MOBILE WATER TREATMENT SYSTEM WITH A FIRST AND A SECOND REVERSE OSMOSIS MODULE AND WITH A SWITCHING VALVE

Description

[0001] The present invention relates to a mobile water treatment plant for producing drinking water in a disaster area with a switching valve for switching between a permeate-stage operation and a concentrate-stage operation of a multi-stage reverse osmosis plant.

[0002] Mobile water treatment plants exist for use in disaster areas, such as after an earthquake or flood. EP 1 690 579 A1, for example, describes a filter arrangement and a method suitable for the pre-treatment of water from rivers, lakes, or seas in a mobile drinking water treatment plant. The filter arrangement provides a filtrate that can be used to feed a reverse osmosis plant for drinking water production. EP 1 690 579 A1 also describes a plant with three filter units that can be used simultaneously or alternately to filter contaminated raw water as a preliminary stage for a subsequent reverse osmosis plant. The reverse osmosis plant enables the production of germ-free drinking water, including desalination and / or the removal of dissolved pollutants such as heavy metals, etc. WO 2016 / 057764 A1 discloses a water treatment plant.

[0003] Reverse osmosis systems are typically operated using a cross-flow process. In this process, the raw water, which may be pre-filtered, is fed to a semipermeable membrane under a certain pressure. Due to the pressure difference, a portion of the raw water diffuses through the membrane, forming a first outlet stream, known as permeate. The portion of the raw water that does not diffuse through the membrane, called concentrate or retentate, forms a second outlet stream. Permeate is therefore the water that has passed through the membrane. Concentrate / retentate is the portion that has not passed through the membrane and, as a type of wastewater, carries away the retained, concentrated substances from the membrane element.

[0004] To increase the permeate yield, multiple membrane elements are typically combined and connected to form multi-stage membrane blocks. This process is called "concentrate staged" when the concentrate stream exiting a first membrane element is fed as raw water (feed) to a subsequent membrane element. The permeate exiting the individual membrane stages is collected and discharged in a common line.

[0005] If a large quantity of permeate is not required, but rather a higher water quality, i.e., purer permeate, is desired, several membrane elements are connected via a "permeate stage." In this case, the permeate stream exiting the first membrane element is fed as raw water (feed) to one or more further membrane elements. The permeate exiting the subsequent membrane element has thus passed through a membrane surface multiple times. The concentrate from the first membrane stage and the concentrate from the second membrane stage are then collected in a common line and discharged or fed back to the inlet of the reverse osmosis system as raw water for further treatment.

[0006] Stationary large-scale plants are typically built for a specific requirement and are therefore designed to be either concentrate-stage or permeate-stage. With mobile reverse osmosis plants, the raw water quality is usually unknown, and it is therefore not clear from the outset whether a single pass through a membrane surface is sufficient to achieve the required permeate quality or whether multiple passes are necessary. It is therefore desirable to design a mobile water treatment plant with a multi-stage reverse osmosis system in such a way that it is possible to switch between concentrate-stage and permeate-stage operation on-site. Since mobile systems are frequently used in crisis situations with changing conditions, a simple, quick, and reliable changeover between these operating modes is also desirable.

[0007] In principle, permeate staged systems allow the permeate from the first stage to discharge at virtually no pressure, with the necessary process pressure for the second stage generated by a subsequent booster pump. However, for mobile systems, size and weight are critical factors, making it desirable to reduce the number and size of the components used. Consequently, without an additional pump, the permeate from the first stage must be under a certain pressure, meaning that not only the valves in the concentrate section but also those in the permeate section must withstand high operating pressures.

[0008] Commercially available ball valves are often unsuitable for this purpose, as those ball valves that have drinking water approval can only withstand low process pressures and available high-pressure ball valves generally do not have drinking water approval.

[0009] Furthermore, for process reliability and permeate quality, it is crucial to prevent permeate contamination from unintentional leaks at shut-off valves. Simple ball valves are disadvantageous in this respect, as leaks are not readily visible from the outside.

