Abstract: A multi-effect evaporator, having an upstream and a downstream end, adapted for distillation of water. It includes a plurality of effects connected in a series manner and arranged into groups. Each group has a common parallel water feed inlet adapted to supply all effects in the group with feed water. The evaporator further includes a main feed water line in fluid communication with the most upstream group. An array of heaters is disposed along the line, adapted for heating the feed water before its entry into the effects of the latter group. Each effect includes means for forwarding the second outlet vapor into one of the heaters for heating the feed water. Each group includes a pump adapted to extract the concentrate from the effects of the group and pump it into the common parallel water feed of an adjacent downstream group.

Abstract: 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.

Abstract: A drive shaft system (100) comprising a shaft (80) connected to a motor via a coupling (50) 65 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.

Abstract: 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.

Abstract: An evaporator having more efficient heat transfer tubes, that are either or both coated and vertically corrugated. The coating, though reducing the heat transfer co-efficient, 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 f

Abstract: A multi-effect evaporator, having an upstream and a downstream end, adapted for distillation of water. It comprises a plurality of effects connected in a series manner and arranged into groups. Each group has a common parallel water feed inlet adapted to supply all effects in the group with feed water. The evaporator further includes a main feed water line in fluid communication with the most upstream group. An array of heaters is disposed along the line, adapted for heating the feed water before its entry into the effects of the latter group. Each effect comprises means for forwarding the second outlet vapor into one of the heaters for heating the feed water. Each group comprises a pump adapted to extract the concentrate from the effects of the group and pump it into the common parallel water feed of an adjacent downstream group.

Abstract: 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.

Abstract: A multi-effect evaporator, having an upstream and a downstream end, adapted for distillation of water. It comprises a plurality of effects serially connected and arranged into groups. Each group has a common parallel water feed inlet adapted to supply all effects in the group with feed water. The evaporator further includes a main feed water line in fluid communication with the most upstream group. An array of heaters is disposed along the line, adapted for heating the feed water before its entry into the effects of the latter group. Each effect comprises means for forwarding the second outlet vapor into one of the heaters for heating the feed water. Each group comprises a pump adapted to extract the concentrate from the effects of the group and pump it into the common parallel water feed of an adjacent downstream group.

Abstract: Disclosed is a compact heat pump using water as refrigerant, including a casing having a first and second end sections and an intermediate section located therebetween, with an evaporator located at the first end section, configured for containing said water and allowing evaporation of at least a part of the water to produce vapor and remove heat from the remainder of the water. At least one agitator scoop is located within said evaporator, with one or more demisters installed between the evaporator and the compressor. The one or more compressors induce evaporation by maintaining vacuum at least at an intake conduit, and are configured for receiving the vapor through the intake conduit after passing through a heated demister. The condenser is configured for receiving the compressed vapor from the compressor, lowering the vapor temperature and condensing it back into a liquid state.

Abstract: 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.

Abstract: A piston for a linear spool valve, the valve comprising a body having a inner surface. The body is made of a material with a relatively low heat expansion coefficient ?1. The piston comprises a contact member having an outer surface and being adapted to reciprocate within the body of the valve so that the outer surface is in contact with the inner surface. The contact member has at least a first layer made of a material with a heat expansion coefficient ?2 essentially greater than ?1, i.e. ?2>>?1, and at least a second layer made of a material with a heat expansion coefficient ?3 close to ?1. This causes the contact member to be adapted to behave, along said outer surface, as a material having a heat expansion coefficient essentially closer to ?1 than to ?2. One of the layers constitutes an outer layer of the contact member and comprises the outer surface.

Abstract: A method of cleaning a fouled RO membrane in a module for RO separation, the membrane having feed side and permeate side, the foulant accumulating at the feed side. The cleaning method comprises: feeding concentrated saline solution to the feed side of the RO membrane under the high gauge pressure of the normal RO separation process; feeding dilute saline solution to the permeate side of the RO membrane under higher pressure than the permeate pressure of the normal RO process, so that a net driving differential ?PN is directed to the feed side, whereby the solvent is being sucked from the permeate side to the feed side, penetrates into the interface between the membrane and the accumulated foulant, and separates the foulant from the membrane surface; and withdrawing the concentrated saline solution together with the separated foulant and the penetrated solvent from the feed side of the RO membrane.

Abstract: A three-way two-position poppet valve (10) comprising a housing (12) with a generally cylindrical valve chamber (14), a first (20) and a second (16) port with coaxial 1 valve seats (26, 28) at the ends of the chamber, and a third lateral working port (18). A poppet body (36) is disposed reciprocably in the valve chamber so that in a first position of the poppet body the first valve seat (26) is sealed and the second port communicates with the working port, and in a second position the second valve seat (28) is sealed and the first port communicates with the working port. The valve is characterized in that the housing has two coaxial cylindrical passages (24, 30) adjacent the respective valve seats, while the poppet body has two coaxial cylinder parts (44, 48) slidingly and sealingly fitting the cylindrical passages, so that the poppet body is always supported in at least one of the cylindrical passages and fluid communication between the first and the second port is always prevented.

Abstract: A method of cleaning a fouled RO membrane in a module for RO separation, the membrane having feed side and permeate side, the foulant accumulating at the feed side. The cleaning method comprises: feeding concentrated saline solution to the feed side of the RO membrane under the high gauge pressure of the normal RO separation process; feeding dilute saline solution to the permeate side of the RO membrane under higher pressure than the permeate pressure of the normal RO process, so that a net driving differential ?PN is directed to the feed side, whereby the solvent is being sucked from the permeate side to the feed side, penetrates into the interface between the membrane and the accumulated foulant, and separates the foulant from the membrane surface; and withdrawing the concentrated saline solution together with the separated foulant and the penetrated solvent from the feed side of the RO membrane.

Abstract: A method of boron removal from saline water containing boron and magnesium or calcium salts including a multi-stage reverse-osmosis (RO) separation process and comprising the steps of a first stage RO separation at pH<8.2; a second stage RO separation over at least part of the first-stage permeate; a third stage RO separation over the second-stage brine. The method is characterized in that the second stage separation is carried at pH>9 and the brine concentration is limited to a degree preventing Mg(OH)2 or CaCO3 scaling on RO membrane surfaces, the permeate constitutes product water, and the brine contains boron and magnesium or calcium ions; the third stage separation is carried at weak-acid pH, whereby the bulk of the magnesium or calcium ions are separated with the brine, while the bulk of the boron ions are retained in the permeate.