Abstract: A roll-to-roll process and apparatus is disclosed for treatment of a membrane substrate. The apparatus and process processes the membrane substrate in a forward direction using one or more treatment solutions, and then processes the membrane substrate in a reverse direction using other treatment solutions. The treatment solutions used in the forward and reverse directions are preferably chosen so that the treatment sequence is the same in both directions. In this manner, the membrane substrate can accumulate reaction time by repeated processing in forward and reverse directions.

Abstract: A liquid pumping system includes at least two water cylinders that are each controlled by a hydraulic piston. A rotary valve controls the hydraulic pistons. The rotary valve has an inner unit that rotates within an outer unit. Slots provided between the inner and outer units control the duration, rate and direction of hydraulic fluid supply to the hydraulic piston. A liquid pumping process comprises distributing an initial flow of pressurized hydraulic fluid between the hydraulic cylinders. The hydraulic cylinders move through a cycle in a phased relationship to provide a constant sum of flow rates from the liquid pumps. In a water treating process, feed water is pumped through the membrane unit. Brine from the membrane unit is returned to each liquid pump while that liquid pump is feeding water to the membrane unit.

Abstract: A method includes driving a fluid pumping unit having a plurality of pumping cylinders via a plurality of hydraulic cylinders respectively of a hydraulic power unit. The method further includes controlling activation of the hydraulic power unit such that each stroke of the corresponding piston assembly between the top dead center and the bottom dead center follows a corresponding trapezoidal velocity profile with respect to a time duration. Controlling activation includes controlling flow of a hydraulic fluid in the hydraulic power unit so as to control the corresponding trapezoidal velocity profile with respect to the time duration of the corresponding piston assembly to obtain a predefined flow rate of the fluid medium from the pumping unit.

Abstract: Membranes are arranged in a stack with flat sheets of feed channel spacer and permeate carrier. Flat feed channels and permeate channels alternate through the thickness of the stack. Edges of the feed channels are sealed along the length of the stack. Edges of the permeate channels are sealed across the width of the stack. The stack may be more than 1.5 m long. Optionally, membranes may be sealed to each other without being folded. A filtration element comprises a stack and a shell. The shell has at least an inlet to the feed channels and a permeate outlet. Optionally, the element may be operated in a permeate side cross flow configuration. Parts of the stack may be pre-assembled, in some cases by an automated process. The filtration element may be used for reverse osmosis, forward osmosis, pressure retarded osmosis or nanofiltration.

Abstract: A filtering module, for example a nanofiltration or reverse osmosis module, is made of membranes arranged in a stack with flat sheets of feed channel spacer and permeate carrier. The stack has packs formed of two membrane sheets sealed on four sides and enclosing a permeate carrier. The packs alternate with sheets of feed channel spacer through the thickness of the stack. One or more permeate-collecting pipes pass through the thickness of the stack. The sheets of feed channel spacer have seals along two sides and around the permeate-collecting pipes. A module is formed by placing one or more stacks in a pressure vessel with a seal between the stack and the pressure vessel at a downstream end of the stack.

Abstract: A novel separator assembly for a spiral flow reverse osmosis apparatus is provided. In one embodiment, the separator assembly comprises a central core element comprising at least two permeate exhaust conduits and not comprising a concentrate exhaust conduit. Each permeate exhaust conduit defines an exhaust channel and one or more openings allowing fluid communication between an exterior surface of the permeate exhaust conduit and the exhaust channel, said permeate exhaust conduits independently defining a cavity between said conduits. The cavity is configured to accommodate a first portion of a membrane stack assembly comprising at least one feed carrier layer, at least two permeate carrier layers, and at least two membrane layers. A first portion of the membrane stack assembly is disposed within the cavity, and a second portion of the membrane stack assembly is wound around the central core element and forms a multilayer membrane assembly disposed around the central core element.

Abstract: A novel separator assembly for a spiral flow reverse osmosis apparatus is provided. In one embodiment, the separator assembly comprises a central core element comprising at least one permeate exhaust conduit and at least one concentrate exhaust conduit. Each exhaust conduit defines an exhaust channel and one or more openings allowing fluid communication between an exterior surface of the exhaust conduit and the exhaust channel, said exhaust conduits independently defining a cavity between said conduits. The cavity is configured to accommodate a first portion of a membrane stack assembly comprising at least one feed carrier layer, at least one permeate carrier layer, and at least one membrane layer. A first portion of the membrane stack assembly is disposed within the cavity, and a second portion of the membrane stack assembly is wound around the central core element and forms a multilayer membrane assembly disposed around the central core element.