[0010] Finally, in systems where the generated permeate is to be used as drinking water, all valves and all other components that may come into contact with the permeate to be discharged in any operating mode must be suitable for drinking water and must not adversely affect the drinking water quality.

[0011] DE 10 2010 042 265 A1 discloses a valve for various applications, but without reference to a water treatment plant. The known valve has a first valve element and a second valve element. The first valve element comprises a first support part made of plastic and a first surface element made of silicon or silicon oxide, which is attached to the first support part. The second valve element comprises a second support part made of plastic and a second surface element made of silicon or silicon oxide, which is attached to the second support part. The valve elements are arranged such that the first and the second surface elements bear against each other at least partially along a contact surface, wherein the valve elements are movable relative to each other in at least one direction parallel to the contact surface of the surface elements.The first surface element has at least one first opening, and the second surface element has at least one second opening. The valve elements are movable relative to each other in at least one direction parallel to the contact surface into at least one first position in which the at least one opening and the at least one second opening are in fluid communication, and at least one second position in which the at least one first opening and the at least one second opening are not in fluid communication.

[0012] DE 10 2011 088 678 A1 discloses a valve arrangement for the distribution and mixing of liquids in an analytical instrument for the automated determination of a measured quantity of a liquid. The valve arrangement comprises a first ceramic disk and a second ceramic disk resting against a contact surface of the first ceramic disk. Furthermore, the valve arrangement comprises a valve formed by a channel cut into the contact surface of the first ceramic disk, and at least two through-bores in the second ceramic disk associated with the channel, which are connected to each other via the channel in a valve position that can be adjusted by a relative movement between the first and second ceramic disks.

[0013] CN 205 155 248 U discloses a tap with ozone water treatment, having one inlet for public water and another inlet for purified water. The two inlet openings can be selectively connected to the outlet by a rotational movement of a housing part.

[0014] DE 10 2007 059 651 A1 discloses a sampler for high-performance liquid chromatography with a high-pressure injection valve and a circuit configuration designed so that switching operations do not occur in a direction that reduces service life. Slots in the rotor and / or port opening cross-sections in the stator and the direction of rotation are selected to prevent fluid flows from high-pressure slots towards narrow, essentially pressureless ports. Against this background, an object of the present invention is to provide a mobile water treatment plant that fulfills the specific and partly conflicting requirements of such a plant in the most efficient way possible. In particular, an object is to provide a mobile water treatment plant that enables reliable and cost-effective operation, optionally in permeate-stage or concentrate-stage mode.

[0015] According to one aspect of the invention, a mobile water treatment plant for producing drinking water in a disaster area is proposed to solve these problems, comprising a first reverse osmosis module and a second reverse osmosis module, and a switching valve for switching between permeate-stage operation and concentrate-stage operation, with a valve housing having a first housing part and a second housing part, wherein the first housing part has a plurality of connection openings designed for connecting fluid lines, wherein the second housing part has a plurality of channels designed to fluidly connect defined connection openings from the plurality of connection openings, and wherein the first housing part and the second housing part are spatially adjustable relative to each other and define a first position and a second position.the channels, depending on their respective position, connect different connection openings from the multitude of connection openings in a fluid-conducting manner.

[0016] Preferably, one or more channels in the second housing part connect connection openings in the first housing part in pairs, depending on the respective position. Furthermore, in some embodiments, it is preferred if the first housing part and the second housing part can be rotated relative to each other, preferably by 90°, in order to switch between a first defined rotational position and a second defined rotational position as the respective position. In principle, however, more than two alternative rotational positions and / or other rotational angles between the rotational positions are also conceivable. Furthermore, in some embodiments, it is preferred if the first housing part and the second housing part can be adjusted translationally relative to each other along an adjustment axis.Preferably, the housing parts are held together in such a way that adjustment from the first position to the second position, or vice versa, is possible while the two housing parts are mechanically coupled. In principle, however, it is also conceivable that the housing parts can be completely detached from each other and connected in the desired position. For example, in some embodiments, the second housing part can be completely detached (removed) from the first housing part and then reattached to the first housing part in a position rotated by an angle.

