Hollow fiber filter module with symmetrical distribution arrangement and method for operating and cleaning the filter module

Abstract

The invention relates to a filter module comprising a bundle of hollow fiber membranes. First ends of the membranes are closed, second ends of the membranes are open. A first distributor connects a first connection chamber, which is provided with a fluid connection, with the space between the hollow fiber membranes. A second connection chamber, which is provided with another fluid connection, is in fluid communication with the lumens of the fiber membranes via the open ends of the fiber membranes. A second fluid connection is connected to a second distributor by a tube that can pass through the second connection chamber. Both distributors have the same construction. Radial flow channels are provided to distribute the fluid between the outer surfaces of the fiber membranes. Both distributors have a central passage that is accessible to the fluid via the radial flow channels and an axial opening.A check valve blocks the axial flow of fluid from the central passage through the axial opening into the space between the fiber membranes, while allowing the axial flow of fluid from the space between the fiber membranes through the axial opening into the central passage. During filtration, the inflow pattern from the first distributor is preferably perpendicular to the fiber membranes. This increases filtration efficiency. Various flow schemes can be used for cleaning. One of the fluid ports is selected to introduce clean water. The other fluid ports are selectively opened or closed. The check valves open or close automatically depending on which fluid port is selected for inflow and which fluid port is selected for outflow.

Description

Technical area

[0001] The present invention relates to a filter module, the filter module comprising: - a cylindrical housing circumferentially surrounding an interior space; - an upper cap at an upper end of the housing and a lower cap at a lower end of the housing, each of the caps defining a connection chamber and each of the caps having a first fluid port in fluid communication with the connection chamber; - a plurality of hollow fiber membranes extending through the interior; - an upper and a lower distribution assembly, each of the distribution assemblies comprising: ◯ a central passage extending from a first opening at the connecting chamber to a second opening at the interior space; ◯ a plurality of radial arms, each arm enclosing a flow channel from the central passage to at least one flow opening opening into the interior space; - a tube fluidly connecting the central passage of the upper manifold assembly to a second fluid port. State of the art

[0002] Such a filter module is known, for example, from KR101975495B1.

[0003] Such filter modules are used primarily for large-scale wastewater treatment, for example, in industrial plants, sewage treatment plants, or fracking plants. Often, several modules, such as 50 or 100, are used together in a filter system.

[0004] During operation, dirt accumulates inside the filter modules. This accumulated dirt can eventually clog the walls of the hollow filter membranes and the flow openings. Therefore, regular cleaning of the filter module is necessary to maintain proper filtration performance. Backwashing the filter module can be performed for this purpose.

[0005] It is an object of the invention to provide a filter module with improved filtration and cleaning properties.

[0006] This is achieved by a filter module according to claim 1 and methods for its use according to claims 9 and 12 to 16. Advantageous embodiments are specified in the subclaims and in the description. Disclosure of the invention

[0007] According to the invention, a filter module, in particular for wastewater treatment, is provided. The invention further relates to a filter system comprising a plurality of filter modules, in particular at least 10, at least 50, preferably at least 100, in particular connected in parallel.

[0008] The filter module comprises a cylindrical housing that circumferentially surrounds an interior space. The housing generally extends along an axis. Directional terms such as radial or circumferential generally refer to the axis of the housing. In use, the housing is typically oriented vertically. Height terms such as "top" and "bottom" generally refer to a vertical orientation of the housing. However, it goes without saying that the housing can also be oriented obliquely or horizontally during use. In this respect, reference to a lower or upper region or part should be understood as reference to a first or second region or part, respectively.

[0009] The filter module further comprises an upper cap at an upper end of the housing and a lower cap at a lower end of the housing. Each of the caps defines a connection chamber, and each of the caps includes a first fluid port in fluid communication with the connection chamber. In particular, the end caps allow for the introduction of wastewater into the housing and the removal of permeate (filtered water) and / or retentate (water with accumulated dirt) from the housing. During use, wastewater is typically introduced through the first fluid port of the lower cap. Permeate is generally removed through the first fluid port of the upper cap. During cleaning, one or both caps can be used to introduce clean water and to flush water with dislodged dirt.

[0010] An upper sealing body separates the upper terminal compartment from the interior. A lower sealing body separates the lower terminal compartment from the interior. The sealing bodies can be cast from synthetic resin, preferably epoxy resin, with the resin being introduced and solidified particularly when the housing is rotated about its axis.