Abstract: The present disclosure describes an axial bypass sleeve for use with a spiral wound membrane element. The axial bypass sleeve has a protrusion and an opening that defines a flow path to provide fluid flow communication through the axial bypass sleeve. In use, the axial bypass sleeve is wrapped around a spiral wound membrane element and both are placed in a pressure housing. A pressurized feedstock is introduced into the pressure housing. A portion of the pressurized feedstock flows through the spiral wound membrane element to produce a permeate stream and a retentate stream. A portion of the pressurized feed stock flows around the spiral wound membrane element, called bypass flow. The protrusion extends into the annular space to restrict the bypass flow. A portion of the bypass flow passes through the opening and enters into the spiral wound membrane element to increase permeate production.

Abstract: A method includes driving a fluid pumping unit having a plurality of pumping cylinders via a plurality of hydraulic cylinders respectively of a hydraulic power unit. The method further includes controlling activation of the hydraulic power unit such that each stroke of the corresponding piston assembly between the top dead center and the bottom dead center follows a corresponding trapezoidal velocity profile with respect to a time duration. Controlling activation includes controlling flow of a hydraulic fluid in the hydraulic power unit so as to control the corresponding trapezoidal velocity profile with respect to the time duration of the corresponding piston assembly to obtain a predefined flow rate of the fluid medium from the pumping unit.

Abstract: A liquid pumping system includes at least two water cylinders that are each controlled by a hydraulic piston. A rotary valve controls the hydraulic pistons. The rotary valve has an inner unit that rotates within an outer unit. Slots provided between the inner and outer units control the duration, rate and direction of hydraulic fluid supply to the hydraulic piston. A liquid pumping process comprises distributing an initial flow of pressurized hydraulic fluid between the hydraulic cylinders. The hydraulic cylinders move through a cycle in a phased relationship to provide a constant sum of flow rates from the liquid pumps. In a water treating process, feed water is pumped through the membrane unit. Brine from the membrane unit is returned to each liquid pump while that liquid pump is feeding water to the membrane unit.

Abstract: The present disclosure describes a means to provide structural reinforcement for spiral wound membrane elements. The reinforcement includes a wire and, optionally, an outer wrap. The wire is wrapped around an outer layer of the spiral wound membrane layer and reinforces the spiral wound membrane element. The wire is made from materials that do not deform substantially during sanitization procedures. The outer wrap is wrapped around the wire and limits unsanitary areas of tight tolerance between the perimeter of the spiral wound membrane element and a housing.

Abstract: The present disclosure describes an axial bypass sleeve for use with a spiral wound membrane element. The axial bypass sleeve has a protrusion and an opening that defines a flow path to provide fluid flow communication through the axial bypass sleeve. In use, the axial bypass sleeve is wrapped around a spiral wound membrane element and both are placed in a pressure housing. A pressurized feedstock is introduced into the pressure housing. A portion of the pressurized feedstock flows through the spiral wound membrane element to produce a permeate stream and a retentate stream. A portion of the pressurized feed stock flows around the spiral wound membrane element, called bypass flow. The protrusion extends into the annular space to restrict the bypass flow. A portion of the bypass flow passes through the opening and enters into the spiral wound membrane element to increase permeate production.

Abstract: The present disclosure describes a brine seal for use with a spiral wound membrane element. The brine seal has an elongate body with a flexible wing. The brine seal is wrapped around the spiral membrane element with a space between each turn of the brine seal. The wrapped spiral wound membrane unit is placed inside a pressure housing. Between the wrapped spiral wound membrane element and an inner surface of the pressure housing is an annular space. The brine seal, the spiral wound membrane element and the pressure housing establish a bypass flow channel that spirals around the spiral wound membrane element, through the annular space. Feedstock can enter the bypass flow channel to provide sanitary flushing of the annular space. Some of the feedstock in the bypass flow channel enters the spiral wound membrane to improve the efficiency of the spiral wound membrane element.

Abstract: A novel separator assembly for a spiral flow reverse osmosis apparatus is provided. In one embodiment, the separator assembly comprises a central core element comprising at least one permeate exhaust conduit and at least one concentrate exhaust conduit. Each exhaust conduit defines an exhaust channel and one or more openings allowing fluid communication between an exterior surface of the exhaust conduit and the exhaust channel, said exhaust conduits independently defining a cavity between said conduits. The cavity is configured to accommodate a first portion of a membrane stack assembly comprising at least one feed carrier layer, at least one permeate carrier layer, and at least one membrane layer. A first portion of the membrane stack assembly is disposed within the cavity, and a second portion of the membrane stack assembly is wound around the central core element and forms a multilayer membrane assembly disposed around the central core element.