[0017] The switching valve can be manufactured very simply and cost-effectively and enables a process-reliable switching between a permeate-stage and a concentrate-stage operation in a multi-stage reverse osmosis system, as is explained in detail below using a preferred embodiment.

[0018] The switching action of the diverter valve is achieved by rotating and / or sliding one housing part relative to the other. In some preferred embodiments, the first housing part with the connection openings is fixedly mounted in the water treatment system, and the second housing part is rotatably mounted on the first housing part. The rotation of the two housing parts relative to each other enables a very compact, robust, and reliable design. In other preferred embodiments, the first housing part with the connection openings is fixedly mounted in the water treatment system, and the second housing part is slidably mounted on the first housing part. In advantageous embodiments, the housing parts are each manufactured from a solid block of material in which the connection openings or channels are implemented as bores.

[0019] The second housing part has defined through-channels. Preferably, each channel in the second housing part has exactly one inlet opening and exactly one outlet opening, so that each channel in the second housing part can connect exactly two connection openings of the first housing part. In preferred embodiments, for manufacturing reasons, the channels may each have an additional channel opening on an outer surface of the second housing part, wherein these additional channel openings are permanently closed during system operation and are inoperative with respect to the switching function of the valve. In this case, the additional channel openings facilitate the cost-effective manufacture of the switching valve if the channels are produced as simple bores in a solid block of material. In principle, however, the channels can also be realized using a 3D printing process and / or with the aid of hoses and / or pipes.

[0020] External lines that supply raw water, permeate, and / or concentrate from the new water treatment plant to or from the diverter valve are preferably connected to the diverter valve's connection ports in a fluid-tight manner. Depending on the position of the second housing part relative to the first housing part, one or more channels in the second housing part connect or disconnect selected lines.In a preferred embodiment, the switching valve has exactly four connection openings on the first housing part, wherein a first connection opening is connected to a permeate outlet of a first reverse osmosis module, wherein a second connection opening is connected to a permeate outlet of a second reverse osmosis module, wherein a third connection opening is connected to a raw water inlet of the second reverse osmosis module, and wherein the fourth connection opening is connected to the concentrate outlet of the first reverse osmosis module. As will be explained below, switching between permeate-stage operation and concentrate-stage operation in such an embodiment can be carried out very simply and quickly using a central actuator.

[0021] In the switching valve, all connection ports in the first housing part are preferably fluidically isolated from one another. Optionally, selected connection ports are connected in pairs via the channels in the second housing part. This enables highly reliable operation. The ability to rotate or shift entire housing parts relative to each other allows for a very robust and cost-effective design. In light of this, the aforementioned requirements are fully met.

[0022] In a preferred embodiment, the first housing part has a first, preferably flat, contact surface into which the connection openings open, and the second housing part has a second, preferably flat, contact surface into which the channels open, wherein the second contact surface closes selected connection openings depending on the respective position.

[0023] In this configuration, individual connection openings in the first housing part can be covered and thus sealed by a solid surface section of the second housing part. Accordingly, the first and second contact surfaces are in contact with each other during operation of the changeover valve. In some embodiments, they can be separated for adjustment. In this configuration, the changeover valve not only has the ability to create / provide selected fluid paths, but also the ability to completely seal selected connection openings depending on the respective position. This design thus reduces the risk of concentrate unintentionally entering a permeate channel or permeate line. Process reliability is further increased.

[0024] In a further embodiment, the switching valve has a number of grooves that extend in at least one of the aforementioned contact surfaces and define a plurality of contact surface segments, with each connection opening opening in a surface segment. In preferred embodiments, the grooves are arranged in the contact surface of the second housing module.