[0011] A plurality of hollow fiber membranes extend through the interior. The lower ends of the fiber membranes are sealed by the lower sealing body. The upper ends of the fiber membranes are open to the upper connection space. Typically, the hollow fiber membranes extend completely through the upper sealing body. The hollow fiber membranes consist of a lumen surrounded by a wall that is typically selectively permeable to water. Preferably, both ends of the bundle of hollow fiber membranes are fixed by the upper and lower sealing bodies, respectively.

[0012] The filter module further comprises an upper and a lower distribution unit. Each of the distribution assemblies comprises ◯ a central passage extending through the associated sealing body from a first opening at the associated connection chamber to a second opening at the interior; ◯ a plurality of radial arms, each arm enclosing a flow channel from the central passage to at least one flow opening opening into the interior space ◯ a check valve configured to block fluid flow from the central passage through the second opening into the interior space while allowing fluid flow from the interior space through the second opening into the central passage.

[0013] The central passage provides fluid communication between the connecting chamber and the interior when the check valve is open. Fluid entering one of the connecting chambers causes the check valve of the associated manifold assembly (also called the "manifold") to be pushed against and closes the second opening of the central passage; the fluid can cause the check valve of the other manifold assembly to open, allowing particles trapped in the cylindrical module body during wastewater treatment to be removed through the open central passage. Generally, the check valves allow fluid flow between the central passage and the flow channels in the arms in both the open and closed states.

[0014] The flow ports of the multiple arms are open to the outer surfaces of the hollow fiber membranes. The flow ports of the arms ensure fluid communication between the connection chamber and the interior of the housing.

[0015] A tube connects the central passage of the upper distribution unit to a second fluid connection. The second fluid connection can be formed by the tube or the upper cap. The tube and the upper sealing body fluidically separate the interior and the upper connection chamber. In particular, the tube prevents retentate from entering the upper connection chamber and mixing with the permeate. A fluidic connection between the upper connection chamber and the interior is established by the hollow-fiber membranes, whereby the fluid must pass through their walls to pass from the interior to the upper connection chamber and from the upper connection chamber to the interior.

[0016] At least one of the check valves, in particular both check valves, can have a valve insert. The valve insert can be a sphere, preferably a hollow sphere. A ball valve is simple and reliable. A hollow sphere tends to rise in the liquid, thus assisting in closing the lower check valve and opening the upper check valve during the filtration process.

[0017] Preferably, the flow channels are closed in the axial direction. The flow openings of the arms can be oriented circumferentially. This guides the water between the hollow-fiber membranes in the circumferential direction. In other words, the flow direction of the water passing through the flow openings is perpendicular to the extension of the hollow-fiber membranes. This design significantly increases the penetration of the wastewater between the fiber membranes at the lower end. Compared to an axial flow, higher filtration efficiency and better utilization of the membrane area are achieved.

[0018] At least one of the manifold assemblies, in particular both manifold assemblies, may (each) comprise a base and a cover, wherein the base and the cover together define the arms and the flow channels. This design can facilitate the manufacture of the manifolds. The first opening of the central passage may be formed on the base, and the second opening of the central passage may be formed on the cover.

[0019] Preferably, the base of at least one of the distribution units has axial flaps embedded in the associated sealing body. This allows the base to be firmly secured. Furthermore, the sealing body of the distribution unit provides mechanical support.

[0020] The cover of at least one of the manifold assemblies may have projections that overlap the base and are embedded in the associated seal body. This allows the base to be firmly secured, preventing the base and cover from becoming loose. Attaching the cover to the seal body can simplify the design and reduce manufacturing costs compared to attaching the cover directly to the base.

[0021] Preferably, the base of at least one of the manifold assemblies comprises a cage in which a valve insert of the check valve is received. The cage limits the movement of the valve insert from the second opening toward the first opening of the central passage. When the cover is mounted on the base, the valve insert is trapped inside the cage, which can enable efficient manufacturing. The valve insert can be a sphere, preferably a hollow one.

[0022] Particularly preferably, the upper and lower distribution units are identical in design. This reduces the number of different parts and ensures cost efficiency. The distributors can be arranged mirror-symmetrically.

[0023] A first check valve may be provided to selectively block or allow fluid flow through the first fluid port of the top cap.

[0024] A second check valve may be provided to selectively block or allow fluid flow through the second fluid port.

[0025] A third check valve may be provided to selectively block or allow fluid flow through the first fluid port of the bottom cap. During normal use, the third check valve is generally open.

[0026] The lower cap may include an air notch nozzle and preferably a locking device for the air notch nozzle. During normal use, the air notch nozzle is generally locked by the locking means. During the backwash process, the locking device can be removed to open the air notch nozzle of the lower cap.

