a delivery pipe (2i, 4i) for delivering feed water to a reverse osmosis or nanofiltration (8); a pump (6) to deliver the feed water from one of the chambers (2, 4) through its associated delivery pipe (2i, 4i) to the reverse osmosis or nanofiltration (8) to create a concentrated feed stream and a product water stream (PW);return pipes (2R, 4R) for selectively returning the concentrated feed stream to one or other of the at least two feed chambers (2, 4); a product water outlet for removal of the product water (PW); and means for switching the delivery of the concentrated feed stream between the selectable return pipes (2R, 4R) upon detection of a predetermined reduction in the efficiency of the RO or NF process within one or other of the feed chambers (2, 4). The pressure of the concentrated feed stream is reduced to atmospheric pressure prior to its delivery back to the chamber and the feed stream passes through a desaturation unit (20).
A method of cleaning an evaporator that includes at least one heat transfer element for the evaporation of water, comprising forming a sacrificial layer of a first material on a surface of the heat transfer element (1 ); evaporating water that includes a second material to deposit the second material on top of the sacrificial layer (2, 3); and cleaning the evaporator by removing both the sacrificial layer formed on the heat transfer element and the second layer formed on top of the sacrificial layer; wherein the first material is more easily removed from the heat transfer element than the second material (4).
B05D 7/22 - Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to internal surfaces, e.g. of tubes
13.
PRESSURE EXCHANGER SYSTEM WITH A VESSEL ELONGATION ABSORBER
A pressure exchanger is provided with an elongation absorber (50) having a housing element (70) configured for connection to a pressure vessel stand and an inner element (60) configured for connection to a high pressure feed check valve outlet wherein the inner element is slidable with respect to the outer element in response to an axial length changes of the pressure vessel. The inner element may comprise an annular element defining an internal cavity (62), the element having a leading (63) and a trailing edge (61), the annular element further comprising a flange (64) extending outwardly for receipt in a recess (76) formed in the housing element, the flange being of a smaller cross section than the cross section of the recess to allow sliding of the inner element with respect to the housing element.
F15B 3/00 - Intensifiers or fluid-pressure converters, e.g. pressure exchangersConveying pressure from one fluid system to another, without contact between the fluids
F16L 27/12 - Adjustable jointsJoints allowing movement allowing substantial longitudinal adjustment or movement
F16L 51/00 - Expansion-compensation arrangements for pipe-lines
A pumping apparatus for a water treatment plant, the pumping apparatus comprising a gas supply, at least one gas turbine 11 connected to the gas supply, the at least one gas turbine connected to drive at least one primary pump 12 through a reduction gear train 13 and clutch 14, a waste heat boiler 26 having a feed water input, the waste heat boiler having an exhaust gas input 26a to receive exhaust gas from the at least one gas turbine 11 and generate steam from the feed water, the waste heat boiler having an steam output 18, the apparatus further comprising at least one steam turbine 20, the at least one steam turbine connected to drive at least one secondary pump 21, the at least one steam turbine being connected to the steam output 18 of the waste heat boiler, the at least one steam turbine 20 further having an exhaust steam output 27, the apparatus further comprising a condensing apparatus 28 to receive steam from the exhaust steam output and generate a feed water stream at a feed water output, the feed water outlet being connected to the feed water input of the waste heat boiler 26.
F01K 15/00 - Adaptations of steam engine plants for special use
F01K 9/00 - Steam engine plants characterised by condensers arranged or modified to co-operate with the engines
F01K 23/10 - Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled combustion heat from one cycle heating the fluid in another cycle with exhaust fluid of one cycle heating the fluid in another cycle
F01K 17/04 - Use of steam or condensate extracted or exhausted from steam engine plant for specific purposes other than heating
15.
METHOD OF OPERATING A PRESSURE-RETARDED OSMOSIS PLANT
A method of operating a pressure-retarded osmosis plant, the plant comprising at least one osmosis element having a semi-permeable membrane, the semi-permeable membrane defining a feed side and a permeate side of the osmosis element, the method comprising, in a first mode of operation, supplying a feed stream having a relatively high concentration of solute to the feed side, supplying a permeate stream having a relatively low concentration of solute to an inlet of the permeate side, and receiving a feed outlet stream from the feed side wherein permeate has passed through the semi-permeable membrane from the permeate side to the feed side, in a second mode of operation, supplying a backwash stream having a relatively low concentration to the feed side of the osmosis element such that water passes through the semi-permeable membrane, and receiving a permeate outlet stream from an outlet of the permeate side, the method further comprising alternately performing the first mode of operation, to perform a production step, and performing the second mode of operation, to reduce fouling of the semi-permeable membrane.