[0025] In this embodiment, the connection openings of the first housing part are located in separate surface segments defined by grooves. Consequently, the connection openings are also separated from each other by the grooves during operation of the diverter valve. The grooves form advantageous leakage channels in which leakage water, in particular permeate or concentrate from the water treatment plant, can collect should a leak occur in the area of ​​one or more connection openings. In preferred embodiments, the channels extend to one or more outer surfaces of the valve housing, so that the leakage water can exit the grooves on one or more of these outer surfaces. This has the advantage that the leak is easily detectable from the outside, and a defective diverter valve can be replaced or repaired promptly. Contamination of the permeate is thus more easily avoided.

[0026] In a further embodiment, the switching valve has a clamping mechanism designed to clamp the first housing part and the second housing part against each other in a respective position.

[0027] Such a clamping mechanism makes it possible to change the contact pressure with which the first and second housing parts are pressed against each other during operation of the changeover valve. In particular, this embodiment makes it possible to reduce the contact pressure of the housing parts relative to each other to facilitate rotation and / or displacement. Conversely, after rotation and / or displacement, the clamping mechanism can generate a high contact pressure, which promotes a fluid-tight, leak-free connection between the housing parts. In some advantageous embodiments, the clamping mechanism is configured to effect an axial movement parallel to a rotational and / or displacement axis of the second housing part relative to the first housing part, in order to selectively clamp or release the housing parts against each other.The design facilitates the adjustment movement of the switching valve and contributes to high process reliability.

[0028] In a further embodiment, the switching valve has a plurality of sealing rings which are arranged on the first housing part and / or on the second housing part and which are designed to fluidly separate the connection openings from each other.

[0029] In advantageous embodiments, each connection opening is surrounded by at least one sealing ring. Accordingly, at least one sealing ring can be arranged in each surface segment. For example, the sealing rings can be O-rings made of an elastic material, which are held in complementary recesses of the first and / or second housing part. In preferred embodiments, the sealing rings are held on the first housing part, while the aforementioned grooves are formed on the second housing part. This design improves the separation of the different fluid flows and advantageously contributes to high process reliability.

[0030] In another embodiment, the second housing part has a plate-like body in which the multitude of channels are formed.

[0031] In this embodiment, the second housing part comprises a solid body into which the channels are formed as recesses and / or preferably internal bores. Accordingly, the channels preferably run inside the second housing part and only open into the contact surface of the second housing part at their channel openings. In preferred embodiments, the channels are formed as or by means of bores in the plate-like body. This design enables a very cost-effective and robust implementation.

[0032] In a further embodiment, the multitude of connection openings includes four connection openings, of which in the first position two connection openings are fluid-conductingly connected in pairs by a respective channel from the multitude of channels.

[0033] In this configuration, the channels form two separate flow paths in the first position. This allows for the highly efficient implementation of the frequently desired concentration gradation of two reverse osmosis modules. In preferred embodiments, the switching valve has exactly four connection openings, which form exactly two separate flow paths in the first position.

[0034] In a further embodiment, three of the four connection openings form an isosceles triangle, and a fourth connection opening is arranged such that it has different lateral distances to at least two of the three connection openings mentioned.

[0035] The isosceles triangle of this design is visible in a top view of the first contact surface and results in the first of the three connection openings having equal lateral distances to the second and third connection openings. Therefore, the first of the three connection openings can be very easily and selectively connected to either the second or the third connection opening via a channel in the second housing part. In principle, such a selective connection is also possible if the lateral distances differ, but the present design allows for a very compact and particularly cost-effective implementation.Preferably, the fourth connection opening lies outside the isosceles triangle, and it is further preferred that the fourth connection opening, together with the first, second, and third connection openings, forms a quadrilateral with outer sides defining two 90° angles, one angle greater than 90°, and one further angle less than 90°. The four connection openings thus form a quadrilateral corresponding to the schematic side view of a house with a shed roof. Such an arrangement of the four connection openings enables a very compact and cost-effective implementation of the diverter valve.