[0027] The invention also relates to a method for filtration operation of a filter module according to the invention, as described above. For filtration operation, raw water is fed into the filter module through the first fluid connection of the lower cap. The water forces the check valve of the lower distributor to close. The water flows through the flow channels of the arms of the lower distributor unit into the interior and penetrates through the walls of the hollow-fiber membranes into their lumens. Clean water enters the upper connection space through the upper open ends of the hollow-fiber membranes. The clean water leaves the filter module through the first fluid connection of the upper cap.

[0028] In a first variant, open-end filtration is performed. The second fluid port is open during the filtration process. The retentate (contaminated water) flows through the check valve of the upper manifold during filtration. The retentate leaves the filter module through the second fluid port. Since the contaminated retentate is continuously sucked out of the filter module, the time between cleaning cycles can be extended.

[0029] In a second variant, dead-end filtration is performed. The second fluid port is blocked during filtration. Dirt accumulates inside the housing between the fiber membranes. Since the retentate cannot escape from the filter module during dead-end filtration, all the water must flow through the hollow fiber membranes. This allows for a higher volume flow of clean water.

[0030] The invention further relates to methods for cleaning (backwashing or pre-washing) a filter module according to the invention, as described above.

[0031] In a first variant, clean water is fed into the filter module through the first liquid port of the upper cap while the first liquid port of the lower cap is open, and preferably while the second liquid port is closed. The water enters the lumens of the hollow fiber membranes at their open ends and penetrates through their walls into the interior space. The water forces the check valve of the lower distribution unit to open. The water exits through the central passage of the lower distribution unit. Part of the water, containing detached dirt, can leave the interior space through the second opening of the lower central port, and part of the water can leave the interior space through the flow openings and the flow channels of the lower distribution arms. The water (and dirt) is flushed out of the filter module through the first liquid opening of the lower cap.This method enables a top-down backwash process. This variant efficiently removes contaminants from the outer walls of the hollow-fiber membranes.

[0032] In a second variant, clean water is fed into the filter module through the first fluid port of the upper cap, while the first fluid port of the lower cap is closed and the second fluid port is open. If provided, the air notch nozzle is closed. The water enters the lumens of the hollow fiber membranes at their open ends and penetrates through their walls into the interior space. The water forces the check valve of the upper distribution unit to open. The water exits through the central passage of the upper distributor. Some of the water, containing detached dirt, can leave the interior space through the second opening of the upper central passage, and some of the water can leave the interior space through the flow openings and the flow channels of the upper distribution arms. The water (and dirt) are discharged through the second fluid opening.This variant offers a top-to-top backwash process. This variant cleans the outer walls of the hollow-fiber membranes and the upper distributor.

[0033] In a third variation, clean water is directed into the filter module through the first fluid port of the lower cap, while the first fluid port of the upper cap is closed and the second fluid port is open. If provided, the air notch nozzle is closed. The water forces the check valve of the lower distribution unit to close. The water flows through the flow channels and the flow openings of the arms of the lower distribution unit into the interior space. The water forces the check valve of the upper distribution unit to open. The water exits through the central passage of the upper distribution unit. Some of the water, containing dislodged dirt, can leave the interior space through the second opening of the upper central passage, and some of the water can leave the interior space through the flow openings and channels of the upper distribution arms.The water (and dirt) is drained through the second fluid port. This variant offers a forward flushing process from bottom to top. This variant efficiently cleans the lower distribution arms and adjacent areas of the outer walls of the hollow fiber membranes.

[0034] In a fourth variation, clean water is fed into the filter module through the second fluid port while the first fluid port of the upper cap is closed and the first fluid port of the lower cap is open. The water forces the check valve of the upper manifold to close. The water flows through the flow channels and flow openings of the arms of the upper manifold assembly into the interior space. The water forces the check valve of the lower manifold to open. The water exits through the central passage of the lower manifold assembly. Some of the water, containing dislodged dirt, can leave the interior space through the second opening of the lower central passage, and some of the water can leave the interior space through the flow openings and channels of the lower manifold arms. The water (and dirt) is drained through the first fluid opening of the lower cap.This variant offers a top-down forward flushing process. This variant efficiently cleans the upper distribution arms and adjacent areas of the outer walls of the hollow fiber membranes.

[0035] The invention further relates to a method for operating a filter module according to the invention as described above. At least one period of the filtration operation according to the invention, as described above, is carried out. The filtration operation is followed by at least one cleaning operation according to the invention, as described above. Further periods of filtration operation and cleaning can follow.