C02F 1/44 - Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
B01D 61/00 - Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltrationApparatus, accessories or auxiliary operations specially adapted therefor
An osmosis element comprising a central permeate tube and a membrane element, the membrane having a first part and a second part, the first part having a top edge for location adjacent the central tube, the second part being disposed at the opposite edge, the first part comprising a material to allow water to flow therethrough, the second part comprising at least two adjacent permeate spacers extending from the first part to allow water to flow therethrough, the permeate spacers having a semi-permeable membrane attached to opposed faces of the two adjacent permeate spacers, the first part comprising a barrier extending from the vicinity of the top edge, the central tube comprising an external wall and a longitudinally extending internal separator defining a first channel and a second channel each extending longitudinally of the central permeate tube, at least one first aperture extending from the first channel though the external wall and at least one second aperture extending from the second channel through the external wall.
B01D 61/00 - Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltrationApparatus, accessories or auxiliary operations specially adapted therefor
An evaporator array for a water treatment system, the evaporator array comprising a produced water feed and a first evaporator to receive produced water from the produced water feed, a makeup water feed and a second evaporator to receive makeup water from the makeup water feed, an output feed to receive distillate from the first evaporator and the second evaporator, and a blowdown feed to receive blowdown from the first evaporator and the second evaporator, wherein the first evaporator and the second evaporator each have a working pH, the working pH of the first evaporator being higher than that of the second evaporator.
An evaporator having an extemal vessel and an inner cavity, and a heat exchanging tube assembly, the external vessel comprising an opening closable by a hatch, the heat exchanging tube assembly being insertable into and removable from the inner cavity through the opening. In oil production and in other industrial processes, waste water is often produced which requires treatment. This water may be contaminated with amongst other contaminants Oil & Grease, minerals, Silica, and organic contamination.
A system and method for the structure and operation of a work exchanger system in a reverse osmosis plant is disclosed. The work exchanger system is characterized by a an array of multiple work exchanger chambers each being individually controlled and operated to a meet an aggregate need of pressure recovery by the entire system. Each work exchanger chamber is characterized by at least one valve having a bypass system which is configured to equalize pressure on both sides of the valve. Such an equalizing process's delays are monitored and controlled by the central systems' controlling system to create no restrictions to reject high pressure brine flow in a reverse osmosis system at any given time.
Water mineralization is carried out by mixing carbonate in powder form in a fast process into the water, generating C02 in the water but adding turbidity to it. The treated water is then delivered through a reactor with granular carbonate, in which the C02 in the water dissolves additional carbonate in a slow process. The reactor acts simultaneously to add further minerals as well as alkalinity to the water, and to remove the turbidity out of the water by dissolving residual powder and filtering non-dissolvable particles.
Locally backwashing portions of filter media allows a simple and effective design of intake and pretreatment units, as well as their integration. An enclosure is used to limit portions of filter media and backwash them locally by suction, utilizing filtered water from adjacent filter media as the back wash water. Wastewater is produced at small amounts that allows efficient sludge treatment. This design enables water pretreatment at the intake unit, simplifying overall plant design and preventing damage to organisms living outside the intake unit.
B01D 24/20 - Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with the filter bed stationary during the filtration the filtering material being provided in an open container
B01D 24/46 - Regenerating the filtering material in the filter
A produced water treatment system that removes, step by step, oil contamination from produced water, to yield purified water for use as boiler feedwater. The system reduces the concentration of oil contamination a thousand fold by using dissolved air flotation, walnut shell filters and a evaporator (MED, MVC or FCE), and uses sludge to generate heat for the process and heat exchangers to minimize energy costs of the system.
A compound multi effect distillation (MED) system of integrated backward and forward fed MED systems. Heated concentrate from the hottest effect of the backward fed MED system is delivered as feed to the hottest effect in the forward fed MED system, to generate a more concentrated brine than possible using any of the systems alone. Furthermore, coupling the systems creates additional operational advantages and increases distillation efficiency.