[0036] In a further embodiment, the multitude of channels includes two channels that run parallel to each other and parallel to a plane spanned by the connection openings.

[0037] This design also contributes advantageously to a very compact and cost-effective implementation.

[0038] In a further embodiment, the first housing part and the second housing part are each made of a material approved for drinking water.

[0039] Alternatively, a drinking water-compatible surface coating could be applied to those housing surfaces that may come into contact with the permeate in the water treatment plant. This preferred design, however, facilitates a robust and durable implementation.

[0040] In a further embodiment, the switching valve has a guide pin which is arranged in a cam and together with the cam defines a switching path between the first position and the second position.

[0041] This design contributes advantageously to a process-reliable and durable switching valve by reducing the risk of incorrect operation.

[0042] In another embodiment of the water treatment plant, the switching valve is located downstream of the first reverse osmosis module and upstream of the second reverse osmosis module.

[0043] This design allows switching between permeate-stage and concentrate-stage operation with a small number of actuators and therefore facilitates a compact implementation of the new water treatment plant.

[0044] In a further embodiment, the water treatment system has a pressure booster pump located upstream of the first reverse osmosis module. Preferably, the water treatment system has a common pressure booster pump for several or all reverse osmosis modules located downstream of the first reverse osmosis module.

[0045] In this configuration, the new water treatment plant advantageously manages with a small number of pumps, which is facilitated by the switching valve.

[0046] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0047] Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. They show: Fig. 1 a side view of an embodiment of a water treatment plant with the diverter valve, Fig. 2 an embodiment of the diverter valve in a side view, Fig. 3 a lower housing part of the diverter valve made of Fig. 2 , Fig. 4 a housing upper part of the changeover valve made of Fig. 2 , Fig. 5 a flow diagram showing the water treatment plant from Fig. 1 in a concentrate-stage operation, and Fig. 6 a flow diagram illustrating the operation of the water treatment plant. Fig. 1 in a permeate-graded operation.

[0048] In the Fig. 1 This is an embodiment of a new water treatment plant, designated in its entirety by reference numeral 10. The plant 10 comprises a first reverse osmosis module 12 and a second reverse osmosis module 14, as well as a switching valve 16, which enables simple and robust switching between concentrate-stage and permeate-stage operation. Furthermore, the water treatment plant here has two pre-filters 17, as described by way of example in the aforementioned EP 1 690 579 A1.

[0049] Fig. 2 Figure 1 shows an embodiment of the changeover valve 16 in a side view. The changeover valve 16 has a first housing part 18 with a first contact surface 20, a second housing part 22 with a second contact surface 24, and a clamping mechanism 26 that makes it possible to selectively press the contact surfaces 20 and 24 firmly against each other or to reduce the contact pressure in order to allow the housing parts 18 and 22 to rotate relative to each other about an axis of rotation 28. Hereinafter, the first housing part 18 is referred to, without limitation of generality, as the lower housing part, and the second housing part 22 is accordingly referred to as the upper housing part.

[0050] How to in Fig. 2 As can be seen, the clamping mechanism 26 in this embodiment includes a clamping lever 30 which is mounted on an axis 32 (see Fig. 4 ) is located. The axis 32 runs along the axis of rotation 28 through the upper housing part 22 and holds the upper housing part 22 to the lower housing part 18.

[0051] Fig. 3 Figure 1 shows a top view of the contact surface 20 of the lower housing part 18 in the center, and to the right and left of it, cross-sections through the lower housing part 18 along the section planes AA and BB, respectively. Figure 2 shows a cross-section through the lower housing part 18 along the section planes AA and BB, respectively. Figure 3 shows a cross-section through the lower housing part 18 along the section planes AA and BB, respectively. Fig. 4 In the center is a top view of the contact surface 24 of the housing upper part 22, and to the right and left of it are cross-sections through the housing upper part 22 along the corresponding section planes AA and BB, respectively. The same reference numerals denote the same elements as before.