[0036] Preferably, the cleaning of the filter module between two consecutive periods of filtration operation comprises at least two cleaning periods according to different variants, as described above. Particularly preferably, the cleaning of the filter module comprises three cleaning periods, in particular a top-to-bottom backwash period, a top-to-bottom backwash period, and a bottom-to-top pre-wash period. The cleaning may include a fourth top-to-bottom forward wash period. The cleaning periods can be performed in any order. By combining different cleaning techniques, a particularly thorough removal of deposited dirt is achieved.

[0037] The inventive arrangement of the filter module with two check valves on the lower and upper distributors enables the use of different cleaning techniques. To switch between the different cleaning techniques, it is sufficient to open or close the respective fluid connections and supply clean water via a suitable fluid connection. At the same time, the lower check valve closes automatically during filtration, which enhances the distribution of the wastewater between the multiple hollow fiber membranes by the lower distributor arms. This increases the filtration performance. Short description of the drawings

[0038] Further advantages and features of the invention will become apparent from the following description of embodiments of the invention with reference to the figures of the drawing, which show essential details, as well as from the claims. The individual features, as described above or explained below, can be implemented individually or in any useful combination in variants of the invention. Fig. 1 shows a filter module according to the invention in a schematic longitudinal section, wherein the module comprises an upper and a lower distributor arrangement, each of which is fastened to a housing via a sealing body; Fig. 2 shows a distribution assembly for the filter module of the Fig. 1 in a schematic perspective view; Fig. 3 shows a schematic cross section through the distribution unit of Fig. 2, wherein the cutting plane passes through two radial arms of the distribution unit; Fig. 4 shows a further schematic cross-section through the distribution unit of Fig. 2 and the associated sealing body, the sectional plane extending between adjacent radial arms of the distribution unit; Fig. 5 shows a schematic flow diagram of a method according to the invention. Embodiments of the invention

[0039] Fig. 1 shows a filter module 10. A plurality of filter modules 10 can be connected in parallel to form a filter system (not shown in detail).

[0040] The filter module 10 comprises a housing 12. The housing 12 consists of a cylindrical body extending along an axis 13 and enclosing an interior space 14. Two caps 16a, 16b are arranged at a first and a second axial end of the housing 12.

[0041] The first and second caps 16a, 16b, or the first and second ends, are also referred to as the upper cap 16a and lower cap 16b, or the upper and lower ends. It should be noted that the filter module 10 is typically used in a vertical orientation, as shown in Fig. shown, but an inclined or horizontal orientation is also possible.

[0042] Note that in the description, for features that have an upper and a lower instance, the letters "a" and "b" are appended to the reference numerals to indicate the "upper" and "lower" instances, respectively. The reference numeral without any appended letters is used to describe these features regardless of their location at the upper or lower end.

[0043] The caps 16a, 16b are sealed against the housing 12, e.g., via a sleeve. A sealing body 18a, 18b is arranged at each end of the housing 12. An upper and a lower connecting space 20a, 20b are formed between the caps 16a, 16b and the associated sealing bodies 20a, 20b.

[0044] Each cap 16a, 16b includes a first fluid port 22a, 22b. The fluid ports 22a, 22b establish a fluid connection between the connecting chambers 16a, 16b and an external piping system. A check valve 24a, 24b may be provided at each of the first fluid ports 22a, 22b.

[0045] The lower connecting chamber 20b is provided with an air nozzle 26, which can be closed by a locking means 28, e.g. a screw plug.

[0046] Two manifold assemblies (or manifolds) 30a, 30b establish a fluid connection between opposite sides of the respective sealing bodies 18a, 18b. In this embodiment, the manifolds 30a and 30b are identical in construction. Both manifolds 30a, 30b are arranged such that their identical sides face the interior space 14 or the associated sealing body 18a, 18b.

[0047] The distributors 30a, 30b each have a central passage 32a, 32b extending axially through the associated sealing body 18a, 18b. Specifically, the upper central passage 32a extends from a first opening or orifice 34a at the connection chamber 20a to a second opening or orifice 36a at the interior space 14; the lower central passage 32b extends from a first opening or orifice 34b at the connection chamber 20b to a second opening or orifice 36b at the interior space 14.

[0048] A tube 38 is provided on the upper manifold 30a, connecting the central passage 32a to a second fluid port 40. In this embodiment, the tube 38 extends from the first opening 34a of the central passage 32a through a bore 42 in the upper cap 16a. The tube 38 establishes the fluid connection between the interior 14 and an external piping system. A check valve 44 may be provided on the second fluid port 40.

[0049] The central passage 32b is open at the first opening 34b to the lower connection chamber 20b. This establishes a fluid connection between the lower connection chamber 20b and the lower central passage 32b.