Coldness generated by gasifying liquid natural gas is utilized to freeze desalinate sea water using a specially designed ice slurry generator (110) that generates fine ice with high energy efficiency using plates (111), of which subgroups are periodically warmed during the continuous operation of the ice slurry generator (110) to flake of ice. Brine is washed from ice slurry produced by the generated coldness on an ice concentrator (130), and the resulting rinsed ice is melted in a precooling unit (140) to pre-cool sea water feed (101). Heating the cooling fluid from the gasification alleviates the heating need from the gasifying plant.
A desalination system (100) having an intake unit (110) providing seawater to a pre - treatment unit (120) connected to a reverse osmosis (RO) desalination unit (130) and a post treatment unit (150). The desalination system (100) is configured to operate without any external addition of chemicals to simplify logistics and regulation concerns. The units of the system are configured to prevent biofouling, scaling and corrosion by mechanical and biological means including high flow speeds, biological flocculation of colloids, and making the water entering the RO units inhospitable to bacteria and other organisms that cause biofouling, hence preventing their settlement and removing them with the brine. Recovery rate is lowered and energy is recovered to increase the energetic efficiency and minerals that are added to the product water are taken from the brine.
A drive shaft system (100) comprising a shaft (80) connected to a motor via a coupling (50) and arranged to transmit a rotary movement from the motor to the rotor, at least two supports (65,75) arranged to position the shaft within a shaft housing (90), each support comprising at least one bearing (95,98), and at least one forcing element (135,145) arranged to force at least one of the supports against either an inner side of the shaft housing or an outer side of the shaft (80); such as to prevent turning and radial movements of the supports within the shaft housing while enabling axial movement of the shaft within the shaft housing. The bearings may be forced at either their inner or outer rings, and may be enclosed in a bearing housing (120) for protection and stiffness.
An evaporator having more efficient heat transfer tubes, that are either or both coated and vertically corrugated. The coating, though reducing the heat transfer coefficient, lengthens the time between cleaning treatment to increase the overall efficiency of the evaporator. The corrugation of the tubes controls the film characteristics and enhances evaporation from the film upon condensation of vapor within the tubes. The corrugation profile is selected to enhance waviness and turbulence of the films and thereby increase evaporation and condensation and hence the effectivity of the evaporator.
F28D 3/00 - Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium flows in a continuous film, or trickles freely, over the conduits
F28D 5/00 - Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, using the cooling effect of natural or forced evaporation
F28F 1/00 - Tubular elementsAssemblies of tubular elements
F28F 3/00 - Plate-like or laminated elementsAssemblies of plate-like or laminated elements
Combining flue gas treatment, and in particular CO2 sequestration, with hardening of reverse osmosis (RO) permeate. Flue gas is compressed and injected into pressurized water, being either cooling water or RO permeate. The water with dissolved CO2 is either dispensed into the sea for biological fixation of the CO2 or, in the case of RO permeate, mixed with limestone to harden the product water.
B01D 53/14 - Separation of gases or vapoursRecovering vapours of volatile solvents from gasesChemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases or aerosols by absorption
Periodically operating a forward osmosis (FO) semi-permeable membrane element in reverse osmosis (RO), to yield product extraction on a feed side of the membrane, to flush out a concentration polarization (salt concentration of the feed side and dilution of draw solution on the draw side) across the membrane. Utilizing treated waste water to generate the flushing solution of low osmotic pressure, and gauge pressurizing the flushing solution to the gauge pressure of the draw solution to keep a constant gauge pressure of the solutions. FO process is interrupted every 5-20 minutes for a 10-60 seconds long flushing RO process, thereby increasing the FO throughput five fold and recovering power from the increased throughput, i.e. from the osmotic pressure of the brine.
B01D 61/00 - Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltrationApparatus, accessories or auxiliary operations specially adapted therefor
A vertical desalination element comprising a vertical pressure vessel (PV), membrane elements, and a loading mechanism for loading the membrane elements into the vertical PV. The vertical arrangement of the membrane elements and the vertical PV enhances air bubble percolation, increases construction efficiency and allow handling heavy membrane elements. The membrane elements may be loaded singly or groupwise, from either the upper or the lower end of the vertical PV. The loading mechanism may comprise various appliances and devices for supporting and securing the membrane elements, and may apply various ways of loading and releasing the membrane elements.