[0052] How to in Fig. 3 As can be seen, the lower housing part 18 in this embodiment has four connection openings 34A, 34B, 34C, 34D, each of which is formed here as stepped through-holes in a solid body 36. The opening diameter of the stepped through-holes is smaller in the area of ​​the contact surface 20 than in the area of ​​the rear side 37 of the lower housing part 18 facing away from the contact surface 20. A sealing ring 38 is arranged concentrically around each of the four connection openings 34A, 34B, 34C, 34D. A connector 40 for attaching a pipe or hose is screwed into each of the four connection openings 34A, 34B, 34C, 34D on the rear side 37. Fig. 2 ).

[0053] In the area of ​​the center of the (in this case largely square) lower housing part 18, but laterally adjacent to the receptacle for the axis 32, a guide pin 42 is arranged, which engages in a cam 44 in the upper housing part 22 during operation of the switching valve and is guided there. The guide pin 42 and the cam 44 define a switching path between a first rotational position and an alternative second rotational position of the upper housing part 22 relative to the lower housing part 18, as described below with reference to the Figuren 5 und 6 This will be explained later.

[0054] How to in Fig. 4 As can be seen, the upper housing part 22 in this embodiment has two internal channels 46, 48. Each of the two channels 46, 48 has two channel openings 50a, 50b and 52a, 52b, respectively. The channel openings 50a, 50b, 52a, 52b open into the second contact surface 24 and are arranged relative to each other such that they align with the connection openings 34A to 34D in pairs when the two housing parts 18, 22 are in one of the rotational positions. In this embodiment, for example, channel opening 50a aligns with connection opening 34B and channel opening 50b aligns with connection opening 34A when the two housing parts 18, 22 are in the first rotational position. Furthermore, in this case, channel opening 52a is aligned with connection opening 34D and channel opening 52b with connection opening 34C. Channels 46 and 48 create a flow diagram as shown in Fig. 5 is shown.

[0055] How to in Fig. 4 As can be further seen, the lateral distance between the channel openings 50a, 50b is greater than the lateral distance between the channel openings 52a, 52b. In contrast, the lateral distance between the channel openings 50a, 50b in this embodiment is largely equal to the lateral distance between the channel openings 50a, 52a. The channel openings 50a, 50b, 52a thus form a largely isosceles triangle in the top view of the contact surface 24, with the channel opening 50a forming the apex of the isosceles triangle. In the same way, the connection openings 34A, 34B, 34D form a congruent isosceles triangle in the top view of the contact surface 20 of the lower housing part 18, which in Fig. 3 as indicated by reference numeral 54. Consequently, channel opening 50b can align with connection opening 34B, and channel opening 50a can align with connection opening 34D, when the two housing parts 18, 22 are in the alternative second rotation position. However, in this case, connection openings 34A, 34C do not align with channel openings 52a, 52b. Therefore, in this case, only channel 46 creates a connection between connection openings 34B, 34D, while channel 48 does not. A corresponding flow diagram is shown in Fig. 6 depicted.

[0056] How to in Fig. 4 Furthermore, as can be seen, two cross-shaped grooves 56 are arranged in the contact surface 24, dividing the contact surface 24 into four surface segments 24A, 24B, 24C, 24D. In this embodiment, the grooves 56 extend in two mutually orthogonal directions over the entire length of the contact surface 24, so that the grooves open onto the side surfaces of the upper housing part. Accordingly, for example, in Fig. 2 One of the grooves 56 forms a small lateral opening in the two-part housing of the changeover valve 16. The grooves 56 ensure that any (undesired) leakage water from the connection openings 34A, 34B, 34C, 34D or any other leakage can escape to the outside of the changeover valve 16, as indicated by an arrow. A leak inside the changeover valve 16 is therefore quick and easy to detect. Furthermore, the grooves 56 contribute to the fluid separation of the connection openings 34A, 34B, 34C, 34D from each other, even in the event of a leak, since each connection opening 34A, 34B, 34C, 34D is arranged in a separate surface segment.