[0050] A bundle of hollow fiber membranes 46 extends through the interior 14 of the housing 12. The fiber membranes 46 are aligned parallel to the axis 13. One wall of the fiber membranes 46 is selectively permeable to water. Each cylindrical wall encloses a lumen of the respective fiber membrane 46. The walls separate the lumens of the membranes 46 from the interior 14. Water can pass through the walls, while contaminants are retained by the walls.

[0051] The fiber membranes 46 are embedded in the sealing bodies 18a, 18b. The membranes 46 extend completely through the upper sealing body 18a. The upper ends 48a of the membranes 46 are open toward the upper connection chamber 20a. At the open upper ends 48a of the membranes 46, a fluid connection is established between the upper connection chamber 20a and the lumens of the membranes 46. The lower ends 48b of the membranes 46 are arranged within the volume of the lower sealing body 18b. The lower sealing body 18b seals the lower ends 48b of the membranes 46.

[0052] Each distribution unit 30 comprises a plurality of arms 50 extending in the radial direction (see Fig. ). In this embodiment, ten arms 50 are provided, see Fig. . As a rule, at least six arms are provided.

[0053] Each arm comprises a flow channel 52, see in particular Fig. , which extends from the central passage 32 to a plurality of flow openings 54. The flow openings 54 open the flow channels 52 toward the interior space 14, see. Fig. . The flow channels 52 establish a fluid connection between the central passage 32 and the interior space 14.

[0054] In this embodiment, the flow openings 54 are arranged on circumferentially oriented surfaces of the arms 50. The axial surfaces of the arms 50 are closed, see in particular the Fig. 2 and Fig. 3. In other words, the flow channels 52 are completely closed in the axial direction, while the flow openings 52 allow a liquid flow to the interior space 14 in a flow direction that is substantially perpendicular to the fiber membranes 46.

[0055] Each distribution unit includes a check valve 56. In this embodiment, the check valves 56 consist of a valve insert, which is a preferably hollow ball 58. The ball 58 is received in a cage 60 at the second opening 36.

[0056] The check valves 56 are configured to block the flow of fluid from the central passage 32 through the second opening 36 into the interior space 14. When the fluid attempts to flow in this direction, i.e., when the pressure in the central passage 32 exceeds the pressure in the interior space 14, the ball 58 is pressed against the periphery of the second opening 36, sealing the second opening 36. This is shown at the lower check valve 56b of the lower manifold 30b in Fig. and the Fig. shown.

[0057] The check valves 56 are configured to allow fluid flow from the interior 14 through the second opening 36 into the central passage 32. When the fluid flows in this direction, ie, when the pressure in the interior 14 exceeds the pressure in the central passage 32, the ball 58 is lifted from the periphery of the second opening 36. This is shown at the upper check valve 56a of the upper manifold 30a in Fig. shown.

[0058] Regardless of the position of the ball 58, the check valves 56 allow fluid flow between the central passage 32 and the flow channels 52 in the arms 50.

[0059] In this embodiment, the manifolds 30 include a base 62 and a cover 64. The base 62 and the cover 64 together define the central passage 32 and the flow channels 52.

[0060] The base 62 has flaps 66 which protrude axially from the bottom surfaces of the flow channels 52, cf. Fig. 2 and Fig. 3. The flaps 66 are embedded in the corresponding sealing body 16, see. Fig. 1.

[0061] The cover 64 engages over the base 62 at the arms 50. The cover 66 has, in particular, projections 68 that are embedded in the associated sealing body 18. Furthermore, the projections 68 can establish a snap connection with the base 62.

[0062] In the illustrated embodiment, the cage 60 for the ball 58 is formed monolithically with the base 62. For assembly, the ball 58 is inserted into the cage 60. Then, the cover 64 is pre-assembled on the base 62. The distributors 30 are arranged at the ends of the housing 12. Liquid resin, e.g., epoxy, is poured in. As the housing 12 is rotated about the axis 13, the resin solidifies and forms the sealing body 18.

[0063] For filtration operation, see step 102 in Fig. , raw water is introduced into the filter module 10 through the first fluid port 22b of the lower cap 16b. The water enters the lower connection chamber 20b and forces the check valve 56b of the lower distributor 30b to close. The water flows from the central passage 32b through the flow channels 52 of the arms 50 of the lower distributor unit 30b into the interior space 14. The water penetrates through the walls of the hollow fiber membranes 46 into their lumens. Clean water enters the upper connection chamber 20a through the upper open ends 48a of the hollow fiber membranes 46. The clean water is drained from the filter module 10 through the first fluid port 22a of the upper cap 16a while the check valve 24a is open.