A desalination system based on forward osmosis, that uses a draw solution at high osmotic and gauge pressures to generate mechanical power from the expansion of the draw solution due to water extracted from feed water through a semi-permeable membrane. The extracted water is produced during the regeneration of the draw solution. The generated power may be used to desalinate additional feed water, e.g. via reverse osmosis, such that most power needed for the reverse osmosis is supplied from the expanding draw solution, e.g. via a work exchanger. After power recovery, partly dilute draw solution may be used to extract additional water from feed water via an additional forward osmosis module.
A system and method for separating at least a part of the solids from brine having an initial temperature T1, the system comprising a crystallizer comprising a crystallizer inlet for receiving therein said brine, a crystallizer first outlet for discharging vapor having a first pressure P1, evaporated from at least a part of said brine, and a crystallizer second outlet for discharging a slurry having a final temperature T2 lower than said initial temperature T1; a separator comprising a separator inlet for receiving therein said slurry, a separator first outlet for discharging therefrom said part of the solids separated from said slurry, and a separator second outlet for discharging therefrom a remaining liquid having a temperature substantially equal to T2; a compressor comprising a compressor inlet for receiving therein said vapor, and a compressor outlet for discharging therefrom a compressed vapor having a second pressure P2 higher than said pressure P1; and a condenser comprising a condenser first inlet for receiving therein said compressed vapor, a condenser second inlet for receiving therein said remaining liquid discharged from said separator, for absorbing a latent heat released from said compressed vapor, condensing thereby said compressed vapor, and a condenser outlet for discharging therefrom an outlet liquid having a temperature substantially equal to T1.
A system and method for desalination of seawater W having an original water salinity and a original water concentration of scale forming components, the system comprising: a pre-treatment sub-system for at least partial removal from said water W of said scale forming components, producing thereby a pre-treated feed water having a first concentration of scale forming components lower than said original concentration of scale forming components; a forward feed flow multi-effect evaporator adapted for distillation of said pre-treated feed water, producing thereby main desalted water product WM having a desalted water salinity lower than said water salinity, and main brine having a salt concentration of approximately 10%; a concentrator adapted for receiving therein said main brine and concentrating it, producing thereby more concentrated brine with an increased salt concentration of approximately 20%-22%, and releasing a first additional desalted water product W1; and a crystallizer for receiving said more concentrated brine, adapted for crystallization thereof to obtain at least solid salt products and releasing a second additional desalted water product W2.
A method for improving performance of an original reverse osmosis system for seawater desalination, the original system comprising a high pressure pump, a reverse osmosis membrane arrangement, a pump hydraulic line and a turbine hydraulic line, the method comprising operating the motor at a power lower than a normal operation power; providing an energy recovery device; splitting new brine flow to a first brine flow; supplying an additional seawater; providing a booster pump; providing an energy recovery device hydraulic line; providing a first booster pump hydraulic line; and providing a second booster pump hydraulic line.
According to one aspect of the present invention, there is provided a desalination system comprising a plurality of elongated pressure vessels (PV). Each PV has a longitudinal axis, oriented such that the longitudinal axis thereof is of a vertical orientation. Each of the PVs is adapted to receive therein a plurality n of desalination membranes. The membranes located above the lowermost membrane within the PV have a total weight allowing them to function as a mechanism limiting axial expansion of the lowermost membrane, whereby the PV is free of any additional limiting mechanism.
A process for producing re-hardened water, including: a) an infusion step in which at least CO2 is introduced into water to be re-hardened, to produce a first solution containing free CO2 of a concentration C1; b) a re-hardening step including passing the first solution through a re-hardening material to perform a dissolution process. The dissolution process has a contact time t during which the re-hardening material is dissolved in the first solution and a chemical reaction takes place between the dissolved re-hardening material and a part of the CO2. The CO2 constitutes an aggressive CO2, such that the process produces a second solution of water. The solution contains at least dissolution products, aggressive CO2 of reduced concentration of about C2a, and an equilibrium CO2 of increased concentration of about C2e; c) a separation step including separating from the second solution of a free excess CO2 constituted by aggressive CO2 of concentration C2a and equilibrium CO2 of concentration C2e. The separation step further includes removing free excess CO2 in a gas form, to produce the re-hardened water wherein step (b) is performed so that at least one of the following conditions is met: - C2a C2e and (C2a + C2e) < C1; - C2 0.25C1; - t 15min;
C02F 1/68 - Treatment of water, waste water, or sewage by addition of specified substances, e.g. trace elements, for ameliorating potable water
C02F 5/08 - Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