[0057] In Fig. 2 and Fig. 4 Two sealing plugs 58 are also shown, which close the boreholes or lateral inlet openings into the channels 46, 48 on the side of the upper housing part 22. The sealing plugs 58 facilitate the production of the channels 46, 48 when the upper housing part 22 is manufactured from a solid piece of material. However, if the upper housing part 22 is manufactured using a 3D printing process, the inlet openings and sealing plugs can be omitted, as those skilled in the art will readily recognize.

[0058] Fig. 5 Figure 1 shows a schematic diagram of the water treatment plant 10 with the switching valve 16 in a concentrate-stage operation. The same reference numerals denote the same elements as before. Upstream of the first reverse osmosis module 12, a pump 60 is arranged, which pressurizes raw water in a raw water feed line 61 to a pressure that enables reverse osmosis in both the first reverse osmosis module 12 and the subsequent reverse osmosis module 14. Alternatively, in other embodiments, it would be possible to use additional pressure booster pumps and, for example, to arrange one pump 60 upstream of the raw water inlet of each reverse osmosis module 12 and 14.

[0059] In the concentration-graded operation according to Fig. 5 The permeate from the first reverse osmosis module 12 is routed via line 62 and channel 46 in the diverter valve 16 to a manifold 64. The manifold 64 is further connected via line 66 to the permeate outlet of the second reverse osmosis module 14 and also receives the permeate from the second reverse osmosis module 14. The concentrate from the first reverse osmosis module 12 is routed via line 68, channel 48 in the diverter valve 16, and line 70 to the raw water inlet (feed) of the second reverse osmosis module 14. The reverse osmosis module 14 produces permeate again from the concentrate of the first reverse osmosis module 12 and routes this permeate via line 66 into the manifold 64. In this operation, a higher quantity of permeate is thus produced from the raw water in line 62.The concentrate from the second reverse osmosis module 14 can be discharged as wastewater via a further line 72 or, in further embodiments, fed to another reverse osmosis module (not shown here).

[0060] If, however, the drinking water treatment is to be carried out with a higher drinking water quality (purity), the channels 46, 48 in the diverter valve 16 can be switched to the channels 46, 48 by a rotational movement of the second housing part 22 relative to the first housing part 18 in the Fig. 6 The depicted rotational position can be brought into place. The rotational movement is in Fig. 5 indicated by an arrow 74. In this case, the permeate from the first reverse osmosis module 12 is fed via line 62, channel 46, and line 70 to the raw water inlet (feed) of the second reverse osmosis module 14 and thus undergoes reverse osmosis a second time. Advantageously, the concentrate from the first reverse osmosis module 12 is fed directly into the wastewater line 72 via a control valve 76, which is open in this case. The control valve 76 and another control valve 78 at the concentrate outlet of the second reverse osmosis module 14 are preferably needle valves, which regulate the operating pressures in the membrane stages. In concentrate-stage operation according to Fig. 5 The control valve 76 is preferably completely closed, and the operating pressure, and thus the permeate flow rate, is regulated via the valve 78. In permeate-stage operation according to Fig. 6 Pressure regulation is preferably achieved via both valves.

[0061] Alternatively or additionally to this embodiment, in which the housing parts 18, 22 are rotatable relative to each other, it is in principle possible to design the switching valve 16 with two housing parts that are displaceable relative to each other. In simplified terms, Fig. 5 At reference numeral 46' a channel is indicated which can be brought into a positioning position by a translational movement along an adjusting axis 80, as is the case with channel 46 in Fig. 6 occupies this position, i.e., after a shift, the in Fig. 5 The depicted channels 46 and 48 no longer have a connection to either of the connection openings. From a fluid dynamics perspective, this results in a condition as described in Fig. 6 is shown.