[0064] When the check valve 44 is open, open-end filtration is performed. The retentate (contaminated water) opens the upper check valve 56a during the filtration process. The retentate can flow through the second opening 36a and the flow channels 52 of the upper distributor. The retentate is discharged from the filter module 10 through the line 38 and the second liquid connection 40.

[0065] When the check valve 44 is closed, dead space filtration is performed alternatively. Dirt accumulates in the housing 12 between the fiber membranes 46 in the interior space 14. Water from the interior space 14 passes through the hollow fiber membranes 46 into the upper connection chamber 20a.

[0066] After a certain period of filtration operation 102, the filter module 10 is cleaned, see step 104. Preferably, several different cleaning techniques are used sequentially in cleaning step 104. The check valves 56a, 56b and the shut-off valves 24a, 24b, 44 enable easy switching between different cleaning methods. It is understood that the various cleaning steps can be performed in any order. It is further understood that not all of the cleaning techniques described below need to be applied during cleaning process 104.

[0067] During backwashing from top to bottom, see step 106, clean water enters the filter module 10 through the first fluid connection 22a of the upper cap 16a. The shut-off valve 24b on the first fluid connection 22b of the lower cap 16b is open. The shut-off valve 44 on the second fluid connection 40 is closed. The water enters from the upper connection chamber 20a into the lumens of the hollow fiber membranes 46 at their open upper ends 48a. The water enters the interior space 14 through the walls of the fiber membranes 46. The water opens the check valve 56b of the lower distributor unit 30b. From the interior space 14, water and detached dirt pass through the flow channels 52 in the arms 50 and the second opening 36b of the lower distributor 30b into the central passage 32b. Water and dirt are drained from the central passage 32b through the lower connection chamber 20b and the first fluid opening 22b of the lower cap 16b.

[0068] During top-to-top backwashing, see step 108, clean water enters the filter module 10 through the first fluid port 22a of the upper cap 16a. The shutoff valve 24b at the first fluid port 22b of the lower cap 16b is open. The check valve 24b at the first fluid port 22b of the lower cap 16b is closed. The locking valve 44 at the second fluid port 40 is open. The air rupture nozzle 28 is closed. The water enters from the upper connection space 20a into the lumens of the hollow fiber membranes 46 at their open upper ends 48a. The water enters the interior space 14 through the walls of the fiber membranes 46. The water opens the check valve 56a of the upper distribution unit 30a. From the interior space 14, water and detached dirt pass through the flow channels 52 in the arms 50 and the second opening 36a of the upper distributor 30a into the central passage 32a.Water and dirt are drained from the central passage 32a through the pipe 38 and the second fluid opening 40.

[0069] During the forward flush from bottom to top, see step 110, clean water enters the filter module 10 through the first liquid opening 22b of the lower cap 16b. The shut-off valve 24a at the first liquid opening 22a of the upper cap 16a is closed. The locking valve 44 at the second liquid connection 40 is open. The air rupture nozzle 26 is closed. The water closes the check valve 56b of the lower distributor unit 30b. The water flows through the flow channels 52 and the flow openings 54 of the arms 50 of the lower distributor unit 30b into the interior space 14. The water opens the check valve 56a of the upper distributor. From the interior space 14, water and detached dirt pass through the flow channels 52 in the arms 50 and the second opening 36a of the upper distributor 30a into the central passage 32a. Water and dirt are drained from the central passage 32a through the pipe 38 and the second fluid opening 40.

[0070] During the forward flush from top to bottom, see step 112, clean water enters the filter module 10 through the second liquid opening 40. The check valve 24a on the first liquid opening 22a of the upper cap 16a is closed. The check valve 24b on the first liquid opening 22b of the lower cap 16b is open. The water closes the check valve 56a of the upper distributor 30a. The water flows through the flow channels 52 and the flow openings 54 of the arms 50 of the upper distributor assembly 30a into the interior space 14. The water opens the check valve 56b of the lower distributor 30b. From the interior space 14, water and loosened dirt pass through the flow channels 52 in the arms 50 and the second opening 36b of the lower distributor 30b into the central passage 32b. Water and dirt are drained from the central passage 32a through the lower connection chamber 20b and the first fluid opening 22b of the lower cap 16b.

[0071] After completion of the cleaning 104, the filtration operation 102 can be resumed.