Abstract: The present invention provides a central core element for a separator assembly comprising at least two porous exhaust conduits; each porous exhaust conduit defining an exhaust channel and one or more openings allowing fluid communication between an exterior surface of the porous exhaust conduit and the exhaust channel, said porous exhaust conduits independently defining a cavity between said porous exhaust conduits, said cavity being configured to accommodate a first portion of a membrane stack assembly. In another aspect, the present invention provides a central core element for a separator assembly comprising at least two identical core element components, each of said core element components comprising at least one porous exhaust conduit and at least one friction coupling, said friction couplings being configured to join said core element components to form a central core element defining a cavity configured to accommodate a first portion of a membrane stack assembly.

Abstract: A novel separator assembly for a spiral flow reverse osmosis apparatus is provided. In one embodiment, the separator assembly comprises a central core element comprising at least two permeate exhaust conduits and not comprising a concentrate exhaust conduit. Each permeate exhaust conduit defines an exhaust channel and one or more openings allowing fluid communication between an exterior surface of the permeate exhaust conduit and the exhaust channel, said permeate exhaust conduits independently defining a cavity between said conduits. The cavity is configured to accommodate a first portion of a membrane stack assembly comprising at least one feed carrier layer, at least two permeate carrier layers, and at least two membrane layers. A first portion of the membrane stack assembly is disposed within the cavity, and a second portion of the membrane stack assembly is wound around the central core element and forms a multilayer membrane assembly disposed around the central core element.

Abstract: The present invention provides a central core element for separator assemblies useful in the purification of fluids, for example separator assemblies useful for the desalination of seawater. The central core element provided by the present invention comprises at least two porous exhaust conduits wherein each porous exhaust conduit comprises an exhaust channel and one or more openings which allow fluid communication between an exterior surface of the porous exhaust conduit and the exhaust channel. The central core element defines a cavity into which may be disposed a first portion of a membrane stack assembly. In the preparation of a separator assembly comprising the central core element provided by the present invention, a second portion of the membrane stack assembly forms a multilayer membrane assembly disposed around the central core element. Also provided are central core elements for salt separator assemblies and spiral flow reverse osmosis devices.

Abstract: A separator assembly is provided comprising a membrane stack assembly comprising a feed carrier layer, a permeate carrier layer, and a membrane layer, and a central core element comprising a concentrate exhaust conduit and a permeate exhaust conduit; wherein the concentrate exhaust conduit and the permeate exhaust conduit are separated by a first portion of the membrane stack assembly; and wherein a second portion of the membrane stack assembly forms a multilayer membrane assembly disposed around the central core element; and wherein the feed carrier layer is in contact with the concentrate exhaust conduit and not in contact with the permeate exhaust conduit; and wherein the permeate carrier layer is in contact with the permeate exhaust conduit and not in contact with the concentrate exhaust conduit; and wherein the permeate carrier layer does not form an outer surface of the separator assembly.

Abstract: The present invention provides a central core element for separator assemblies useful in the purification of fluids, for example separator assemblies useful for the desalination of seawater. The central core element provided by the present invention comprises at least two porous exhaust conduits wherein each porous exhaust conduit comprises an exhaust channel and one or more openings which allow fluid communication between an exterior surface of the porous exhaust conduit and the exhaust channel. The central core element defines a cavity into which may be disposed a first portion of a membrane stack assembly. In the preparation of a separator assembly comprising the central core element provided by the present invention, a second portion of the membrane stack assembly forms a multilayer membrane assembly disposed around the central core element. Also provided are central core elements for salt separator assemblies and spiral flow reverse osmosis devices.

Abstract: The present invention provides a separator assembly comprising a central core element comprising at least two permeate exhaust conduits and not comprising a concentrate exhaust conduit; and a membrane stack assembly comprising at least one feed carrier layer, at least two permeate carrier layers, and at least two membrane layers, the membrane layers being disposed between the feed carrier layer and the permeate carrier layers; wherein the permeate exhaust conduits are separated by a first portion of the membrane stack assembly, and wherein a second portion of the membrane stack assembly forms a multilayer membrane assembly disposed around the central core element, and wherein the feed carrier layer is not in contact with a permeate exhaust conduit, and wherein the permeate carrier layers are in contact with at least one permeate exhaust conduit. Also provided are salt separator assemblies and spiral flow reverse osmosis devices.