Claims

1. A mobile water treatment system for producing potable water in a disaster area, comprising first and second reverse osmosis modules (12, 14), and comprising a changeover valve (16) configured for selectively connecting the first reverse osmosis module (12) and the second reverse osmosis module (14) for permeate-stepped operation or for concentrate-stepped operation, wherein the changeover valve comprises a valve housing having a first housing part (18) and a second housing part (22), wherein the first housing part (18) has a plurality of port openings (34A, 34B, 34C, 34D) configured for connecting fluid lines (62, 64, 68, 70), wherein the second housing part (22) has a plurality of channels (46, 48) configured for interconnecting defined port openings (34A, 34B, 34C, 34D) from the plurality of port openings in a fluid-conducting manner, and wherein the first housing part (18) and the second housing part (22) are held spatially adjustable relative to one another and define a first setting position and a second setting position, wherein the channels (46, 48) connect different port openings from the plurality of port openings (34A, 34B, 34C, 34D) to one another in the fluid-conducting manner as a function of the respective setting position.

2. The mobile water treatment system according to claim 1, wherein the first housing part (18) has a first contact surface (20), in which the port openings open, wherein the second housing part (22) has a second contact surface (24), in which the channels (46, 48) open, and wherein the second contact surface (24) closes selected port openings as a function of the respective setting position.

3. The mobile water treatment system according to claim 2, wherein the changeover valve further comprises a number of grooves (56) extending in at least one of said contact surfaces (24) and defining a plurality of contact surface segments (24A, 24B, 24C, 24D), wherein one respective port opening opens in a respective surface segment.

4. The mobile water treatment system according to any one of claims 1 to 3, wherein the changeover valve further comprises a clamping mechanism (26) which is configured for clamping the first housing part (18) and the second housing part (22) against each other in a respective setting position.

5. The mobile water treatment system according to any one of claims 1 to 4, wherein the changeover valve further comprises a plurality of sealing rings (38) arranged on the first housing part (18) and / or the second housing part (22) and which are arranged to separate the port openings (34A, 34B, 34C, 34D) from each other with respect to fluid.

6. The mobile water treatment system according to any one of claims 1 to 5, wherein the second housing part (22) has a plate-like body in which the plurality of channels (46, 48) are formed.

7. The mobile water treatment system according to any one of claims 1 to 6, wherein the plurality of port openings (34A, 34B, 34C, 34D) comprises four port openings, of which two respective port openings are connected in pairs by a respective channel from the plurality of channels (46, 48) in a fluid-conducting manner in the first setting position.

8. The mobile water treatment system according to claim 7, wherein three (34A, 34B, 34D) of the four port openings span an isosceles triangle (54), and wherein a fourth port opening (34C) of the four port openings is arranged such that it has different lateral distances from at least two of said three port openings.

9. The mobile water treatment system according to any one of claims 1 to 8, wherein the plurality of channels (46, 48) comprises two channels running parallel to each other and parallel to a plane spanned by the port openings (34A, 34B, 34C, 34D).

10. The mobile water treatment system according to any one of claims 1 to 9, wherein the first housing part (18) and the second housing part (22) are each made of a material approved for drinking water.

11. The mobile water treatment system according to any one of claims 1 to 10, further comprising a guide pin (42) which is arranged in a link (44) and together with the link (44) defines a switching path between the first setting position and the second setting position.

12. The mobile water treatment system according to any one of claims 1 to 11, wherein the first setting position and the second setting position are different rotational positions from each other about an axis of rotation (28).

13. The mobile water treatment system according to any one of claims 1 to 12, wherein the first setting position and the second setting position are different setting positions from each other along a translatory adjustment axis (80).

14. The mobile water treatment system according to any one of claims 1 to 13, wherein the changeover valve (16) is arranged downstream of the first reverse osmosis module (12) and upstream of the second reverse osmosis module (14).