[0072] In summary, the invention relates to a filter module comprising a bundle of hollow fiber membranes. The first ends of the membranes are closed, the second ends of the membranes are open. A first distributor connects a first connection chamber, which is provided with a fluid connection, to the space between the hollow fiber membranes. A second connection chamber, which is provided with another fluid connection, is in fluid communication with the lumens of the fiber membranes via the open ends of the fiber membranes. A second fluid connection is connected to a second distributor by a tube that can pass through the second connection chamber. Both distributors have the same construction. Radial flow channels are provided to distribute the fluid between the outer surfaces of the fiber membranes. Both distributors have a central passage that is accessible to the fluid via the radial flow channels and an axial opening.A check valve blocks the axial flow of fluid from the central passage through the axial opening into the space between the fiber membranes, while allowing the axial flow of fluid from the space between the fiber membranes through the axial opening into the central passage. During filtration, the inflow pattern from the first distributor is preferably perpendicular to the fiber membranes. This increases filtration efficiency. Various flow schemes can be used for cleaning. One of the fluid ports is selected to introduce clean water. The other fluid ports are selectively opened or closed. The check valves open or close automatically depending on which fluid port is selected for inflow and which fluid port is selected for outflow.During filtration, the closed check valve of the first manifold ensures the distribution of raw water between the fiber membranes through the radial flow channels. During cleaning, the open check valve of the first manifold allows a high volume flow to discharge dirt through its axial opening. The check valve of the second manifold allows dirt to be discharged through its axial opening during filtration and cleaning. The use of identical manifolds simplifies manufacturing. Reference symbol 10 filter module 12 housings 13 Axis 14 Interior 16a Upper cap 16b Lower cap 18a Upper sealing body 18b Lower sealing body 20a Upper connection compartment 20b Lower connection compartment 20a First fuel connection 22a of the upper connection compartment 20b First fluid connection 22b of the lower connection chamber 22a Locking valve 24a for the first upper fluid connection 22b Locking valve 24b for the first lower connection 26 Air notch nozzle 28 Locking device 30a Upper distribution unit 30b Lower distribution unit 32a Upper central passage 32b Lower central passage 32a First opening 34a of the upper central passage 32b First opening 34b of the lower central passage 32a Second opening 36a of the upper central passage 32b Second opening 36b of the lower central passage 38 pipeline 40 Second fluid connection 42 bore 44 Shut-off valve 46 hollow fiber membrane 46 Upper end 48a of the membrane 46 Lower end 48b of the membrane 50 arms 52 flow channel 54 flow openings 56 Check valve 58 ball 60 cage 62 Base 64 Cover 66 flaps 68 projections 102 Filtration operation 104 Cleaning operation 106 Backwash from top to bottom 108 Backwash from top to bottom 110 Forward flush from bottom to top 112 Forward flush from top to bottom QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] KR 101975495B1

[0002]

Claims

[1] Filter module (10), in particular for waste water treatment, with - a cylindrical housing (12) circumferentially surrounding an interior space (14); - an upper cap (16a) at an upper end of the housing (12) and a lower cap (16b) at a lower end of the housing (12), each of the caps (16a, 16b) defining a communication chamber and each of the caps (16a, 16b) having a first fluid opening (22a, 22b) in fluid communication with the communication chamber (20a, 20b); - an upper sealing body (18a) which separates the upper connecting chamber (20a) from the interior space (14); - and a lower sealing body (18b) separating the lower connecting chamber (20b) from the interior space (14); - a plurality of hollow fiber membranes (46) extending through the interior space (14), the lower ends (48b) of the fiber membranes (46) being sealed by the lower sealing body (18b) and the upper ends (48a) of the fiber membranes (46) being open into the upper connecting chamber (20a); - an upper manifold assembly (30a) and a lower manifold assembly (30b), each of the manifold assemblies (30a, 30b) comprising: ◯ a central passage (32a, 32b) extending through the associated sealing body (18a, 18b) from a first opening (34a, 34b) on the associated connecting chamber (20a, 20b) to a second opening (36a, 36b) on the interior space (14); ◯ a plurality of radial arms (50), each arm (50) enclosing a flow channel (52) from the central passage (32a, 32b) to at least one flow opening (54) opening into the interior space (14); ◯ a check valve (56a, 56b) configured to block fluid flow from the central passage (32a, 32b) through the second opening (36a, 36b) into the interior space (14) while allowing fluid flow from the interior space (14) through the second opening (36a, 36b) into the central passage (32a, 32b); - a tube (38) fluidly connecting the central passage (32a) of the upper distributor arrangement (30a) to a second fluid connection (40). [2] Filter module (10) according to claim 1, wherein at least one of the check valves (56a, 56b) has a valve insert in the form of a ball (58), preferably a hollow ball (58). [3] Filter module (10) according to one of the preceding claims, wherein the flow channels (52) are closed in the axial direction, and wherein the flow openings (54) of the arms (50) are aligned in the circumferential direction. [4] Filter module (10) according to one of the preceding claims, wherein at least one of the manifold assemblies (30a, 30b) comprises a base (62) and a cover (64), the base (62) and the cover (64) together defining the arms (50) and the flow channels. [5] Filter module (10) according to claim 4, wherein the base (62) of at least one of the manifold assemblies (30a, 30b) has axial tabs (66) embedded in the associated sealing body (18a, 18b). [6] Filter module (10) according to one of claims 4 or 5, wherein the cover (64) of at least one of the distributor assemblies (30a, 30b) has projections (68) which overlap the base (62) and are embedded in the associated sealing body (18a, 18b). [7] Filter module (10) according to one of claims 4 to 6, wherein the base (62) of at least one of the distributor assemblies (30a, 30b) has a cage (60) in which a valve insert is received. [8] Filter module (10) according to one of the preceding claims, wherein the upper and lower distribution units (30a, 30b) are of identical construction. [9] A method for filtering operation of a filter module (10) according to any one of the preceding claims, wherein raw water is fed into the filter module (10) through the first fluid port (22b) of the lower cap (16b), thereby forcing the check valve (56b) of the lower manifold assembly (30b) to close, so that the water passes through the flow channels (52) of the arms (50) of the lower manifold assembly (30b) into the interior space (14), penetrates into the lumens of the hollow fiber membranes (46) through their walls, and clean water leaves the filter module (10) through the first fluid port (22a) of the upper cap (16a). [10] The method of claim 9, wherein the second fluid opening (40) is open during the filtration operation and wherein the retentate flows through the check valve (56a) of the upper manifold assembly (30a) during the filtration operation and exits the filter module (10) through the second fluid opening (40). [11] The method of claim 9, wherein the second liquid port (40) is blocked during the filtration operation. [12] A method for cleaning a filter module (10) according to any one of claims 1 to 8, wherein clean water is fed into the filter module (10) through the first fluid opening (22a) of the upper cap (16a) while the first fluid opening (22b) of the lower cap (16b) is open, and preferably while the second fluid opening (40) is closed, wherein the water enters the lumens of the hollow fiber membranes (46) at their open ends (48a), through whose walls penetrates into the interior space (14), and wherein the water forces the check valve (56b) of the lower manifold assembly (30b) to open and the water is drained through the first fluid port (22b) of the lower cap (16b). [13] A method for cleaning a filter module (10) according to any one of claims 1 to 8, wherein clean water is introduced into the filter module (10) through the first fluid opening (22a) of the upper cap (16a) while the first fluid opening (22b) of the lower cap (16b) is closed and the second fluid opening (40) is open, wherein the water enters the lumens of the hollow fiber membranes (46) at their open ends (48a), through whose walls penetrates into the interior space (14), and wherein the water forces the check valve (56a) of the upper distribution unit (30a) to open and the water is flushed through the second fluid connection (40). [14] A method for cleaning a filter module (10) according to any one of claims 1 to 8, wherein clean water is introduced into the filter module (10) through the first fluid port (22b) of the lower cap (16b) while the first fluid port (22a) of the upper cap (16a) is closed and the second fluid port (40) is open, wherein the water forces the check valve (56b) of the lower distributor arrangement (30b) to close, so that the water passes through the flow channels (52) and the flow openings (54) of the arms (50) of the lower distributor arrangement (30b) into the interior space (14), and wherein the water forces the check valve (56a) of the upper manifold assembly (30a) to open and the water is discharged through the second fluid port (40). [15] A method for cleaning a filter module (10) according to any one of claims 1 to 8, wherein clean water is fed into the filter module (10) through the second fluid port (40) while the first fluid port (22a) of the upper cap (16a) is closed and while the first fluid port (22b) of the lower cap (16b) is open, wherein the water forces the check valve (56a) of the upper distributor arrangement (30a) to close, so that the water passes through the flow channels (52) and the flow openings (54) of the arms (50) of the upper distributor arrangement (30a) into the interior space (14), and wherein the water forces the check valve (56b) of the lower manifold assembly (30b) to open and the water is flushed through the first fluid port (22b) of the lower cap (16b). [16] Method for operating a filter module (10) according to one of claims 1 to 8, wherein at least one period of filtration operation according to one of claims 9 to 11 is followed by at least one period of cleaning according to one of claims 12 to 15. [17] Method according to claim 16, wherein the cleaning of the filter module (10) comprises a period according to one of claims 12 to 14 and preferably also according to claim 15.

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